areva np inc. report document no. anp-2858-001 ...a ar eva document no.: anp-2858-001 areva np inc.,...

ATTACHMENT 4

AREVA NP Inc. Report

Document No. ANP-2858-001

PALISADES SFP REGION 1 CRITICALITY EVALUATION

WITH BURNUP CREDIT

84 pages follow

A 20004-016 (07/23/2009)

AREVANON PROPRIETARY

AREVA NP Inc.,an AREVA and Siemens company

Document No: ANP - 2858 - 001

Palisades SFP Region I Criticality Evaluation with Burnup Credit

AREVA NP INC. NON PROPRIETARY

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AAREVAAREVA NP Inc.,an AREVA and Siemens company

Document No.: ANP-2858-001

NON PROPRIETARY

Palisades SFP Region 1 Criticality Evaluation with Burnup Credit

Record of RevisionRevision Pages/Sections/

No. Date Paragraphs Changed Brief Description / Change Authorization

000 August 2009 all Original Release

001 August 2009 re-issue complete document Incorporated Entergy Comments

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AAR EVA Document No.: ANP-2858-001AREVA NP Inc.,an AREVA and Siemens company NON PROPRIETARY


Table of Contents

Page

RECO RD O F REVISIO N .......................................................................................................................... 2

LIST O F TABLES ..................................................................................................................................... 5

LIST O F FIG URES ................................................................................................................................... 7

1.0 EXECUTIVE SUM M ARY ......................................................................................................... 8

2.0 INTRO DUCTIO N ........................................................................................................................... 8

3.0 ANALYTICAL M ETHO DS ....................................................................................................... 9

3.1 Com puter Program s and Standards ............................................................................ 9 ,

3.2 Analytical Requirem ents and Assum ptions ................................................................ 10

3.3 Com putational M odels and M ethods .......................................................................... 11

3.3.1 Bounding Fuel Assem bly Description ...................................................... 11

3.3.2 Region 1 Rack Data ................................................................................... 12

3.3.3 M aterial Specification ................................................................................ 15

3.3.4 M odels for Degradation of Carborundum® Plates ...................................... 15

3.3.5 Swelling M odel ........................................................................................... 15

3.4 Analytical M odel Conservatism s ................................................................................ 18

3.5 Tolerances, Penalties, Biases, and Uncertainties ........................................................ 18

3.5.1 Method Discussion of Tolerances, Biases, and Uncertainties ................... 18

3.5.2 System and Tolerance Effects .................................................................. 19

3.5.3 System and Tolerance Results ................................................................ 20

3.5.4 Sum m ary of Bias and Uncertainty Values ................................................ 22

4.0 RACK ANALYSIS ........................................................................................................................ 22

4.1 Region 1B (3-of-4 Configuration) ................................................................................ 23

4.1.1 M isload Conditions ..................................................................................... 25

4.1.2 Conservatism s ........................................................................................... 25

4.2 Region 1C (4-of-4 Configuration) ................................................................................ 25


4.2.2 Conservatism s ......................................................................................... 27

4.3 Region 1 E (4-of-4 Configuration) ................................................................................ 27


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Table of Contents(continued)

Page

4 .3.2 C onservatism s .......................................................................................... 29

4.4 Non-Fuel Bearing Components (NFBC) ..................................................................... 29

4 .4.1 M isload C onditions .................................................................................... 30

4 .5 R a ck Inte ra ctio ns ............................................................................................................. 3 1

4.5.1 Regions 1A, 1B, and 1C Interaction Effects Results ................................. 31

4.5.2 Regions 1B and lC with Region 2 Interaction Effects Results .................. 33

4.5.3 Region 1 E and Region 2 Racks Interaction Effects Results ..................... 34

5.0 SUMMARY AND CONCLUSIONS .......................................................................................... 35

6.0 LICENSING REQ UIREM ENTS .............................................................................................. 35

7 .0 R E F E R E N C E S ............................................................................................. ............................... 3 8

APPENDIX A: KENO-V.A BIAS AND BIAS UNCERTAINTY ........................................................................... 40

APPENDIX B: CASMO CALCULATIONS FOR BURNUP ............................................................................... 54

APPENDIX C: KENO.V-A TOLERANCE CALCULATIONS ............................................................................ 61

APPENDIX D: SPACER GRID, FUEL ROD, AND GUIDE BAR EFFECTS ...................................................... 69

APPENDIX E: RACK C AND E KENO-V.A INPUT DECKS AND CASMO-3 DEPLETION INPUT DECK ..... 73

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List of Tables

Page

TABLE 3-1: BATCH Xl DIMENSIONS AND TOLERANCES ............................................................ 11

TABLE 3-2: DIMENSIONS OF PALISADES REGION 1 RACKS ...................................................... 12

TABLE 3-3: 'C' NOMINAL RACK WITH BIAS/UNCERTAINTIES .................................................... 21

TABLE 3-4: 'E' NOMINAL RACK 4-OF-4 WITH BIAS/UNCERTAINTIES ......................................... 21

TABLE 3-5: K95/95 DETERMINATION BASED UPON CALCULATED BIAS/UNCERTAINTY ........... 22

TABLE 3-6: 5% DEPLETION REACTIVITY UNCERTAINTY ................................... 22

TABLE 4-1: REGION 1B (3-OF-4 LOADING) REQUIREMENTS .................................................... 24

TABLE 4-2: REGION 1B K95/95 DETERMINATION FOR BORON DILUTION ................................... 24

TABLE 4-3: REGION 1B K95/95 DETERMINATION FOR MISLOAD CONDITIONS .......................... 25

TABLE 4-4: REGION 1C (4-OF-4 LOADING) REQUIREMENTS ..................................................... 26

TABLE 4-5: REGION 1C K95195 DETERMINATION FOR BORON DILUTION ................................... 26

TABLE 4-6: REGION 1C K95/95 DETERMINATION FOR MISLOAD CONDITIONS .......................... 27

TABLE 4-7: E-RACK REQ UIREM ENTS .......................................................................................... 28

TABLE 4-8: REGION 1E K95/95 DETERMINATION FOR BORON DILUTION ................................... 28

TABLE 4-9: REGION 1E K95/95 DETERMINATION FOR MISLOAD CONDITIONS .......................... 29

TABLE 4-10: NFBC REACTIVITY EVALUATION FOR 3-OF-4 BUC RACK ..................................... 30

TABLE 4-11: NFBC REACTIVITY EVALUATION FOR 4-OF-4 BUC RACK ..................................... 30

TABLE 4-12: INTERACTION RESULTS FOR REGIONS 1A, 1B, AND 1C RACKS ......................... 33

TABLE 4-13: INTERACTION RESULTS FOR REGIONS 1B AND 1C TO REGION 2 RACKS ...... 34

TABLE 4-14: INTERACTION RESULTS FOR REGION 1 E AND REGION 2 RACKS ..................... 34

TABLE A-1: RANGE OF VALUES OF KEY PARAMETERS IN SPENT FUEL POOL ...................... 41

TABLE A-2: DESCRIPTIONS OF THE CRITICAL BENCHMARK EXPERIMENTS .......................... 42

TABLE A-3: RESULTS FOR THE SELECTED BENCHMARK EXPERIMENTS ............................... 45

TABLE A-4: TRENDING PARAM ETERS .......................................................................................... 47

TABLE A-5: SUMMARY OF TRENDING ANALYSIS ....................................................................... 49

TABLE A-6: RANGE OF VALUES OF KEY PARAMETERS IN BENCHMARK EXPERIMENTS .......... 53

TABLE B-i: DEPLETION MODELING CONSIDERATIONS ............................................................ 54

TABLE B-2: AXIAL MODERATOR TEMPERATURE DISTRIBUTION .............................................. 56

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List of Tables(continued)

Page

TABLE B-3:

TABLE C-1:

TABLE C-2:

TABLE C-3:

TABLE C-4:

TABLE C-5:

TABLE C-6:

TABLE C-7:

TABLE D-1:

15 AND 30 GWD/MTU BURNUP PROFILES - 336.81 CM HEIGHT ........................... 57

RA CK C VO IDING EFFECTS ...................................................................................... 61

FABRICATED BOX MODEL DIMENSIONS ................................................................. 62

INTER-BOX M ODEL DIM ENSIONS .............................................................................. 62

RACK 'C' NOMINAL TOLERANCE RESULTS ............................................................. 66

RACK 'E' NOMINAL TOLERANCE RESULTS ............................................................. 67

'C' RACK NOMINAL FUEL TOLERANCES ................................................................. 67

'E' RACK NOMINAL FUEL TOLERANCES ................................................................... 68

SPAC ER G R ID R ESU LTS ............................................................................................ 70

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NON PROPRIETARY


List of Figures

FIGURE 2-1:

FIGURE 3-1:

FIGURE 3-2:

FIGURE 3-3:

FIGURE 3-4:

FIGURE 4-1:

FIGURE 4-2:

FIGURE 4-3:

FIGURE 6-1:

Page

PALISADES FUEL STORAGE AREAS ............................... ......................................... 8

SKETCH OF MODEL OF 'C' RACK ............................................................................ 13

SKETCH OF MODEL OF 'E' RACK ........................................................................... 14

PHOTOGRAPH OF DISTORTED PLATE ................................................................... 16

FU EL SW ELLIN G M O D EL ........................................................................................... 17

REGION 1 B ADJACENT TO REGION 1A ................................................................... 32

REGION 1B ADJACENT TO REGION 1C ................................................................... 32

REGION 1C ADJACENT TO REGION 1A ................................................................... 33

FUEL LOADING PATTERN FOR REGION 1B ........................................................... 35

FIGURE A-1: DISTRIBUTION OF KEFF DATA VERSUS EALF FOR THE SELECTED POOL OFBENCHMARK EXPERIM ENTS ................................................................................. 49

FIGURE A-2: DISTRIBUTION OF KEFF DATA VERSUS ENRICHMENT (235U) FOR THE SELECTEDPOOL OF BENCHMARK EXPERIMENTS ................................................................ 50

FIGURE A-3: DISTRIBUTION OF KEFF DATA VERSUS H/X FOR THE SELECTED POOL OFBENCHMARK EXPERIM ENTS ................................................................................. 50

FIGURE A-4: DISTRIBUTION OF KEFF DATA VERSUS SOLUBLE BORON CONCENTRATION FORTHE SELECTED POOL OF BENCHMARK EXPERIMENTS ...................................... 51

FIGURE A-5: PLOT OF STANDARD RESIDUALS FOR REGRESSION ANALYSIS WITH EALF ASTR EN D IN G PA RA M ETER .......................................................................................... 51

FIGURE A-6: PLOT OF STANDARD RESIDUALS FOR REGRESSION ANALYSIS WITH

ENRICHMENT AS TRENDING PARAMETER .......................................................... 52

FIGURE B-i: BURNUP PROFILES FOR CYCLES 18-21 FOR BURNUPS 30-34 GWD/MTU ...... 58

FIGURE C-1: SKETCH OF KENO-V.A MODEL AT EDGE OF REGION 2 RACKS .......................... 63

FIGURE C-2: SKETCH OF A PORTION OF THE 'C'-REGION 2 MODEL ........................................ 64

FIGURE C-3: SKETCH OF A PORTION OF THE REGION 1 E -REGION 2 MODEL ...................... 65

FIG URE D-1: SKETCH O F G UIDE BAR .......................................................................................... 72

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1.0 EXECUTIVE SUMMARY

This report contains the criticality evaluation of the Palisades Spent Fuel Storage Racks for the Region 1racks that contain Carborundum® plates (Reference [1]) as a poison. There are indications of swelling andof boron loss through attenuation measurements. This evaluation assumes total boron loss from theCarborundum® plates, bumup credit, and a swelling model. The same soluble boron credit that was usedin Region 2 is assumed for the Region 1 evaluations. Rack interaction effects are evaluated and found tobe acceptable.

2.0 INTRODUCTION

The Palisades Nuclear Plant (PNP) requires a criticality analysis to address the Spent Fuel Storage Racks(SFSR) that are currently designated as Region 1 and contain Carborundum® boron carbide (B4C) neutronabsorbing plates that are degraded. These fuel storage locations at Palisades are shown in Figure 2-1.

Figure 2-1: Palisades Fuel Storage Areas

47 48 49 50 s5 52 53 54 5S 56 57 559 40 61 62 63 64l65 66 67 U 69

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MECHANISMRegion 2 cr-1] EEIDi Region]2

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SElCE K E )F~PLATFORM - m e. a F n Region2MiSpet Fu el oI

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DWWW DWWU WW FEL SATU70 "N1 72 73 74 75 ?6 T7 7E 79 W 0 81 82 8 84 85 86 87 88 8g 90 91 92 93 W WESTINGHOUSE CREDIT FOR BUCRIUP WA.CKW

, F D ET100 0 F1O O 310 11 0 0 O0 0 0 0 0,.s E1 13EE El PLSDES NUCLEAR PLANT]

Z O00]-IIDDDI-]F]OO OO O O FI[3BO0000O- FUEL STATUSI

NEW FUEL STORAGE RACK CAS;K WASHIDOWN

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AAR EVA Document No.: ANP-2858-001

AREVA NP Inc.,an AREVA and Siemens company NON PROPRIETARY


This study determines the maximum K-effective (k~f) of different regions for the effects associated withfuel storage in the Palisades Region 1 Spent Fuel Storage racks relative to a conservative treatment of thedegradation of the Carborundum® plates. The four regions are:

1) Region 1A - Region 1 Main Spent Fuel Pool with checkerboard loading of fuel with empty cellsfor fuel having nominal planar average U-235 enrichments less than or equal to 4.54 weightpercent with no burnup credit.

2) Region IB - Region 1 Main Spent Fuel Pool with 3-of-4 loading having nominal planar averageU-235 enrichments less than or equal to 4.54 weight percent and bumup credit as shown in Table4-1.

3) Region 1C - Region 1 Main Spent Fuel Pool with 4-of-4 loading having nominal planar averageU-235 enrichments less than or equal to 4.54 weight percent and bumup credit as shown in Table4-4.

4) Region lE - Region 1 North Tilt Pit with 4-of-4 loading having nominal planar average U-235enrichments less than or equal to 4.54 weight percent and burnup credit as shown in Table 4-7.

This report includes the bumup credit analysis for only Regions 1B, IC, and 1E and, for the three regions,defines the acceptable geometries, and demonstrates that the reactivity effects of the rack and fuelassembly manufacturing tolerances, the reactivity effects of pool moderator temperature variations,swelling in the poison plates, complete loss of the absorber material contained within the walls, andaccident conditions are acceptable. The analyses for Region 1A and Region 2 that were approved inReference [2] and [3], respectively, remain valid.

Criticality results and Licensing Requirements are summarized in Sections 5.0 and 6.0, respectively.

3.0 ANALYTICAL METHODS

The analytical methods are discussed in this section. It briefly describes computer programs, licensingrequirements, and computer models used for this analysis.

3.1 Computer Programs and Standards

The KENO-V.a computer code (Reference [4]), a part of the SCALE 4.4a package, was used to calculatethe kcff of 100 critical systems (criticality benchmark experiments). The 44 group cross section set44GROUPNDF5 was used by the SCALE driver module CSAS25, which used modules BONAMI-2 andNITAWL to perform spatial and energy self-shielding of the cross sections for use in KENO-V.a. While'holes' were used in the geometry models, they were modeled to preclude the error described in NRCInformation Notice 2005-13, "Potential Non-conservative Error in Modeling Geometric Regions in theKENO-V.A Criticality Code," May 17, 2005.

The CASMO-3 computer code (Reference [5]), a multi-group two dimensional transport theory programwas used to calculate burmup for the assemblies. CASMO-3 is primarily a cross section generator withdepletion capability. The code handles a geometry consisting of cylindrical fuel rods of varyingcompositions in a square pitch array. Typical fuel storage rack geometries can also be handled.

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3.2 Analytical Requirements and Assumptions

The purpose of the spent fuel storage racks is to maintain the fresh and irradiated assemblies in a safestorage condition. The current licensing basis as defined by the existing Technical SpecificationRequirements and federal code requirements, 10 CFR 50.68(b), specifies the normal and accidentparameters associated with maintaining the fresh and irradiated assemblies in a safe storage condition. 10CFR 50.68(b) defines the criticality accident requirements associated with the spent fuel racks and statesthe following: "If credit is taken for soluble boron, the k-effective of the spent fuel storage racks loadedwith fuel of the maximum fuel assembly reactivity must not exceed 0.95, at a 95 percent probability, 95percent confidence level, if flooded with borated water, and the k-effective must remain below 1.0(subcritical) at a 95 percent probability, 95 percent confidence level, if flooded with unborated water."

The current analysis basis for Region 2 from Reference [6] is a maximum kcff of less than 1.0 whenflooded with unborated water, and less than, or equal to 0.95 when flooded with water having a solubleboron concentration of 850 ppm. In addition, the klff in accident or abnormal operating conditions is lessthan 0.95 with 1350 ppm of soluble boron.

This analysis demonstrates that the effective neutron multiplication factor, keff, is less than 1.0 with theracks loaded with fuel of the highest anticipated reactivity, and flooded with un-borated. water at atemperature corresponding to the highest reactivity. In addition, the analysis demonstrates that kaf is lessthan or equal to 0.95 with the racks loaded with fuel of the highest anticipated reactivity, and flooded withborated water at a temperature corresponding to the highest reactivity. The maximum calculated kffincluded a margin for uncertainty in reactivity calculations including manufacturing tolerances and isshown to be less than 0.95 with a 95% probability at a 95% confidence level with soluble boron credit.Reactivity effects of abnormal and accident conditions were also evaluated to assure that under allcredible abnormal and accident conditions, the klff will not exceed the regulatory limit of 0.95 underborated conditions or a limit of 1.0 with unborated water. The double contingency principal of ANS-8.1/N 16.1-1975 (and the USNRC letter of April 1978; see fourth bullet below) specifies that it shallrequire at least two unlikely, independent and concurrent events before a criticality accident is possible.This principle precludes the necessity of considering the simultaneous occurrence of multiple accidentconditions.

Applicable codes, standard and regulations or pertinent sections thereof, include the following:

" Code of Federal Regulations, Title 10, Part 50, Appendix A, General Design Criterion 62,"Prevention of Criticality in Fuel Storage and Handling."

" Code of Federal Regulations, Title 10, Part 50.68(b), "Criticality Accident Requirements."

* USNRC Standard Review Plan, NUREG-0800, Section 9. 1. 1, "Criticality Safety of Fresh and SpentFuel Storage and Handling," Rev. 3 - March 2007.

* USNRC letter of April 14, 1978, to all Power Reactor Licensees - OT Position for Review andAcceptance of Spent Fuel Storage and Handling Applications (GL-78-01 1), including modificationletter dated January 18, 1979 (GL-79-004).

* L. Kopp, "Guidance on the Regulatory Requirements for Criticality Analysis of Fuel Storage atLight-Water Reactor Power Plants," NRC Memorandum from L. Kopp to T. Collins, August 19,1998. [7]

* USNRC Regulatory Guide 1. 13, "Spent Fuel Storage Facility Design Basis," Rev. 2, March 2007.

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* ANSI ANS-8.17-1984, "Criticality Safety Criteria for the Handling, Storage and Transportation ofLWR Fuel Outside Reactors."

