ML20029E000

Responds to NRC Requests for Info Re AP600 from 940307 & 0316 Ltrs

ML20029E000
Person / Time
Site:	05200003
Issue date:	05/11/1994
From:	Liparulo N WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP.
To:	Borchardt R NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NTD-NRC-94-4128, NUDOCS 9405160017
Download: ML20029E000 (73)

Text

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Westinghouse Energy Systems Q3yg gg3g g33 Electric Corporation NTD-NRC-94-4128 DCP/NRC0058 Docket No.: STN-52-003 May 11,1994 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555 ATTENTION: R.W.BORCHARDT

SUBJECT:

WESTINGHOUSE RESPONSES TO NRC REQUESTS FOR ADDITIONAL INFORMATION ON THE AP600

Dear Mr. Borchardt:

Enclosed are three copics of the Westinghouse responses to NRC requests for additional information on the AP600 from your letters of March 7,1994 and March 16,1994.

A listing of the NRC requests for additional information responded to in this letter is contained in Attachment A.

These responses are also provided as electronic files in Wordperfect 5.1 format with Mr. Hasselberg's copy.

If you have any questions on this material, please contact Mr. Brian A. McIntyre at 412-374-4334.

(

) m. T Nicholas k 'paruto, Manager Nuclear Safety & Regulatory Activities

/nja Enclosure cc: B. A. McIntyre - Westinghouse F. Hasselberg - NRR 4

y 9405160017 DR 940511 ADOCK 05200003 PDR

NTD-NRC-94-4128 ATTACHMENT A AP600 RAI RESPONSES SUBMITTED MAY l1,1994

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l RAINo. Issue  !

100.011  : Classification of SSCs 220.053 l Rationale for 6 ft thick foundation 220.060  : Wind loads in Level A&C combinations 220.062  : Descriptions for polar crane system 220.067  : Operating pressure in load combinations 220.079  : IRWST design information in SAR - i 220.087  : Energy component for embedment effect 220.088  : Use of coated rebar 220.090  : Type and characteristics ofwater seals l 230.050  : Auditable trail for final seismic calculations 230.053 l Inclusion of other site conditions i 230.055  : Use of SASSI 230.062  : Validity of fixed base seismic analysis 230.069  : Shallow soil site conditions 230.070 l Procedure for developing seismic response envelope 230.079  : Use of Seed-Idriss 1970 curves in SSI analyses 230.080  : Adequacy of using only 3 soil site conditions 230.081  : Use of computer code SAP or BSAP 230.084  : Additional information in Section 3.7.2.1.1 231.015  : Geography & demography limits for a site 231.016 l Flood level to plant grade design features 231.022  : SSI studies for the rock model 231.030  : Impact of non-vertically incident ground motion 231.031  : SSAR Appendix 2A.2 1 1 i

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l NRC REQUEST FOR ADDITlONAL INFORMATION Question 100.11 Provide a matrix indicating which non-saf ety-related structures, systems, and components (SSCs) of the APNN) listed in Table 3.2-3 of the standard safety an dysis report (SSAR) are (1) Quality Class D because they contain radioactivity (in accordance with Regulatory Guide 1.26),(2) Quality Class D defense-in-depth (DID) systems that direc fly act to prevent unnecessary actuation of the pas.;ive safety-related systems or support those non-safety-related SSCs that directly act to prevent unnecessary actuation of the pa. ..'ve safety-related systems, or (3) risk-significant j as identified through the analysis pneess described in the draft Commission paper on regulatory treatment of non-safety related systems (RTNSS) (issued September 10. lW3). Are there other non safety-related SSCs that are not listed in Tanic 3.2-3 that have been detennined to be risk significant through the RTNSS process?

i Response.

l The attached table identifies those lunctions of APNio systems that ;ue salety related, nonsafety-related defense-m- i lepth. Regulatory Guide 1.26, and reyulatory treatment of nonsafety-related systems (RTNSS) important functions.

Column I This column identifim those f unctions that are safety-relate 1. Equipment classified as safety-related is relied upon to remain f unctional during or f ollowing a design basis event to provide a saf ety-telated function. SS AR Table 3.2-3 idenuties the APUN) components that have been classified as safety-related.

Column 2 l

This colamn identifies those functions that have been identified as important in the APNM) implementation of the RTNSS process. The RTNSS process and the results of the AP69) implementation of the process are contained in

)

WCAP.13856. "APNN) Implementation of the Regulatory Treatment of Nonsafety-Related Systems Process." Where additional regulatory oversight has been proposed in WCAP-13856, the components that perform these f unctions are I classified as APNK) equipment class D in SSAR Table 3.2-3. j I

I As discussed in WCAP 138% additional regulatory m ersight for the nonsafety-related componenty that must operate to support pmer production, beyond that provided sia the SSAR design details and the existing operational controls on current plants. will not provide significant PR A benefit. Therefore, add;tional regulatory oversight is not pniposed for these nonsafety-related components that are required to operate during power production and these components have not been classified as AP600 equipinent class D components.

Column 3 This column identifies those functions that are not included in AP600 Class A, B, C, or APNX) defense-in-depth functions but are classified as Regulatory Guide 1.26, Quality Group D functions because components within the associated systems may contain radioactive material. The components that perfonn these functions are classified as AP600 equipment class D in SS AR Table 1.2-3.

W-Westinghouse

NRC REQUEST FOR ADDITIONAL INFORMATION n!" ius H !ji Column 4 Tliis column identifies those f unctions identified as ArW H) nonsaf ety-related defense-in-depth functions. The systerns.

that perforrn defense-in-depth functions are those nonsafety-related active systems that: .

1. Act to prevent unnecessary actuation of the safety-related passive systems

2. I'rovide support lunctions (<uch as heat removal, electrical power, or instrumentation and control) to the nonsafety-related systems required by the first criteria.

The components utdized for these functions are classified as AIYdH) equipment class D in SS AR Table 3.2-3.

100.11-2 W-Westinahouse a

NRC REQUEST FOR ADDITIONAL INFORMATION itui HHi N

II SSAR Revision:

The first paragraph in the Conteinment High Range Radiation Monitor subsection of Section i1.5.2.3.2 on page i1.5-6 should be revised at follows:

Containment liigh Range Radiation Monitor The containment high range radiation monitor s-has (detectors RMS-JWREI 10PXS-J E-RE160.

RMLJH-RBIIIPXS-JE-RE161. RMLJRRE112PXS-JE-RE162. and RMLJRRE111PXS JE-RE163) measure and record the radiation f rom the radioactive gases in the containment aunosphere. The local radiation processors receive Class IE power.

Table i1.5-1 on page 11.5-12 should be modified as follows:

Table i1.5-1 Radiation Monitor Detector Parameters Detector Type Sen ice Isotopes Nominal Range B DS-J E-RE007 y Steaun Generator Hlowdown Cs-137 1.OE-6 to 1.0E-1 pCi/cc CCS-J E-RE001 y Component Cooling Water System Cs-137 1.0E-8 to 1.0E-2 pCi/ec CVS-JE-RE003 y Reactor Coolant Letdown Cs-137 1.0E-4 to 1.0E+2 pCi/cc R MS-J E-RE001 p Plant Vent Particulate Sr-90 Cs-137 1.0E-13 to 1.0E-7 pCi/cc R MS-JE-RE002 y Plant Vent todine I-131 1.0E-12 to 1.0E-6 pCi/cc R MS-J E-RE003 p Plant Vent Gas (Normal Range) Kr-X5 Xe-133 1.0E-7 to 1.0E-2 pCi/cc R MS-J E-RE005 p P.V. Extended Range Gas ( Accident Range)Kr-85 Xe-133 1.0E-4 to 1.0E+5 pCi/cc RMS-J E-RE024 p Containment Atmosphere Particulate Sr-90 Cs-137 1.0E-13 to 1.0E-7 pCi/cc RMS-JE-RE025 y Containment Atmosphere lodine 1-131 1.0E-12 to 1.0E-6 pCi/cc RMS JE-RE026 p Contaimnent Atmosphere Gas Kr-85 Xe-133 1.0E-7 to 1.0E-2 pCi/cc RMS-JERB140 PXS-JE-RE160 y Containment High Range Kr-85 Xe-133 1.0E-0 to 1.0E+7 R/hr RMS-J WREll i PXS JE-REl61 y Containment High Range Kr-85 Xe-133 1.0E-0 to 1.0E+7 R/hr R MLJR-R E142 PXS JE-RE162 y Containment High Range Kr-85 Xe-133 1.0E-0 to 1.0E+7 R/hr RMLJR-REl13 PXS-JE.RE163 y Containment liigh Range Kr-85 Xe-133 1.0E-O to 1.0E+7 R/hr SGS-J E-RE026 y Main Steam Line CS 137 1.0E-1 to 1.0E+3 pCi/cc SGS-J E-RE027 y Main Steam Line Cs- 137 1.0E-1 to 1.0E+3 pCi/cc W Westinghouse

