transmittal of non-proprietary version of app-gw-gln-147 (tr … · 00318psa.doc dcp/nrc2077...

O Westinghouse

U.S. Nuclear Regulatory CommissionATTENTION: Document Control DeskWashington, D.C. 20555

Westinghouse Electric CompanyNuclear Power PlantsP.O. Box 355Pittsburgh, Pennsylvania 1 5230-0355USA

Directtel: 412-374-6306Directfax: 412-374-5005

e-mail: [email protected]

Your ref: Project Number 740Our ref: DCP/NRC2077

January 29, 2008

62 -I2- S52- 1

Subject: Transmittal of Non-Proprietary Version of APP-GW-GLN- 147 (TR 147)

In support of past NRC Acceptance Review issues, Westinghouse submitted APP-GW-GLN-147,Revision 0, (Proprietary), "AP1000 Containment Recirculation and IRWST Screen Design", TechnicalReport Number 147 (TR 147), under Westinghouse letter DCP/NRC2066 dated January 11, 2008. Thereport enclosed herein is the non-proprietary version of the aforementioned document and is providedsolely to satisfy the requirements of 10 CFR 2.390.

This report is submitted as part of the NuStart Bellefonte COL Project (NRC Project Number 740).

Pursuant to 10 CFR 50.30(b), APP-GW-GLN- 147-NP, Revision 0, (Non-Proprietary), "AP 1000Containment Recirculation and IRWST Screen Design," is submitted as Enclosure 1 under the attachedOath of Affirmation.

Questions or requests for additional information related to the content and preparation of this reportshould be directed to Westinghouse. Please send copies of such questions or requests to the prospectiveapplicants for combined licenses referencing the AP 1000 Design Certification. A representative for eachapplicant is included on the cc: list of this letter.

Very truly yours,

A. Sterdis, ManagerLicensing and Customer InterfaceRegulatory Affairs and Standardization

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DCP/NRC2077January 29, 2008

of 2

/Attachment

1. "Oath of Affirmation," dated January 29, 2008

/Enclosure

1. APP-GW-GLN-147-NP, Revision 0, "AP 1000 Containment Recirculation and IRWST ScreenDesign," Technical Report Number 147

cc: D. JaffeE. McKennaP. RayP. HastingsR. KitchenA. MonroeJ. WilkinsonC. PierceE. SchmiechG. ZinkeR. GrumbirC. Steuck

- U.S. NRC- U.S. NRC-TVA- Duke Power- Progress Energy- SCANA- Florida Power & Light- Southern Company- Westinghouse- NuStart/Entergy- NuStart- Westinghouse

1E1E1E

1E1E1E1E1E1E1E1E1E

IAIA1AIAIAIAIA1AIAIAIA1A

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ATTACHMENT 1

"Oath of Affirmation"

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ATTACHMENT 1

UNITED STATES OF AMERICA

NUCLEAR REGULATORY COMMISSION

In the Matter of: )

NuStart Bellefonte COL Project )

NRC Project Number 740 )

APPLICATION FOR REVIEW OF

"AP 1000 GENERAL COMBINED LICENSE INFORMATION"

FOR COL APPLICATION PRE-APPLICATION REVIEW

W. E. Cummins, being duly sworn, states that he is Vice President, Regulatory Affairs and

Standardization, for Westinghouse Electric Company; that he is authorized on the part of said company to

sign and file with the Nuclear Regulatory Commission this document; that all statements made and

matters set forth therein are true and correct to the best of his knowledge, information and belief.

W. E. CumminsVice PresidentRegulatory Affairs and Standardization

Subscribed and sworn to

before me this~q"' dayof January 2008.

COMMONWEALTH OF PENNSYLVANIANotarial Seal

Patricia S. Aston, Notary PublicMurryVille Boro, Westmoreland countyMy Commission Expires July 11, 2011

Member, Pennsylvania Association of Notaries

otary Public

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ENCLOSURE 1

APP-GW-GLN-147-NP, Revision 0

"APi1000 Containment Recirculation and IRWST Screen Design"

Technical Report 147

(Non-Proprietary)

00318psa.doc

AP1000 DOCUMENT COVER SHEETTDC: Permanent File:

AP1000 DOCUMENT NO. REVISION PAGE ASSIGNED TO OPEN ITEMS (Y/N)

APP-GW-GLN-147-NP 0 1 of 13 W-Schulz N

ALTERNATE DOCUMENT NUMBER: TR-147 WORK BREAKDOWN #:

ORIGINATING ORGANIZATION: NPP/NS

TITLE: AP1000 Containment Recirculation and IRWST Screen Design

ATTACHMENTS: DCP #/REV. INCORPORATED IN THISDOCUMENT REVISION:j

CALCULATION/ANALYSIS REFERENCE:

ELECTRONIC FILENAME ELECTRONIC FILE FORMAT ELECTRONIC FILE DESCRIPTION

APP-GW-GLN-147-NP.doc MSWord

o 2008 WESTINGHOUSE ELECTRIC COMPANY LLC

[ WESTINGHOUSE NON PROPRIETARY CLASS 3Class 3 Documents being transmitted to the NRC require the following two review signatures In lieu of a Form 36.