Code benchmarking was performed according to the general methodology described in Reference [8] thatis also briefly described in Section A. 1. The critical experiments selected to benchmark the computercode system are discussed in Section A.3. The results of the criticality calculations, the trending analysis,the basis for the statistical technique chosen, the bias, and the bias uncertainty are presented in SectionsA.4, A.5, and A.6.

3.3 Computational Models and Methods

This section describes the basic models used to evaluate the three regions in the PNP SFSR. Results usingthese models are described in later sections.

3.3.1 Bounding Fuel Assembly Description

Batch Xl with an initial nominal planar average enrichment of 4.54 wt% 2 3 5"U is used to bound

the possible enrichments and different fuel types in the storage rack evaluations. Table 3-1shows the dimensions of the bounding Xl model employed in this report. Reference [9]provides a discussion of the appropriate biases to apply to bound the other assembly designs.Some legacy fuel (e.g. Batches A-K) had lumped burnable absorber pins in empty tubes and/orhad fuel rods replaced with either stainless steel rods or empty pin cells. Special considerationwas given to these fuel assemblies in the burnup credit analysis. This is described in SectionB.2. Fuel end details are not modeled. Fuel in the racks are modeled as surrounded by full (12inches) water reflection at top and bottom. Reference [9] also shows that a zone loadedassembly has an equivalent or less reactivity than an assembly with a constant enrichmentequal to the average of the assembly.

Table 3-1: Batch Xl Dimensions and Tolerances

Parameter Nominal ToleranceUnits in in

Pitch 0.55Pellet OD 0.3600 ±0.0005Clad ID 0.3670 ±0.0015Clad OD 0.417 ±0.002# Guide Bars 8

Effective Area* 0.1586 in2

# Instrument Tubes 1IT ID 0.3670 ±0.0015ITOD 0.417 +0.002Active Fuel 132.6 +0.29Density, %TD 96%** +1.50%

*Represents a conservatively small area for this parameter.

**A slightly higher percent theoretical density (TD) of 96% is used to bound the densities of other

assemblies.

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NON PROPRIETARY


3.3.2 Region 1 Rack Data

Region 1 of the Palisades spent fuel storage pool comprises two rack designs. The mainregion consists of six 'C' racks for storage of 372 fuel assemblies. Regions IA, 1B, and ICare rack type 'C'. Another rack, the 'E' rack is placed in the 'North Tilt Pit' and can hold 50assemblies on a slightly wider pitch than the 'C' racks. Region lE is rack type 'E'. Table 3-2lists the dimensions of the two racks. Figure 3-1 and Figure 3-2 provide sketches of each racktype, which illustrate the geometries used in KENO-V.a for each fuel cell. The actual comersof the box walls are rounded whereas the sketch is squared off. A single SS-304 separationrod of-0.25" OD is placed at each comer of the 'C' rack. A set of two similar SS-304separation rods is placed before the rounded section of each comer of the 'E' rack. The fuelbox in the rack is primarily SS-304, absorber material, and moderator. The standard SS-304mixture of the SCALE composition library is used for this material. The moderator is water at1.0 g/cc.

The current analysis in Reference [9] for the Region 1 rack assumed that the absorber platewas composed of only B 4C with a reduction in the plate density due to the neglect of thephenol filler material. A carbon mass of 0.2720 g/cc was calculated for the reduced densityplate. For this evaluation of Regions 1B, 1C, and lE the absorber material was assumed to bedegraded as described in Section 3.3.4 which is the same as the absorber plate model inReference [9].

Table 3-2: Dimensions of Palisades Region 1 Racks

Region I Rack Type 'C' Rack 'E' RackDimension Nominal, in Tolerance, in Nominal, in Tolerance, inCell Pitch-x 10.25 +0.04/-0.04 11.25 +0.04/-0.04Cell Pitch-y 10.25 +0.04/-0.04 10.69 +0.04/-0.04Box ID 8.56 +0.00/-0.12 9.00 +0.00/-0.12Box OD 9.56 +0.12/-0.00 10.00 +0.12/-0.00Box Wall Thickness, Inside 0.125 +0.010/-0.010 0.125 +0.010/-0.010Box Wall Thickness, Outside 0.125 +0.010/-0.010 0.125 +0.010/-0.010Absorber Thickness 0.210 +0.035/-0.02 0.210 +0.035/.-0.02Absorber Width 8.26 +0.05/-0.010 8.26 +0.05/-0.010

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NON PROPRIETARY


Figure 3-1: Sketch of Model of 'C' Rack

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NON PROPRIETARY


Figure 3-2: Sketch of Model of 'E' Rack

7 7 ý 7 7 ý 7 ý 7 1 1 1 17 7 7 7 7 7 7 7 7 7 7 ý 7

'd 11.25"

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3.3.3 Material Specification

The fuel materials include the uranium oxide pellets, the clad material, and the moderatorsurrounding the cladding. All materials in the base model are assumed to be at 293 K. Themoderator for the base case is assumed to be unborated water with a density of 1.0 g/cc. Thefuel pellets are assumed to have a 96% TD to correspond to the highest nominal density ofpast, current, or proposed pellets. No dish or chamfer is included in the density, thus the fuelcolumn is conservatively modeled as a solid cylinder of fuel.

The cladding, instrument tubes, and guide bar are zirconium alloys. In the past thesecomponents were Zirc-4. Beginning with Batch Y (loaded in the Spring 2009 outage, andsubsequent batches) M5® cladding is used for the fuel rods and the instrument tube. At somepoint in the future, M5® may be used for the spacer and guide bars. These components areassumed to be composed of pure zirconium. This approximation will be slightly conservativebecause the alloy additives (such as Tin and Niobium) generally have a higher capture crosssection than Zr and thus tend to slightly reduce the assembly reactivity.

The fuel box in the rack is primarily SS-304, absorber material and moderator. The standardSS-304 mixture of the SCALE composition library is used for this material. The moderator isagain water at 1.0 g/cc. The absorber material composition is based upon an assumption of thedegraded condition of the B4C absorber material.

3.3.4 Models for Degradation of Carborundum® Plates

Evidence of stuck assemblies and recent attenuation testing of the absorber plates in Region 1has indicated a reduction in the absorption capability of the flux trap between the fuel locationsin the Region 1 rack. A possible cause is leaching of boron from the B4C absorber plates dueto a combination of gamma irradiation of the phenol material and water in the absorber regionof the box. An alternate, or complementary, cause of the loss of attenuation capability couldbe swelling of the box walls that reduce the moderator between the fuel assembly and the walland between the walls of the flux trap. Either condition can reduce the effectiveness of theabsorber plates. To bound the boron loss, the boron contained in the Carborundum® plates isassumed to be zero. The poison plate is modeled with its original dimensions but containingonly the carbon from the B4C with a density of 0.2720 g/cc. No other materials are assumed inthe poison plate even though the Carborundum® plate contains hydrogen, oxygen, andadditional carbon. Complete loss of boron is unlikely since limited testing has shown thepresence of attenuation larger than the complete absence of boron but less than the minimumdesign value. Credit for the remaining amount is not taken since the cause of degradation andthe rate of degradation are not well characterized and the assumption of no boron avoids themore complex surveillance that would be required for the amount of poison credited in theCarborundum® plates.

3.3.5 Swelling Model

There is also evidence of swelling of the stainless steel wall next to the assembly cell thatcontains the Carborundum® plates. The nature of the swelling is a central bulge (side to side)on one face of the fuel cell and is shown in Figure 3-3. It is not clear whether the bulge is fullheight.

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Figure 3-3: Photograph of Distorted Plate

The cause of this distortion is not understood, however the effect of moving the walls towardor away from the fuel requires examination. See Figure 3-4. Three different possibleconfigurations were examined. In the first, the outer stainless steel wall is displaced to theouter edge of the rack cell. The second is where the stainless steel wall on the interior movesinward until it rests against the fuel pins, and the third is where movement of both wallsoccurs.

To model the three swelling configurations, bowing in the outer wall was modeled byrelocating the stainless steel outer wall until it contacts the adjacent cell. The stainless steelwas thinned to conserve mass. Water filled the area formerly occupied by the wall, so that thewater mass is also conserved. Bowing in the inner wall was modeled by relocating thestainless steel inner wall to the edge of the row of fuel pins. The stainless steel was notthickened to conserve mass, so this is conservative as stainless steel is lost in this model. Thethird configuration is where both the inner and outer walls were bowed. The configurationwith only the outer steel wall bowed outward is the most restrictive, and is used in subsequentKENO-V.a cases.

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Figure 3-4: Fuel Swelling ModelSpacer Rod

Weld\

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The space created by the wall movement is modeled as water. Voiding of the area created bywall movement is not considered to be likely because:

1. A 0.50" gap above each spacer rod provides a communication path between the foursides such that a vent hole on one wall vents all four sides of the fuel box. (See Section 3.3.2for information on spacer rods.) Gas generated in absorber material will collect at the top ofthe fuel box, displacing water until the elevation of the vent hole is reached and the gasescapes through the vent. This layer of gas is nominally 0.25 inches and is above the activefuel.

2. The spacer rod is tack welded to the inner box and is not welded to the outer box (seeFigure 3-4), so a vent path between the spacer rod and bends of the outer box already exists.An additional vent path between the spacer rod and the inner box could be also expected ifswelling of a box wall occurred.

3. The individual fuel boxes are formed into an 8 x 8 array by welding the fuel boxes to agrid of spacer bars. These spacer bars have four 0.88" diameter vent holes drilled in the gridassembly. Additionally, the rack assemblies are open on the sides. Any gas formed within

Page 17



the flux trap region between the fuel boxes would then collect as bubbles on the bottom ofthe upper spacer bars and migrate to a spacer bar vent hole or to the edge of the rackassembly and escape, thus water is free to flow through the rack and not trap air pockets.

3.4 Analytical Model Conservatisms

This section lists the major conservatisms associated with this evaluation.

1) No credit is taken for intermediate spacer grids, or end fittings (see Appendix 1)).

2) No credit is taken for any boron in the Carborundum® plates.

3) The maximum fuel enrichment tolerance of 0.05 wt% is considered in the tolerance evaluation.

4) All fuel box outer steel walls are assumed bowed outward and filled with water (no voiding), and

5) For the tolerance calculations, the four-of-four loading configuration bounds the three-of-fourloading configuration as shown in Tables B- 12 and B- 13 of Reference [9].

3.5 Tolerances, Penalties, Biases, and Uncertainties

This section describes the tolerances, penalties, uncertainties, and biases utilized in the analysis of RacksC (Regions 1B, and IC) and E (Region 1E). The penalties that pertain to the rack design tolerances andsystem parameters are discussed in detail in Appendix C. Additionally, the KENO-V.a bias with itsassociated uncertainty is discussed in Appendix A. The results of these sections are summarized in thissubsection.

3.5.1 Method Discussion of Tolerances, Biases, and Uncertainties

Criticality analysis methodology involves the computation of a base klff for -the Spent FuelStorage Rack (SFSR) using a code such as KENO-V.a. A KENO-V.a code bias plusuncertainty on the bias is determined based on comparison to measured critical fuelconfigurations (i.e., critical benchmarks; see Appendix A) and is then applied to the baseabsolute kcff. The bias is not assembly specific but can be dependent on the type of fuelinvolved (U0 2 versus MOX for example) or on intervening absorber materials. Typically, abias is determined using critical benchmark calculations that are appropriate for the type ofrack and fuel being analyzed. There is an uncertainty component on the bias that is the resultof both measured and calculated uncertainties associated with the critical configurationsanalyzed. The uncertainty on the bias may be statistically combined with other uncertaintiesas it is independent.

Reactivity penalties due to fuel and rack structural tolerances and other uncertainties aredetermined by difference calculations and applied to the base kff plus bias (See Appendix C).When Monte-Carlo codes are used in difference calculations an answer is provided with anassociated uncertainty and the uncertainty on the difference calculation must be considered atthe 95/95 confidence level.

Page 18



The K 95/9 5 for the evaluation is calculated using the following formulation:

K 9 5/95 = keff + biasm + Aksys + [C 2(aYk 2 + Gm,-' + -o22) + Ak 0

2+ o + Ak~u,

where,

kcff = the KENO-V.a calculated result;

biasm = the bias associated with the calculation methodology underpredicting thebenchmarks;

Aksys = summation of Ak values associated with the variation of system and basecase modeling parameters, e.g. moderator temperature and geometry biases;

C confidence multiplier based upon the number of benchmark cases;

Cyk, am, Usys = standard deviation of the calculated kff, methodology bias,, and system Aksys;

Aktoj. cycto = statistical combination and standard deviation of statistically independent Akvalues due to manufacturing tolerances, e.g. fuel enrichment, cell pitch, etc.

AkBu = 5% depletion reactivity uncertainty for Bumup Credit cases

3.5.2 System and Tolerance Effects

System and tolerance effects are calculated for several combinations of conditions. Theyinclude:

* Four out of four fuel loading configurations.

* Rack C (Regions lB and 1C) and Rack E configurations.

KENO-V.a is used for all the system and tolerance calculations. A two by two cell KENO-V.amodel is used to calculate these effects.

3.5.2.1 System Effects

The system effects are different conditions from the base model of the fuel and rack that couldresult in a higher calculated keff. These effects are considered additive unless otherwise noted.The system effects are listed below.

1) Rack to Rack Interaction Model (see Section 4.5),

2) Non Fuel Bearing Components in the Empty Cells (see Section 4.4)

Page 19




3.5.2.2 Fuel and Rack Tolerance Effects

The fuel and rack tolerances that are examined for the nominal (nonswollen) racks are listedbelow:

1) Centered to Off-Centered Assembly in Fuel Cell

2) Fuel Tolerance - Enrichment, ±0.05 weight percent U-235

3) Fuel Tolerance - Theoretical Density, ±1.5%

4) Fuel Tolerance - Pellet OD, +0.0005"

5) Fuel Tolerance - Clad Inner Dimension, ±0.0015"

6) Fuel Tolerance - Clad Outer Dimension, ±0.002"

7) Fuel Tolerance - Instrument Tube Dimension, ID, ±0.0015"

8) Fuel Tolerance - Instrument Tube Dimension, OD, ±0.002"

9) Rack Tolerance - Box Inner Dimension, -0.12"

10) Rack Tolerance - Inner Box Wall Thickness, ±0.01"

11) Rack Tolerance - Absorber Thickness, +0.035/-0.02"

12) Rack Tolerance - Absorber Width, +0.05/-0.01"

13) Rack Tolerance - Outer Box Wall Thickness, ±0.01"

14) Rack Tolerance - Box Outer Dimension, +0.12"

15) Rack Tolerance - Cell Pitch, ±0.04"

16) Rack Tolerance -Stainless Steel Separation Rod, OD, ±0.005"

See Appendix D for the effect of fuel rod pitch tolerance

3.5.3 System and Tolerance Results

Table 3-3 and Table 3-4 summarize the tolerance and uncertainty values obtained in theevaluation. Only positive bias/uncertainty values have been extracted from the variousevaluations previously described, excluding values that are less than 0.0002, as they are withinthe bias of the code. Detailed results can be found in Appendix C. The additive biases aregenerally related to the rack configuration or environment that is defined in the equation asAksys. The parameters related to randomly varying manufacturing tolerances for fuel and/orracks are statistically combined and defined in the equation as Ako01. In addition, the off-centerplacement is assumed to be a random parameter.

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NON PROPRIETARY


Table 3-3: 'C' Nominal Rack with Bias/Uncertainties

Description Ak g of Ak

Storage Pool Model Configuration Bias

Interaction Model I _ __

NFBC in empty cell of 3-of-4 for only 0 ppm 0.0013 0.0008

TOTAL (Arithmetic Sum of Penalties) 0.0013 0.0008

Tolerance Uncertainty Ak

Assembly Not Centered In Rack 0.0036 0.0001

Fuel Tolerance - Enrichment +0.05 wt% 0.0022 0.0001

Fuel Tolerance - Theoretical Density +1.5% 0.0011 0.0001

Fuel Tolerance - Clad ID +0.0015" 0.0003 0.0001

Fuel Tolerance - Clad OD -0.002" 0.0017 0.0001

Fuel Tolerance - Pellet OD + 0.0005" 0.0002 0.0001

Rack Tolerance - Inner Box Wall Thickness Inside, -0.01 0.0024 0.0001

Rack Tolerance -Absorber Thickness +0.035 0.0103 0.0001

Rack Tolerance -Absorber Width +0.05 0.0003 0.0001

Rack Tolerance - Outer Box Wall Thickness Outside -0.01 0.0012 0.0001

Rack Tolerance -Pitch -0.04" 0.0066 0.0001

TOTAL (Statistical Combination of Uncertainties) 0.0134 0.0004

Table 3-4: 'E' Nominal Rack 4-of-4 with Bias/Uncertainties

Description Ak a of Ak

Storage Pool Model Configuration Bias

Interaction Model I - -

TOTAL (Arithmetic Sum of Penalties) 0 0

Tolerance Uncertainty Ak

Assembly Not Centered In Rack 0.0252 0.0003

Fuel Tolerance - Enrichment +0.05 wt% 0.0019 0.0003

Fuel Tolerance - Theoretical Density +1.5% 0.0012 0.000.3

Fuel Tolerance - Clad ID +0.00 15" 0.0007 0.000.3

Fuel Tolerance - Clad OD -0.002" 0.0022 0.0003

Rack Tolerance - Inner Box Wall Thickness Inside -0.01 0.0017 0.000:3

Rack Tolerance -Absorber Thickness +0.035 0.0074 0.0003

Rack Tolerance - Outer Box Wall Thickness Inside -0.01 0.0008 0.0003

Rack Tolerance -Pitch -0.04" 0.0050 0.0003

TOTAL (Statistical Combination of Uncertainties) 0.0270 0.0008

Page 21



3.5.4 Summary of Bias and Uncertainty Values

Table 3-5 and Table 3-6 summarize the variables shown in the formula in Section 3.5.1 for each ofthe configurations examined.

Table 3-5: K95/95 Determination Based Upon Calculated Bias/Uncertainty

biasm Aksy a m Aktol c of Ako1

Rack C 3-of-4 0.00542 0.0013* 0.0051 0.0134 0.0004

(Region 1 B)

Rack C 4-of-4 0.00542 0 0.0051 0.0134 0.0004

(Region I C)

Rack E 4-of-4 0.00542 0 0.0051 0.0270 0.0008

(Region I E)

* For 0 ppm only.

Table 3-6: 5% Depletion Reactivity Uncertainty

Enrichment (wt %) GWD/MTU AkBU

3.2 15 0.0097

4.0 24 0.0132

4.54 15 0.0093

4.54 30 0.0150

4.0 RACK ANALYSIS

In order to determine depletion and burnup credit, the same basic methodology as in Reference [10] wasused. This methodology addresses the applicability of NUREG/CR-6801 (Reference [ 11]) for axialburnup profiles, the use of 5% reactivity decrement from 0 burnup to burnup of interest, and the use ofCASMO-3 to generate the fuel assembly isotopic compositions at specified burnups. In addition, a large,10%, additional burnup uncertainty allowance is added to the required fuel burnup limits to bound themeasurement uncertainty. Appendix B presents the calculation of burnup credit.

