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0Nuclear InnovationNorth America LLC4000 Avenue F, Suite ABay City, Texas 77414

April 25, 2012U7-C-N INA-NRC- 120035

U. S. Nuclear Regulatory CommissionAttention: Document Control DeskOne White Flint North11555 Rockville PikeRockville, MD 20852-2738

South Texas ProjectUnits 3 and 4

Docket Nos. 52-012 and 52-013Response to NRC Staff Audit Report

References: 1. Audit Report, "Nuclear Regulatory Commission Staff Audit of the SouthTexas Project, Units 3 and 4, Regulatory Guide 1.143, Revision 2,Radioactive Waste Building Calculated Dose Rates," dated March 21, 2012(ML120730602).

2. Letter, Scott Head to Document Control Desk, "Response to Request forAdditional Information," dated September 8, 2011 (MLI 1257A136).

3. Letter, Tom M. Tai to Scott Head, "Request for Additional InformationLetter No. 384 Related to SRP Section 03.08.04 for the South Texas ProjectCombined License Application," dated August 17, 2011 (ML 112290721).

This letter submits the response from Nuclear Innovation North America (NINA) to the NRCstaff audit report of the STP Units 3 & 4 Regulatory Guide 1.143 (RG 1.143) Radioactive WasteBuilding calculated dose rates (Reference 1). The attachment to this letter provides the responseto the audit report as well as comments on Request for Additional Information (RAI) No. 6404Revision 7 and No. 6405 Revision 7, which are the additional RAls noted in the conclusion ofthe audit report.

The NRC audit report documents audit activities on November 2, 2011, and on February 8, 2012,with the objective to review NINA's calculations used to support NINA's response (Reference 2)to NRC staff RAI 03.08.04-7 (Reference 3).

STI 33507597

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U7-C-NINA-NRC- 120035 of 3

There are no changes to the COLA required as a result of this response.

There are no commitments in this letter.

If there are any questions regarding this response, please contact me at (361) 972-7136, orBill Mookhoek at (361) 972-7274.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on 4/s./I Z/

Scott HeadManager, Regulatory AffairsSouth Texas Project Units 3 & 4

Attachment: Application of RG 1.143 to STP Units 3 & 4

U7-C-NINA-NRC-120035 of 3

cc: w/o attachment except*(paper copy)

Director, Office of New ReactorsU. S. Nuclear Regulatory CommissionOne White Flint North11555 Rockville PikeRockville, MD 20852-2738

Regional Administrator, Region IVU. S. Nuclear Regulatory Commission1600 E. Lamar Blvd.Arlington, Texas 76011-4511

Kathy C. Perkins, RN, MBAAssistant CommissionerDivision for Regulatory ServicesTexas Department of State Health ServicesP. 0. Box 149347Austin, Texas 78714-9347

Alice Hamilton Rogers, P.E.Inspection Unit ManagerTexas Department of State Health ServicesP. 0. Box 149347Austin, Texas 78714-9347

*Steven P. Frantz, Esquire

A. H. Gutterman, EsquireMorgan, Lewis & Bockius LLP1111 Pennsylvania Ave. NWWashington D.C. 20004

*Michael Eudy*Tom Tai

Two White Flint North11545 Rockville PikeRockville, MD 20852

(electronic copy)

*George F. Wunder*Michael Eudy*Tom Tai

Fred BrownU. S. Nuclear Regulatory Commission

Jamey SeelyNuclear Innovation North America

Peter G. NemethCrain, Caton and James, P.C.

Richard PefiaKevin PolloL. D. BlaylockCPS Energy

Application of RG 1.143 to STP Units 3 & 4 U7-C-NINA-NRC-120035Attachment

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WHITE PAPER REGARDING APPLICATION OF REGULATORY GUIDE 1.143 TOSTP UNITS 3 AND 4

I. EXECUTIVE SUMMARY

This White Paper responds to questions raised during the NRC Staff review of the classificationof the STP 3 & 4 Radwaste Building (RWB) design in accordance with Regulatory Guide 1.143(RG 1.143), as reflected in the NRC audit report dated March 21, 2012 and draft RAIs numbered6404 revision 7 and 6405 revision 7. The NRC audit was conducted to review NINA'scalculation in support of classification of the RWB as RW-IIb.

The discussion below shows that:

1. Contrary to the assertions in the audit report, the STP 3 & 4 calculations are consistentwith RG 1.143. The NRC staff s positions regarding the RG 1.143 requirements are notsupported by the wording of RG 1.143, and are inconsistent with the references cited inRG 1.143 and NRC regulations.

2. Any continuing questions about the interpretation of RG 1.143 should be resolved byNRC approval of the current RWB design. as an acceptable alternative to compliance withRG 1.143.