NRC REQUEST FOR ADDITIONAL INFORMATION r

er if Sy stem Function 1 2 3 4 Sa fety- RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafety- Additional Group D, AP600 Equipment related, RTNSS Regulatorv AP600 Equipment Class D Important Oversight Class D OVCA P-13856) Proposed OVCAP-13856)

Stfam Generator May contain radioactise material Yes Blowdow n (BL)S)

Compressed and Containment isolation Yes Instrument Air (CAS)

Component Containment isolation Yes Cooling Water (CCS) Pmvides cooling for nonnal Yes RilR heat exchangers and pumps when die reactor coolant system pressure and temperature are below 450 psig and 350 F Westinghouse

NRC REQUEST FOR ADDITIONAL INFORMATION System Function 1 2 3 4 Safety- RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-1)epth, Nonsafety- Additional Group D, AP600 Equipment related, RTNSS Regulatory AP600 Equipment Class D Important Os ersight CI ** O OVCAP-13856) Proposed OVCAP-13856)

Component Provides cooling for nnnual Yes Yes Yes Cooling Water RifR heat exchangers and (CCS) pumps during reduced reactor (continued) coolant inventory operations in Modes 5 or 6.

Provides cooling for the Yes minillow heat exchangers of the chemical and volume control system makeup pumps Provides cooling for the spent Yes fuel pit heat exchangers for heat removal from the spent fuel pit Westiligh00Se

NRC REQUEST FOR ADDITIONAL INFORMATION En as

=. 5 System Function 1 2 3 4 Safety- RTNSS Nonsafety-related. Nonsafety-related, related ItG 1.26 Quality Defense-in-Depth, Nonsafety- Additional Group D. AP600 Equipment related. RTNSS Regulatory AP600 Equipment Class D Important Oversiglit Class D (WCAP-13856) Proposed (WCAP-13856) j Containment Provide the imlation function by Yes I

(CNS) establishing a banier between th0 Containment cHvironment and the outside environunent Condensate (CDS) Provide continuous operation Yes No l during power production to l prevent plant trips I

l Condensate May contain radioactive material Yes Polishing (CPS) (resin dis [msal)

I Chemical and Reactor coolant system pressure Yes l Volume Control boundary preservation. including (CVS) isolation of nomial chemical and volume control system letdown from the reactor coolant system l

100.11-6 1

Wm Westinghouse l

NRC REQUEST FOR ADDITIONAL INFORMATION 55M EE i

Sy stem Function i 2 3 4 Safety- RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafet3 - Additional Group D, AP600 Equipment related,1(TNSS Regulatory AP600 Equipment Class D Important Osersight Class D (WCA P-13856) Proposed (WCAP-13856)

Chemical and Containment isolation Yes Volume Control Termination of inadvenent Yes (CVS) reactor ('oolant system immn (continued) dilution lsolation of excessive makeup Yes

( Supply makeup and boration to Yes the reactor coolant system Supply coolant to the pressuri/cr Yes auxiliary spray line I

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NRC REQUEST FOR ADDITIONAL INFORMATION r,. . g r- g System Function 1 2 3 4 Safety- RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafety- Additional Group D, AP600 Equipment related, RTNSS Regulatori AP600 Equipment Class D

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Important Oversight Class D

( WCA P-13856) Proposed (WCAP-13856)

Diverse Actuation Provide automatic actuation Yes Yes Yes (DAS) signals for a reactor trip and a (Turbine trip / (Turbine trip /

selected set of engineered PRIIR PRilR safeguard features as a result of actuation only) actuation only) certain plant parameters exceeding setpoints.

Provide the capability for Yes independent manual actuation of a reactor trip and a selected set of engineered safeguard features.

Pmvide independent indication Yes of selected plant parameters.

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NRC REQUEST FOR ADDITIONAL INFORMATION N 55 4r Sy stem l' unction 1 2 3 4 Safet3 - RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafety- Additional Group D, AP600 Equipment related, RTNSS Regulatorv AP600 Equipment Class D Important Oversight Class D (WCAP-13856) Proposed (WCA P-13856)

Data Display and Provide display of plant Yes Processing (DDS) parameters for defense-in-depth functions.

Provide an altentative means of Yes displaying infonnation from the protection and safety monitoring system.

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Standby Diesel Supply diesel fuel for the Yes and Auxiliary defensc-in-depth function of the Boiler Fuel Oil onsite standby power system (DOS) i 100.11-9 l T Westinghouse l

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NRC REQUEST FOR ADDIT!ONAL INFORMATION

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Sy stem Function 1 2 3 4 Safety- RTNSS Nonsafety-related. Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafetv- Additional Group D, AP600 Equipment related. RTNSS Regulatory AP600 Equipment Class D Class D Important Oversight (WCA P-13856) Proposed (WCAP-13856)

Demineralized Containment isolation Yes Water Transfer and Storage Pn> vide water supply to suppon Yes (DWS) startup feedwater Main ac Power Provide the capability for Yes (ECS) interrupting the power to the reactor coolant pump motors.

Provide the capability for Yes distributing non-Class lE ac power from offsite and onsite sources to selected components in the defense-in-depth systems.

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1 l NRC REQUEST FOR ADDITIONAL INFORMATION l

Sy stem Function 1 2 3 4 l Safety- RTNSS Nonsafety-related. Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafetv- Additional Group D, AP600 Equipment related, RTNSS Regulatory AP600 Equipment Class D Important Oversight Class D OVCAP-13856) Proposed (WCAP-13856) hiain ac Power Provide the capability for Yes Yes Yes (ECS) supplying and distributing non-(continued) Class lE ac power to the norn '11 residual heat removal system and required support systems during reduced reactor coolant inventory operations in Nhxles 5 or 6.

Non-Class lE de Provide electrical power for Yes Yes Yes and UPS (EDS) control and monitoring of the (Turbine trip / (Turbine trip /

defense-in-depth functions PRIIR PRIIR actuation only) actuation only)

W Westinohouse o

NRC REQUEST FOR ADDITIONAL INFORMATION

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.g System Function i 1 3 4 Safety- RTNSS Nonsafety-related, Nonsafety-related, related _ RG 1.26 Quality Defense-in-1)epth, Nonsafety- Additional Group D, AP600 Equipment related, RTNSS Regulatorv Al'600 Erguipment Class D Class D Important Oversight (WCAP-13856) Proposed (WCA P-13856)

Plant Lighting Provide emergency lighting in Yes (ELS) the main control room and the remote snutdown workstation area to illuminate these areas for emergency operations upon loss of nomial lighting Fuel Handling and Prevent dropping or jamming of Yes Refueling (FHS) fuel assemblies during transfer operation l Prevent dropping of fuel Yes handling devices during the fuel transfer operation Contairunent isolation Yes W85tiligh0LISO

NRC REQUEST FOR ADDITIONAL INFORMATION E~ "Ei 3:

System Function 1 2 3 4 Safety- RTNSS Nonsafety-related. Nonsafety-related, related ItG 1.26 Quality Defense-in-Depth, Nonsafety- Additional Gr""P D, AP600 Equipment related, RTNSS llegulatory AP600 Equipment Class D Important Os ersight Class D (WCAP-13856) Proposed (WCAP-13856)

Fuel llandling and Prevent criticality during fuel Yes Refueling (FilS) handling operations by (continued) maintaining the geometrically safe configuration of the fuel Store new fuel in a mamter to Yes maintain the required degree of subcriticality Store spent fuel in a manner to Yes maintain the required degree of suberiticality Limit spent fuel lift height so Yes that the minimum required depth of water shielding is maintained westirigtiouse

NRC REQUEST FOR ADDITIONAL INFORMATION EE EE

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System Function 1 2 3 4 Safety- RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafety- Additional Group D, AP600 Equipment related, RTNSS Regulatory AP600 Equipment Class D

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Oversight Class D Important (WCAP-13856) Proposed (WCA P-13856)