LEGAL REVIEW

T. WhitePATENT REVIEW*D. Ekeroth

El WESTINGHOUSE PROPRIETARY CLASS 2This document is the property of and contains Proprietary Information owned by Westinghouse Electric Company LLC and/or itssubcontractors and suppliers. It Is transmitted to you in confidence and trust, and you agree to treat this document in strictaccordance with the terms and conditions of the agreement under which it was provided to you.

ORIGINATOR(S) SIGN R 'DATEP. Greco A" , C/'/ 8

REVIEWER(S) SIGNXTURE / ATE

SIGNATURE / DATE

SIGNATURE / DATE

VERIFIER(S) S; N IE/iAT /Verification Method Independent Review

D. Lindgren 64e_ _ _ _ _ _ _ _ _ _ _ _

*Plant Applicability• [ All AP1000 plant e

[ Only the following plants: IAPPLICABILITY REVIEWER*.' SIGNATURE / DATE

J. A. Speer acG q-'~ V21 0 1 0RESPONSIBLE MANAGER* SIGNATL,/,DATE

C. McGinnis SlGN, 7 , / i.4

Approval of the responsible manager signifies that the document and all required reviewsre complete, the appropriate proprietaryclass has been assigned, electronic file has been provided to the EDMS. and the document is released for use.

Westinghouse Non-Proprietary Class 3APP-GW-GLN-147-NPRevision 0

January 2008

AP1000 Containment Recirculation and IRWST Screen

Design

Westinghouse Electric Company LLCP.O. Box 355

Pittsburgh, PA 15230-0355

© 2008 Westinghouse Electric Company LLCAll Rights Reserved

APP- GW-GLN-147-NP Revision 0

TABLE OF CONTENTS

IN TRO D U CTION ....................................................................................................................................... 4

TECH N ICA L D ESCR IPTION ................................................................................................................... 4

D CD M A RK -U P ........................................................................................................................................ .5

A TTA CH M EN T A - D CD M A RK UPS ..................................................................................................... 8

A TTA CH M EN T B - FIG U RES ............................................................................................................... 10

WESTINGHOUSE ELECTRIC COMPANYAP1000 Licensing Design Change Document Page 4 of 13

Document Number: APP-GW-GLN-147-NP Revision Number: 0

Title: AP1000 Containment Recirculation and IRWST Screen Design

I. INTRODUCTION

This Technical Report (TR) provides additional design detail of the AP 1000 Incontainment Refueling WaterStorage Tank (IRWST) screens and the Containment Recirculation screens to allow a safety evaluation of theacceptability of the design to be performed. In addition to providing more screen design detail, this TRprovides references to Design Control Document (DCD) figures and text, other TRs and to relevant DSEROpen Item Responses that provide information about the AP 1000 long term cooling design and performanceevaluations.

II. TECHNICAL DESCRIPTION

Westinghouse has shown in TR-26, Revision 2 (Reference 1), that the AP1000 plant including the IRWSTscreens and the Containment Recirculation screens provide acceptable long term core cooling. The AP 1000-long term core cooling is robust considering:

* Very low debris loadings, including fiber, particulate and chemical* Low recirculation flow rates* Delayed initiation of recirculation" High floodup levels" Large screen areas

The screen differential pressures (DP) that could potentially occur in the AP 1000 were evaluated consideringthe AP 1000 design features and characteristics. These screen DPs are expected to be essentially zero becausethere is not enough debris to form a contiguous bed. This evaluation assumes that the screens are flat which isconservative relative to the geometry of the screens described in this TR. Testing will be performed toconfirm that the screens limit the DP to acceptable values as described in COL item 6.3.8.2.

Westinghouse has shown that the AP 1000 can tolerate some DP increase across the screens due to debris andas a result demonstrated that there is margin between the expected screen performance and what the plant cantolerate. This evaluation is contained in several DSER Open Item Responses as discussed in the followingparagraphs. Additional analysis will be performed to establish DP limits for the screen designs as described inCOL item 6.3.8.2.