3. The Turbine Building and the other structures and systems cited in draft RAI 6405revision 7 are within the scope of the NRC-approved ABWR DCD. Under NRCregulations, NRC's approval of these designs has finality and is not subject to furtherNRC review.

H. BACKGROUND

A. NRC Review of the STP 3 & 4 COLA RWB Classification as RW-Ilb

The STP 3 & 4 COLA, as submitted on September 20, 2007, included several departures relatedto the design of the RWB and the radwaste management system, as discussed in section B,below. NRC completed review of the radwaste management systems and issued the advancedsafety evaluation for chapter 11 in early March, 2011, with no open items.

In August 2011, as part of the chapter 3 review, NRC issued RAI 03.08.04-37, which requestedthe basis for the classification of the RWB as RW-IIb under the classification scheme in RG1.143. After NINA's response described the supporting calculation, the NRC reviewersquestioned NINA's interpretation of RG 1.143. In response, NINA prepared a new calculation,and NRC began an audit of the new calculation on November 9, 2011. During the audit, theNRC reviewers identified additional positions regarding interpretation of RG 1.143 and NINArevised the calculation in an attempt to address these positions. This revised calculation was


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reviewed in the resumed portion of the audit on February 8, 2012. The NRC's March 21, 2012Audit Report identified additional NRC interpretations of RG 1.143, and raised a question aboutthe Turbine Building which was not within the scope of the calculation reviewed in the audit.NINA has now received draft RAIs numbered 6404 revision 7 and 6405 revision 7, which statefurther positions regarding the requirements of RG 1.143, including changing the 500 mrem/yracceptance criterion for the accident dose at the protected area boundary to 100 mrem/yr basedon SRP 11.2. The new draft RAI would request that NINA revise the FSAR to change theclassification and related requirements of the RWB, individual SSCs in the RWB, the turbinebuilding offgas system, including the portions of the turbine building housing this system, theradwaste pipe tunnel, and any additional pertinent SSCs.

NINA disagrees with these various NRC Staff interpretations of RG 1.143, and does not agreethat there is a need to make such changes to the FSAR.

B. STP 3 & 4 Combined License Application (COLA) Departures Related to RG 1.143

NRC certified the ABWR DCD based on revision 1 of RG 1.143 (1979), which did not includeany provision for assigning safety classifications to radwaste buildings. The regulatory schemefor classification of radwaste buildings was first adopted in revision 2 of RG 1.143 (2001), whichis the current version of RG 1.143. The STP 3 & 4 Combined License Application (STP 3 & 4COLA) incorporates by reference the p'ortions of the ABWR DCD related to compliance'withRG 1.143 with certain departures. Only two of the departures are relevant to the classification ofthe RWB: (1) STD DEP TI 2.15-1, Re-classification of Radwaste Building Substructure fromSeismic Category I to Non-Seismic; and (2) STD DEP 1.8-1, Tier 2* Codes, Standards, andRegulatory Guide Edition Changes. No other departures changed any DCD provisions thataddress the considerations discussed in RG 1.143, rev. 1, or that were relied upon by the NRC inFinal Safety Evaluation Report Related to the Certification of the Advanced Boiling WaterReactor Design, NUREG-1503 (1994) and Supplement 1 (1997) as a basis for finding that theABWR design met the requirements of RG 1.143, rev. 1. The NRC staff review of thedepartures concerning the radwaste management systems has been completed, and there are noopen issues related to any of them. Departure STD DEP 3.8-1, Resizing the Radwaste Building,is within the scope of the NRC staff review of FSAR Subsections 3.7 and 3.8, which is nearingcompletion. The evaluation of STD DEP 3.8-1 in COLA, Part 7 shows that it meets the criteriafor a departure which can be made without prior NRC review.

STD DEP 1.8-1 changes Tier 2, Table 1.8-20, which addresses compliance with NRCregulatory guides, and Table 1.8-2 1, which addresses the applicability of industry codesand standards. The changes updated some of the table entries to more currentrevisions/editions. Table 1.8-20 was revised to reference RG 1.143, rev. 2, and Table1.8-21 was revised to update the reference to Section III of the ASME Boiler andPressure Vessel Code (BPVC). The reference to a newer edition of BPVC Section III inTable 1.8-21 does not affect the compliance of the STP 3 & 4 COLA with RG 1.143.