The current analysis basis for Region 2 from Reference [6] is a maximum keff of less than 1.0 whenflooded with unborated water, and less than or equal to 0.95 when flooded with water having a boronconcentration of 850 ppm. In addition, the kcff in accident or abnormal operating conditions is less than0.95 with 1350 ppm of soluble boron. This same basis is used for Region 1B, 1C, and 1E, and was also

Page 22



used in Reference [9] for Region IA. The following abnormal conditions are considered for Region 1B,IC, and 1E:

1. The deboration of the pool,

2. Misplacement of a fresh assembly within a cell that should be empty or replacement of a burnupcredit (BUC) assembly,

3. Drop of a fuel assembly outside the rack but adjacent to the rack,

4. Off-center assembly (addressed in Section 3.5),

5. The 'straight deep drop' accident,

6. T-Bone drop accident, and

7. Rack interactions.

The deboration of the SFSR is considered the baseline case and the K 95/9 5 is calculated at both 0 ppmboron and 850 ppm boron. All other abnormal conditions are evaluated at-1350 ppm boron. Themisplacement of an assembly into an empty cell is referred to as a 'misload.' The misload is important toevaluate since empty cells are used to control reactivity. The misload condition bounds the drop outsidethe rack module because the misloaded assembly can increase the number of face adjacent fuelassemblies by at least four whereas outside the rack will at most be two face adjacent assemblies to thedropped assembly. The off-center assembly which is a horizontal movement of the assembly within therack is included in the tolerance evaluation. The drop accident within an empty cell is represented by themisload condition. The T-Bone drop accident has an assembly lying on top of the rack structure and iseffectively isolated from assemblies in the rack due to the distance provided by the end fittings and therack height above the active fuel in the rack. Thus, the T-bone accident is bounded by the misloadedcondition.

The analysis for each of the regions is presented in this section for the unborated and borated condition(boron dilution event). The assembly misload conditions are presented for the borated condition of 1350ppm boron. In addition, non-fissile components are addressed relative to being placed into empty cellsand rack interface effects are addressed.

4.1 Region 1B (3-of-4 Configuration)

Region lB is analyzed with soluble boron credit. The acceptance criteria with credit for soluble boronare K 9 5/95 <1.0 without soluble boron and <0.95 with 850 ppm of soluble boron. Region lB is defined asMain Spent Fuel Pool with 3-of-4 loading having nominal planar average U-235 enrichments less than orequal to 4.54 weight percent and bumup credit as shown in Table 4-1.

The results are presented in Table 4-2 for the Region lB geometry.

Page 23




Table 4-1: Region 1B (3-of-4 Loading) Requirements

nominal planar average > BurnupU-235 enrichment Burnup (GWD/MTU) (GWD/MTU) with

(Wt%) 10% Uncertainty

2.50 0 0

2.60 0.74 0.81

2.80 2.21 2.43

3.00 3.68 4.05

3.20 5.15 5.67

3.40 6.62 7.28

3.60 8.09 8.90

3.80 9.56 10.52

4.00 11.03 12.13

4.20 12.50 13.75

4.40 13.97 15.37

4.54 15.00 16.50

Table 4-2: Region 1B K95/95 Determination for Boron Dilution

Assembly Dissolved

Enrichment Average Boron, kcff yk K 95/9 5 CriterionBurnup, ppm

GWD/MTU

4.54 15 850 0.8423 0.0007 0.8737 _ 0.95

4.54 15 0 0.9339 0.0007 0.9667 < 1.0

2.50 0 850 0.8121 0.0007 0.8342 < 0.95

2.50 0 0 0.9368 0.0008 0.9603 < 1.0

Page 24



NON PROPRIETARY

4.1.1


Misload Conditions

It is necessary to examine the accident condition of misloading a fresh assembly into theempty location in a '3-of-4' loading pattern. For this, it is assumed the fresh assembly has anenrichment of 4.54%. A soluble boron concentration of 1350 ppm is used. The freshmisloaded fuel assembly is placed into a position near the center of the matrix (8x8). Theresults are shown in Table 4-3.

Table 4-3: Region 1B K95/95 Determination for Misload Conditions

Assembly Dissolved

Enrichment Average Boron, lff Tk K 9 5/95 CriterionBurnup, ppm

GWD/MTU

4.54 15 1350 0.8539 0.0008 0.8853 < 0.95

2.50 0 1350 0.8347 0.0009 0.8568 < 0.95

4.1.2 Conservatisms

The major conservatisms are no boron in the poison plates, swollen geometry, and 1350 ppmboron rather than 1720 ppm minimum boron (a Technical Specification Requirement).

4.2 Region 1C (4-of-4 Configuration)

Region 1C is analyzed with soluble boron credit. The acceptance criteria with credit for soluble boronare K 95/9 5 <1.0 without soluble boron and <0.95 with 850 ppm of soluble boron. Region IC is defined asthe Region I Main Spent Fuel Pool with 4-of-4 loading having nominal planar average U-235enrichments less than or equal to 4.54 weight percent and burnup credit as shown in Table 4-4.

The results are presented in Table 4-5 for the Region 1C geometry.

Page 25



Table 4-4: Region 1C (4-of-4 Loading) Requirements

nominal planaraverage U-235 Burnup > Burnup (GWD/MTU)

enrichment (GWD/MTU) with 10% Uncertainty(Wt%)

1.80 0 0

2.40 6.43 7.07

2.60 8.57 9.43

2.80 10.71 11.78

3.00 12.86 14.15

3.20 15.00 16.50

3.40 17.25 18.98

3.60 19.50 21.45

3.80 21.75 23.93

4.00 24.00 26.40

4.20 26.22 28.84

4.40 28.44 31.28

4.54 30.00 33.00

Table 4-5: Region 1C K95195 Determination for Boron Dilution

Assembly Dissolved

Enrichment Average Boron, keff Fk K95 /95 CriterionBurnup, ppm

GWD/MTU

4.54 30 850 0.8369 0.0006 0.8740 _< 0.95

4.54 30 0 0.9312 0.0006 0.9683 < 1.0

4.00 24 850 0.8329 0.0006 0.8682 < 0.95

4.00 24 0 0.9318 0.0007 0.9671 < 1.0

3.20 15 850 0.8427 0.0006 0.8745 < 0.95

3.20 15 0 0.9510 0.0007 0.9828 < 1.0

1.80 0 850 0.7967 0.0006 0.8188 <0.95

1.80 0 0 0.9413 0.0006 0.9634 <1.0

Page 26



NON PROPRIETARY

. Palisades SFP Region 1 Criticality Evaluation with Burnup Credit

4.2.1 Misload Conditions

It is necessary to examine the accident condition of misloading a fresh assembly into adesignated location in a 4-of-4 loading patterns. For this, it is assumed the fresh assembly hasan enrichment of 4.54%. A soluble boron concentration of 1350 ppm is used. The freshmisloaded fuel assembly is placed into a position near the center of the matrix. The results areshown in Table 4-6.

Table 4-6: Region 1C K95/95 Determination for Misload Conditions

Assembly Dissolved

Enrichment Average Boron, keff Gk K95 /95 CriterionBurnup, ppm

GWD/MTU

4.54 30 1350 0.8184 0.0009 0.8555 < 0.95

4.00 24 1350 0.8186 0.0008 0.8539 < 0.95

3.20 15 1350 0.8165 0.0008 0.8483 • 0.95

1.80 0 1350 0.7984 0.0009 0.8205 < 0.95

4.2.2 Conservatisms

The major conservatisms are no boron in the poison plates, swollen geometry, and 1350 ppmboron rather than 1720 ppm minimum boron (a Technical Specification Requirement).

4.3 Region 1E (4-of-4 Configuration)

Region IE is analyzed with soluble boron credit. The acceptance criteria are K95/95 < 1.0 without solubleboron and < 0.95 with 850 ppm of soluble boron. Region 1E contains a five by ten rectangular array ofcells with Region 2 racks placed on both ends of the rack as shown in Figure 2-1 in the North Tilt Pit.Region 1E is defined as North Tilt Pit with 4-of-4 loading having a nominal planar average U-235enrichments less than or equal to 4.54 weight percent and burnup credit as shown in Table 4-7.

The results are presented in Table 4-8 for Region 1 E.

Page 27




Table 4-7: E-Rack Requirements

nominal planaraverage U-235 Burnup > Burnup (GWD/MTU)

enrichment (GWD/MTU) with 10% Uncertainty(Wt%)

2.50 0 0

2.60 0.74 0.81

2.80 2.21 2.43

3.00 3.68 4.05

3.20 5.15 5.67

3.40 6.62 7.28

3.60 8.09 8.90

3.80 9.56 10.52

4.00 11.03 12.13

4.20 12.50 13.75

4.40 13.97 15.37

4.54 15.00 16.50

Table 4-8: Region 1E K95/ 95 Determination for Boron Dilution

Assembly Dissolved

Enrichment Average Boron, keff Ck K95/95 CriterionBurnup, ppm

GWD/MTU

4.54 15 850 0.8307 0.0006 0.8742 < 0.95

4.54 15 0 0.9345 0.0007 0.9780 < 1.0

2.50 0 850 0.8034 0.0007 0.8376 < 0.95

2.50 0 0 0.9380 0.0008 0.9722 < 1.0

Page 28

AAR EVA Document No.: ANP-2858-001AREVA NP Inc.,an AREVA and Siemens company NO!N PROPRIETARY


4.3.1 Misload Conditions

It is necessary to examine the accident condition of misloading a fresh assembly into adesignated location in a 4-of-4 loading patterns. For this, it is assumed the fresh assembly hasan enrichment of 4.54%. A soluble boron concentration of 1350 ppm is used. The entireRegion 1E is assumed to be misloaded with fresh 4.54 w/o assemblies. The results are shownin Table 4-9.

Table 4-9: Region 1E K95195 Determination for Misload Conditions

Assembly Dissolved

Enrichment Average Boron, keff Uk K95/95 CriterionBurnup,

GWD/MTU ppm

4.54 0 1350 0. 8876 0.0007 0.9218 < 0.95

4.3.2 Conservatisms

The major conservatisms are no boron in the poison plates, swollen geometry, all fresh fuel,and 1350 ppm boron rather than 1720 ppm minimum boron (a Technical SpecificationRequirement).

4.4 Non-Fuel Bearing Components (NFBC)

There are several NFBC that may potentially be inserted into the racks. Only Rack C is evaluated since itcurrently contains required empty cells. The four components are:

1. Heavy Test Assembly - A Standard Assembly with lead (Pb) pellets rather than U02,

2. Test Gauge Assembly - comprised of stainless steel angles and plates to allow testing the box innerdimension,

3. An assembly containing only SS-304 Replacement Rods (no fuel rods), and

4. Vessel Fluence Capsule and Carrier (bounded by a 5.48" square block of SS304 or square shell withthe same mass, -522 Kg or 1100 lbs).

For the 3-of-4 BUC portion of the rack, the most reactive configuration is the fresh 2.50% enriched fuel at0 ppm dissolved boron. Placement of NFBC is considered in both an open cell and as a replacement for afuel assembly.

For the 4-of-4 BUC portion of the rack, the most reactive configuration examined for a 4-of-4arrangement is the 3.20% enriched fuel at 15 GWD/MTU and 0 ppm dissolved boron. Placement of aNFBC is considered as a replacement for a fuel assembly. The results are shown in Table 4-10 and Table4-11. The positive Ak of 0.0013 for Component 3 in empty cell versus Base Case shown in the 3-of-4Rack is contained in the system tolerance Ak in Table 3-3.

Page 29



Table 4-10: NFBC Reactivity Evaluation for 3-of-4 BUC Rack

Description I kff OykBASE RACK 'C' 3-of-4 8x8 Array Model 0.9368 0.0008

Dummy Assembly ResultsComponent I in empty cell 0.9377 0.0008Component 1 replacing assembly 0.9359 0.0007Component 2 in empty cell 0.9360 0.0008Component 2 replacing assembly 0.9353 0.0008Component 3 in empty cell 0.9381 0.0007Component 3 replacing assembly 0.9337 0.0007

Stainless Steel Block/Tubes Component 4SS Square Shell in Water cell with 7.75" OD 0.9377 0.0008and 5.48" ID in empty cellSS Square Shell in Water cell with 7.75" OD 0.9352 0.0007and 5.48" ID replacing assembly

Table 4-11: NFBC Reactivity Evaluation for 4-of-4 BUC Rack

Description lkef Ok

BASE RACK 'C' 4-of-4 8x8 Array Model 0.9510 0.0007

Dummy Assembly ResultsComponent 1 replacing assembly 0.9471 0.0007

Component 2 replacing assembly 0.9482 0.0007Component 3 replacing assembly 0.9488 0.0007

Stainless Steel Block/Tubes Component 4SS Square Shell in Water cell with 7.75" OD and 5.48" ID 1 0.9481 0.0008

Misload Conditions

A misloading of a NFBC (other than the heavy test assembly or the test gauge assembly) intoa designated empty cell in Region 1A or lB that is within 10 cells of another NFBC (other

than the heavy test assembly or the test gauge assembly) loaded into a designated empty cell,is bounded by a fuel misloading described in Section 4.1.1 above for Region lB. A fuel

assembly is more reactive than an NFBC.

4.4.1

Page 30

AAR EVA Document No.: ANP-2858-001AREVA NP Inc.,an AREVA and Siemens. company NON PROPRIETARY


4.5 Rack Interactions

The interactions evaluated are:

* between Region IA and Region 2 (This was analyzed in Reference [9], and is still valid).

* between Region lB and lA.

* between Region lB and IC.

" between Region IC and IA.

* between Region lB and Region 2.

" between Region IC and Region 2.

" between Region IE and Region 2.

The detailed models to perform this study are defined and discussed in detail in Appendix C. 1.2. Theswelling model is used for Regions IB, IC, and lE. Interaction between any two regions is examined byevaluating the two regions together. If k~ff increases above the maximum of either individual region, thenthere is an effect.

The fuel elevator and fuel inspection stations, which will handle fresh fuel, are located in a regionadjacent to the C-rack. Fresh fuel assemblies at these stations are nominally water isolated from the rackdue to distance. However, a fresh assembly may be inadvertently placed next to the C-rack. This wouldbe bounded by either a misload described above or the interactions described below. Therefore, thepresence of the fuel elevator and fuel inspection station does not cause additional restrictions to theacceptable fuel loading patterns.

4.5.1 Regions IA, 1B, and 1C Interaction Effects Results

The interaction between the loading zones (2-of-4, 3-of-4, and 4-of-4) is examined.

The case with the highest value of kff from KENO-V.a for the 4-of-4 has an enrichment of3.20% and a burnup of 15 GWD/MTU. For the 3-of-4 situation, it is fresh fuel with anenrichment of 2.50%. For 2-of-4 loadings, fresh fuel with a maximum enrichment of 4.54% isallowed. All cases were at 0 ppm dissolved boron. These situations are examined in variouscombinations. The 4-of-4 with 3-of-4 situation was examined in the empty cell of the 3-of-4arrangement adjacent to the 4-of-4 region. The situation with the full row of the 3-of-4adjacent to the 4-of-4 would not be allowed since it would create another 4-of-4 cluster thatwould have to comply with the 4-of-4 loading restrictions. (See Figure 4-1, Figure 4-2, andFigure 4-3)

As seen in Table 4-12, the boundary areas are not limiting, and that Region I.C is the limitingregion.

Page 31

AAR EVAAREVA NP Inc.,an AREVA and Siemens company


NON PROPRIETARY


Figure 4-1: Region 1B Adjacent to Region 1A

UUUU

UUU

UUUU

iI Empty cell

Region 1A (4.54% fresh fuel), 2-of-4

Region 1B (2.50% and a burnup of 0 GWD/MTU), 3-of-4

Figure 4-2: Region lB Adjacent to Region IC

Empty cell

Region 1B (2.50% and a burnup of 0 GWD/MTU), 3-of-4

Region 1C (3.20% and a burnup of 15 GWD/MTU), 4-of-4

Page 32



NON PROPRIETARY


Figure 4-3: Region 1C Adjacent to Region 1A

This configuration is not allowed as it creates a non-allowed 3-of-4 pattern.This conservatively bounds the allowable pattern.

I I Empty cell

Region 1A (4.54% fresh fuel), 2-of-4

Region 1C (3.20% and a burnup of 15 GWD/MTU), 4-of-4

Table 4-12: Interaction Results for Regions 1A, 1B, and 1C Racks

Case Description k ff akBase - Region 1B, 2.5%, 0 GWD/MTU 0.9368 0.0008Base - Region IC, 3.2%, 15 GWD/MTU 0.9510 0.0006Region lB adjacent to Region IA 0.9146 0.0009Region IB adjacent to Region IC 0.9500 0.0009Region IC adjacent to Region IA (4-of-4 next to 2-of-4) 0.9351 1.0007

4.5.2 Regions lB and 1C with Region 2 Interaction Effects Results

The interaction between the loading zones (3-of-4 and 4-of-4 with Region 2) for both 0 ppmand 850 ppm soluble boron is examined. These situations are examined in variouscombinations. No additional restrictions on Regions lB or IC are necessary.

As seen in Table 4-13 the boundary areas are not limiting.

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NON PROPRIETARY


Table 4-13: Interaction Results for Regions 1B and 1C to Region 2 Racks

Case Description Dissolved keff Cyk

Boron, ppmBase- Region IB, 2.5%, 0 GWD/MTU 0 0.9368 0.0008Base - Region I C, 3.2%, 15 GWD/MTU 0 0.9510 0.0007Base - Region 2 0 0.9564 0.0002Region lB adjacent to the Region 2 0 0.9563 0.0001Region IC adjacent to the Region 2 0 0.9564 0.0001

Base- Region 1B, 4.54%, 15 GWD/MTU 850 0.8423 0.0007Base - Region 1C, 3.2%, 15 GWD/MTU 850 0.8427 0.0006Base - Region 2 850 0.7541 0.0002Region 1B adjacent to the Region 2 850 0.8160 0.0001Region IC adjacent to the Region 2 850 0.8007 0.0001

4.5.3 Region 1E and Region 2 Racks Interaction Effects Results

The Region 1E is a five by ten array of cells reflected by 12" of water so that some effect isexpected between Region 1 E and the neighboring Region 2 racks. The same set of cases ismodeled as for Region 1 C and Region 2 except the minimum separation distances are modeledas 0.1", 3.33" and 10" to evaluate the impact of separation distances. Table 4-14 lists theresults for the 'E' rack interaction evaluation at 0 and 850 ppm.

The first section examines the unborated condition and shows no interaction effects for theunborated condition, and that the Region 2 rack controls the combined reactivity. A smallreactivity increase is seen for a 0.1" gap (from 0.9400 to 0.9432), which is significantly lessthan actual separation but is still significantly less than the base koff for a larger Region 2model. The second set of cases in the table examines the interaction effects with 850 ppmsoluble boron. No interaction effect is noted, but for 850 ppm the 'E' rack controls thecombined reactivity. Therefore, no minimum separation distance between Region lE andRegion 2 Racks is needed.