Fire Protection Containment isolation Yes (FPS)'

Provide manual tirefighting Yes equipment in areas containing equipment required for safe shutdown Main and Stanup Feedwater isolation by tripping Yes Feedwater (FWS) of the main feedwater pumps Provide startup feedwater for Yes heat removal from the reactor coolant system (stanup feedwater)

V] Westinghouse

NRC REQUEST FOR ADDITIONAL INFORMATION

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ig System Function 1 2 3 4 Sa fety- RTNSS Nonsafety-related. Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafetv- Additional Group D, AP600 Equipment related, RTNSS Regulatorv AP600 Equipment Class D Class D Important Os ersight (WCAP-13S56) Proposed (WCAP-13856)

Main anti Startup Provide continuous operation Yes No Feedwater (FWS) during pmver production to (continued) prevent plant trips (main feedwater)

Class IE de and Provide de power to the safe Yes UPS (IDS) shutdown loads for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (Divisions A B, C, and D) and for 24 and 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (Divisions B and C) respectively, as required, without the support of the battery chargers during a loss of all ac power sources W Westinghouse

NRC REQUEST FOR ADDITIONAL INFORMATION EE: 351 System Function i 2 3 4 Safety- RTNSS Nonsafety-related. Nonsafety-related.

related RG 1.26 Quality Defense-in-Depth, Nonsafetv- Additional Group D, AP600 Equipment related, RINSS Regulatorv AP600 Equipment Class D Important Oversight Class D (WCAP-13856) Proposed

( WCAP-13856)

Class 1E de and Provide electrical isolation Yes UPS (IDS) between die main ac pinver (continued) system and Class 1E 125 vdc circuits Provide ac pnver to the Yes instrument and control devices, and the emergency lighting Provide electrical isolation Yes between die main ac power system and Class IE UPS circuits w weangnouse

NRC RiEQUEST FOR ADDTIONAL INFORMATION 5N

= q Sy stem Function 1 2 3 4 Safety- ItTNSS Nonsafety-related, Nonsafety-related.

related IIG 1.26 Quality Defense-in-Depth, Nonsafetv- Additional Group D. AP600 Equipment related, IIINSS Regulatorv AP600 Equipment Class D Important Oversight Class D OVCAP-13856) Proposed (WCAP-13856)

Class IE de and Supply the continuous load Yes UPS (IDS) demand while maintaining the (continued) associated hatteries in charged condition Provide backup power to the Yes Class IE UPS loads if one of the inverters in that division is not available incore Provide reactor coolant system Yes histrumentation pressure boundary integrity (llS)

Provide the protection and Yes safety monitoring system with core exit temperature signals T Westinghouse

NRC REQUEST FOR ADDITIONAL INFORMATION Hi:: Eis i: E System Function 1 2 3 4 Safety- RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafety- Additional Group D, AP600 Equipment related. RTNSS Regulatorv AP600 Equipment Class D

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Oversight Class D Important (WCA P-13856) Proposed OVCAP-13S56)

Nicchanical Prevent uncontmlied lowering of Yes llandling (N111S) heavy loads in safety-related areas (containment polar crane and the spent fuel shipping cask crane)

Niain Steam Provide continuous operation Yes No (NISS) during power production to prevent plant trips N1ain Turbine Provide continuous operation Yes No (NITS) during power production to prevent plant trips

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l NRC REQUEST FOR ADDITIONAL INFORMATION an:

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System Function 1 2 3 4 Safet3 - RTNSS Nonsafety-related, Nonsafety-related.

related _

RG 1.26 Quality Defense-in-Depth, Nonsafety- Additional oup D. AP600 Equipment related, RTNSS Regulatory AP600 Equipment Class D

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Important Oversight Class D l ( WCAP-13856) Proposed OVCAP-13856)

N1ain Turbine During design basis accidents. Yes (NITS) the main turbine system (continued) supplements the steam generator l system to prevent excessive i

steam generator blowdown by isolating the main steam lines.

' Passive Provide containment heat Yes Containment removal capability following a l Cooling (PCS) postulated design basis accident.

l The PCS removes containment i heat to limit containment peak pressure to less than the design pressure.

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NRC REQUEST FOR ADDITIONAL INFORMATION HE si}

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_ t System Function 1 2 3 4 Sa fety- RTNSS Nonsafety-related. Nonsafety-related, related RG 1.26 Quality Defense-in = Depth, Nonsafetv- Additional Group D. Al*600 E(luipment related. RTNSS Regulatory AP600 Intuipment Class D Class D Important Oversight (WCAP-13856) Proposed (WCAP-13856)

Passive Reduce containment pressure to Yes Containment less than one half of Cooling (PCS) containment de. sign pressure (continued) within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following a postulated loss-of-coolant accident Provide containment heat Yes removal for at least 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> with no operator actions or outside assistance such that the containment design pressure will not be exceeded.

W Westinghouse

NRC REQUEST FOR ADDITIONAL INFORMATION Em

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Systern Function 1 2 3 4 Safety- IITNSS Nonsafety-related. Nonsafety-related, related RG 1.26 Quality Defense-in-Depth.

Nonsafetv- Additional CF"up D. AP600 Equipnient related. RTNSS llegulatort AP600 Equipinent Class D

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Important Oversight Class D (WCA P-13856) Proposed (WCAP-13856)

Passive Provide a temporary, safety- Yes Containment related cooling water connection Cooling (PCS) for continued containment (continued) cooling water flow following water storage tank depletion after 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

The passive containment cooling Yes water storage tank provides a water source for the fire protection system.

Plant Control Provide control signals for Yes (PLS) defense-in-depth components

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l NRC REQUEST FOR ADDITIONAL INFORMATION nip -"E

g System l' unction 1 2 3 4 Safety- RTNSS Nonsafetj-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafety- Additional Group D. AP600 Equipment related, RTNSS Regulatory AP600 Equipment Class D CI ** O Important Oversight (WCA P-13856) Proposed (WCA P-13856)

Plant Control Validate signals received from Yes (PLS) the protection and safety (continued) monitoring system to prevent the failure of a sensor or division in protection and safety monitoring system from propagating into the plant contml system Provide continuous operation Yes No during power production to prevent plant trips l Protection and Pmvide tripping of the reactor Yes Safety Monitoring by opening the reactor trip (PMS) breakers

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NRC REQUEST FOR ADDITIONAL INFORMATION g .;

= y System Function 1 2 3 4 Safet3 - RTNSS Nonsafety-related, Nonsafety-related.

related RG 1.26 Quality Defense-in-Depth.

Nonsafet s - Additional Group D, AP600 Equipment related, RTNSS Regulatory AP600 Equipment Class D Important Oversight Ci ss D

(\VCAP-13856) Proposed (WCAP-13856)

Protection and Provide actuation of the Yes Safety N1onitoring engineered salety features (PNIS) equipment (continued)

Provide safety-related plant Yes parameter monitoring prior to.

during, and after an accident or plant transient Primary Sampling Containment isolation Yes (PSS)

Obtain samples from the reactor Yes coolant system loops and the containment recirculation inlet.

T Westinghouse

NRC REQUEST FOR ADDITIONAL INFORMATION IIm sii E' 'iH System Function 1 2 3 4 Safety- RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafetv- Additional Group D, AP600 Equipment related, RTNSS Regulatory AP600 Equipment Class D Important Oversight Class D (WCA P-13856) Proposed (WC AP-13856)

Passive Core Provide emergency core decay Yes Cooling (PXS) heat removal Provide emergency reactor Yes coolant system makeup and boration Provide safety injection to the Yes reactor coolant system to provide core cooling for the complete range of loss-of-coolant accidents, up to and including the deuble-ended rupture of the largest reactor coolant system piping.

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NRC REQUEST FOR ADDITIONAL INFORMATION pas}

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System Function 1 2 3 4 Safety- RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality I)efense-in-1)epth, Nonsafetv- Additional Group 1), AP600 Equipment related, R[NSS Regulatorv AP600 Equipment Class D

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Important Oversight Class D (WCAP-13856) Proposed (WCAP-13856)

Passive Core Provide for chemical addition to Yes Cooling (PXS) the containment during post-(conti'lued) accident conditions to establish floodup chemistry conditions that support radionuclide retention in the event of high radioactivity in containment.

Measure the radioactivity levels Yes in the containment atmosphere and provide signals to the protection and safety monitoring system Reactor Coolant Provide a controlled sequenced Yes (RCS) depressurization of the reactor

{ coolant system.