DSER 016.2.1.8.3-3, Revision 2, addressed the potential for increased DP across the containmentrecirculation screens due to accumulation of debris. The discussion indicated that a DP of 0.18 psi would beacceptable because it represented a very small part (approximately 6%) of the total DP in the recirculation linetotal of approximately 2.8 psi. As a result, the potential impact on the recirculation flow would beinsignificant.

DSER 016.2.1.8.2-1, Revision 2, addressed the potential for increased DP across the IRWST screens due toaccumulation of debris. The discussion indicated that a DP of 0.03 psi would be acceptable 'because it,represented a very small part (less than 1%) of the total DP in the IRWST injection line total of approximately5.8 psi. As a result, the potential impact on the IRWST flow would be insignificant.

DSER 01 6.2.1.8.3-1, Revision 3, addressed the potential for increased DP across the core due to

WESTINGHOUSE ELECTRIC COMPANY

AP1000 Licensing Design Change Document Page 5 of 13Document Number: APP-GW-GLN-147-NP Revision Number: 0


accumulation of debris. The discussion indicated that the water level in the AP 1000 downcomer is about 70inches below the DVI connection during recirculation. The core DP would have to increase by about 2.3 psibefore the downcomer level would increase to the DVI elevation and there would be any impact on corecooling performance.

AP1000 Containment Recirculation Screen and IRWST Screen Design Description

The following provides additional design details for the AP 1000 Containment Recirculation and IRWSTScreens over and above what is provided in the Design Control Document (DCD).

The DCD provides significant information about the locations of these screens in the plant, their integrationinto the Passive Core Cooling System (PXS) and their sizing / design. The DCD also provides a description ofthe features of the AP 1000 that greatly reduce the challenge to these screens due to debris generation andtransport.

A design description of the IRWST screens is provided in DCD section 6.3.2.2.7.2. This section discusses thelocation of the screens in the plant, the reduction of debris loadings in the plant, and the benefits of low flowvelocities. DCD Figure 6.3-6 shows a plan view of the screens in the IRWST. DCD Figure 6.3-7 shows asection view of the screens.

Section 6.3.2.2.7.3 of the AP 1000 DCD describes the Containment Recirculation screens. Just as the sectionon IRWST screens, this section discusses the location of the screens in the plant, features that reduce theamount of debris as well as the deep flood-up levels associated with the containment recirculation screens.DCD Figure 6.3-8 shows a plan view of the containment recirculation screens. DCD Figure 6.3-9 shows asection view of the containment recirculation screens.

DCD Table 6.3-2 sheet 2 of 2 shows certain design requirements for both sets of screens, including number,screen surface area, material and AP 1000 equipment class.

The same screen design approach will be used for both screens.

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The screen is formed of stainless steel and does not employ soft parts to further increase the robustness of thedesign. For this reason the design has the benefit of not requiring replacement of parts due to environmentaldegradation. The strainers are seismically qualified through analytical methods to Seismic Category I levels.The screens are designed to withstand hydrodynamic loads considering full debris loading without loss ofstructural integrity.


AP1000 Licensing Design Change Document Page 6 of 13DocumentNumber: APP-GW-GLN-147-NP Revision Number: 0


The front face of the screen design performs as a trash rack to filter out large pieces of debris and prevent themfrom blocking excessive amounts of screen area or from damaging the screen.

Inspection of Figure B-I shows the pocket inlet tapers slightly. This taper forms a channel between adjacentpockets on all sides. These channels allow the flow, after it passes through the perforated sheets that make upthe pocket sides / top / bottom, to pass between the adjacent pockets to the plenum that is located behind thepockets. The back end of the pocket is also perforated. See Figure B-I for more detail.

The following sections give approximate information on both the Containment Recirculation and IRWSTscreens.

IRWST screens* The IRWST screens are shown on Figure B-2 of this document." Each of two screens is about 7.5' wide and 5' high and contains about 600 pockets." The pockets are arranged such that the flow enters from one side of the screen.* Flow Path Description:

o Flow enters the front of the pocket and passes through the perforated sheets that make up thepocket sides, top, bottom and back.

o Upon passing through perforated sheets that make up the pockets, the flow passes between theadjacent pockets and enters a plenum located behind the pockets.

o The plenum is sealed from the IRWST on the front, top, and sides. The wall of the IRWSTprovides the back side and the IRWST floor / sump pit provide the bottom of the plenumrespectively.

o The water flows from the plenum down into the sump pit and then into the PXS piping.o The PXS piping contains no pumps, throttle valves or orifice plates on its way to the reactor

vessel Direct Vessel Injection (DVI) nozzle.o The flow path does travel through a few valves and a venturi. The venturi has a large opening

(4" ID).