Table 4-14: Interaction Results for Region 1E and Region 2 Racks

Case Description Boron, ppm keff ak

Interaction Model, 0.1" Minimum Gap 0 0.9432 0.0003Interaction Model, 3.33"Minimum Gap 0 0.9399 0.0003Interaction Model, >10" Minimum Gap 0 0.9400 0.0003Base - Region 2 Model 0 0.9564 0.0003Base - Rack E Interaction Model 0 0.9409 0.0004

Case Description Boron, ppm kff OkInteraction Model, 0.1" Minimum Gap 850 0.8017 0.0003Interaction Model, 3.33"Minimum Gap 850 0.8016 0.0003Interaction Model, >10" Minimum Gap 850 0.8015 0.0003Base - Region 2 Model 850 0.7541 0.0002Base - Rack E Interaction Model 850 0.8139 0.0003

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NON PROPRIETARY


5.0 SUMMARY AND CONCLUSIONS

This report documents the criticality safety analysis for the Palisades Region 1 fuel pool storage andshows that all requirements are met. The Region lB/lC/1E racks are analyzed to allow storage of fuelapplying a burnup credit for a complete loss of boron in the Carborundum plates. More than 0.017 Akmargin to the respective criterion is calculated for the boron dilution events (both borated and unborated).All abnormal conditions meet the 0.95 criterion at 1350 ppm of boron.

6.0 LICENSING REQUIREMENTS

This analysis requires that the Technical Specifications for the Region 1 SFSR be modified toaccommodate fuel in the manner defined by this document. Final wording of the Technical Specificationsmay differ from the wording presented here as long as the intent of the requirements remains the same.The following requirements apply to Region 1.

1) Change the Region 1 definition to the following new regions

a) Region 1A - Region 1 Main Spent Fuel Pool with checkerboard loading of fuel with empty ornon-fuel bearing component cells for fuel having nominal planar average U-235 enrichments lessthan or equal to 4.54 weight percent. This region should not contain any face adjacent fuel.

b) Region 1B - Region 1 Main Spent Fuel Pool with 3-of-4 loading having nominal planar averageU-235 enrichments less than or equal to 4.54 weight percent and meeting the requirements setforth in Table 4-1 (see Figure 6-1).

Figure 6-1: Fuel Loading Pattern for Region 1B

[ I il ..]

Empty cell

•: 4.54 wt% U-235 Assembly

Page 35



CNON PROPRIETARY


c) Region IC - Region 1 Main Spent Fuel Pool with 4-of-4 loading with no required empty cells,having nominal planar average U-235 enrichments less than or equal to 4.54 weight percent andmeeting the requirements set forth in Table 4-4.

d) Region lE - Region 1 North Tilt Pit with 4-of-4 loading having nominal planar average U-235enrichments less than or equal to 4.54 weight percent and meeting the requirements set forth inTable 4-7.

e) Regions 1A, lB & IC can be distributed in Region 1 in any manner providing that any 2-by-2grouping of cells and the assemblies in them meet the requirements above for the number of cellsoccupied. For example, for a 4 x 4 group of cells, all of the following configurations must beexamined against the above requirements:

M

2) Non-fuel bearing components

a) Any component with non-fissile material can be stored in any designated fuel location in Region1A, IB, 1C, or lE without restriction.

b) If a non-fissile material meets the criteria for a non-fuel bearing component (NFBC) as listedbelow it can be stored face adjacent to fuel in a designated empty cell in Region IA or lB.

i) The gauge dummy assembly and the lead dummy assembly can be stored:

(1) Diagonally adjacent to each other anywhere in Region 1A, or

(2) Anywhere in Regions lB or 1C.

Page 36




ii) A fuel assembly composed of up to 216 solid SS rods can be stored face adjacent to fuel in adesignated empty cell as long as the non-fuel bearing component is at least ten locations awayfrom another NFBC that is face adjacent to fuel.

iii) A component composed of primarily SS that displaces less than 30 in2 of water in any planewithin the active fuel can be stored face adjacent to fuel in a designated empty cell as long asthe NFBC is at least ten locations away from another non-fuel bearing component that is faceadjacent to fuel.

3) Legacy Fuel Storage

a) For fuel in batches A through K stored in Region 1, a 1.0 GWD/MTU penalty must be subtractedfrom the burnup value, as indicated by the core monitoring system, prior to applying therequirements set forth in Licensing Requirement 1) above.

Page 37

AR EVA Document No.: ANP-2858-0O01AREVA NP Inc.,an AREVA and Siemens company NON PROPRIETARY


7.0 REFERENCES

1. "Quality Assurance Data Final Report, Boron Carbide Neutron Absorbing Plate, NUS CorporationPurchase Order No. PT-5097-9 SI," Research & Development Division, The Carborundum Company,Niagara Falls, New York, September, 1977.

2. NRC Letter to Palisades Nuclear Plant, Docket No. 50-255/License No. DPR-20, "Palisades Plant -Issuance of Amendment Re: Spent Fuel Pool Region I Storage Requirements (TAC ME0161),"ML090160238, 2009-02-06.

3. NRC Letter to Palisades Nuclear Plant, Docket No. 50-255/License No. DPR-20, "Palisades Plant -Issuance of Amendment To Change Enrichment Limits in Fuel Pool (TAC MB 1362)," ML0204400482002-02-26.

4. SCALE4.4a, "A Modular Code System for Performing Standardized Computer Analysis for LicensingEvaluation," NUREG/CR-0200, Revision 6, May 2000, Oak Ridge National Laboratory (ORNL).

5. M. Edenius, et al., "CASMO-3 - A Fuel Assembly Burnup Program," STUDSVIKiNFA-89/3, StudsvikAP, Nyk6ping, Sweden, November 1989.

6 EA-SFP-99-03, "Palisades New Fuel Storage, Fuel Pool and Fuel Handling Criticality Safety Analysis,"10/23/2000.

7. L. Kopp, ",Guidance on the Regulatory Requirements for Criticality Analysis of Fuel Storage at Light-Water Reactor Power Plants," NRC Memorandum from L. Kopp to T. Collins, August 19, 1998,ML072710248.

8. Nuclear Regulatory Commission, "Guide for Validation of Nuclear Criticality Safety CalculationalMethodology," NUREG/CR-6698, January 2001.

9. Palisades Nuclear Plant, Docket No. 50-255, License No. DPR-20, "License Amendment Request forSpent Fuel Pool Region I Criticality, Enclosure 4" ML083360624, November 25, 2008.

10. Shearon Harris Nuclear Power Plant, Unit No. 1 Docket No. 50-400/License No. NPF-63 Request forLicense Amendment, Framatome ANP, Inc 77-5069740-NP-00, "Shearon Harris Criticality Evaluation."ML052510504, 2005-08-31.

11. Nuclear Regulatory Commision, "Recommendations for Addresing Axial Bumup in PWR Burnup CreditAnalysis," NUREG/CR-680 1, March 2003.

12. Bierman, S.R., Durst, B.M., Clayton, E.D., "Critical Separation Between Subcritical Clusters of 4.29Wt% 235U Enriched U02 Rods in Water With Fixed Neutron Poisons," Battelle Pacific NorthwestLaboratories, NUREG/CR-0073 (PNL-2615).

Page 38




13. Baldwin, M. N., et al., "Critical Experiments Supporting Close Proximity Water Storage of PowerReactor Fuel," BAW-1484-7, July 1979.

14. Hoovler, G. S., et al., "Critical Experiments Supporting Underwater Storage of Tightly PackedConfigurations of Spent Fuel Pins," BAW-1645-4, November, 1981.

15. "Dissolution and Storage Experimental Program with U[4.75]02 Rods," Transactions of the AmericanNuclear Society, Vol. 33, pg. 362.

16. Nuclear Energy Agency, "International Handbook of Evaluated Criticality Safety BenchmarkExperiments." NEA/NSC/DOC(95)03, Nuclear Energy Agency, Organization for Co-operation andDevelopment, 2002.

17. D'Agostino, R.B. and Stephens, M.A., Goodness-of-fit Techniques. Statistics, Textbooks andMonographs, Volume 68. New York, New York, 1986.

18. ANSI/ANS-57.2 - "Design Requirements for Light Water Reactor Spent Fuel Storage Facilities atNuclear Power Plants," American Nuclear Society, 1983.

19. Rosenkrantz W.A., Introduction to Probability and Statistics for Scientists and Engineers, The McGraw-Hill, New York, NY, 1989.

20. Owen, D.B., Handbook of Statistical Tables, Addison-Wesley, Reading, MA.

21. EMF-96-029(P)(A), "Reactor Analysis System for PWRs," January 1997.

22. BAW-10180A, "NEMO-NODAL Expansion Method Optimized - Revision 1," March 1993.

23. Natrella, M.G., Experimental Statistics. National Bureau of Standards Handbook 91, Washington, D.C.,U.S. Deparatment of Commerce, National Bureau of Standards, 1963.

Page 39



APPENDIX A: KENO-V.A BIAS AND BIAS UNCERTAINTY

The purpose of the present analysis is to determine the bias of the krff calculated with SCALE 4.4a computer codeby using a statistical methodology to evaluate criticality benchmark experiments that are appropriate for the rangeof parameters expected for spent fuel pool criticality analysis. The scope of this report is limited to the validationof the KENO-V.a module and CSAS25 driver in the SCALE 4.4a code package for use with the 44 energy groupcross-section library 44GROUPNDF5. These results were previously submitted in Reference [10].

This calculation is performed according to the general methodology described in Reference [8] (NUREG/CR-6698 "Guide for Validation of Nuclear Criticality Safety Methodology") that is also briefly described in SectionA. 1. The critical experiments selected to benchmark the computer code system are discussed in Section A.4. Theresults of the criticality calculations, the trending analysis, the basis for the statistical technique chosen, the bias,and the bias uncertainty are presented in Section A.4. Final results are summarized in Section A.8.

A.1 Statistical Method for Determining the Code Bias

As presented in Reference [8], the validation of the criticality code must use a statistical analysis to determine thebias and bias uncertainty in the calculation of krff. The approach involves determining a weighted mean of klffthat incorporates the uncertainty from both the measurement (aTeyp) and the calculation method (Gcaic). Acombined uncertainty can be determined using the Equation 3 from Reference [8], for each critical experiment:

3t= (O 'calc2 + C 'exp2)1/2

The weighted mean oflkff(keff ), the variance about mean (s), and the average total uncertainty of the benchmark

experiments (U:2) can be calculated using the weighting factor 1 / o-2 (see Eq. 4, 5, and 6 in Reference [8]). The

final objective is to determine the square root of the pooled variance, defined as (Eq. 7 from Reference [8]):

S $2 "-•2

s P= 5S +0U2

The above value is used as the mean bias uncertainty, where bias is determined by the relation:

Bias = keff - 1, if keff is less than 1, otherwise Bias = 0 (Eq. 8 from Reference [8])

The approach for determining the final statistical uncertainty in the calculational bias relies on the selection of anappropriate statistical treatment. Basically, the same steps and methods suggested in Reference: [8] fordetermining the upper safety limit (USL) can be applied also for determining the final bias uncertainty.

First, the possible trends in bias need to be investigated. Trends are identified through the use of regression fits tothe calculated kcff results. In many instances, a linear fit is sufficient to determine a trend in bias. Typicalparameters used in these trending analyses are enrichment, hydrogen to fuel atom ratio (H/X) or a generic spectralparameter as the energy of the average lethargy causing fission (EALF).

Reference [8] indicates that the use of both weighted or unweighted least squares techniques is an appropriatemeans for determining the fit of a function. For the present analysis linear regression was used on both weighted

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NON PROPRIETARY


and unweighted kcff values to determine the existence of a trend in bias. Typical numerical goodness of fit testswas applied afterwards to confirm the validity of the trend.

When a relationship between a calculated keff and an independent variable can be determined, a one-sided lowertolerance band may be used (Reference [8]) to express the bias and its uncertainty. When no trend is identified,the pool of kaff data is tested for normality. If the data is normally distributed, then a technique such as a one-sided tolerance limit is used to determine bias and its uncertainty. Ifthedata is not normally distributed, then anon-parametric analysis method must be used to determine the bias and its uncertainty (Reference [8]).

A.2 Area of Applicability Required for the Benchmark Experiments

The spent fuel pool at Palisades will primarily contain commercial nuclear fuel in uranium oxide pins in a squarearray. This fuel is b6unded by the typical parameter values provided in Table A- 1. These typical values wereused as primary tools in selecting the benchmark experiments appropriate for determining the code bias.

Table A-1: Range of Values of Key Parameters in Spent Fuel Pool

Parameter Range of Values

Fissile materialPhysical/Chemical Formr

Enrichment natural to 5.05 wt% U-235

Moderation/Moderator Heterogeneous/Water

Lattice Square

Pitch 1.2 to 1.45 cm

Clad Zircaloy

Soluble BoronAnticipated Absorber/Materials

Stainless steel, Boron

H/X ratio 0 to 445

Reflection Water, Stainless Steel

Neutron Energy Spectrum (Energy of the 0.25 to 2.5 eVAverage Lethargy Causing Fission)

Benchmark calculations have been made on selected critical experiments, chosen, in so far as possible, to boundthe range of variables in the spent fuel rack designs. In rack designs, the most significant parameters affectingcriticality are (1) the fuel enrichment, (2) the '°B loading in the neutron absorber, and (3) the lattice spacing.Other parameters have a smaller effect but have been also included in the analyses.

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NON PROPRIETARY


One possible way of representing the data is through a spectral parameter that incorporates influences from thevariations in the parameter. Such a parameter is computed by KENO-V.a, which prints the EALF. The expectedrange for this parameter was also included in Table A-I above. Note that there are no critical experiments for lowdensity (mist) moderator cases; however, interspersed moderator cases analyzed in subsequent sectionsdemonstrate that the interspersed moderator cases were not limiting (had very low values of kcff) compared tofully flooded (100% dense moderator) cases.

A.3 Description of the Criticality Experiments Selected

The set of criticality benchmark experiments has been constructed to accommodate large variations in the range ofparameters of the rack configurations and also to provide adequate statistics for the evaluation of the code bias.

One hundred critical configurations were selected from various sources as the International Handbook ofEvaluated Criticality Safety Benchmark Experiments (Reference [16]) and previous validation analyses done withconfigurations from References [12], [13], [14], and [15]. These benchmarks include configurations performedwith lattices of U0 2 fuel rods in water having various enrichments and moderating ratios (H/X). A set of MOXcriticality benchmarks is also included in the present set (Reference [16]). The area of applicability (AOA) isestablished within this range of benchmark experiment parameter values.

A brief description of the selected benchmark experiments, including the name of the SCALE 4.4a input files thathave been constructed to model them, is presented in Table A-2. The table includes the references where adetailed description of the experiments and their range of applicability are presented.

Table A-2: Descriptions of the Critical Benchmark Experiments

Experiment Measured Ia exp I Brief Description Neutron Absorber ReflectorCase Name keff-NUREG/CR-.073 PNL-ex' eriments (Referencefl2])i -.- -21__-. ._,_ . , "c00 4 1.0000 0.0020 U0 2 pellets with 4.31 wt% 235U None Water and acrylicc005b 1.0000 0.0018 0.625 cm Al plates plates as well as ac006b 1.0000 0.0019 Cluster of fuel rods on a 25.4 mm 0.625 cm Al plates biological shieldc007a 1.0000 0.0021 pitch. Moderator; water or 0.302 cm SS-304L serve as primarycOO8b 1.0000 0.002 1 borated water. plates reflector material.c009b 1.0000 0.0021 0.298 cm SS-304L A minorcOlOb 1.0000 0.0021 Various separation distances used absorber plates with contribution comescOl lb 1.0000 0.0021 between clusters. Those so 1.05 wt% or 1.62 from the channelcOl2b 1.0000 0.0021 indicated have plates of neutron wt% B that supports the

cOl3b 1.0000 0.0021 absorbing material poison placed 0.485 cm SS-304L rod clusters and

cOl4b 1.0000 0.0021 between clusters of fuel rods. For plates the 9.52 mmadditional details on the carbon steel tankc029 1.000 00021Zircaloy-4 absorber

c029b 1.0000 0.0021 experiments and the computer plates wall.c03Ob 1.0000 0.0021 models used, see Reference [ 18] plates

c03 l b 1.0000 0.0021 and evaluated experiments LEU- Boral absorber

COMP-THERM 002 and LEU- platesCOMP-THERM-009 in Reference[4].

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Experiment Measured [ exp Brief Description Neutron Absorber ReflectorCase Name kcff

ýBAW-PI,84- x" 1im:iis(Rfrne 1)aclpl 1.0002 0.0005 Enrichments of 2.459 wt% 235U None Water andaclp2 1.0001 0.0005 3x3 array of fuel clusters. 1037 ppm boron aluminum baseaclp3 1.0000 0.0006 Various B 4C pins and stainless 764 ppm boron plate are theaclp4 0.9999 0.0006 steel and boron-aluminum sheets None primary reflectiveaclp5 1.0000 0.0007 were used as neutron absorbers. None materials in theaclp6 1.0097 0.0012 Cases so indicated also had None experiments.

aclp7 0.9998 0.0009 dissolved boron in the water None Minor contribution

aclp8 1.0083 0.0012 moderator. None from the steel tank

aclp9 1.0030 0.0009 None walls

aclpl0 1.0001 0.0009 143 ppmboronaclpl la 1.0000 0.0006 510 ppm boronaclpl lb 1.0007 0.0007 514 ppm boronaclp l c 1.0007 0.0006 501 ppm boronaclp I Id 1.0007 0.0006 493 ppm boronaclpIl e 1.0007 0.0006 474 ppm boronaclp IIf 1.0007 0.0006 462 ppm boronaclpl lg 1.0007 0.0006 432 ppm boronaclpl2 1.0000 0.0007 217 ppm boronaclpl3 1.0000 0.0010 15 ppm boronaclpl3a 1.0000 0.0010 28 ppm boronaclpl4 1.0001 0.0010 92 ppm boronaclpl5 0.9998 0.0016 395 ppm boronaclpl6 1.0001 0.0019 121 ppm boronaclpl7 1;0000 0.0010 487 ppm boronaclpl8 1.0002 0.0011 197 ppm boronaclpl9 1.0002 0.0010 634 ppm boronaclp20 1.0003 0.0011 320 ppm boronaclp2l 0.9997 0.0015 72 ppm boron

BAW-1 ~~6i5ep'erifinents. eeenelrconO1 1.0007 0.0006 2.46 wt% 2 3 5

U 435 ppm boron Water andrcon02 1.0007 0.0006 426 ppm boron aluminum basercon03 1.0007 0.0006 5x5 array of fuel cluster. Rod 406 ppm boron plate are thercon04 1.0007 0.0006 pitch between 1.2093 cm and 383 ppm boron primary reflectivercon05 1.0007 0.0006 1.4097 cm. Cases so indicated 354 ppm boron materials in thercon06 1.0007 0.0006 also had dissolved boron in the 335 ppm boron. experiments.'

rcon07 1.0007 0.0006 water moderator. 361 ppm boron Minor contribution

rcon08 1.0007 0.0006 121 ppm boron from the steel tank

rcon09 1.0007 0.0006 886 ppm boron walls.

rconlO 1.0007 0.0006 871 ppm boronrcon 11 1.0007 0.0006 852 ppm boronrconl2 1.0007 0.0006 834 ppm boronrconl3 1.0007 0.0006 815 ppm boronrconl4 1.0007 0.0006 781 ppm boronrconl5 1.0007 0.0006 746 ppm boronrconl6 1.0007 0.0006 1156 ppm boronrconl7 1.0007 0.0006 1141 ppm boronrconl8 1.0007 0.0006 1123 ppm boron

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NON PROPRIETARY


Experiment Measured a expCase Name k~ffrconl9 1 1.0007 1 0.0006rcon20 1.0007 0.0006rcon2l 1.0007 0.0006CEA Valduic CriticalMass Ldboratbmdis0l 1.0000 0.0014mdis02 1.0000 0.0014mdis03 1.0000 0.0014mdis04 1.0000 0.0014mdis05 1.0000 0.0014mdis06 1.0000 0.0014mdis07 1.0000 0.0014mdis08 1.0000 0.0014mdis09 1.0000 0.0014mdisl0 1.0000 0.0014mdisl _1 1.0000 0.0014mdisl2 1.0000 0.0014mdisl3 1.0000 0.0014mdisl4 1.0000 0.0014mdisl5 1.0000 0.0014mdisl6 1.0000 0.0014mdisl7 1.0000 0.0014mdisl8 1.0000 0.0014

CEA Valduc Critical MassLaboratory experiments. A keyaspect of these experiments wasto examine the reactivity effectsof differing densities ofhydrogenous materials within across shaped channel box placedbetween a two by two array offuel rod assemblies. Theassemblies each consisted of an18 x 18 array of aluminum alloyclad fuel U02 pellet columns.