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STD DEP TI 2.15-1 changes the classification of the RWB substructure from SeismicCategory I to non-seismic. RG 1.143, rev. 1 stated that the ground motion at thefoundation of the building housing radwaste systems should be normalized to theoperating base earthquake (OBE). With NRC's elimination of the OBE as a designrequirement, the ABWR DCD classified the RWB substructure as Seismic Category I asan alternative approach to meeting this RG 1.143, rev. 1 provision. This classificationalso is cited in NUREG- 1503 as a basis for concluding that the RWB design compliedwith the acceptance criteria of Standard Review Plan Section 15.7.3. The STP 3 & 4COLA states that although the RWB is classified as RW-IIb, its seismic design meets therequirements for radwaste buildings classified as RW-IIa, i.e., it is designed for theearthquake loads due to one-half of the Safe Shutdown Earthquake (SSE) as defined in

the DCD. Therefore, the STP 3 & 4 RWB seismic design is at least equivalent to RG1.143, rev. 1. The reclassification of the RWB substructure from Seismic Category I tonon-seismic also is discussed in the departure report for departure STD DEP 11.2-1,Liquid Radwaste Process Equipment, which the NRC reviewed as part of its review ofFSAR Chapter 11. The Advanced Safety Evaluation for Chapter 11 states that the NRCdid not identify any issues with NINA's conclusion, based on the provisions of 10 CFR52, Appendix A, Section VIII.B.5.b, that this departure does not require prior NRCapproval.

C. Adoption of RG 1.143, rev. 2 Based on the Department of Energy (DOE) Practice

RG 1.143, rev. 2, was based on "Re-evaluation of Regulatory Guidance Provided in RegulatoryGuides 1.142 and 1.143," NUREG/CR-5733, August 1999, the reference cited in footnote 1 ofRG 1.143, rev. 2. NUREG/CR-5733 discusses various codes and standards, designs of existingplants and advanced reactor designs, such as the ABWR, industry codes and standards, and NRCand DOE documents. Based on review of these documents, NUREG/CR-5733, section 4.7.3.6"Suggested Approach" says:

It is suggested that a graded approach similar to that used by DOE be provided inRegulatory Guide 1.143. This approach would correlate radiation exposurepotential to a specific level of natural phenomena and man made hazard designand provide for a graded approach for such design.

This recommendation is the basis for the safety classification scheme NRC adopted in RG 1.143,

rev. 2. Therefore, NUREG/CR-5733 and the DOE documents it cites provide valuable insightregarding the intent of RG 1.143, rev. 2.

MI. NINA'S CALCULATIONS ARE CONSISTENT WITH RG 1.143

A. Summary of the RG 1.143 Classification Scheme

RG 1.143, rev. 2, Regulatory Position 5 establishes a scheme of three safety classes for radwastemanagement structures, systems and components (SSC): RW-IIa (High Hazard), RW-IIb


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(Hazardous), and RW-IIc (Non-Safety). Under Position 5.1, the external structures of a building

housing radwaste processing systems or components is classified as RW-IIa "if the total design

basis unmitigated radiological release (considering the maximum inventory) at the boundary of

the unprotected area" is greater than 500 mrem/yr or the "maximum unmitigated exposure to site

personnel within the protected area" is greater than 5 rem/yr. Under position 5.2, all other

external structures are to be classified as RW-IIb.

B. NINA's Response to RAI 03.08.04-37

1. Initial Assumptions

NINA's response to RAI 03.08.04-37 described the calculation of the dose at the unrestricted

area boundary due to the postulated release of liquid radwaste housed in the RWB below grade

that is discussed in FSAR subsection 2.4S. 13. Focusing on the radioactive material housed

below grade was reasonable because the only departure from the ABWR DCD that could have

affected the dose due a failure or malfunction in the RWB was the reclassification of the RWB

substructure from Seismic Category I (STD DEP TI 2.15-1). The result of a very conservative

calculation was a small fraction of the RG 1.143 limit. With respect to the potential exposure of

site personnel, NINA stated that the RWB is designed so that the area outside the RWB will have

a dose rate that allows continuous access without radiation monitoring, and the unmitigated

release will not compromise the radiation shielding for the RWB. Since the RWB does'not

contain any safety related equipment, site personnel would not be required to access the RWB

before access controls under normal plant procedures could be established to assure compliance

with the annual exposure limit of 5 rem/yr, as required by 10 CFR 20.1201. Thus, the Radiation

Protection Program will assure that the dose to site personnel due to the unmitigated release will

be less than the RG 1.143 criterion of 5 rem/yr.

2. NRC Staff's Objections to the Initial Assumptions

The NRC staff took the position that the NINA calculation did not comply with RG 1.143

because it did not consider release of the radioactive material housed in the RWB above grade,

and it disagreed with the point of compliance used by NINA for the member of the public. NRC

staff stated that "the boundary of the unprotected area" in RG 1.143 means the boundary of the

protected area, as indicated in the figure attached to RG 1.143. In essence, this position applied

the dose limit at the security fence.