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12RC REQUEST FOR ADDITIONAL INFORMATION EE EE

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E System Function 1 2 3 4 Safety- RTNSS Nonsafety-related. Nonsafety-related, related RG 1.26 Quality Defense-in-Depth.

Nonsafetv- Additional Group D, AP600 Equipment related RTNSS Regulatorv AP600 Equipment Class D CI SS U Important Oversight (WCAP-13856) Proposed (WCAP-13856)

Reactor Coolant Provide the pressure boundary Yes (RCS) for the reactor coolant.

(continued)

Provide the pressure boundary Yes for the secondary fluid and the connection to the steam generator system (the shcIl side of the steam generator).

Provide circulation of coolant Yes when the reactor coolant pumps do not operate.

Pmvide flow cortst down on loss Yes of power to the reactor coolant pumps. ,

[ Westingi10US8

NRC REOUEST FOR ADDITIONAL INFORMATION q =4 System Function 1 2 3 4 Safety- RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafetv- Additional Group D, AP600 Equipment related, RTNSS Regulators AP600 Equipment Class D

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Oversight Class D Important (WCA P-13S56) Proposed (WCA P-13856)

Reactor Coolant Provide overpressurc protection. Yes (RCS)

Provide circulation of reactor Yes (continued) coolant through the reactor vessel and the primary side of the steam generator transferring heat to the secondary side of the steam generator.

Maintain the system pressure Yes during operation. During the reduction or increase of plant load. the pressurizer accommodates volume thanges in the reactor coolant and limits pressure inmsient:;.

W Westinghouse

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NRC REQUEST FOR ADDITIONAL INFORMATION

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i Sy stem Function 1 2 3 4 Safety - RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafet t- Additional Group D. AP600 Equipment related, kTNSS Regulatory AP6W Equipment Class D Important Oversiglit Class D OVCAP-13856) Proposed OVCA P-13S56)

Radiation Nicasure. display, and record tht. Yes N1onitoring (RNIS) concentration of radioactive materials in the plant vent efHuent to the atmosphere and provide alarms and indication in the main control reor.:

Nicasure display, and record the Yes amount of radioactivity in the condenser air removal discharge path to the atmosphere and pmvide alanns and indication in the main control room Nonnal Residual Reactor coolant system pressure Yes lleat Removal boundary (RNS) i .u -28 v1 wesungnase

NRC REQUEST FOR ADDITIONAL INFORMATION

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System Function 1 2 3 4 Safety - RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defer.se-in-Depth, Nonsafetv- Additional Group D. Al'6M Equipment related, RTNSS Regulatory AP600 Equipment Class D Important Oversight Class D (WCAP-13856) Proposed (WCAP-13856)

Nonnal Residual Containment inilation Yes lleat Removal Remove heat from the reactor Yes (RNS)

(continued) c olant system during shutdown operation at reduced pressure and temperature Remove heat from the reactor Yes Yes Yes during reduced reactor coolant inventory operations in Modes 5 or 6.

Provide low temperature Yes userpressure protection for the reactor coolant system 3 Westinghouse

NRC REQUEST FOR ADDITIONAL INFORMATION is" *E

_ e.

Sy stem l~ unction 1 2 3 4 Safety- RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsa fetv- Additional Group D, AP600 Equiprnent

~

related, RTNSS Regulatory AP600 Equipment Class D Class D Important Osersight (WCAP-13856) Proposed (WCA P-13856)

Nonnal Residual Pmvide low pressure makeup to Yes Heat Removal the reactor coolant system and (RNS) remove heat from the reactor (continued) coolant system following actuation of the automatic depressurization system.

Reactor (RXS) Reactor coolant system pressure Yes boundary Provide suppon and alignment Yes for the mactor intemals and core.

Direct main coolant flow Y es through the core.

~

T Westinghouse

MRC REQUEST FOR ADDITIONAL INFORMATION idi iHE

= :d System Finnetion 1 2 3 4 Safety- RTNSS Nonsafety-related. Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafety- I Additional Group D. AP600 Equipment Regulatory AP600 Equipment Class D related. RTNSS ~

Oversight Class D Important (WCAP-13S56) Proposed

( WCAP-13856)

Reactor (RXS) Provide support and alignment Yes (continued) for the control red drive mechanisms.

Provide support and alignment Yes for the in-core instrumentation assemblies.

Initiate insertion of the control Yes rod drive assembly on electncal pmver interruption.

Spent Fuel Pit Containment isolation. Yes Cooling (SFS)

W Westinghouse

NRC REQUEST FOR ADDITIONAL INFORMATION HEi M W JE System Function 1 2 3 4 Safety- RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafety- Additional Group D. AP600 Equipment related. RTNSS Regulatory AP600 Equipment Class D CI"" U Important Os ersight (WCAP-13856) Proposed (WCAP-13856)

Spent Fuel Pit Provide heat removal from the Yes Cooling (SFS) spent fuel using the initial (continued) inventory of water in the spent fuel pit.

Provide safety-related Yes connections used for temporary emergency makeup to the spent fuel pit.

Provide for heat removal from Yes the spent fuel stored in the spent fuel pit by pumping the water from the pit through a heat exchanger, and then retuming the water to the pit.

W Westinghouse

NRC REQUEST FOR ADDITIONAL INFORMATION L :i y;j System Function 1 2 3 4 Safety - RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsa fets- Additional Group D, AP600 Equipment related. RTNSS Regulatory AP600 Equipment Class D CId*S U Important 05ersight (WCAP-13856) Proposed (WCAP-13856)

Steam Generator Provide oserpressure protection Yes (SGS) for the steam generator secondary side, as well as portions of the main steam line.

feedwater lines and blowdown lines by means of the safety relief valves for events that result in steam generator pressure tnmsients.

Provide for heat removal from Yes the reactor coolant by releasing the steam generated from the steam generator inventory to the atmosphere via the safety valves.

m w wesungnouse

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NRC REQUEST FOR ADDITIONAL INFORMATION FM :E

• f y Sy stem Function i 2 3 4 Safety- RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafetv- Additional Gr up D, AP600 Equipment related. Irl NSS Regulatory AP600 Equipment Class D Cl ss D Important Os ersight (WCAP-13856) Proposed (WCA P-13856)

Steam Generator Pmvide the capability to isolate Yes (SGS) main feedwater. startup (continued) feedwater, blowdown, and main steam lines to prevent excessive steam generator blowdown and excessive feedwater flow froin die main and startup feedwater system during design basis accidents.

Containment isolation. Yes Provide feedwater and stanup Yes feedwater isolation to avoid steam line flooding after a steam generator tube rupture accident.

[ W85tiligh00Se

NRC REQUEST FOR ADDITIONAL INFORMATION

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.=

System Function 1 2 3 .

Safety- IITNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafet s- Additional Group D. AP600 Equipment related RTNSS Regulatory Al'600 Equipment Class D

~

Important Oversight Class D OVCAP-13856) Proposed OVCAl'-13856)

Steam Generator Provide decay heat removal Yes (SGS) capability during shutdown (continued) operations by delivery of startup feedwater flow to the steam generator and venting of steam from the steam generators to the atmosphere via the Iwwer-operated relief valves.

Service Water Provide the capability for yes (SWS) removing heat fnnn the component cooling water system.

100.H -35 T Westinghouse

I NRC REQUEST FOR ADDITIONAL INFORMATION is: "ig Sy stem Function 1 2 3 4 Safety- ItTNSS Nonsafety-related, Nonsafety-related, related IIG 1.26 Quality Defense-in-Depth, Nonsafety- Additional CF"up D, AP600 Equipment related, itTNSS Ilegulatory AP600 Equipment Class D CI SS U Important Oversight

( WCAP-13856) Proposed (WCA P-13856)

Service Water Provide the capability for Yes (SWS) removing heat imm the spent (continued) fuel pool via the spent fuel cooling and component cooling water systems.

Provide the capability for decay Yes heat removal at shutdown conditions through the nonnal residual heat removal and component cooling systems.

]

W Westinghouse

NRC REQUEST FOR ADDITIONAL INFORMATION

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.- =

Sy stem Function 1 2 3 -1 Sa fety- RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafet s- Additional Group D, Al'600 Equipment related, RTNSS Regulatorv AP600 Equipment Class D Important Oversight CI ** O (WCAP-13856) Proposed

( WCA P-13856)

Service Water Pruvide die capability for decay Yes Yes Yes (SWS) heat removal through the nomnd (continued) residual heat removal and component cooling systems during reduced reactor coolant imentory operatiorts in Modes 5 or 6.