The reader is referred toReference [18] for a descriptionof the critical mass experimentsand the computer models usedfor these validation cases.

reflectorboundaries varyfrom case tocase.

mdis19 1.0000 0.0014

LEU-COMP-THERM-022,-"-024,-025:Experiments: (Refeience116]).-- ___ _, _

leuct022-02 1.0000 0.0046 9.83 and 7.41 wt% enriched None Water is theleuct022-03 1.0000 0.0036 U02 rods of varying numbers in primary reflector.leuct024-01 1.0000 0.0054 hexagonal and square lattices inleuct024-02 1.0000 0.0040 water. Minor

leuct025-01 1.0000 0.0041 contribution from

leuct025-02 1.0000 0.0044 the steel tankwalls.

Mixed Oxide (Refereice" 11i6)', ,

epri70b 1.0009 0.0047 Experiments with mixtures of 687.9 ppm boron Reflected by water(PNL-31) natural U02-2wt%PuO2 and Al.epri70un 1.0024 0.0060 (8%240Pu). 1.7 ppm boron(PNL-30)epri87b 1.0024 0.0024 Square pitched lattices, with 1090.4 ppm boron(PNL-33) 1.778 cm, 2.2098 cm, andepri87un 1.0042 0.0031 2.5146 cm pitch in borated or 0.9 ppm boron(PNL-32) pure water moderator.

Epri99b 1.0029 0.0027 767.2 ppm boron(PNL-35)Epri99un 1.0038 0.0025 1.6 ppm boron(PNL-34)

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NON PROPRIETARY


Experiment Measured a exp Brief Description Neutron Absorber ReflectorCase Name kcff

saxtn104 1.0000 0.0023 Experiments with mixtures of None Reflected by water(case 6) natural U02-6.6wt%PuO2 and Al.saxtn56b 1.0000 0.0054 mixed-oxide (MOX), square- 337 ppm boron(case 3) pitched, partial moderator heightsaxtn792 1.0049 0.0027 lattices. None(case 5)saxton52 1.0028 0.0072 Moderator: borated or pure None(case 1) water moderator.saxton56 1.0019 0.0059 None(case 2)(PNL-35)

A.4 Results of Calculations with SCALE 4.4a

The critical experiments described in Section A.3 were modeled with the SCALE 4.4a computer system. Theresulting keff and calculational uncertainty, along with the experimental keff and experimental uncertainty aretabulated in Table A-3. The parameters of interest in performing a trending analysis of the bias (including EALFcalculated by SCALE 4.4a) are also included in the table.

Table A-3: Results for the Selected Benchmark Experiments

No Case name Benchmark values SCALE 4.4aCalculated Values

EALF Enrichment B(eV) wt% 235U (ppm)

H/X

keff U-ep k~f U-ca123456789101112131415161718192021222324252627282930

c004c005bc006bc007acOO8bc009bc0lObcOl lbcO2bcO13bcO4bc029bc03Obc03 lbACLPIACLP2ACLP3ACLP4ACLP5ACLP6ACLP7ACLP8ACLP9ACLP10ACP11AACPllBACP11CACPIHDACPlIEACPI IF

1.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00021.00011.00000.99991.00001.00970.99981.00831.00301.00011.00001.00071.00071.00071.00071.0007

0.0020.00180.00190.00210.00210.00210.00210.00210.00210.00210.00210.00210.00210.00210.00050.00050.00060.00060.00070.00120.00090.00120.00090.00090.00060.00070.00060.00060.00060.0006

0.99660.99500.99640.99730.99660.99670.99770.99490.99670.99690.99580.99720.99720.99930.99120.99510.99580.98890.99060.98990.98910.98730.99080.99160.99480.99470.99440.99520.99400.9932

0.00080.00080.00080.00090.00080.00080.00080.00090.00080.00080.00080.00080.00090.00090.00070.00060.00060.00080.00070.00090.00080.00070.00080.00070.00070.00070.00060.00070.00060.0007

0.11260.11280.11300.11280.11350.11360.11420.11430.11480.11300.11330.11260.11320.11440.17250.25040.19630.19120.16600.17120.14960.15370.14090.14950.19960.19940.20190.20280.20370.2050

4.314.314.314.314.314.314.314.314.314.314.314.314.314.312.462.462.462.462.462.462.462.462.462.462.462.462.462.462.462.46

0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.01037.0764.00.00.00.00.00.00.0143.0510.0514.0501.0493.04.74.0

462.0

255.92255.92255.92255.92255.92255.92255.92255.92255.92255.92255.92255.92255.92255.92215.57215.79215.83215.91215.87215.87215.87215.87215.87215.22215.32215.73215.32215.14214.70214.52

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AARE VAAREVA NP Inc.,an AREVA and Siemens company


NON PROPRIETARY


No Case name Benchmark values SCALE 4.4aCalculated Values

31 ACPIlG32 ACLP1233 ACLP1334 ACPI3A35 ACLPI436 ACLP1537 ACLP1638 ACLPI739 ACLPI840 ACLP1941 ACLP2042 ACLP2143 RCON0144 RCON0245 RCON0346 RCON0447 RCON0548 RCON0649 RCON0750 RCON0851 RCON0952 RCONI053 RCON1154 RCON1255 RCON 1356 RCONI457 RCON1558 RCONI659 RCONI760 RCON1861 RCON1962 RCON2063 RCON2164 RCON2865 MDIS0166 MDIS0267 MDIS0368 MDIS0469 MDIS0570 MDIS0671 MDIS0772 MDIS0873 MDIS0974 MDIS1O75 MDISll76 MDIS1277 MDISI378 MD1SI479 MDISI580 MDISI681 MDIS1782 MDIS1883 MDISI984 leuct022-0285 leuct022-0386 leuct024-0187 leuct024-0288 leuct025-0189 leuct025-0290 epri70b (PNL-31)91 epri70un (PNL-30)92 epri87b (PNL-33)93 epri87un (PNL-32)

keff

1.00071.00001.00001.00001.00010.99981.00011.00001.00021.00021.00030.99971.00071.00071.00071.00071.00071.00071.00071.00071.00071.00071.00071.00071.00071.00071.00071.00071.00071.00071.00071.00071.00071.00071.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00001.00091.00241.00241.0042

acxp

0.00060.00070.0010.0010.0010.00160.00190.0010.00110.0010.00110.00150.00060.00060.00060.00060.00060.00060.00060.00060.00060.00060.00060.00060.00060.00060.00060.00060.00060.00060.00060.00060.00060.00060.00140.00140.00140.00140.00140.00140.00140.00140.00140.00140.00140.00140.00140.00140.00140.00140.00140.00140.00140.00460.00360.00540.00400.00410.00440.00470.00600.00240.0031

kcff

0.99540.99300.99330.99020.98910.98550.98560.98990.98860.99120.98990.98830.99971.00040.99850.99831.00020.99820.99841.01550.99730.99820.99580.99790.99710.99670.99800.99540.99630.99290.99520.99520.99450.99700.99290.98620.98450.98950.99011.00100.99010.98580.98560.99281.00291.00800.99160.98870.98811.00150.99870.99610.99281.00561.00480.9991.00480.98510.99360.99950.99671.00461.0034

Ocnk0.0007

0.00080.00080.00070.00080.00070.00070.00060.00080.00060.00070.00080.00070.00070.00080.00070.00070.00070.00060.00080.00070.00080.00070.00070.00060.00070.00060.00060.00070.00070.00070.00070.00070.00080.00080.00090.00090.00080.00090.00080.00090.00080.00090.00090.00090.00080.00090.00080.00100.00080.00080.00080.00090.00130.00130.00150.00140.00140.00130.00160.00150.00130.0013

EALF(ev)

0.20450.17000.19650.19810.20110.20630.17300.20530.17250.20610.17300.15322.42822.43602.49722.49892.49882.51191.63131.11341.44811.46231.50061.49421.49731.51851.51220.41820.42930.43540.43710.43670.44040.99840.28220.26410.26360.25130.24110.22920.22500.24930.24830.22210.20430.19460.19470.22990.22700.19050.17940.17470.17470.29200.12531.05680.14350.44010.20150.76310.56480.27800.1894

Enrichment Bwt%

235U (ppm)

2.46 432.02.46 217.02.46 15.02.46 28.02.46 92.02.46 395.02.46 121.02.46 487.02.46 197.02.46 634.02.46 320.02.46 72.02.46 435.02.46 426.02.46 406.02.46 383.02.46 354.02.46 335.02.46 361.02.46 121.02.46 886.02.46 871.02.46 852.02.46 834.02.46 815.02.46 781.02.46 746.02.46 1156.02.46 1141.02.46 1123.02.46 1107.02.46 1093.02.46 1068.02.46 121.04.74 0.04.74 0.04.74 0.04.74 0.04.74 0.04.74 0.04.74 0.04.74 0.04.74 0.04.74 0.04.74 0.04.74 0.04.74 0.04.74 0.04.74 0.04.74 0.04.74 0.04.74 0.04.74 0.09.83 0.09.83 0.09.83 0.09.83 0.07.41 0.07.41 0.0- 688.0

2.01090.01.0

H/X

215.97215.05215.67215.91215.83215.83215.83215.89215.89215.89215.89216.1917.4117.4017.4017.4117.4117.4117.4317.4344.8144.8144.7944.8144.8144.7944.79118.47118.47118.44118.44118.44118.4417.44137.61137.61137.61137.61137.61137.61137.61137.61137.61137.61137.61137.61137.61137.61137.61137.61137.61137.61137.6180.00151.0041.00128.0066.30106.10146.15146.20308.83308.99

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AAR IEVA Document No.: ANP-2858-001AREVA NP Inc.,an AREVA and Siemens company NON PROPRIETARY


No Case name Benchmark values SCALE 4.4a EALF Enrichment B H/XCalculated Values (eV) wt%

235U (ppm)

klff Gcxp kcff Gý.[ý

94 epri99b (PNL-35) 1.0029 0.0027 1.0066 0.0009 0.1802 767.0 445.4195 epri99un (PNL-34) 1.0038 0.0025 1.0088 0.0019 0.1353 2.0 445.5796 saxtn104 (case 6) 1.0000 0.0023 1.0056 0.0017 0.1001 0.0 473.1197 saxtn56b (case 3) 1.0000 0.0054 0.998 0.0019 0.6523 3:37.0 95.2498 saxtn792 (case 5) 1.0049 0.0027 1.0027 0.0019 0.1547 0.0 249.7099 saxton52 (case 1) 1.0028 0.0072 0.9987 0.0013 0.8878 0.0 73.86100 saxton56 (case 2) 1.0019 0.0059 0.9997 0.0018 0.5450 0.0 95.29

In order to address situations in which the critical experiment being modeled was at other than a critical state (i.e.,slightly super or subcritical), the calculated koff is normalized to the experimental lxp, using the following formula(Eq.9 from Reference [8]):

knorn . kcalc /Ik,5 p

In the following, the normalized values of the keff were used in the determination of the code bias and biasuncertainty.

A.5 Trending Analysis

The next step of the statistical methodology used to evaluate the code bias for the pool of experiments selected isto identify any trend in the bias. This is done by using the trending parameters presented in Table A-4.

Table A-4: Trending Parameters

Energy of the Average Lethargy causing Fission (EALF)

Fuel Enrichment (wt% 235U)

Atom ratio of the moderator to fuel (H/X)

Soluble Boron Concentration

The first step in calculating the bias uncertainty is to apply regression-based methods to identify any trending ofthe calculated values of keff with the spectral and/or physical parameters. The trends show the results ofsystematic errors or bias inherent in the calculational method used to estimate criticality.

For the critical benchmark experiments that were slightly super or subcritical, an adjustment to the kcff valuecalculated with SCALE 4.4a (klate) was done as suggested in Reference [8]. This adjustment is done bynormalizing the calculated (kcalc) value to the experimental value (kexp). This normalization does not affect theinherent bias in the calculation due to very small differences in k~ff. Unless otherwise mentioned, the normalizedkoff values (knorm) have been used in all subsequent calculations.

Each subset of normalized klff values is first tested for trending against the spectral and/or physical parameters ofinterest (in this case, presented in Table A-4 above), using the built-in regression analysis tool from any generalstatistical software (e.g., Excel). Trending in this context is linear regression of unweighted calculated kcff on thepredictor variable(s) (spectral and/or physical parameters). In addition, the equations presented in Reference [8]

are also applied to check a linear dependency in case of weighted keff, using as weight the factor 1 / o-2 as

previously discussed.

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AR EVA Document No.: ANP-2858-001AREVA NP Inc.,an AREVA and Siemens company NON PROPRIETARY


The linear regression fitted equation is in the form y(x) = a + bx, where y is the dependent variable (krff) and x isany of the predictor variables mentioned in Table A-4. The difference between the predicted y and actual value ofit is known as the random error component (residuals).

The final validity of each linear trend is checked using well-established indicators or goodness-of-fit testsconcerning the regression parameters. As a first indicator, the coefficient of determination (r2) that is available asa result of using linear regression statistic can be used to evaluate the linear trending. It represents the proportionof the sum of squares of deviations of the y values about their mean that can be attributed to a linear relationbetween y and x.

Another assessment of the adequacy of the linear model can be done by checking the goodness-of-fit against anull hypothesis on the slope (b) (Reference [19], p. 371). The slope test requires calculating the test statistic "T'as in the following equation along with the corresponding statistical parameters (Reference [19], p. 371).

T=A

iS~

where, A81 is the estimated slope of the fitted linear regression equation

i=1,n

and,

(n - 2) ,= t, )

where, 5i is the estimated value using the regression equation.

The test statistic is compared to the Student's t-distribution (t,/2,n-2) with 95% confidence and n-2 degrees offreedom (Reference [23]p.T-5), where n is the initial number of points in the subset. Given a null hypothesisH0:P31=0, of "no statistically significant trend exists (slope is zero)", the hypothesis would be rejected if TJ >ta/2,n-2. By only accepting linear trends that the data supports with 95% confidence, trends due to the randomnessof the data are eliminated. A good indicator of this statistical process is evaluation of the P-value probability(calculated by the regression tool in Excel) that gives a direct estimation of the probability of having a lineartrending due only to chance.

The last step employed as part of the regression analysis is determining whether or not the final requirements ofthe simple linear regression model are satisfied. The error components (residuals) need to be normally distributedwith mean zero, and also the residuals need to show a random scatter about the center line (no pattern). Theserequirements were verified for the present calculation using the built-in statistical functions in Excel and byapplying an omnibus normality test (Anderson-Darling, Reference [ 17] p.372]) on the residuals.

The results of the trending parameter analysis for the criticality benchmark set (unweighted kff) are summarizedin Table A-5.

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Table A-5: Summary of Trending Analysis

Trend ValidParameter n Intercept Slope r2 T tO.025,n-2 P-value Goodness-of-fit Tests TrendEALF 100 0.9937 0.002 0.061 2.53 1.987 0.013 Not Passed (residuals No

not normal and showa pattern -see FigureA-5)

Enrichment 90a 0.9911 0.0008 0.070 2.57 1.991 0.012 Not passed (residuals No(wt%

231U) not normal and show

a pattern - see FigureA-6)

H/X 100 0.9952 -2.2E-06 0.001 - 1.987 0.714 Not Passed No0.37

Boron in 100 0.9945 1.5E-06 0.009 0.95 1.987 0.345 Not passed Nomoderator(ppm)

1NoLe: BenchmarIk epeimnt WItH1 IVI'.JA. uel excluded.

The results in above table show that there are no statistically significant and valid trends of kff with the trendingparameters. An additional check was done by determining if there are any trends on the weighted data. The

results of the regression analysis obtained using weighted kff (with the weight factor 1/a ' as previously

discussed) show that the determination coefficient (r2) has similar low values as in the above table, evidencingvery weak and statistically insignificant trends.

Figure A-I to Figure A-6 show the distribution of the normalized krff values versus the trending parametersinvestigated.

Figure A-I: Distribution of keff Data versus EALF for the Selected Pool of BenchmarkExperiments

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Figure A-2: Distribution of keff Data versus Enrichment (235U) for the Selected Pool ofBenchmark Experiments

1.02

1.01

1-

0.99

0.98

Ii:I

S

0.97 1

0.0 0 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00

Enrichment (wt%)

Figure A-3: Distribution of keff Data versus H/X for the Selected Pool of Benchmark Experiments

1.02

1.01

1

0.99

0.98

!9-19

0.97 , ,0.00 50.00 100.00 150.00 200.00 250.00 300.00 350.00 400.00 450.00 500.00

H/X

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Figure A-4: Distribution of keff Data versus Soluble Boron Concentration for the Selected Poolof Benchmark Experiments

1.02

1.01

1

0.99

0.98

0.97 1 ,

0.00 200.00 400.00 600.00 800.00

Boron (ppm)

1000.00 1200.00 1400.00

Figure A-5: Plot of Standard Residuals for Regression Analysis with EALF as Trending.Parameter

4.0000

3.0000

2.0000 -- -*

"o 1.0000

M 0.0000 _-____

0.000 0W000 1.0000 1.5-0 0 2.0000 2.5%00 3.0 )00U) -1.0000 R-

-2.0000

-3.0000

EALF (eV)

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Figure A-6: Plot of Standard Residuals for Regression Analysis with Enrichment as TrendingParameter

5.0000

4.0000

3.0000

i 2.0000

1.0000

0.0000

0.1-1.0000

-2.0000

-3.0000

Enrichment (wt % 23 5U)

A.6 Bias and Bias Uncertainty

For situations in which no significant trending in bias is identified, the statistical methodology presented inReference [8] suggests to first check the normality of the pool of krff data. Applying the Shapiro-Wilk test(Reference [8]) the null hypothesis of a normal distribution is not rejected. A visual inspection of the normalprobability plot of the keff data is also evidencing that the pool of k~ff data for the selected benchmarks can beconsidered normally distributed.