3. NINA's Disagreement With These NRC Positions

a. The above grade part of the RWB is not within the scope of any departure related to

RG 1.143

In NINA's view, the release scenario should only consider material housed below grade because

the NRC's certification of the ABWR DCD approved the above grade portion of the RWB. As

discussed above, the only departure that could affect the RWIB's compliance with RG 1.143 is


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the departure that reclassifies the RWB substructure to non-seismic. The reclassification of thesubstructure does not affect the bases of NRC approval of the above-grade part of the RWB,since the ABWR DCD provides for the above-grade part of the RWB to be non-seismic, and thisis not changed in the COLA. Therefore, requiring NINA to consider a release of the materialhoused above grade in the RWB effectively challenges the finality of NRC's approval of theABWR DCD.

b. Applying the dose limit at the security fence is inconsistent with 10 CFR Part 20

RG 1.143 is not clear about the point of compliance. The introduction to RG 1.143 section 5,"Classification of Radwaste Systems for Design Purposes" states "The radiological releasecriteria (500 millirem at the unprotected area boundary ... ) was selected to be consistent with thecriteria of 10 CFR Part 20, 'Standards for Protection Against Radiation."' NUREG/CR-5733,subsection 5.2.2.2, makes the same statement. Part 20 uses the boundary between the "restrictedarea" and "unrestricted area" to define the point of compliance. At the end of section 5,however, RG 1.143 references Figure 1 for use in connection with classification of radwastebuildings. Figure 1 depicts the "Protected Area Boundary (Secured Area)"as the security fence,and designates the balance of the owner controlled area as unprotected. Figure 1 does not use thePart 20 terms "restricted area" and "unrestricted area." The NRC staff interpreted Figure 1 asindicating that the dose limit at the unprotected area boundary applies at the security fence.Since Part 20 does not use the security fence as a point of compliance, there is no regulatoryjustification for Figure 1, as that figure is interpreted by the NRC staff. In addition, sinceadoption of RG 1.143 there have been changes in NRC security requirements that result inincreased assurance that members of the public are not present in the owner-controlled areaoutside the security fence. The use of the security fence as the point of compliance isparticularly inappropriate for the ABWR RWB because it does not house the gaseous radwastesystem. The dose due to a gaseous release would occur over the short time that the individual isexposed within the gas plume. For liquid releases and direct radiation, exposures are calculatedover longer periods that could not reasonably apply to a member of the public in the ownercontrolled area.

For the STP 3 & 4 site, the boundary of the protected area is approximately 106 meters from theRWB, while the boundary of the restricted area is approximately 900 meters from the RWB.Because the direct dose decreases as the square of the distance, accepting this NRC positionresulted in unnecessarily increasing the calculated direct dose by more than a factor of 70. Evenusing the restricted area boundary, as NINA did, was excessively conservative because itassumed that an individual would be exposed for a year in an area where there are no residencesor other buildings. A catastrophic failure of the RWB, of the sort postulated in this scenariowould be immediately obvious and would prompt action to exclude people from the affectedarea. It is not credible that someone could actually stay at that point for a long time.

Application of RG 1.143 to STP Units 3 & 4 U7-C-NINA-NRC- 120035Attachment

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C. NINA's New Calculation

1. New Calculation Assumptions

In response to the NRC staff s positions regarding the RAI response, NINA prepared a newcalculation to comply with the NRC staff s positions, U7-RWB-M-CALC-DESN-6002, RevisionB, "Radwaste Building Classification in Accordance with Regulatory Guide 1.143," 10/19/2011.This new calculation assumed the release of the inventory of radioactive material that could behoused in the above-grade part of the RWB. The direct dose at the security fence wasdetermined, taking credit for the shielding due to the concrete walls and roof of the RWB, butneglecting the shielding due the enclosure ceilings. The resulting direct dose was added to thedose due to release of iodines from liquid radwaste to determine the total exposure of a memberof the public at the security fence. This resulted in a total dose of 225 mrem/yr, which still wasless than 500 mrem/yr. As with the RAI response, the new calculation credited the RadiationProtection Program to assure that the dose to site personnel due to the unmitigated release wouldbe less than 5 rem/yr.

2. NRC objections to NINA's new calculation

NRC reviewed the new calculation during the initial part of the NRC audit on November 9,2011. During the audit, the NRC staff stated that by "unmitigated exposure" RG 1.143 meansthat the calculation cannot credit administrative controls, such as the Radiation ProtectionProgram.