Main Turbine Provide continuous operation Yes No Control and during power production to Diagnostics (TOS) prevent plant trips (turbine control)

W Westinghouse

NRC REQUEST FOR ADDITIONAL INFORMATION

n g

1. 3 System Function 1 2 3 4 Safety- RTNSS Nonsafety-related, Nonsafet t-related, related RG 1.26 Quality Defense-in-Depth, Nonsafety- Additional Group D, AP600 Equipment related. RTNSS Regulatory AP600 Equipment Class D Important Oversight Class D (WCA P-13856) Proposed (WCAP-13856)

Radiologically Niay contain radioactive matenal Yes Controlled Area Ventilation (VAS)

Nuclear Island hiain control mom envelope Yes Nonradioactive isolation.

Ventilation (VBS)

Provide ventilation and cooling Yes to the main control room envelope. Class IE instrumentation and control rooms. Class IE de equipment rooms, and Class IE battery rooms.

3 Westinghouse

NRC REQUEST FOR ADDITIONAL INFORMATION s -- ":11

;r Sy stem Function 1 2 3 4 Safety- RTNSS Nonsafety-related. Nonsafety-related, related RG 1.26 Quality I)efense-in-Depth, Nonsafet V- Additional Group D. AP600 Equipment related, RTNSS Regulatorv AP600 Equipment Class D Important Oversigh{ Class D

( WCA P-13856) Proposed (WCAP-13856)

Nuclear Island Provide filters to limit the Nonradioactive Yes airbome radioactivity lesel Ventilation (VBS) within the main control room (continued) envelope.

Alcasure the concentration of Yes radioactivity in the main control room normal supply air and provide a signal to the plant control system N!casure the concentration of Yes radioactivity in the main control room nomial supply air and provide signals to the protcetion and safety monitoring system W

- Westinehouseo

NRC REQUEST FOR ADDITIONAL INFORMATION g =

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System Function 1 2 3 4 Safety- RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth.

Nonsafetv- Additional Group D. <W600 Equipmen*

~

related. RTNSS Regulatory AP600 Equipment Class D Important Osersight Class D (WCAP-13856) Proposed (WCAP-13856) l Main Control Provide breathable air for the Yes Roorn liabitability occupants of the main control (VES) room for at least 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> via compressed air storage tanks.

Provide a safety-related refilling Yes connection for the compressed air storage tanks.

Provide pressuritation of the Yes main control room envelope.

Westillgil0llSe

NRC REQUEST FOR ADDITIONAL INFORMATION t- g a

System Function 1 2 3 4 Sa fety- ItTNSS Nonsafety-related. Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafety- Additional Group D, AP600 Equipment related. RTNSS Regulatory AP600 Equipment Class D Important Os ersight Class D (WCAP-13856) Proposed

( WCA P-13856)

Main Control Provide passive heat sinks for Yes Room liabitability the main control room, the (VES) protection and safety monitoring (continued) system instmmentation and control rooms, and the Class IE de equipment rooms. The heat sinks for these rooms provide cooling capacity for at least 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

Containment Air Containment isolation. Yes Filtration (VFS)

May contain radioactive material Yes W

Westinohouse

=

NRC REQUEST FOR ADDITIONAL INFORMATION ist sti 6d g Sy stem Function 1 2 3 4 Safety- RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafetv- Additional Group D, AP600 Equipment related, RTNSS Regulatory AP600 Equipment Class D Important Oversight CI 'S U (WCAP-13856) Proposed (WCAP-13856)

Contaimnent Prmide containment hydmgen Yes Ilydrogen Control concentration measurement.

(VLS) '

Provide hydrogen recombiners Yes to control containment long tenn hydrogen concentra' ions, Provide hydrogen igniters to Yes control hydrogen concentration in excess of the recombiner capability.

Containment Leak Containment isolation Yes Rate Test (VUS)

Central Chilled Containment isolation. Yes Water (VWS)

W Westinghouse

NRC REQUEST FOR ADDITIONAL INFORMATION r-System Function 1 2 3 4 Sa fety- RTNSS Nonsafety-related, Nonsafety-related, related RG l 26 Quality I)efense-in-1)epth, Nonsafetv- Additional Group D, AP6W Equipruent related, RINSS Regulatory AP600 Equipment Class D Important Os ersight Class D (WCAP-13856) Proposed (WCAP-13856)

Central Chilled Provide chilled water to suppon Yes Water (VWS) the nuclear island nonradioactive (continued) ventilation system cooling of the main control room envelope.

Class IE instrumentation and control rooms. Class IE de equipment rooms. and the Class lE battely rooms.

Provide chilled water to suppon Yes the cooling functions of the companment unit coolers for the nonnal residual heat removal system pump.

W

- Westinehouse o

NRC REQUEST FOR ADDITIONAL INFORMATION

!His ' EEE W "il System Function 1 2 3 4 Safety- RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafety- Additional Group D, AP600 Equipment related. RTNSS Regulatory AP600 Equipment Class D Important

~

Os ersight Cl w D (WCAP-13S56) Proposed (WCAP-13856)

Central Chilled Provide chilled water to support Yes Water (VWS) the cooling functions of the (continued) companment unit coolers for the chemical and volume control system makeup pump.

Annex / Auxiliary Panide ventilation of the Yes Building electrical switchgear rooms that Nonradioactive contain the diesel bus Ventilation (VXS) switchgear.

Diesel Generator Pmvide ventilation cooling, and Yes Building heating of the dicsci generator Ventilation (VZS) building to suppen operation of the onsite standby power system.

W85tingh00S8

NRC REQUEST FOR ADDITIONAL INFORMATION EE T:

p =

e Sy stern Function 1 2 3 4 Sa fety - RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Additional Group D. AP600 Equipment Nonsafet3-related. RTNSS Regulaton AP600 E<juipnient Class D Important Os ersight CId" U (WCA P-13856) Proposed (WCAP-13856)

Gaseous Radwaste May contain radioactive material Yes (WGS)

Liquid Radwaste Containinent isolatiott Yes (WLS)

May contain radioactive materia! Yes Measure and record the Yes concentration of radioactive materials in the liquid discharge to the environment and provide alann and indication in the main control room I r l Radioactive Waste May contain radioactive material Yes l Drain (WRS)

I l 100.11-45 l T Westinghouse l

l l

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T NRC REQUEST FOR ADDITIONAL INFORMATION

Ei HE E.

= .

Sy stem Function 1 2 3 I Sa fety- RTNSS Nonsafety-related, Nonsafety-related, related RG 1.26 Quality Defense-in-Depth, Nonsafetv- Additional Group D, AP600 Equipment related, Irl NSS Regulatory AP600 Equipment Class D Important Oversight Class D (WCA P-13S56) Proposed

( WCAP-13856)

Solid Radwaste Stay contain radioactive material Yes (WSS)

Waste Water N1ay contain radioactive material Yes (WWS)

Transmission Provide electrical power to Yes Yes Yes Switchyard and onsite equipment needed to Offsite Power support decay heat removal (ZBS) operation during reduced reactor coolant inventory operations in N1 odes 5 or 6.

Pmvide electrical power to Yes onsite equipment needed to support defense-in-depth system functions.

Y Westingh0US0

NRC REQUEST FOR ADDITIONAL INFORMATION GE EE r y Sy stem Function 1 2 3 4 Safety- RTNSS Nonsafety-related. Nonsafety-related, related RG 1.26 Quality Defense-in-Depth.

Nonsafety- Additional Group D, AP600 Equipment related, RTNSS Regulatory AP600 Equipment Class D Important Oversight CId** U (WCAP-13856) Proposed (WCAP-13S56)

Onsite Standby Supply ac power to the Class IE Yes Pow er (ZOS) de and UPS system.

Supply ac power to selected Yes electrical components of the plant defense-in-depth.

nonsafety-related systems.

Supply ac power to onsite Yes Yes Yes equipment needed to support decay heat removal operation during trduced reactor coolant inventory operations in N! odes 5 or 6.

"~"

w westingnouse

NRC REQUEST FOR ADDITIONAL INFORMATION Question 220.53 Provide the rationale that the use of 6-foot thick foundation, especially the foundation mat underneath the containment vessel, is adequate. (Conventional contamment bmiding found ition is 10-foot thick)

Pasponse:

The design of the nuclear island basemat is described in SS AR Subsection 3.8.5. The analyses described therein demonstrate that the design meets the specified acceptance criteria.