This situation allows the application of the weighted single-sided lower tolerance limit to determine the biasuncertainty (Reference [8]). First by determining of the factor for 95% probability at the 95% confidence level(C 95/9 5) and then multiplying it with the evaluated square root of the pooled variance, the uncertainty limit isdetermined.

From Reference [20], C 9 5/95 for n equal to 100 is 1.927. The square root of the pooled variance calculated usingthe formulas presented is:

S, + 5-2 = (2.45212E-05+1.63005E-06) 0.5 =0.00511

Bias Uncertainty = C 9 5/9 5"* Sp = 1.927 * 0.00511 = 0.00985

The bias is obtained using the formula that includes the weighted average of kff

Bias = /ff - 1 = 0.99458 - 1 = -0.00542

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These represent the final results that can be further used to evaluate the maximum keff values in the criticalityanalysis of the Palisades spent fuel pool.

A.7 Areas of Applicability

A brief description of the spectral and physical parameters characterizing the set of selected benchmarkexperiments is provided in Table A-6.

Table A-6: Range of Values of Key Parameters in Benchmark Experiments

Parameter Range of Values

Geometrical shape Heterogeneous lattices;Rectangular and hexagonal

Fuel type U0 2 rodsMOX fuel rods

Enrichment (for U0 2 fuel) 2.46 to 9.83 wt % 235.U

Lattice pitch 1.04 to 2.6416 cm

H/X 17.4 to 445

EALF 0.11 to 2.51 eV

Absorbers Soluble boronBoron in plates

Reflectors WaterStainless SteelAluminum

Bias Summary and ConclusionsA.8

The results of this evaluation for a selected set of criticality benchmark experiments with enrichments rangingfrom about 2.5 to about 10 wt% 235U and including also some experiments with MOX fuel rods provide thefollowing information relative to the SCALE4.4a bias.

Bias = kTff - 1 = 0.99458 - 1 = -0.00542

Note that this bias will be applied as a positive penalty in the equation for computation of kmax.

Bias Uncertainty = C95/95" S = 1.927 * 0.00511 = 0.00985

The bias and its uncertainty (95/95 weighted single-sided tolerance limit) was obtained applying the appropriatesteps of the statistical methodology presented in Reference [8] (NUREG 6698) taking into account the possibletrending of koff with various spectral and/or physical parameters. The results are intended to support the criticalityanalysis of Palisades spent fuel pool.

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APPENDIX B: CASMO CALCULATIONS FOR BURNUP

This section describes the methods and results for the burnup credit analysis. A summary of key aspects of theburnup credit analysis is given in the following table:

Table B-i: Depletion Modeling Considerations

Parameter Value/Model Comment

Bumup Uncertainty 5% of the reactivity decrement from 0 Standard value consistent withburnup and the bumup of interest Reference [6]

Measured Bumup Uncertainty 10% Conservatively large value taken.

Sm Equilibrium value More conservative than using peak Sm.Peak Sm is less for low power

operation at end of cycle.

Xe Zero

Pu239+Pu241 Buildup * Moderator temperature chosen tomaximize Pu production byhardening the spectrum.

* All Np-239 is assumed instantlydecayed to Pu239.

Axial Burnup Profile 0 10 axial nodes used.

* 3 axial shapes taken fromReference [11], validated againstcore monitoring data.

Fuel Temperature 0 1260 OF (955.4K). 100 OF higher Conservatively high to increasethan maximum predicted fuel production of Pu through resonancetemperature. absorption.

Moderator Temperature 0 A bounding axial temperature Conservatively high to harden spectrumprofile was calculated. and increase Pu production.

Soluble Boron Concentration 0 Cycle-average concentration of700 ppm.

Core Power * Nominal value of 2565.4 MW

Operating History * Nominal, unrodded

Fixed/Integral Burnable absorbers 0 None modeled Conservative to ignore Gad integralpoisons and lumped burnable poisons

are currently not used.

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B.1 BUC Calculational Method

The Palisades Region 1 storage rack used the fixed spacing, burnup credit (BUC), and soluble boron (PPM) creditto provide safe storage of discharged fuel assemblies. The application of BUC requires more calculations than thetypical fresh fuel rack analysis. For BUC applications the reactivity effect of the following items must beevaluated and factored into the analysis:

* Operating history of the fuel including fuel and moderator temperatures

* Axial burnup distributions as a function of assembly average burmup

a 5% uncertainty of reactivity decrement due to burnup

0 Measured burnup uncertainty

These parameters contribute to the residual reactivity of the burned fuel with the axial distribution having asignificant impact at higher assembly average burnups.

The methodology used to apply BUC utilizes CASMO-3 to generate the fuel assembly isotopic composition at agiven burnup for each axial assembly node. CASMO-3 is used for the generation of cross sections and depletedisotopes for the PRISM and NEMO core simulators, which are used to support licensing and operation of PWRs.The adequacy of CASMO-3 for this usage is reflected in the results provided in the PRISM and NEMO Topicalreports, References [21] and [22], respectively.

For this analysis, the Batch XI assembly is used. The isotopics are then provided to KENO-V.a to perform thekcff calculations for the specific SFP rack configuration and loading. The process is complicated by the fact thatKENO-V.a cross section data bases do not have the ability to accept all of the isotopes for a burned assembly (i.e.,actinides plus all fission products) and CASMO-3 uses a "lumped" fission product cross section set. Therefore,an intermediate step is needed in which CASMO-3 is used to perform a reactivity equivalencing calculation withthe rack geometry for the given burnup state point in which B-10 is used to represent the lumped fission products.Within KENO-V.a, the generated Sm-149 is explicitly modeled, the Xe-135 concentration is set to 0, the Np-239is added to Pu-239, and all other fission products are modeled as B-10. The following additional isotopes aretransferred from CASMO-3 to KENO-V.a: U-235, U-236, U-238, Pu-240, Pu-241, and 0-16.

Thus, the isotopic composition provided to KENO-V.a represents an equivalent reactivity composition which issupported by the KENO-V.a cross section data base.

B.1.1 Assembly Operation and Depletion Data

In order to perform the burnup credit (BUG) SFP storage rack calculations the design basis fuel assembly must becharacterized with in-core depletion calculations. The depletion calculations are intended to maximize theassembly reactivity at a given burnup by conservatively modeling moderator and fuel temperatures during reactoroperation. This section documents the reactor operational data needed to perform the CASMO-3 depletioncalculations.

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The moderator temperatures and fuel temperatures are sensitive to operating temperatures, which are a function ofcore power level and RCS core flow. A bounding axial temperature profile was calculated based on an inlettemperature of 544°F and a temperature rise across the assembly of 58.3 OF. These values are shown in Table B-2.Note that the resulting moderator temperature distribution provides a core exit temperature that is near, or slightlyabove, the value that is allowed by plant operating Technical Specifications.

Table B-2: Axial Moderator Temperature Distribution

Node Center (cm) Temperature (°C) Temperature (K)9.36 284.5 557.7

28.06 286.5 559.746.78 287.8 561.084.20 292.7 565.9140.42 298.7 571.9196.46 304.7 577.9252.61 311.0 584.2290.03 314.6 587.8308.75 315.9 589.1327.45 316.8 590.0

A conservative fuel temperature of 1260 °F (955.4K) is used for all nodes. This includes a 100 OF allowance tothe maximum estimated fuel temperature of 1160 OF (PRISM core averaged at each axial node). A conservative(higher) moderator and fuel temperature produces more fissile material (i.e., Pu-239).

B.1.2 Assembly Axial Burnup Data for Rack BUC Analysis

Typical burnup credit analyses submitted to the US NRC have used a uniform, average burnup distribution overthe entire length of the assembly. Such a uniform distribution underestimates the burnup at the center of theassembly and over estimates the burnup at the top and bottom of the assembly. Thus, to adequately utilize bumupcredit the impact of the axial bumup distribution at any given assembly average burnup must be understood. Thisrequires that an estimate of the reactivity effects of the axial burnup distribution relative to a uniform distributionbe determined and appropriately applied to the results (i.e., an axial bumup distribution penalty factor).Alternatively, an explicit axial burnup distribution can be modeled in KENO-V.a calculations directly whichremoves the need for application of an axial bumup distribution penalty. The BUC evaluation for the PalisadesSFP racks will use the latter approach (i.e., use an explicit axial burnup distribution).

The relative axial distribution provided in Table B-3 is derived from NUREG/CR-6801, and has been shown to beapplicable to Palisades, based on PRISM (Reference [21]) code output and data reports for Palisades Cycles 18-21(see Figure B-l), which are representative of past and future operations. Note that these axial burnup values areindependent of the initial enrichment of the fuel, and generally the burnup in the top of the core is higher for theEOC burnup profiles (lines) than the bounding profile (circles) from NUREG/CR-6801 except for the very topnode, which is an axial blanket with reduced enrichment.

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AAREVA Document No.: ANP-2858-001AREVA NP Inc.,an AREVA end Siemens company NON PROPRIETARY


Table B-3: 15 and 30 GWD/MTU Burnup Profiles - 336.81 cm Height

Center Node Top Node Burnup KENO Node Burnup KENO NodeAxial 15 Node 30 GWD/MTU BurnupHeight GWD/MTU Burnup

cm cm

9.36 18.71 9.74 9.74 18.57 18.57

28.06 37.42 15.66 15.66 27.72 27.72

46.78 56.13 18.12 18.12 31.68 31.68

65.48 74.84 18.23 18.19 32.91 33.01

84.20 93.57 18.21 33.09

102.93 112.28 18.12 33.03

121.62 131.02 17.96 17.87 33.09 33.40

140.42 149.73 17.84 33.36

159.04 168.44 17.82 33.75

177.84 187.15 17.88 17.89 34.08 34.22

196.46 205.82 17.93 34.29

215.19 224.53 17.85 34.29

233.88 243.24 17.34 14.67 34.08 32.98

252.61 261.97 15.33 33.45

271.33 280.68 11.34 31.41

290.03 299.39 9.21 9.21 26.46 26.46

308.75 318.10 7.22 7.22 21.03 21.03

327.45 336.81 4.26 4.26 13.68 13.68

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Figure B-I: Burnup profiles for Cycles 18-21 for burnups 30-34 GWD/MTU

(EOC burnup profiles (lines) and the bounding profile (circles). The locationsof the upper and lower blankets are indicated by gray lines.)

a)

0L_

°L

C)

0

c~o

C:;(D6

0 50 100 150 200 250 300

height (cm)

B.1.3 Isotopics Generation Method

The process of generating isotopic data set for a given assembly burnup begins with a CASMO-3 hot full powerin-core depletion with selected core fuel and moderator temperatures. Generally, a CASMIO-3 restart file iswritten to save the assembly depletion data to facilitate repeated use. A set CASMO-3 restart calculation(s) at theselected burnup state point is then performed to generate isotopic data set which is supported by KENO-V.a andrepresents a reactivity equivalent assembly in the SFP rack geometry. The general process is outlined as follows:

1) Develop a base CASMO-3 input deck for the Palisades fuel assembly in a standard infinite latticedepletion model of the type used for in-core modeling. Create a second CASMO-3 model of that assemblyin a fuel rack cell.

2) Obtain the appropriate axial burnup shape for the desired assembly averaged burnup. Segment this axialshape to fit a 10-node axial model in KENO-V.a, and determine a burnup value for each node. Determinea conservative moderator temperature (i.e., one that is higher than nominal) for each node. Use aconservative fuel temperature (i.e., one that is higher than nominal) for each node.

3) For each burnup value determined in step 2, use the CASMO-3 depletion model to deplete the fuel to thatburnup at the determined fuel and moderator temperatures. The top and bottom axial nodes are modeled

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with the same enrichment as the rest of the assembly rather than a reduced enrichment for the axialblanket regions. Write a restart file.

4) Have CASMO-3 calculate a value of kif using that restart file with the isotopics in the spent fuel rackgeometry model. This value of kinf will be used for the reactivity equivalency step (Step 5).

5) Re-run CASMO-3 iterating on the B-10 concentration to replace the fission products and minor actinidesuntil a value is found where the generated value of kinf matches the original value of kin,.

6) Record the final isotopic concentrations from that final .CASMO-3 run. These isotopes will be used tomodel that node in KENO-V.a. Repeat steps 3-5 for each node bumup. The end product will be 10 sets ofisotopic and B-10 concentrations for the 10 axial nodes in KENO-V.a.

Note that this is a reactivity equivalencing process which uses B10 to adjust the equivalent assembly reactivity tothe base assembly reactivity. Therefore, the process is not dependent upon having the exact isotopic numberdensity for 016 and is self correcting in the sense that the B10 concentration is adjusted to obtain the correctassembly reactivity by definition. Small variations in the 016 number density can be obtained due the thermalexpansion adjustment in the CASMO-3 depletion runs. The process used here provides an easy verification thatthe correct assembly reactivity is obtained.

In accordance with NRC directives (Reference [7]), an additional penalty is taken when burnup credit is applied.This penalty is 5% of the difference between the reactivity of the assembly when fresh and the reactivity of theassembly at the desired burnup point. This penalty, then, is specific to assembly enrichment and the desiredburnup. The values are obtained from the CASMO-3 depletion of the nominal assembly in core geometry at 700ppm. The calculated penalties are:

4.54% Fuel: 0 GWD/MTU kcff = 1.3257215 GWD/MTU kcff= 1.1392230 GWD/MTU keff = 1.02497

4.00% Fuel: 0 GWD/MTU kcff = 1.2987724 GWD/MTU k~ff = 1.03531

3.20% Fuel: 0 GWD/MTU koff = 1.2460415 GWD/MTU kaff = 1.05231

Penalty for 4.54% Fuel at 15 GWD/MTU = 0.05*(1.32572-1.13922) = 0.0093Penalty for 4.54% Fuel at 30 GWD/MTU = 0.05*(1.32572-1.02497) = 0.0150Penalty for 4.00% Fuel at 24 GWD/MTU = 0.05*(1.29877-1.03531) = 0.0132Penalty for 3.20% Fuel at 15 GWD/MTU = 0.05*(1.24604-1.05231) = 0.0097

Even though core conditions are used to estimate the reactivity penalty rather than rack geometry, the estimateduncertainties remain applicable since a conservative additive adjustment is used rather than a statisticalcombination.

B.1.4 Loading Curve Generation Method

The general objective of the loading curve is to determine the physical requirements for which assemblies of agiven initial enrichment loading and assembly average burnup can be stored in a given storage rack configuration.The general process for generating a BUC loading curve is to calculate the KENO-V.a BUC data, based on initialassembly enrichments and various burmups. A set of enrichment and burnup points was established in Section 4.0for the various loading patterns at selected enrichments (see Table 4-2, Table 4-5, Table 4-8) using the process

Page 59




outlined in the previous section. The intermediate enrichments in Table 4-1, Table 4-4, and Table 4-7 were thendeveloped by linear interpolation between these derived limits. For example, for C-Rack region 1B (the 3-of-4loading pattern), the enrichment/burnup values were determined by interpolating between the 4.54% fuel at 15GWD/MTU and 2.50% fuel at 0 GWD/MTU. For region 1C (the 4-of-4, or fully loaded section), the values weredetermined by interpolating between 1.80% at 0 GWD/MTU, 3.20% at 15 GWD/MTU, 4.00% -at 24 GWD/MTU,and 4.54% at 30 GWD/MTU. For the E-rack, the values were determined by interpolating between 4.54% at 15GWD/MTU and 2.5% at 0 GWD/MTU.

Also, for implementing as Technical Specifications, a 10% measurement uncertainty is added to all burnup valuesin the tables. This conservatively bounds the differences that may occur between the average two-dimensionalassembly burnup values as determined by the incore monitoring system and the actual burmup.

The loading limits are as shown in Table 4-1, Table 4-4, and Table 4-7.

B.2 Legacy Fuel Storage

Several assemblies are legacy fuel from very early cycles. A number of assemblies may have had lumpedburnable absorber pins in empty tubes and other assemblies may have had fuel rods replaced with either stainlesssteel rods or empty pin cells. These fuel configurations were examined in Section B. 1.3 of Reference [9]. Thepresence of guide tubes for burnable poison pins or empty pin cells may result in a reactivity increase as much as0.005 Ak. The effect of actinide buildup due to the presence of burnable poisons during depletion and subsequentburnable poison removal is small and estimated by an additional 0.005 Ak penalty. The continued storage ofbatches A through K in Region 1 is acceptable, if a 1.0 GWD/MTU penalty is subtracted from the burnup asindicated by the core monitoring system to meet the requirements set forth in Section 6.0. This was determined byexamining fuel depletions of similar enrichment which indicates that this burnup penalty covers theapproximately 0.01 Ak reactivity bias of these assemblies.

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APPENDIX C: KENO.V-A TOLERANCE CALCULATIONS

This appendix includes the details of the system and tolerance studies that define the additional data for the K 9 5/95

equation.

C.1 System Bias (Aksys and asys)

These are the calculations that define the biases on the reactivity calculations that are not considered randomvariation. These effects that could lead to such biases are fuel rack swelling, rack interaction effects, the use ofNFBC in required empty cells, modified fuel assemblies, and pool temperature. These effects are represented inthe K95/95 equation by Aksys and asy, (see Section 3.5.1).

C.1.1 Fuel Rack Swelling

As discussed in Section 3.3.5 (Swelling Model), persistent, major voiding of the flux trap region is not expected.However, a scenario in which voiding could occur along the height of a cell's absorber plates' gap or plenum washypothesized. In this scenario, a plugged vent hole in a fuel cell occurs, with a second defect lower in the samefuel box (such as a crack in a weld), which could allow water to exit the annular region as a bubble expanded inthe plenum. The total width of the voided annular region is 0.040 inches, because the absorber cavity isnominally 0.250 inches wide and the absorber material is nominally 0.210 inches wide. In this case, swelling ofthe cell walls would not be expected, but a pocket of gas could displace the water in the upper regions of the fuelbox that typically surrounds the absorber plate. Given the required assumptions for this scenario to occur, it isconsidered improbable. To assess the impact of this scenario, a sensitivity study was examined where water isdisplaced between depleted Carborundum' plates and the stainless steel walls for a small number of cells. Thiswould theoretically occur only in a cell that accumulated gas or swelled due to oxidation of the material.

Models were created to examine this for one voided cell in an 8x8 rack, and for two adjacent cells bothexperiencing displaced water.

Table C-1: Rack C Voiding Effects

DissolvedDescription Boron, klff 7k

ppm

Base Case, no voiding, 4-of-4 850 0.8329 0.0006

Base Case, no voiding, 4-of-4 0 0.9312 0.0006

One Voided Cell 850 0.8316 0.0006

One Voided Cell 0 0.9251 0.0007

Two adjacent Voided Cells 850 0.8330 0.0006

Two adjacent Voided Cells 0 0.9238 0.0006

It is seen that the voided cell cases do not give statistically different values, usually being actually slightly lowerthan the non-void base case. As such, unless voiding is anticipated to be a wide spread problem rather thanoccurring in isolated cells, it does not affect the conclusions of this analysis.

Section 3.3.5 contains further information on the swelling model.

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NON PROPRIETARY


C.1.2 Rack Interaction Models

This section describes the rack interface models to support the results presented in Section 4.5. The Region 2 rackgeometry is needed to perform a rack interface model and is more complicated than either of the racks in Region1. The model must split the rack into unit arrays that in this case requires a portion of the fabricated rack cell tobe modeled in the inter-box cell. The cut off portion encompasses a large portion of the Boraflex gap region(hence forth referred to as the gap region).