3. NINA's disagreement with this NRC position

In NINA's view, NRC's rejection of reliance on routine radiation protection is inconsistent withRG 1.143. The only reasonable interpretation of RG 1.143 is that the limit applies to thepersonnel exposure due to a postulated malfunction or release. During normal plant operationthe radiation dose rate will exceed 5 rem/yr in some parts of any radwaste building that houseswaste processing systems. This will be true without any malfunction. If the RadiationProtection Program controls must be disregarded, site personnel would have uncontrolled andunrestricted access to those areas, and could be exposed to more than 5 rem/yr. Consequently,excluding reliance on the Radiation Protection Program would make it impossible for any suchradwaste building to be classified RW-IIb. If that was the intent of RG 1.143, it never wouldhave adopted a system of safety classification.

A more logical interpretation is that the calculation should assume that the Radiation ProtectionProgram is implemented as routinely applied during normal plant operation in accordance with10 CFR 20.1101. This would allow the calculation of an unmitigated exposure required by RG1.143 to assume that, in accordance with the Radiation Protection Program, (1) radiation surveyswill be conducted on the frequencies specified in that program and as required in response toknown circumstances (such as significant earthquakes or structural failures) in accordance with10 CFR 20.1501; (2) occupational exposure to radiation will be monitored in accordance with 10


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CFR 20.1502; and (3) exposures of site personnel will be controlled in accordance with 10 CFR

§§ 20.1601, 20.1602, 20.1201 and 20.1206.

D. NINA's Revised Calculation

1. Assumptions

Despite its disagreement with this NRC staff position, NINA revised calculation U7-RWB-M-CALC-DESN-6002 to use assumptions that would satisfy the NRC staff's interpretation. The

calculation of the dose to a member of the public at the protected area boundary due to anunmitigated release was not changed, but to assess the unmitigated exposure of site personnel therevised calculation assumed release of the radwaste from the tanks and equipment within theirenclosures. The site personnel were assumed to spend working hours in the RWB as a routinematter over the course of a year without the required the monitoring and controls that would berequired by the Radiation Protection Program upon discovery of the increased radiation levels.The results were still less than the RG 1.143 limits.

2. NRC Staff's Objections to the Revised Calculation

The revised NINA calculation was reviewed during the second part of the audit on February 8,

2012. The NRC audit report provides additional NRC staff positions as a basis for finding thatthis calculation also does not satisfy RG 1.143. The audit report dated March 21, 2012, objectsto the assumption that the RWB walls and roof would continue to provide shielding for the

calculation of both the dose at the unprotected area boundary and the unmitigated exposure tosite personnel. It states that the NRC staff's position is that no credit can be taken for building orsystem design features in reducing the source term or exposure.

3. NINA's Disagreement with the NRC Staff's Additional Position

The NRC staff's position that no credit can be taken for building or system features is not basedon any statement in RG 1.143 and is unjustified. NINA calculated the dose at the protected areaboundary as the sum of the dose due to direct radiation from the radiation sources that are notmobile and the dose due to iodines assumed to be released in gaseous form. The calculation ofthe direct radiation contribution was conservative, but did credit the passive shielding that would

be provided by the RWB walls and roof. Gross failure of the RWB walls and roof is preventedfor the following reasons:

* RW-IIb classification requires the building meet the seismic design requirements ofASCE-7.

* In order to meet seismic I/I requirements with respect to collapse onto adjacent safety-related buildings, the RWB is designed for SSE.


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Also, it is acceptable to take credit for this shielding for the following reasons:

* The amount of shielding would be essentially the same, whether provided by intact wallsand roof or the collapsed structure.

" As discussed below, DOE guidance regarding unmitigated release calculations allowscredit for passive shielding.

RG 1.143 does not require the calculation to be based on a scenario that is not credible. TheDOE standards used by NUREG/CR-5733 as the basis for the classification system show that theunmitigated release is to be based on conservative, but credible scenarios. DOE-STD-3009-94,"Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility DocumentedSafety Analyses," at pages A-4 and A-5, provides the following specific guidance:

UNMITIGATED RELEASE CALCULATION

The unmitigated release calculation represents a theoretical limit to scenarioconsequences assuming that all safety features have failed, so that the physical releasepotential of a given process or operation is conservatively estimated. The unmitigatedrel6ase should characteriie both the energies driving the release, and the releage fractionsin accordance with the physical realities of the accident phenomena at a given facility orprocess. As a result, there may be assumptions that are necessary to make in order todefine a meaningful scenario, but which also impact the magnitude of the resultantconsequences. In order to clearly capture these assumptions, and their resulting potentialimpact on safety SSC designation and/or Technical Safety Requirements (TSR)protection, the unmitigated calculation should:

(1) Take no credit for active safety features - such as ventilation filtration systems inthe case of a spill.