The basemat under the auxiliary building is stilfened by the vertical shear walls w hich are spaced at approximately 18 to 26 feet, rensequently, the spans of the 6-foot thick basemat for resisting the applied forces are relatively short.

Most of the walls enend fiom elevation 66'-6"(top of the basemau to elevation 100' (grade), and a number extend the entire height of the miliary building. These walls provide stif fening to the basemat. In effect, the basemat can be considered to be equivalent to a basemat approximately 40-feet thick.

Typical consentional containment building foundation thicknesse.s are in the range of 9 to 10 feet thick. In a separate, prestressed containment building, the foundation thickness is norm:dly governed at the foundation / wall interface by the soil pressore due to seismie huds and the containment pressure loads. In the case of'he AP600, the soil pressure due to dead and seismie loads is minimi/ed due to the large footprint of the common nuclear island basemat. The bottom head of the steel containment vessel is able to resist the containment internal pressure. It is also noted that due to the ellipsoidal bottom head of the steel containment vessel, the basemat thickness becomes lo-feet thick at 29 feet f rom the centerline of the containment and increases to 22-feet at the junction bciween the shield nuilding wall and the basemat.

SSAR Revision: NONE

. 220.53-1 W-Westinehouse u

3 NRC REQUEST FOR ADDITIONAL INFORMATION i

Question 220.60 Provide the basis lor not considering the wind lo;ul in the Level A and C load coinbinations in which the external pressure is included (Table 3.8.2-1 of Revision I to the SS AR).

Response

As described in SS AR Subsection 3.3.2.4, wind loads on the containment vessel and the air halue are determined using the results of wind tunnel tests. The test re3ults have been provided in Reference 220.60 - 1. The tests show that the wind taases a reduction in pressure in the annulus between the contailunent vessel and the shield building.

This reduction in pressure wouhl reduce the external pressure on the containment veuel. The governing design condition for external pressure is thus the aise without wind loads.

SSAR Revision: None Reference 220.60 - I WCAP 1332AP, Phase 11 Wind Tunnel Testing lor the Westinghouse AP600 Reactor. June,1992 220404 W Westinghouse

l NRC REQUEST FOR ADDITIONAL INFORMATION Question 220.62 Provide descriptions for the polar crane systern in Section 3.8.2.1. of the SSAR.

Response

The polar trane system is desenbed in Subsection 9.1.5.

SSAR Revision:

Revise the next to the last paragraph of Subsection 3.8.2.1.1 as show n below:

The polar crane is designed for handling loads up to 275 tons during norinal retueling. The crane girder and whcci assemblies are designed to support a special 4(NFlon trolley to be installed in the event of steam generator replacernent. The polar trane systern is described in Subsection 9.1.5.

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l W- WestinEhouse l

NRC REQUEST FOR ADDITIONAL INFORMATION TT ~~M Question 220.67 l'or loads and load combinations listed in SSAR Table 3.8.2-1, explain w by the operating pressure "Pg " was not I included in lead Combinations 6 and 7 (Service 1.cvel C) as specified in Equation (iii).(c).(2)in SRP Subsection

3. 8. 2. I 1. 3. b.

Response: l I

SSAR Table 3.8,2-1 will be revised as shown below to include the operating pressure in the load combinations 6, l safe shutdown earthquake, and 7, Tornado. The range of operating pressure is - 0.2 to + 1.0 psig as given in SSAR l Table 3D.5-1. j SSAR Revision: Revise Table 3.8.2-1 as shown on the next page.

l l

220.67-1 3 Westinghotise

NRC REQUEST FOR ADDITIONAL INFORMATION l

Table 3.8.2-1 Load Combinations and Service Limits For Containment Vessel Load combination and service limit Load Description Test De. sign A A C C C D A C Dead D x x x x x x x x x x Live L x x x x x x x x x x Wind W x SSE Es x x x TornaJo Wt X Test pressure Pg x Test temperature Tt X Operating pressure Po x x. x Normal reaction Ro x x x x x Normal thermal To x x x x x Design pressure Pd X X X X External pressure (2.5 psid) Pe x External pressure (3.0 psid) To x Accident thermal Ta X X X X Accident thermal reactions Ra X X X X Accident pipe reactions Yr X Jet impingement Y- x Pipe impact m X Notes:

1. Senice limit lesels are per ASME-NE.

2. Where any load reduces the effects of other loads, that load shall be taken as zero, unless it can be demonstrated that the load is always present or occurs simultaneously with the other loads.

220.67-2 W -

Westinghouse l

NRC REQUEST FOR ADDITIONAL INFORMATION t i Hi IH @

Question 220.79 For the in-contairuncut refueling water storage tank (IRWST). pnivide in the SS AR. figures and cross sections showing: (a) overall configuration of the tank. (b) the relationship between the tank walls, channel heads. concrete-foundation and structur:d steel inodules, and (c) areas covered by the stainless steel or cladding for preventing corr osion.

Response

SS AR Figure 3 A-4 (Sheet 2 of 12) shows the tuerall configuration of the in-containinent refueling w ater storage tank (IRWST), the relationship between the tank walls, concrete foundation, and structural steel inodules. SSAR Figure 3 A 4 (Sheet 7 of 12) shows a cross section through the IRWST wall which consists of stilfened plate. The other walls of the IRWST are structural steel inodules shown on SSAR Figure 3 A-4 (Sheet 6 of 12). The walls, floor.

and ceiling of the IRWST exposed to water durmg nonnal operation or refueling are f abricated from stainless steel.

SSAR Revision: NONE t

t 220.79-1 W=

Westinghouse 1

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l NRC REQUEST FOR ADDITIONAL INFORMATION l l

Hm ! Hit ,

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Question 220.87 l

l For evaluating the dynamic stability of the Ni structures acainst overtuming, provide tonnulas for calculating the )

energy conynnent due to embedment cileet "W r" and energy component due to buoyancy "W s" in Section 3.8.5.5.4 i of the SS AR.  !

l 1

Renponse:

In the dynamic stability evaluation o tne f Nl structures against os erturning, the energy component due to embedment l cflect "Wp" was conservatively nylected and assumed equal to zero. The energy component due to huoyancy "Wh" is determined as follow:

l l

6, - Bs h l w here

# = buoyant force h = height to which the center of mass must he lifted to reach the overturning position SSAR Revision:

Resisc she second paragraph of Subsection 3.S.5.5.4 as shown below:

The potential energy is calculated a.s f ollows:

E = m_yh + Wp - W s w here:

E, = potential enerpy til,, = lolal InaNs of the skuCluIe and haNernal y = acceleration due to gravity h = height to which the center of mass inust he lif ted to reach the overturning position W p

= energy component due to the embedment ef fects W, energy component due to buoyancy The energy component due to the embedment effects is awumed equal 10 7ero and conservatively neglected. l The energy component due to the buoyancy is detennined assuming a constant buoyant force (B) throughout the overturning prcecss and is equal to:

W s

= Bh 220.87-1 W -

Wesl.inehouse o

l NRC REQUEST FOR ADDITIONAL INFORMATION II!P li!!!

Question 220.88 To prevent the potential of rebar corrosion, evaluate, in the SSAR, the use of coated reinforcing bars for the design of the Nl foundation.

Response

Picase see response to R AI No. 220.40.

1 SSAR Revision:

Add the following paragraph to the end of SSAR Subsection 3.8.4.6.1.2:

As stated in Subsection 3.4. l.l.l. seismic Category i structures which are located below grade elevation are protected against flooding by waterproofing mernbranes and waterstops. This, in conjunction with the two inches of concrete cover for the reinforcing steel, provides sufficient protection for the reinforcing steel. Thercore, the '

use of coated reinforcing steel is not. phmned.

l 20.88-1 W-Westinahouse o

NRC REQUEST FOR ADDITIC NAL INFORMATION

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Question 220.90 For the nuclear island structures, provide, in the SSAR, the type and characteristics of water seals to be used at the penetrations (mechanical and electrical) and accesses kicated below the flood level for preventing and mitigating the .

external flooding effects.

Response

SSAR Chapter 2 and Subsection 3.4.1.1.1 establish the maximum flood at less than the finished grade. As stated in the response to RAI 410.38, the Ap600 design minimites the number of penetrations through the walls below grade. Those few penetrations located below the maximum flood level (elevation 100 ) will be watertight. Any process piping penetrations and electrical conduits through the exterior walls below grade will be embedded in the wall or will be welded to a steel sleeve embedded in the wall. There are no accesses or tunnels penetrating the exterior walls below grade.