The fabricated box model is the simplest because it is simply a stainless steel box with a smallslice of the gapregion. Table C-2 lists the dimensions in the model.

Table C-2: Fabricated Box Model Dimensions

Component in Cumulative cm 1/2 cmCell ID 9.00 9.00 22.860 11.43Box Wall thickness 0.075 9.15 23.241 11.6205Gap/wrapper 0.010 9.17 23.292 11.6459Gap length 7.400 7.400 18.796 9.398Gap/wrap box 1 horizontal length - 9.17 23.2918 11.6459Gap/wrap box 1 vertical length 9.15 23.241 11.6205

The inter-box is a bit more complicated due to the need to have different units for the gap/wrapper on each side.Table C-3 lists the dimensions for the model.

Table C-3: Inter-Box Model Dimensions

Component in Cumulative cm 1/2 cmCell ID 9.066 9.066 23.028 11.51382Wrapper 0.020 9.106 23.129 11.56462Gap 0.022 9.15 23.241 11.6205wrapper/gap 0.010 9.17 23.292 11.6459gap length - 7.400 18.796 9.398gap+wrapper 7.44 18.898 9.4488gap/wrap box I horizontal length 9.17 23.2918 11.6459gap/wrap box I vertical length 9.066 23.02764 11.51382

This arrangement works fine for an infinite rack array. However, this model is being developed for an evaluationof the possible coupling between the Region 1 and Region 2 racks. Thus, edge units must be developed toprovide a finite rack array. For this evaluation it is assumed that the Region 2 rack will reside to the left of theRegion 1 rack. Thus, right edges are needed to terminate the rack. Figure C-I illustrates an expanded section ofthe KENO-V.a model of the fabricated and inter-boxes at the edge of the rack.

Page 62



Figure C-I: Sketch of KENO-V.a Model at Edge of Region 2 Racks

C.1.2.1 C Rack Interaction Combined Models

The 'C' rack interaction model uses the swelling model for the 'C' rack and the Region 2 model discussedpreviously. The nominal separation distance between the two regions is 2.43" ± 0.25" that gives a minimumseparation of 2.18" (5.5372 cm). The 'C' rack interaction distance uses the minimum separation distance in themodel of the two racks. The 'C' rack is modeled as a lOx 10 array in a 2-of-4 loading pattern. The model extends102.5" in the y direction based upon the 10.25" pitch. The Region 2 rack is modeled as an 1 Wxl0 array with a ydistance of 100.87" based upon the 9.17" pitch. To provide common y-direction values for the joint array, a 1.63"(4.1402 cm) water gap is placed at the top of the array. This is slightly larger than the -1.438" gap between twomodules; however, it is within the 0.25" uncertainty in placement. Figure C-2 provides a sketch of the model(note only 2 of the 10 axial rows are shown to enable enlargement of the sketch). The two separated racks have a12" water reflector in the x and z directions. The y-direction has a periodic condition to simulate an infinite rackin that dimension.

Page 63




Figure C-2: Sketch of a Portion of the 'C'-Region 2 Model

C.1.2.2 E Rack Interaction Combined Models

The 'E' rack interaction model uses the maximum swelling model for the 'E' rack and the Region 2 modeldiscussed previously. The nominal separation distance between the two regions is 3.58" ± 0.25". The 'E' rackinteraction distance uses the nominal separation distance in the model of the two racks. The 'E' rack is modeledas a 5x10 array in the loading pattern defined in Section 4.3 The model extends 53.45" in the y direction basedupon the 10.69" y-pitch. The Region 2 rack is modeled as a 6x7 array with a y distance of 55.02" based upon the9.17" pitch. To provide common y-direction values for the joint array, a 1.57" (3.9878) water gap is split over thetop and bottom of the 'E' rack. Figure C-3 provides a sketch of the model (note only 2 of the axial rows areshown to enable enlargement of the sketch). The two separated racks have a 12" water reflectcr on all sides.Note the lack of top/bottom plates in the Region 2 model is assumed to have an insignificant effect on results.

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NON PROPRIETARY


Figure C-3: Sketch of a Portion of the Region 1E -Region 2 Model

C.1.3 NFBC Models

NFBC, as described in Section B. 1.2 of Reference [9], were analyzed for storage in the 3-of-4 and 4-of-4 areas ofthe rack, and the results are shown in Table 4-10 and Table 4-11 of this document.

C.1.4 Moderator Temperature Effects

Section B.1.4 of Reference [9] examined moderator temperature effects and saw that the pool has a negativemoderator coefficient, i.e., reactivity is highest at low temperatures. In examining the model variations at verylow moderator temperatures, a very small difference was seen between 320 F and maximum density at 390 F,where water density varies by 0.000096 g/cc. This difference was included as a tolerance. In performing thisanalysis, Reference [9] remains valid to identify the limiting water density for this rack as 1.0 g/cc and the biasdifference identified between 320 F and 390 F is not significant. This is consistent with typical practice to modelmaximum moderation at 1.0 g/cc when reactivity peaks at cold temperatures. This approach was used in thisanalysis.

Page 65


Document No.: ANP-2858-0O01

NON PROPRIETARY


C.2 Statistical Tolerance Studies for Akto, and O'toI

This section describes the details of the random varying parameters that contribute to Akto1 and a o1. Whenmultiple conditions are run for the same tolerance, the maximum positive value is used and is in bold face. Thepositive values of these tolerances are listed in the summary tables in Section 3.5.3.

C.2.1 Planar Enrichment and Assembly Placement

The planar enrichment study was documented in Section B.2.1 of Reference [9], and showed that the averageenrichment model for the 4-of-4 rack loading is conservative, and remains applicable for this application.

C.2.2 Rack Tolerance Studies

For the tolerance calculations, the four-of-four loading configuration bounds the three-of-four loadingconfiguration. as shown in Tables B- 12 and B- 13 of Reference [9]. The detailed results of the rack tolerancecalculations are listed in Table C-4 for the 'C' Rack and C-5 for the 'E' Rack using nominal rack geometry (noswelling).

Table C-4: Rack 'C' Nominal Tolerance Results

Description of Case ] k. I a [ Ak to baseBase C Rack 4-of-4 1.1666 0.0001 -

Inner Box Wall ID -0.12 1.1605 0.0001 -0.0061Inner Box Wall Thickness Inside +0.01 1.1641 0.0001 -0.0025Inner Box Wall Thickness Inside -0.01 1.1690 0.0001 0.0024Inner Box Wall Thickness Outside +0.01 1.1654 0.0001 -0.0012Inner Box Wall Thickness Outside -0.01 1.1677 0.0001 0.0011Absorber Thickness +0.035 1.1769 0.0001 0.0103Absorber Thickness -0.02 1.1610 0.0001 -0.0056Absorber Width + 0.05 1.1669 0.0001 0.0003Absorber Width -0.01 1.1665 0.0001 -0.0001Outer Box Wall Thickness Inside +0.01 1.1655 0.0001 -0.0011Outer Box Wall Thickness Inside -0.01 1.1677 0.0001 0.0011Outer Box Wall Thickness Outside +0.01 1.1655 0.0001 -0.0011Outer Box Wall Thickness Outside -0.01 1.1678 0.0001 0.0012Outer Box OD + 0.12 1.1654 0.0001 -0.0012Pitch +0.04" 1.1605 0.0001 -0.0061Pitch -0.04" 1.1732 0.0001 0.0,066SS rod OD -0.005 1.1665 0.0001 -0.0001

Page 66




Table C-5: Rack 'E' Nominal Tolerance Results

Description of Case [ kcf I I Ak to base

Base E Rack 4-of-4 1.0729 0.0002Inner Box Wall ID -0.12 1.0671 0.0002 -0.0058Inner Box Wall Thickness Inside +0.01 1.0710 0.0002 -0.0019Inner Box Wall Thickness Inside -0.01 1.0746 0.0002 0.0(117Inner Box Wall Thickness Outside +0.01 1.0724 0.0002 -0.0005Inner Box Wall Thickness Outside -0.01 1.0738 0.0002 0.0009Absorber Thickness +0.035 1.0803 0.0002 0.0074Absorber Thickness -0.02 1.0690 0.0002 -0.0039Absorber Width + 0.05 1.0728 0.0002 -0.0001Absorber Width -0.01 1.0727 0.0002 -0.0002Outer Box Wall Thickness Inside +0.01 1.0722 0.0002 -0.0007Outer Box Wall Thickness Inside -0.01 1.0737 0.0002 0.0008Outer Box Wall Thickness Outside +0.01 1.0722 0.0002 -0.0007Outer Box Wall Thickness Outside -0.01 1.0735 0.0002 0.01)06Outer Box OD + 0.12 1.0721 0.0002 -0.0008Pitch +0.04" 1.0678 0.0002 -0.0051Pitch -0.04" 1.0779 0.0002 0.0050SS rod OD +0.005 1.0726 0.0002 -0.0003SS rod OD -0.005 1.0728 0.0002 -0.0001

C.2.3 Fuel Assembly Tolerance Results

The results of the assembly tolerance calculations are listed in Table C-6 for the 'C' Rack'E' Rack using nominal rack geometry (no swelling).

and Table C-7 for the

Table C-6: 'C' Rack Nominal Fuel Tolerances

Description ken [ ak I Ak to base

Base C Rack 4-of-4 1.1666 0.0001 -

Off-Center 1.1701 0.0001 0.0036Enrichment +0.05 wt% 1.1688 0.0001 0.0022Enrichment -0.05 wt% 1.1643 0.0001 -0.0023Theoretical Density +1.5% 1.1677 0.0001 0.0011Theoretical Density -1.5% 1.1654 0.0001 -0.0012Pellet OD +0.0005" 1.1666 0.0001 0.0000Pellet OD -0.0005" 1.1668 0.0001 0.0002Clad ID +0.0015" 1.1669 0.0001 0.0003Clad ID -0.0015" 1.1660 0.0001 -0.0006Clad OD +0.002" 1.1650 0.0001 -0.0016

Clad OD -0.002" 1.1683 0.0001 0.0017Instrument Tube ID +0.0015" 1.1664 0.0001 -0.0002Instrument Tube ID -0.0015" 1.1665 0.0001 -0.0001

Instrument Tube OD +0.002" 1.1665 0.0001 -0.0001Instrument Tube OD -0.002" 1.1664 0.0001 -0.0002

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NON PROPRIETARY


Table C-7: 'E' Rack Nominal Fuel Tolerances

Description keff J rk Ak to base

Base E Rack 4-of-4 1.0729 0.0002 -

Off-Center 1.1020 0.0002 0.0252Enrichment +0.05 wt% 1.0748 0.0002 0.0019Enrichment -0.05 wt% 1.0709 0.0002 -0.0020Theoretical Density +1.5% 1.0741 0.0002 0.0012Theoretical Density -1.5% 1.0716 0.0002 -0.0013Pellet OD +0.0005" 1.0730 0.0002 0.0001Pellet OD -0.0005" 1.0729 0.0002 0.0000

Clad ID +0.0015" 1.0736 0.0002 0.0007Clad ID -0.0015" 1.0725 0.0002 -0.0004Clad OD +0.002" 1.0708 0.0002 -0.0021Clad OD -0.002" 1.0751 0.0002 0.0022Instrument Tube ID +0.0015" 1.0730 0.0002 0.0001Instrument Tube ID -0.0015" 1.0730 0.0002 0.0001Instrument Tube OD +0.002" 1.0727 0.0002 -0.0002Instrument Tube OD -0.002" 1.0727 0.0002 -0.0002

Page 68



APPENDIX D: SPACER GRID, FUEL ROD, AND GUIDE BAR EFFECTS

D.1 Spacer Grids

Criticality safety has been ensured in spent fuel racks by performing analyses using such codes as KENO-V.a.The analyses model fuel assemblies located inside rack storage cells. It has been a typical practice to ignorespacer grids while modeling the fuel assemblies. This has been considered conservative since not modeling themreplaces a weak poison (the metal of the spacer grid) with a moderator (water). The question has been asked as towhether this assumption is also valid for borated water, since the spacer grid would then be replaced with amaterial containing a neutron poison. This section examines this issue for the Palisades spent fuel rack.

The analysis here will start with the KENO-V.a model developed for the 'C' rack. The model will be modified toinclude the effects of spacer grids. This will be done in three ways.

1. The first will be to smear the mass of the grids over the length of the fuel region in the moderator within thefuel assembly. (Smeared Grid model)

2. The second will be to increase the diameter of the fuel pins to add a mass of zirconium equal to the spacergrids (hence, displace an equal volume of water as do the spacer grids). (Thick Clad model)

3. The third method will model the grids at their respective axial locations. The reactivity change from the 'no-grid' cases will be determined, and a decision made as to whether the exclusion of spacer grids is aconservative or non-conservative assumption. (Explicit model)

The following situations are modeled:

1) The 2-of-4 (i.e., checkerboard) arrangement of fuel, no boron in the Carborundum® neutron absorber plates,no dissolved boron

2) A 3-of-4 arrangement of fuel, no boron in the Carborundum® neutron absorber plates, no dissolved boron.

3) A 4-of-4 (i.e., fully loaded) arrangement of fuel, no boron in the Carborundum® neutron absorber plates, nodissolved boron

4) A 4-of-4 (i.e., fully loaded) arrangement of fuel, no boron in the Carborundum® neutron absorber plates, at850, 1720, and 2550 ppm dissolved boron.

5) A 4-of-4 arrangement, with 10% of the boron in the Carborundum® neutron absorber plates, remaining, plus850, 1720, and 2550 ppm of dissolved boron.

Each grid weighs 1.08 kg, and that there are a total of 10 grids. Nine spacer grids are in the active fuel region, thetop most grid being above the fuel stack height of 336.81 cm.

The results of the analysis is shown in Table D-1 and demonstrates that it is conservative (or equivalent) not tomodel the spacer grids in KENO-V.a for criticality safety analyses. This is valid whether dissolved boron ispresent or not, or whether residual boron is present in the Carborundum® or not.

Page 69

AAR EVA - Document No.: ANP-2858-001AREVA NP Inc.,an AREVA and Siemens company NON PROPRIETARY


Table D-1: Spacer Grid Results

Case Model Method Residual Boron- Soluble Boron keffDescription Content in (ppm)

Carborundum®

2-of-4 No grids No boron 0 0.8646 +/- 0.0005

Smeared grids No boron 0 0.8581 +/- 0.0005

Explicit No boron 0 0.8591 +/- 0.0005









Thick Clad No boron 850 1.045:2 +/- 0.0004

No grids No boron 1720 0.9552 +/- 0.0005


Thick Clad No boron 1720 0.9535 +/- 0.0004

No grids No boron 2550 0.8837 +/- 0.0004


Thick Clad No boron 2550 0.8837 +/- 0.0003

4-of-4 No grids 10% Boron remaining 850 0.9188 +/- 0.0005

Smeared grids 10% Boron remaining 850 0.9119 +/- 0.0004

Thick Clad 10% Boron remaining 850 0.9136 +/- 0.0004

Explicit 10% Boron remaining 850 0.9146 +/- 0.0004



Page 70



NON PROPRIETARY








D.2 Fuel Rod Pitch Tolerance

The average rod pitch for the assembly is based on the value of 0.550 inches for the inner cells combined with thefuel rod pitch of 0.494 inches for the outer row of cells. Since the majority of the cells are at 0.550 inches, it willconservatively be assumed that all cells are at a pitch of 0.550 inches. There is no actual tolerance on the fuel rodpitch, only minimum gaps for an individual rod.

Even though the fuel rod pitch of 0.550 inches is considered the maximum possible, a sensitivity study wasconducted. A variation of 0.005 inches about an assembly envelope of 8.250 inches resulted in:nominal case: k-eff= 1.0729 +/- 0.0002increase pitch: k-eff= 1.0732+!- 0.0002decrease pitch: k-eff= 1.0724 +/- 0.0002The maximum Ak is for the pitch increase is 0.0003. This demonstrates the insignificance of this effect.

D.3 Guide Bars

Eight guide bars are located at the outer edges of the assembly. The guide bars are irregular shaped pieces ofsolid Zircaloy-4. Two bars are located on each side of the fuel assembly. Figure D-1 provides a sketch of thecross section of the guide bar. The guide bars were represented in KENO-V.a by determining a. minimumequivalent rectangular cross section, therefore adding more water to the under moderated fuel assembly. The basemodel uses a cross sectional area of 0.1586 in2 based upon an assumption that less Zr (more water) producesconservative results.

A series of cases was run to evaluate the rectangular guide bar model, which demonstrated that the equivalentrectangular cross section model was statistically equivalent to cases where the triangular cut-outs were explicitlymodeled, Based on this evaluation, no further tolerance study was performed for the guide bars because of theundermoderated nature of the model.

Page 71



Figure D-1: Sketch of Guide Bar

(Figure is not essential - only shape is important)

Page 72

AAREVA Document No.: ANP-2858-001AREVA NP Inc.,an AREVA and Siemens company NON PROPRIETARY


APPENDIX E: RACK C AND E KENO-V.A INPUT DECKS AND CASMO-3 DEPLETION INPUTDECK

E.1 Type 'C' Rack, base model

=csas25 parm=size=400000mark CE 15x15 fa,assy44groupndf5 latticecelluo2 1 0.96 293 92235 4.54 92238 95.46 end'm5 modeled as pure Zirczr 2 1.0 293 endh2o'arbm-bormod

h2o1.