Containment Recirculation screens:• The containment recirculation screens are shown on Figure B-3 of this document.* Each of two screens is about 13' wide and 10' high and contains about 2550 pockets.* The pockets are arranged such that the flow enters from one side of the screen.* Flow Path Description:

o Flow enters the front of the pocket and passes through the perforated sheets that make up thepocket sides, top, bottom and back.

o Upon passing through perforated sheets that make up the pockets, the flow passes between theadjacent pockets and enters a plenum located behind the pockets.

o The plenum is sealed from the loop compartment on the front, top, and sides. The wall andfloor of the loop compartment form the rear and bottom of the plenum respectively.

o The water flows from the plenum into the PXS piping.o Note that the two containment recirculation screens are located adjacent to each other and are

-interconnected so that in case both flow paths in one PXS subsystem fail there would still beflow through both screens. A LOCA in a DVI line inside of a PXS room can prevent injectionfrom one of the DVI.




o The PXS piping contains no pumps, throttle valves or orifice plates on its way to the reactorvessel Direct Vessel Injection (DVI) nozzle.

o The flow path does travel through a few valves and a venturi. The venturi has a large opening(4" ID).

Note in Figure B-3 the interconnection between screens through the pipe imbedded in the floor concrete. Thisis also shown in DCD Figure 6.3-2 sheet 2.

REFERENCES

1. "AP 1000 Verification of Water Sources for Long-Term Recirculation Cooling Following a LOCA", APP-GW-GLR-079, Revision 2, Westinghouse Electric Company, LLC.

WESTINGHOUSE ELECTRIC COMPANYAP1000 Licensing Design Change Document Page 8 of 13



Attachment A

DCD Markups



Title: .AP1000 Containment Recirculation and IRWST Screen Design

Revise the fourth paragraph of 6.3.2.2.7.2 as follows:

The design of the IRWST screens reduces the chance of debris reaching the screens. The screens are orientedvertically such that debris that settles out of the water does not fall on the screens. The screen design providesa debris curb function at the base of the IRWST screens to prevent high density debris from being swept alongthe floor by water flow to the IRWST screens. The screen design provides the trash rack function. This isaccomplished by the screens having a large surface area to prevent a single object from blocking a largeportion of the screen and by the screens having a robust design to preclude an object from damaging the screenand causing by-pass. The screen prevents debris larger than 0.125" from being injected intoithe reactor coolantsystem and blocking fuel cooling passages. The screen is a type (folded, poket• , etc.) that has sufficientsurface area to accommodate debris that could be trapped on the screen. The design of the IRWST screens isdescribed further in APP-GW-GLN-147 (Reference 4).

Revise the sixth paragraph of 6.3.2.2.7.3 as follows:

The design of the containment recirculation screens reduces the chance of debris reaching the screens. Thescreens are orientated vertically such that debris settling out of the water will not fall on the screens. Theprotective plates described above provide additional protection to the screens from debris. The bottom of thescreens are located 2 feet above the floor, instead of using a debris curb, to prevent high density debris frombeing swept along the floor by water flow to the containment recirculation screens. The screen design providesthe trash rack function. This is accomplished by the screens having a large surface area to prevent a singleobject from blocking a large portion of the screen and by the screens having a robust design to preclude anobject from damaging the screen and causing by-pass. The screen prevents debris larger than 0.125" frombeing injected into the reactor coolant system and blocking fuel cooling passages. The screen is a type (felded,peekets-ete7) that has more surface area to accommodate debris that could be trapped on the fine screen. Thedesign of the containment recirculation screens is described further in APP-GW-GLN-147 (Reference 4).

Revise Subsection 6.3.9 as follows:

6.3.9 References1. WCAP-8966, "Evaluation of Mispositioned ECCS Valves," September 1977.

2. WCAP-13594 (P), WCAP-13662 (NP), "FMEA of Advanced Passive Plant ProtectionSystem," Revision 1, June 1998.

3. APP-GW-GLR-079, "AP1000 Verification of Water Sources for Long-Term RecirculationCooling Following a LOCA," Westinghouse Electric Company LLC.

4. APP-GW-GLN-147. "AP 1000 Containment Recirculation and IRWST Screen Design,"Westinghouse Electric Company LLC.

WESTINGHOUSE ELECTRIC COMPANYAP1000 Licensing Design Change Document Page 10 13



Attachment B

Figures

WESTINGHOUSE ELECTRIC COMPANYAP1000 Licensing Design Change Document Page 11 13

Document Number: APP-GW-GLN-147-NP Revision Number: .0


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Figure B-1

APIO00 Screen Detail