(2) Take credit for passive safety features that are assessed to survive accidentconditions where that capability is necessary in order to define a physicallymeaningful scenario. For example, in the case of a container drop where the impactof the drop does not challenge container integrity, it should not be assumed that thecontents have dropped in an uncontained manner. Similarly, if the presence ofpermanently installed resilient flooring prevents an undesired consequence given adrop, an assessment of the drop against some other non-resilient surface is notmeaningful. However, it is important to note that such defining assumptions maywarrant some level of safety SSC designation to assure that the assumptions remainvalid in the future. In the above examples, the container and the flooring maywarrant designation as SS [safety-significant] or SC [safety class] design features.


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(3) Take no credit for passive safety features producing a leak-path reduction in sourceterm, such as building filtration.

(4) Assume the availability of passive safety features that are not affected by theaccident scenario. For example, in the case of a process vessel rupture, it should beassumed that other vessels not affected by the accident are not ruptured or otherwiseunavailable.

Thus, the scenario should be meaningful, and not assume conditions that are physicallyimpossible or extremely unlikely. Calculations of an unmitigated release may take credit forpassive features that would survive the accident. It is appropriate for NINA to assume that thewalls of the RWB would continue to provide shielding, and it would not be meaningful toassume otherwise. Consequently, NINA's assumptions for the calculation of the direct dose atthe protected area boundary are consistent with the requirements of RG 1.143.

Similarly, it was necessary for NINA's calculation of the dose due to unmitigated exposure tosite personnel to assume that when the tanks in the RWB fail and release the contained wasteinto their respective enclosures, the shield walls around these enclosures remain intact. Thecalculation would not be meaningful if it assumed that site personnel would be present routinelyin the RWB over the course of an entire year after the unmitigated release, unless the shield wallsremained intact. Any significant damage to the shield walls would be detected promptly. It is'.not possible to devise a meaningful scenario in which the RWB shield walls suffer significantstructural failure and yet, plant personnel are continuously allowed to enter the RWB over thecourse of a year without controls being imposed in accordance with the Radiation ProtectionProgram and NRC regulations.

Nothing in R.G. 1.143 suggests that NRC intended "unmitigated release" or "unmitigatedexposure" to encompass such an incredible scenario. Any such requirement would make itimpossible for any building containing radwaste processing systems to be classified as RW-IIb.Since RG 1.143 specifically provides for classifying some radwaste buildings as RW-IIb, aninterpretation that makes such a classification impossible cannot be correct. Consequently, theassumptions in NINA's calculations, as described in the audit report, are consistent with theintent of RG 1.143.

E. Draft RAIs 6404 Revision 7 and 6405 Revision 7

Draft RAIs 6404 revision 7 and 6405 revision 7 add yet another NRC staff position, which wasnot previously mentioned.

In addition, the annual dose limit to members of the public stated in RG 1.143 as being500 mrem/year for the dose at the protected area boundary (PAB), is 100 mrem per year,as required by 10 CFR 20.1301, and the 10 CFR Part 20 limits were adopted in RG 1.143as an acceptance criterion. NUREG-0800, SRP Section 11.2 (March 2007) makes note ofthis inconsistency in the regulatory guide, stating that, "the dose limit cited in Section 5


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of RG 1.143, addressing unmitigated releases of radioactive materials, is revised to beconsistent with that of 10 CFR Part 20.1301." Therefore, it is not acceptable to classify afacility as RW-IIb, unless the applicant demonstrates that both the maximum unmitigatedexposure to site personnel within the protected area is less than 5 rem per year and thatthe total design basis unmitigated radiological release at the unprotected area boundary isless than 100 millirem per year.

This position is not correct for the following reasons:

" Contrary to the implication in these RAIs, SRP 11.2 says "For the purpose of this SRP,the dose limit cited in Section 5 of RG 1.143, addressing unmitigated releases ofradioactive materials, is revised to be consistent with that of 10 CFR Part 20.1301"(emphasis added). SRP 11.2 applies only to the review of the liquid waste managementsystem (LWMS), and NINA has amply demonstrated that the dose at the protected areaboundary due to an unmitigated release from the LWMS would be less than 100mrem/yr.

" 10 CFR 20.1301(b) says "If the licensee permits members of the public to have access tocontrolled areas, the limits for members of the public continue to apply to thoseindividuals." Thus, the dose limit does not apply at the security fence since members ofthe public are not permitted unrestricted access to the owner controlled area bf the STPsite.

" The SRP appears to be premised on an incorrect assumption. Unlike the dose limit in 10CFR 20.1301, the dose criteria in RG 1.143 are not applicable to normal operations; theyare used to assess the consequences of accidents or abnormal occurrences. In thisrespect, the criterion in RG 1.143 is analogous to 10 CFR 30.32(i)(1), which states that abyproduct material licensee must either (i) show that the maximum dose to a personoffsite due to a release of radioactive materials would not exceed 1 rem, or (ii) providean emergency plan. Byproduct material licensees also are subject to 10 CFR 20.1301.