SSAR Revision: 1 Add the fobowing at the end of Subsection 3.4.1.1.1:

Process piping penetrations and electrical conduits through the exterior walls below grade are embedded in the wall or are w elded to a steel sleeve embedd d in the wall.1 here are no access openings or tunnels penetrating the exterior walls below grade.

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220.904 W -

Westingh0Use

NRC REQUEST FOR ADDITIONAL INFORMATION Question 230.50 Seismic analyses hir the AP600 design has been conducted since the late 19XOs :md the sumptions and building configurations have changed during these an;dyses. Some earlier analyses appear to be used .o simplify the number of parametric runs to be considered in the later analyses. Provide a clear auditable trail for the final seismic calcula-tions so that the assumptions made can be fully undershn!

Response

The following analyses were perfonned in 1990 based on Revision 0 of the General Arrangement Drawings:

4D finite element models of the nuclear island structures were desetoped. The 3D tinite element nuxlels were used as the bases for the 2D and 3D lumped mass stick models.

2D and 3D lumped mass stick models were developed.

SASSI analyses of the 2D lumped mass stick models were perf onned for the purpose of establishing the design soil profiles. Three design soil profiles thard rock, solt rock, and sof t-to-medium-soit soil) were established based on the study of multiple soil profiles as deceribed in SS AR Appeinlix 2A.

A lixed base analysis of the 3D lumped mass stick models was perfonned for the hard rock profile using the program BS AP (Mode Superposition Time History Analysis).

Soil-structure interaction analyses of the 3D lumped mass stick models was performed for the sof t n>ck profile using the program SASSl (Complex Frequency Response Analysis).

In 1992 and 1993, the following analyses were perfonned based on Revision 3 of the General Arrangernent Draw ings:

The 3D linite eleinent models of the nuclear island structures were updated to refleet changes in the structural configuration.

The 3D hunped mass stitt models were updated.

A fixed base analysis of the updated 3D lumped mass stick models was perfonned for the hard rock profile using the program BSAP (Mode Superposition Time Ilistory Analysis).

Soil-structure interaction analyses of the updated 3D lumped mass stick models was perionned for the soit rock profile using the program S ASSI (Complex Frequency Response Analysis).

Soil-structure interaction analyses of the updated 3D lumped mass stick models was perlonned for the sof t to medium soit soil profile using the program SASSI (Complex Frequency Response Analysis).

230.50-1 W

- West.inehouse o

-w NRC REQUEST FOR ADDITIONAL INFORMATION

. Response spectnan arudyses of the 3D finite elenient models to obtain the in-plane forces to be used for the design of the fhiors and w: dis was perfonned using the prograin BSAP, lhis was done only for the fixed base hard rock profile.

Floor response spectra for all three design soil profiles were developed, enveloped, and broadened.

The 15)92 and 1991 analyses are the bases for SS AR, Revision 1. It is noted that the General Arrangement Drawings shown cunently in Section 1.2 of the SS AR are based on Revision 5. The general arrangement revisions will be reconciled as follows:

The 3D finite element models of the nuclear island structures will be updated.

Response s[rctrutn analyses of the fixed base 3D linite clernent models will be perfonned for the hard rock profile using the progr;un BSAP. The resulting f requencies. nuxlal ef fective inass, and response accelerations will be compared to the previaus results to verify that the current models are still valid.

Results of this reconcilianon will N submined in March,199i SSAR Revision: NONE 230,50-2 W_ WestinEhouse

NRC REQUEST FOR ADDITIONAL INFORMATION

~

Question 230,53 According to the SSAR, only three soil conditions tshear wave velocity equal to 10(X) f t/sec, 2500 ft/sec and 8(KX) ft/sec) were used in the seismic design of AlVA) standard plant. Provide justification for not including the site conditions with other shear wave velocities, such as 1500 f t/see and 3500 ft/see and different depths from grade -

to bedrock

Response

The subject of this RAI was discussed during a meeting among NRC staff and consultants and Westinghouse and liechtel on seismic analyses on April 14,1994 and will be discussed further during a meeting scheduled at the end of May. A w ritten response to this RAI will be prepared f all wing the May meeting.

SSAR Revision: N O N ii 30.534 W-Westinghause

NRC REQUEST FOR ADDITIONAL INFORMATION Question 230.55 Ju<tily the adequacy of using the S ASSI computer code to calculate member forces foi the structural design.

According to the staf f's experience and understanding, the SASSI analyses will produce inaccurate member forces.

Res.oonse:

The mernher forces calculated by S ASSI for the APNK) analyses are accomte. Tables 3.7.2-11,3.7.2-12 and 3.7.2-13 present the maximum member forces and moments for the three site conditions. The results for the soit rock and sof t to-medium soil conditions are calculated using S ASSI. The member forces were verified by comparison against member forces calculated using the SASSI acceleration responses at each of the mass points.

SSAR Revision: NONE 230.55-1 W .h

- WestinB ouse

NRC REQUEST FOR ADDITIONAL INFORMATION Question 230.02 Justify the validity of performing a lhed-base seismic analysis for the site conditions with shear wave velocity equal to or greater than 8fKX) It/sec.

Response

The subject of this RAI was discussed during a meeting among NRC staff and consultants and Westinghouse and llechtel on seismic analpes on April 14.1994 and will be discussed further during a meeting scheduled at the end of May. A w ritten response to this RAI will be prepared following the May meeting.

SSAR Revision: NONii I

l 230.G2-1 W Westinghouse j

NRC REQUEST FOR ADDITIONAL INFORMATION -

l l

I Question 230.69 Include the shallow soil site conditions in the SSAR and in the seismic analysis of nuclear island structures. In-addition, for these site conditions, the guidance in Section 3.7.1 of the SRP for specifying control motion should be followed.

Response

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'the subjcet of this RAI was discussed dunng a meeting among NRC staff and consultants and Westinghouse and I Ilechtel on seismic analyses on April 14,1994 and will be discussed further during a meeting scheduled at the end 1 of May. A writien response to this RAI will be prepared following the May meeting.

SSAR Revision: NONE l

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NRC REQUEST FOR ADDITIONAL INFORMATION Question 230.70 Document, in the SSAR, the procedures for developing seismic response envelopes (e.g., floor response spectra).

Response

The enveloped response results shown in parenthesis in Tables 3.7.2-5 through 3.7.2-10 is the maximum value of the response at any of the referenced edge nodes (north, south, east and west edge nodes).

The envelopes of the floor response spectra for the three design soil profiles were developed as follows:

• The spectral acceleration was calculated at the same frequencies for all three of the design soil profiles

• The maximum spectral acceleration at each frequency from any of the three design soil profiles was then selected for the envelope

• The enveloped floor response spectra is then broadened by i15%.

SSAR Revision:

Revise the note at the bottom of Tables 3.7.2-5 through 3.7.2-10 as follow s:

Note: Enveloped response results at the north, south, east and west edge nodes of the structure are shown in parentheses. This is the maximum value of the response at any of these edge nodes.

Revise the third paragraph of Subsection 3.7.2.5 as follows:

The floor response spectra for the design of subsystems and components are generated by enveloping the nodal response spectra determined for the different design soil profiles. The envelopes of the floor response spectra for the three design soil profiles are developed as follows:

• The spectral acceleration is calculated at the same frequencies for all three of the design soil profiles

• The maximum spectral acceleration at each frequency from any of the three design soit profiles is then selected for the envelope

• The enveloped floor response spectra is then broadened by 15%.

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1 NRC REQUEST FOR ADDITIONAL INFORMATION 1

Question 230.79 From the review of Figures 3.7.1-14 and 3.7.1-15 of the SSAR. it appears that the soil shear degradation curves for the typical soil used in the analysis and design are based on the soil shear degradation model recommended by H.ll. Seed and I.M. Idriss in 1970. A comparison of the shear degradation curves presented in Figures 3.7. l-14 and 3.7.1-15 in the SSAP. with the current published industry results, such as the results published by 1.M. Idriss and Geomatrix in 1990, shows that the Seed Idriss 1970 curves oserestimated the soil strain degradation. The staff anticipates that the use of the Seed-Idriss 1970 curves in the SSI analyses of the NI structures will underestimate the seismic sinietural responses. Provide the basis for using the Seed ldriss 1970 curves in the SSI analyses.