3 1.0 293 end0 1 1 0 0 5000 100 3 850.0e-6 293 end4 1.0 293 end0 1 1 0 0 5000 100 4 850.0e-6 293 end5 1.0 293 end

'arbm-bormod 1.zr'carbon remaining in absorber w only C densityc 6 den= 0.2720 1.0 293 end'arbm-deplabs 0.34986 3 1 0 0 6012 77.75 5010 3.75' 6 1.0 293 end

5011 18.50

he 7 1.0 2ss304 8 1.0 2h2o 9 1.0 2'arbm-bormod 1.0 1 1arbm-nl 10.22632 9 0 0 0

92236 0.15551352 9223894240 0.04781651 942415010 0.00195354 10 1.0

arbm-n2 10.16979 9 0 0 092236 0.22658973 9223894240 0.09179883 94241

93 end93 end93 end

0 0 5000 100 9 850.0e-6 293 end

5010arbm-n3

92236942405010

arbm-n492236942405010

arbm-n592236942405010

arbm-n692236942405010

arbm-n792236942405010

arbm-n8

0.00249775 11 1.010.14612 9 0 0 00.25164000 922380.10895521 94241

0.00272517 12 1.010.14540 9 0 0 00.25234892 922380.10993850 94241

0.00274357 13 1.010.14849 9 0 0 00.24929510 922380.10846740 94241

0.00272973 14 1.010.14827 9 0 0 00.24954812 922380.10927852 94241

0.00274814 15 1.010.17921 9 0 0 00.21593593 922380.08531319 94241

0.00246887 16 1.010.23130 9 0 0 0

92235 1.9806440085.30581000 94239

0.01942911 62149293 end92235 1.58685300

85.39639000 942390.04505983 62149293 end92235 1.44344000

85.43046000 942390.05765310 62149293 end92235 1.44244200

85.42522000 942390.05857248 62149293 end92235 1.46418000

85.41277300 942390.05756386 62149293 end92235 1.46703500

85.40414000 942390.05842377 62149293 end92235 1.66093820

85.35505000 942390.04421127 62149293 end92235 2.02735420

8016 12.183390000.305257110.00019787

8016 12.251111000.399491010.00021248

8016 12.279700000.425214320.00021730

8016 12.280570000.427963600.00021963

8016 12.276820000.427962030.00022214

8016 12.277090000.431511220.00022549

8016 12.239780000.396083800.00022297

8016 12.17746100

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NON PROPRIETARY


92236 0.14924430 9223894240 0.04622987 942415010 0.00195136 17 1.0

arbm-n9 10.25018 9 0 0 092236 0.12162550 9223894240 0.03286853 942415010 0.00176079 18 1.0

arbm-nlO 10.27812 9 0 0 092236 0.07612709 9223894240 0.01425901 942415010 0.00145416 19 1.0

arbm-nf 10.17609 9 0 0 092236 0.21934110 9223894240 0.08653247 942415010 0.00247719 20 1.0

85.27360000 942390.01861205 62149293 end92235 2.17649100

85.23914000 942390.01064050 62149293 end92235 2.41716430

85.19009000 942390.00293903 62149293 end92235 1.63552920

85.37229100 942390.04506852 62149293 end

0.305337220.00020659

8016 12.155030000.262248930.00019944

8016 12.121990000.175790800.00018339

8016 12.243530000.395015530.00021883

end compsquarepitch 1.3970 0.9144 1 3 1.0592 2 0.9322more datares=10 cylinder 0.4572 dan(10)=0.23801701res=ll cylinder 0.4572 dan(ll)=0.23801701res=12 cylinder 0.4572 dan(12)=0.23801701res=13 cylinder 0.4572 dan(13)=0.23801701res=14 cylinder 0.4572 dan(14'=0.23801701

7 end

res=15res=16res=17res=18res=19res=20

cylindercylindercylindercylindercylindercylinder

0.45720.45720.45720.45720.45720.4572

dan (15) =0.23801701dan (16) =0.23801701dan (17) =0.23801701dan (18)=0.23801701dan (19) =0.23801701dan (20) =0.23801701

end more dataPalisades 15x15read parm tme=100nub=yes end parmread geom

gen=5075 nsk=75 run=yes npg=5000

unit 1'fuel pincylindercylindercylindercuboid

unit 2'fuel pincylindercylindercylindercylindercylindercylindercylindercylindercylindercylinder

cell fresh 4.541 1 0.45727 1 0.46612 1 0.52963 1 4pO. 6 9 8 5

cell 3.20 wt% at

wt%336.81336.81336.81336.81

0.00.00.00.0

10111213141516171819

1111111111

0.45720.45720.45720.45720.45720.45720.45720.45720.45720.4572

15gwt/mtu18.71 0.037.42 0.056.13 0.0

112.28 0.0168.44 0.0224.53 0.0280.68 0.0299.39 0.0318.10 0.0336.81 0.0

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NON PROPRIETARY


cylindercylindercuboid

723

111

0.46610.52964 pO.6985

unit 60'instrumentcylindercylindercuboid

336.81 0.0336.81 0.0336.81 0.0

336.81 0.0336.81 0.0336.81 0.0

tube cell4 1 0.46615 1 0.52964 1 4 pO. 6 9 8 5

unit 70'Tie Bar Top

cuboid 2 1 2pO.4757 0.6985 -0.37715 336.81 0.0cuboid 4 1 4pO.6985 336.81 0.0

unit 71'Tie Barcuboidcuboid

Bottom2 1 2pO.47574 1 4 pO. 6 9 8 5

0.37715 -0.6985336.81 0.0

unit 72'Tie Bar Leftcuboid 2 1 0.37715 -0.6985 2pO.4757cuboid 4 1 4pO.6985 336.81 0.0

unit 73'Tie Bar Rightcuboid 2 1 0.6985 -0.37715 2pO.4757cuboid 4 1 4pO.6985 336.81 0.0

336.81 0.0

336.81 0.0

336.81 0.0

unit 80'Absorber slot Horizontal (+X) Topcuboid 6 1 2plO.49 2pO.2667 336.79 0.0'replicate 4 1 0.00 0.00 0.0508 0.0508 0.0 0.0 1

unit 81'Absorber slot Horizontal (+X) Bottomcuboid 6 1 2plO.49 2pO.2667 336.79 0.0'replicate 4 1 0.00 0.00 0.0508 0.0508 0.0 0.0 1

unit 82'Absorber slot Horizontal (+Y) Leftcuboid 6 1 2p0.2667 2 plO. 4 9

'replicate 4 1 0.0508 0.0508 0.00

unit 83'Absorber slot Horizontal (+Y) Leftcuboid 6 1 2pO.2667 2plO.49'replicate 4 1 0.0508 0.0508 0.00

336.79 0.00.00 0.0 0.0 1

336.79 0.00.00 0.0 0.0 1

unit 85'Space Cylindercylinder 8 1 0.3175 336.79 0.0'cuboid 4 1 0.3175 -0.3175 0.3175 -0.3175 336.79 0.0

Page 75



unit 90'15 x 15arraycuboidreplicatereplicatereplicate'absorber

hole'absorber

hole'absorber

hole'absorberholesupport

holesupport

hole'support

hole'support

holereplicatereplicate

unit 91'15 x 15arraycuboidreplicatereplicatereplicate'absorber

hole'absorberhole

fa in rack - 4.54 fresh assembly1 -10.4775 -10.4775 0.0,4 1 10.4775 -10.4775 10.4775 -10.4775 336.81 0.04 1 0.3937 0.3937 0.3937 0.3937 0.0 0.0 18 1 0.3175 0.3175 0.3175 0.3175 0.0 0.0 14 1 0.635 0.635 0.635 0.635 0.0 0.0 1

slot top80 0.0 11.5062 0.01slot bottom81 0.0 -11.5062 0.01slot left82 -11.5062 ,0.0slot right83 11.5062 0.0

top left85 -11.5062 11

top right85 11.5062 11

bottom right85 11.5062 -11

bottom left85 -11.5062 -11

8 1 0.3175 0.3:4 1 0.8763 0.8

0.01

0.01

.5062 0.01

.5062 0.01

.5062 0.01

.5062 0.01175 0.3175 0.3175 0.0763 0.8763 0.8763 0.0

0.0 10.0 1

fa in rack - 3.20 15gwd/mtu2 -10.4775 -10.4775 0.04 1 10.4775 -10.4775 10.4775 -10.4775 334 1 0.3937 0.3937 0.3937 0.3937 0.0 0.08 1 0.3175 0.3175 0.3175 0.3175 0.0 0.04 1 0.635 0.635 0.635 0.635 0.0 0.0

slot top80 0.0 11.5062 0.01

7 slot bottom81 0.0 -11.5062 0.01

6.81 0.0111

'absorber slot lefthole 82 -11.5062'absorber slot righthole 83 11.5062

support top lefthole 85 -11.5062support top right

hole 85 11.5062support bottom right

hole 85 11.5062support bottom left

hole 85 -11.5062replicate 8 1 0.3175replicate 4 1 0.8763

!

0.0

0.0

0.01

0.01

11.5062 0.01

11.5062 0.01

-11.5062 0.01

-11.5062 0.010.3175 0.3175 0.3175 0.00.8763 0.8763 0.8763 0.0

0.0 10.0 1

Page 76



NON PROPRIETARY


unit 100'Empty Rack Cellcuboid 4 1 10.4775 -10.4775 10.4775 -10.4775 336.81 0.0replicate 4 1 0.3937 0.3937 0.3937 0.3937 0.0 0.0 1replicate 8 1 0.3175 0.3175 0.3175 0.3175 0.0 0.0 1replicate 4 1 0.635 0.635 0.635 0.635 0.0 0.0 1'absorber slot tophole 80 0.0 11.5062 0.01'absorber slot bottomhole 81 0.0 -11.5062 0.01'absorber slot lefthole'absorber

holesupport

holesupport

holesupport

holesupport

holereplicatereplicate

82 -11.5062 0.07 slot right

83 11.5062 0.0top left

85 -11.5062 11top right

85 11.5062 11bottom right

85 11.5062 -11bottom left

85 -11.5062 -118 1 0.3175 0.3:4 1 0.8763 0.8

0.01

0.01

.5062 0.01

.5062 0.01

.5062 0.01

.5062 0.01175 0.3175 0.3175 0.0763 0.8763 0.8763 0.0

0.0 10.0 1

globalunit 110'rack cells arrayarray 20 0.0replicate 4 1 0.0'replicate 4 1 30.48

0.00.0

30.48

0.00.0 0.0

30.48 30.4830.48 30.48 1

0.0 0.0 1

end geom

read array

'4.54 planar average fuel assemblyara=l nux=15 nuy=15 nuz=1fill

1111

7211111

721I11

111111111111111

111111111111111

111111111111111

7111111

1111111

70

111111111111111

111111111111111

1111111

601111111

111111111111111

111111111111111

711111111111111

70

111111111111111

111111111111111

111111111111111

1111

7311111

731111

Page 77

AAREVA Document No.: ANP-2858-001AREVA NP Inc.,an AREVA and Siemens company NON PROPRIETARY


end fill

'fuel assembly 3.20 burned 15gwd/mtuara=2 nux=15 nuy=15 nuz=lfill

2222

7222222

722222

222222222222222

222222222222222

222222222222222

712222222222222

70

222222222222222

222222222222222

2222222

602222222

222222222222222

222222222222222

712222222222222

70

222222222222222

222222222222222

222222222222222

2222

7322222

732222

end fill

'fuel assembly rack arrayara=20 nux=2 nuy=2 nuz=lfill

90 9090 90

end fill

end array

read bounds xyf=periodic +zb=h2o -zb=h2oend boundsend dataend

Page 78

AAREVA



NON PROPRIETARY


E.2 Type 'E' Rack, base model

=csas25 parm=size=400000Palisades,mark CE 15x15 fa,assy, carbon absorber, E rack44groupndf5uo2'm5 modeled aszrh2o'arbm-bormod

h2o'arbm-bormod

zr'carbon remainchess304h2o'arbm-bormod

latticecell1 0.96 293 92235 4.54 92238

pure Zirc2 1.0 293 end3 1.0 293 end

1.0 1 1 0 0 5000 100 3 850.0O4 1.0 293 end

1.0 1 1 0 0 5000 100 4 850.0(5 1.0 293 end

ing in absorber w only C density6 den= 0.2720 1.0 293 end7 1.0 293 end8 1.0 293 end9 1.0 293 end

95.46 end

e-6

e-6

293 end

293 end

1.0 1 1 0 0 5000 100 9 850.0e-6 293 end

end compsquarepitch 1.3970 0.9144 1 3 1.0592 2 0.9322 7 endmore datares=10 cylinderres=1l cylinderres=12 cylinderres=13 cylinderres=14 cylinderres=15 cylinderres=16 cylinderres=17 cylinderres=18 cylinderres=19 cylinderres=20 cylinderend more dataPalisades 15x15read parm tme=100nub=yes end parmread geom

0.45720.45720.45720.45720.45720.45720.45720.45720.45720.45720.4572

dan(10) =0.23801701dan(ll)=0.23801701dan (12) =0.23801701dan (13)=0.23801701dan (14)=0.23801701dan (15) =0.23801701dan (16) =0.23801701dan (17)=0.23801701dan (18)=0.23801701dan (19) =0.23801701dan (20) =0.23801701

gen=5075 nsk=75 run=yes npg=5000

unit 1'fuel pincylindercylindercylindercuboid

cell 4.54 wt%1 1 0.45727 1 0.46612 1 0.52963 1 4 pO.6985

336.81336.81336.81336.81

0.00.00.00.0

unit 60'instrumentcylindercylindercuboid

tube cell4 1 0.46615 1 0.52964 1 4 pO.6985

336.81 0.0336.81 0.0336.81 0.0

unit 70

Page 79



NON PROPRIETARY


'Tie Bar Topcuboid 2 1 2p0.4757 0.6985 -0.37715cuboid 4 1 4p0.6985 336.81 0.0

unit 71'Tie Barcuboidcuboid

Bottom2 1 2 pO. 4 7 574 1 4 p 0 . 6 9 8 5

0.37715 -0.6985336.81 0.0

336.81 0.0

336.81 0.0

336.81 0.0

336.81 0.0

unit 72'Tie Bar Leftcuboid 2 1 0.37715 -0.6985 2pO.4757cuboid 4 1 4pO.6985 336.81 0.0

unit 73'Tie Bar Rightcuboid 2 1 0.6985 -0.37715 2pO.4757cuboid 4 1 4pO.6985 336.81 0.0

unit 80'Absorbercuboidreplicate




slot Horizontal (+X) Top6 1 2plO.49 2 pO. 2 6 6 7 336.79 0.04 1 0.00 0.00 0.0507 0.0507 0.0 0.0

slot Horizontal (+X) Bottom6 1 2 plO. 4 9 2pO.2667 336.79 0.04 1 0.00 0.00 0.0507 0.0507 0.0 0.0

slot Horizontal (+Y) Left6 1 2pO.2667 2plO.494 1 0.0507 0.0507 0.00

slot Horizontal (+Y) Left6 1 2pO.2667 2p10.494 1 0.0507 0.0507 0.00

336.79 0.00.00 0.0 0.0

336.79 0.00.00 0.0 0.0

unit 85'Space Cylindercylinder 8 1 0.3174 336.79 0.0cuboid 4 1 0.3174 -0.3174 0.3174 -0.3174 336.79 0.0

unit 90'15 x 15 fa in rack - 4.54 Planar Averagearray 1 -10.4775 -10.4775 0.0cuboid 4 1 10.4775 -10.4775 10.4775 -10.4775 336.81 0.0'replicate 4 1 0.9525 0.9525 0.9525 0.9525 0.0 0.0 1replicate 4 1 0.5588 0.5588 0.5588 0.5588 0.0 0.0 1replicate 4 1 0.3937 0.3937 0.3937 0.3937 0.0 0.0 1replicate 8 1 0.3175 0.3175 0.3175 0.3175 0.0 0.0 1replicate 4 1 0.635 0.635 0.635 0.635 0.0 0.0 1'absorber slot top

Page 80



NON PROPRIETARY


hole'absorber

hole'absorber

hole'absorber

hole

80 0.0 12.065 0.01slot bottom81 0.0 -12.065 0.01slot left82 -12.065 0.0 0.01slot right83 12.065 0.0 0.01

supportholesupport

holesupport

holesupport

holesupport

holesupport

holesupport

holesupport

holereplicate'replicat

replicatereplicate

top left +x85 -11.1252 12.01

top right -x85 11.1252 12.01

bottom right -x85 11.1252 -12.01

bottom left + x85 -11.1252 -12.01

top left -y85 -12.065 11.1252

top right -y85 12.065 11.1252

bottom right +y

65 0.01

65 0.01

65 0.01

65 0.01

0.01

0.01

85 12.065 -11.1252 0.01bottom left +y

85 -12.065 -11.1252 0.018 1 0.3175 0.3175 0.3175 0.3175 0.0

:e 4 1 1.5875 1.5875 0.8763 0.8763 0.04 1 0.8763 0.8763 0.8763 0.8763 0.04 1 0.7112 0.7112 0.0 0.0 0.0

0.0 10.0 1

0.0 10.0 1

globalunit 210'rack cells arrayarray 20 0.0replicate 4 1 0.0'replicate 4 1 0.0replicate 4 1 30.48

end geom

read array

0.00.0

0.030.48

0.00.030.48

30.48

0.030.48

30.48

30.480.0

0.0

30.48 10.0 1

0.0 1

'4.54 planar average fuel assemblyara=l nux=15 nuy=15 nuz=lfill

1111

7211111

72

11111111111

11111111111

11111111111

711111111111

11111111111

11111111111

1 1 1 711 1 1 11 1 1 11 1 1 11 1 1 11 1 1 1

11 11 11

1

1 1 1 731 1 1 1

160

1 1 1 1 11 11 1 1111

1111111 1 1

111 1i11 11i1i 1 11 173

Page 81

AREVAAREVA NP Inc.,an AREVA and Siemens company


NON PROPRIETARY


1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

1 1 1 1 70 1 1 1 1 1 70 1 1 1 1

end fill

'fuel assembly rack arrayara=20 nux=l0 nuy=5 nuz=lfill

90 90 90 90 90 90 90 90 90 9090 90 90 90 90 90 90 90 90 9090 90 90 90 90 90 90 90 90 9090 90 90 90 90 90 90 90 90 9090 90 90 90 90 90 90 90 90 90

end fill

end array

read bounds xyf=h2oend bounds

+zb=h2o -zb=h2o

end dataend

Page 82



E.3 CASMO-3 Sample Depletion Deck

* Palisades Fuel Assembly @ 4.54 wt% No Gd No LBP* Mirror BCs* Enrichment = 4.54* # of Bp pins (current and previous) = 0, 0* Operating conditions for base case = HFP, 700 ppm* Fuel loading = 443.1 kg U - No Dish, 96.0%TD* Stack height = 132.6 inches* 15 = # of pins per row;

TIT, *Palisades Assembly 4.54wt% Depletion to 19.56 gwd/mtuTFU=955.4, TMO= 557.7, BOR=700.0 IDE='PAL454'

FUM, 0 2INV, 1.OE-3 1.OE-3 1.30 1.30 50 50ITP 50,,50,l.lE-5/BCO, 'MIR'PRE, 142.03BOX, 6.55/302=100.CAN, 6.55/302=99.984 47107=0.0082176 47109=0.0077824 *M5 CladFUE, 1, 10.5216/4.54SPA, 28.86, , , 6.55/302=100PIN, 1, 0.2500 0.4500 0.5707/'BOX' 'BOX' 'BOX' *ZR Guide BarPIN, 2, 0.2500 0.4661 0.5296/'MOD' 'MOD' 'CAN' *ITPIN, 3, 0.4572 0.4661 0.5296/'l' 'AIR' 'CAN' *4.54 FUEL RODLFU

3333033333033333333333333333333333333333333333333333333333330333333333333303333333333333333333333333333333333333033333333333333333333333333333333333330333333333333303333333333333333333333333333333333333333333333 3 3 3 0 3 3 3 3 3 0 3 3 3 3/'F'

LPI333313333313333333333333333333333333333333333

3 3 3 3 3 3 3 3 3 3 3 3 ~3 3 31 3 3 3 3 3 3 3 3 3 3 3 3 3 1

333333333333333

3 3 3 3 3 3 3 3.3 3 3 3 3 3 3

3333333233333333333333333333333

333333333333333

133333333333331

Page 83




333333333333333333333313

PWR, 15 1.397PDE, 28.381XEN, 0THE, 1LST 1,1i,0DEP 0.5 1 2WRE, ALEX BURSTAEND

333333333333333333333333333

3 3 3 3 1 3 3 3 3/'F'20.955,,0.46355 0.13335,,1 2

* 2565.4 MWT core

3 4 5 10 15 19.56 /'E'

*Full Assembly

Page 84

areva np inc. report document no. anp-2858-001 ...a ar eva document no.: anp-2858-001 areva np inc.,...

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