* Under 10 CFR 20.1301(c), the NRC may authorize a licensee to permit members of thepublic to receive doses up to 500 mrem/yr. NRC chose to use this limit as the basis forassessing radwaste building hazards when it adopted RG 1.143. This was a rational andreasonable approach, and there is no apparent basis for saying it was a mistake. In fact,it would be more logical to ask whether it was a mistake for RG 1.143 to fail to use thecriterion in 10 CFR 30.32(i)(1).

" The draft of SRP 11.2 on the NRC Internet site did not discuss the subject of reducing theRG 1.143 dose criterion. In fact, the draft SRP was dated in 1996, before revision 2 ofRG 1.143 was issued. Since RG 1.143, rev. 2 states that NRC considered compliancewith it an acceptable means to meeting NRC requirements, it is not appropriate for NRCto make such a substantive change without providing an opportunity for public comment.


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For all of these reasons, the NRC should reconsider the positions it has taken concerning how tointerpret RG 1.143, and conclude that the STP 3 & 4 RWB is properly classified as RW-IIb inaccordance with RG 1.143.

IV. ANY CONTINUING QUESTIONS ABOUT THE INTERPRETATION OF RG 1.143

SHOULD BE RESOLVED BY NRC APPROVAL OF THE CURRENT RWB DESIGN ASAN ACCEPTABLE ALTERNATIVE TO COMPLIANCE WITH RG 1.143

NINA has been unable to find any examples of NRC-approved calculations to supportclassification of a radwaste building as RW-IIb in accordance with RG 1.143, rev. 2.

" AP1000: The AP1000 is the only new reactor design that has obtained final NRCapproval since the adoption of RG 1.143, rev. 2. However, it does not include a structureanalogous to the RWB. The AP1000 liquid and gaseous waste management systems arehoused in the Auxiliary Building, which is a Seismic Category I structure that houses theseismic Category I mechanical and electrical equipment located outside the containmentbuilding. The AP1000 radwaste building is designed to UBC-1997 and ASCE 7-98,which is consistent with classification as RW-IIb, it does not contain a significant amount

of radioactive material and the NRC apparently did not require a calculation to support itsclassification.

" ESBWR: The ESBWR radwaste building is classified as RW-IIa, but designed towithstand the SSE, which goes beyond the /2 SSE that RG 1.143, rev. requires for anRW-IIa classification. It appears that the design criteria and classification were selectedwithout NRC review of a calculation to support classification of the building.

" EPR: The EPR radwaste building is classified as RW-IIa, and is designed to withstandthe 2 SSE. It appears that the design criteria and classification were selected without anyNRC review of a calculation to support classification of the building.

The absence of any examples of NRC assessment of an applicant's calculation to supportclassification of a radwaste building in accordance with RG 1.143, rev. 2 has made it difficult to

determine the criteria NRC will accept for such a calculation.

RG 1.143 states, at page 1.143-2, that:

Licensees and applicants may propose means other than those specified by the provisionsof the Regulatory Position of this guide for meeting applicable regulations. No newrequirements are being imposed by this regulatory guide. Implementation of thisguidance by licensees will be on a strictly voluntary basis.


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Accordingly, a reasonable alternative to resolving the questions discussed above about themeaning of "unmitigated release" and "unmitigated exposure" is for the NRC to approve thedesign of the STP 3 & 4 RWB as an acceptable alternative to compliance with RG 1.143.

The NRC should conclude that the design of the RWB meets the NRC regulations related to RG1.143 because the NRC has approved the ABWR RWB design, and the only departure relevantto the RG 1.143 requirements is the reclassification of the RWB substructure from seismic

Category I to non-seismic. Although the RWB is classified as RW-IIb, it is designed to meet theRW-IIa seismic requirements. Consequently, changing the classification of the RWB to RW-IIawould not result in any change to the seismic design.

Changing the classification of the RWB from RW-IIb to RW-IIa would change the RG 1.143criteria applicable to other aspects of the RWB design, since the RWB design for loads specifiedin RG 1.143 other than earthquake, wind and tornado is based on the requirements for RW-IIbclassification. There is no departure related to RG 1.143 requirements that affects these aspectsof the RWB design, so these aspects of the design are within the scope of the NRC-approvedABWR DCD.

The principal differences between the STP 3 & 4 RWB design and the RG 1.143 requirementsfor RW-IIa classification are associated with protection of exterior doors and openings frommissiles and floods.