Response

The subject of this RAI was discussed during a meeting among NRC staff and consultants and Westinghouse and liethtel on seismic analyses on April 14,1994 and will be discussed further during a meeting scheduled at the end of May. A w ritten response to this RAI will be prepared following the May meeting.

SSAR Revision: N O N ii i

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l NRC REQUEST FOR ADDITIONAL INFORMATION Question 230.80 Subsection 3.7.2. I of the SSAR (pg. 3.7.2-3) indicates that separate seismic analyses are performed for the nuclear island (NI) for each of the soil profiles defined in Section 3.7.1.4 and the three sets of in-structure seismic responses are enveloped to obtain the seismic design envelope (design member forces, nodal accelerations, nodal displacements, and floor response spectra) used in the design and analysis of seismic Category I structures, components, and seismic subsystem, 'the staff is concerned that the scismie design of the structures, systems and components of the APh(M) standard plant ina) not be sufficient because it considers only three generic site conditions characteiiicd with soil shear wave velocities that are f ar apart from each other. An example of the staf f's concern is shown in the floor response spectra (1 RS) plots of l'igure 3.7.2-25. As show n in these plots, the horitontal (liW component in particular) i RS envelope in the control room area may not cover the 17RS from two possible antermediate site conditions, one with a shear wase velocity between 1(XX) ft/sec and 24(M) It/sec (approximately 15(M) Ithce) and the other with a shear wave sek> city between 24(W) f t/see and WWX) f t/sec (appioximately 35(X) It/sec). Justify the adequacy of using only three generic site conditions for the ApMX) standard plant design.

Response

l The subject of this R AI was discussed during a meeting among NRC staf f and consultants and Westinghouse and Hechtel on seismic analyses on April 14, 1994 and will be discussed further during a meeting scheduled at the end of May. A written response to this RAI will be prepared following the May meeting.

l SSAR Revision: NONE '

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Question 230.81 Sections 3.7.2.1. I and 3.7.2.1.2 of the SSAR state that the computer code " SAP" was used for performing seismic analyses (response spectrum analysis and time-history analysis) of seismic Category I structures and Reference 7 is used. However, the computer code "13 SAP" is referenced in Reference 7. Clarify this inconsistency.

Response

The computer program referenced as SAP in Subsections 3.7.2.1.1 and 3.7.2.1.2 of the SSAR is actually BSAP.

SSAR Revision:

Revise the first paragraph of Subsection 3.7.2.1.1 as shown below:

Response spectrum analyses. using computer program BSAP (Reference 7), are performed to obtain the seismic forces and moments required for the structural design of the auxiliary building, the shield building, and the containment internal structures on the nuclear island.

Revise the first paragraph of Subsection 3.7.2.1.2 as shown below:

Mode superposition time-history analyses using computer program BSAP and complex frequency response analysis using computer program SASSI (Reference 8) are performed to obtain the in-structure seismic response (accelerations, displacements, and floor response spectra) needed in the analysis and design of seismic subsystems.

Revise the third paragraph of Subsection 3.7.2.1.2 as shown below:

For the hard rock site where the shear wave velocity is in excess of 8000 feet per second, the soil-structure interaction ef fect is negligible. Therefore, for the hard rock site, the nuclear island is analyzed as a fixed-base structure, using computer program BSAP without the foundation media. The three components of earthquake (two horizontal and one vertical time histories) are applied simultaneously in the analysis.

230.81-1 W-Westinghouse

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1 NRC REQUEST FOR ADDITIONAL INFORMATION 8=w-Ouestion 230.84 in Section 3.7.2.1.1 of the SSAR, provide information and explanation to demonstrate:

a. that for site conditions with soil shear wave velocity equal or greater than 8(XX) ft/see, the SSI effects.

between N1 structures and soil foundation are negligible and the use of fixed base models is adequate for calculating seismic responses of the Ni stnictures, and

b. that for structures with multimodes, the amplification procedures, described for cases where the responses of soil founded structures er.ceed the responses of rock (shear wave velocity equal or greater than 8(XK)

It/sec) founded structures. will provide reasonable results for the design of structures, systems and components.

Response

The subject of this RAI was discussed during a meeting among NRC staff and consultants and Westinghouse and Bechtel on seismic analyses on April 14,1994 and will be discussed further during a meeting scheduled at the end ol' May. A written response to this RAI will be prepared following the May meeting.

SSAR Revision: N O N Ii i

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NRC REQUEST FOR ADDITIONAL INFORMATION gnr'my Question 231.15 What are the geography and demography limits for a site at which an AlW)0 plant could be located?

Response

The geography and demography are site specific and will be defined by the Combined License applicant. There are no preestablished geography and demography limits for a site at which a plant could be located. 'Ihe site interface parameters for the Al%00 are outlined in SSAR Chapter 2 SSAR Revision: NONI!

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NRC REQUEST FOR AD01'iiONAL INFORMATION I 1

Ouestion 231.16 Intlicale. in the SSAR. what specific design t'c:aures of the APNN) st:uidard plant allow for a flood level up to the plant yrade elevation.

Response

As stated in Subsection 1.4.1.1.1 of the SS AR, seistnic Category I structures w hich :ue located below grade elevation are protected against thuidilig by waterprooling nien:branes and waterstops. Subset tion 3.4.1.2.l of tiie SS AR describes the structural and stability considerations aswiated with the probable inaxinium flood and high ground water table. Also please see response to R AI 220.90.

SSAR Revision: NONE 231.16-1 3 Westinghouse 1

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NRC REQUEST FOR ADDITIONAL INFORMATION Ouestion 231.22 i 1

In the January 22, 1993 response to Q231.5 regarding the assumption of an upper bound value of S(XX) feet per second (fps) for the shear wave velocity of the hard rock site, Westinghouse states that, for the hard rock site profile with shear wave velocity of 8(XX) fps (greater than 35(x) fps), the nuclear island is analyzed as a fixed base structure.

Ilowever, the decision to use fixed base analyses should not be based on a specified rock shear wave velocity, but on the relationship between the SSI frequency and the structural frequency of the N1.

Perfonn necessary SSI studies for the rock model Iwith rock shear wave selocity ranging from S(XX) to 11(XX) fps discussed in Q231.5 tojustify the use of fixed base analysis for the rock site with shear wave velocity of 8(XX) fps.

Response

The subject of this RAI was discussed during a meeting amoung NRC staff and consultants and Westinghouse and Ilechtel on scismic analyses on April 14,1994 and will be discussed further during a meeting scheduled at the end of May. A w ritten response to this R AI will be prepared following the May meeting.

SSAR Revision: NONE l

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NRC REQUEST FOR ADDITIONAL INFORMATION

&w Question 231.30 No specific csaluations have been made on the potentialimpact of non-vertically incident ground motion on the NI responses. On this basis,

a. perform SASSI analyses to stutly the signincance of such motions, and report the results in the SSAR, and

b. consider the impact of using different P and S wave hystcretic damping of site soils using the SASSI analy sis

Response

'!he subject of this R AI was discussed during a meeting among NRC staf f and consultants anti Westinghouse and Hechtel on seismic analyses on April 14,1994 and will be discussed further during a meeting scheduled at the end of May. A written response to this RAI will he prepared following the v meeting.

SSAR Revision: NONI!

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NRC REQUEST FOR ADDITIONAL INFORMATION Question 231.31 For sites where the soil characteristics are outside the range considered in Appendit 2A.2 of the SSAR. why are the cornparisons of the site specific soil-structure interaction analysis results to the design lloor response spectra inade-at only a very limited nuinber of locations?

Response

As stated m Subsection 2.5 of the SSAR. compari',on of the floor response spectra at the following hications is suf ficient demonstration that the site seismie conditions are within the AP600 design ha3is:

. Reactor sessel slipport (Elevation 9W)

. Containment operating floor (Elevation 135.2i')

. Shielil buihimg roof (Elevation 307.25')

Control room floor (Elevation 117.5')

The four locations are judged to be sullicient for the following reasons:

They cover the entire nuclear island Iroin crade (reactor sessel support) to the top (shielJ buihling roof).

They cover the containment internal structures where the major equipment is hicated or supported (reactor vessel support to the containment operating floor).

'Ihey cover the coupled shichi and auxiliary buildings f rotn grade to the top of the shield building, including the control room.

SSAR Revision: NONE l

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