Although the RWB exterior doors and openings are not protected from tornado orhurricane missiles, a tornado or hurricane missile strike through these openings would notresult in a release of radioactive materials in excess of 10 CFR Part 20 limits because

most components containing radwaste are protected by walls and slabs that are designedto provide shielding from radiation, but would also withstand missile strikes. In theunlikely event of damage to the few components that could be vulnerable to a missile,

resulting exposures would be less than the Part 20 and RG 1.143 limits.

* The RWB exterior doors and openings are protected from flooding in accordance with

ASCE-7, while RW-IIa classification would require them to be protected against one halfof the Probable Maximum Flood (PMF). FSAR subsection 2.4S.13 considers the effectsof flooding of the RWB due to a PMF and shows that none of the flooding mechanismsconsidered presents a credible risk of environmental contamination, and if RWB flooding

did occur the potential effects would be limited because there are no known surface water

users downstream of the STP site.

Thus, reclassification of the RWB to RW-IIa would not provide any safety benefit. Accordingly,

the NRC should determine that the current STP 3 & 4 RWB design is acceptable, either becauseit meets RG 1.143, rev. 2, or alternatively because it is an acceptable alternative method of

complying with the applicable NRC regulations.


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V. THE TURBINE BUIJLDING DESIGN IS PART OF THE NRC-APPROVED ABWR

DCD

The NRC audit was conducted for the limited purpose of reviewing the RWB classification.Nevertheless, the NRC audit report noted that NINA has not assigned a classification for theportions of the Turbine Building that house the major components of the offgas system inaccordance with RG 1.143, rev. 2. After the audit, NINA received draft RAI number 6405revision 7, which would ask NINA to revise the FSAR "to classify the turbine building offgassystem, including the portions of the turbine building housing this system, the radwaste pipetunnel, and any additional pertinent SSCs included in the FSAR, in accordance with RegulatoryPositions 5 and 6 of Regulatory Guide 1.143 or propose an acceptable alternative." Thesequestions concern aspects of the NRC-approved ABWR DCD, which are incorporated byreference in the STP 3 & 4 COLA and not changed by departure. Subsection VI.A of 10 CFR

52, Appendix A states that the NRC has determined that the SSC and design features of theABWR design comply with the Atomic Energy Act and the applicable regulations, and thatadditional or alternative SSC, design features, design criteria, testing, analyses, acceptancecriteria, or justifications are not necessary for the ABWR design. In addition, Subsection VI.D

states that:

D. Except in accordance with the change processes in Section VIII of this appendix, theCommission'may not require an applicant or licensee who references this appendix to: "

1. Modify structures, systems, components, or design features as described in the genericDCD;

2. Provide additional or alternative structures, systems, components, or design features

not discussed in the generic DCD; or

3. Provide additional or alternative design criteria, testing, analyses, acceptance criteria,or justification for structures, systems, components, or design features discussed in the

generic DCD.

Draft RAI 6405 would be contrary to these regulations.

Neither the NRC audit report, nor draft RAI 6405 revision 7 provides any justification for thesequestions, and NINA does not believe that the STP 3 & 4 COLA includes any departures thatcould even arguably justify such questions. In particular, it should be noted that the ABWRDCD Table 12.2-14 "Offgas System Inventories" is incorporated by reference in the STP 3 & 4COLA without any changes. This table presents the amount of activity available for a postulatedunmitigated release from the Turbine Building. The Advanced Safety Evaluation for Chapter 15notes that the NRC reviewed the STP 3 &4 site-specific the radwaste system failure dose resultsand independently calculated the doses, and confirmed that the results are acceptable. The STP 3& 4 COLA also does not make any changes to DCD subsections 11.3.7 "Quality Control" and11.3.8 "Seismic Design," which directly address the compliance of the Gaseous Waste


Page 14 of 14

Management System with RG 1.143. Consequently, NRC's approval of the aspects of the design

related to R.G. 1.143 cited in draft RAI 6405 revision 7 have finality, and should not be subject

to further NRC review.

VI. CONCLUSION

NINA's calculations adequately demonstrate that classification of the RWB as RW-IIb is

consistent with RG 1.143, rev. 2. Numerous alternative calculations, with ever more

conservative assumptions also showed that this classification is consistent with R.G. 1.143. The

design of the RWB complies with all applicable NRC regulations, and further NRC review of the

classification in accordance with RG 1.143 could not result in any safety benefit. For these

reasons, no further consideration of the classification under RG 1.143 is justified. Draft RAI

6405 revision 7 is inconsistent with section VI of 10 CFR 52, Appendix A and should not be

issued because it concerns aspects of the design of the Turbine Building and other systems,

structures or components that are within the scope of the NRC-approved ABWR DCD and are

not subject to any departure.

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