Text

Non-proprietary AP600 Multiple SG Tube Rupture Analysis Rept
	ML20199C002
Person / Time
Site:	05200003
Issue date:	11/30/1997
From:	Scobel J; WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP.
To:	;
Shared Package
ML20199B976	List: ML20199C002; NSD-NRC-97-5431, Forwards non-proprietray WCAP-14991, AP600 Multiple SG Tube Rupture Analysis Rept & W Response to NRC RAI 440.683. NRC Requested to Inform W of Status to Be Designated in NRC Status Column of Otis for Numbers 5707 & 4187;
References
	WCAP-14991, NUDOCS 9711190180
	Download: ML20199C002 (175)
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L i . Westinghouse Non Proprietary Class 3 V I i I wc Ae - 14991 L + ++++++++++ I i !~ i i i e l i L AP600 Multiple Steam L Generator Tube Rupture L Analysis Report l l l l l . 4 e ,l .l i i l l i W I Westinghouse Energy Systems W.,

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I AP600 DOCUMENT COVER SHEET TDC: IDS: 1 S F wm 64202G(594)[oW311.wpf.tb) AP(00 CDJTRAL FILE USE ONLY: 00581RM RFSt. RFS '"N # AP600 DOCUMENT NO. REVISION NO. ASSIGNED TO PRA GSR-005 0 Page 1 of 2 ALTERNATE DOCUMENT NUMBER: WCAP.14991 WORK BREAKDOW 1 #: DEJN AGENT ORGANIZATION: PROJECT: TITLE: AP600 Multiple Steam Generator Tube Rupture Analysis RepDrt ATTACHMENTS: DCP #/REV. !NCORPORATED IN THIS DOCUMENT REVISION: CALCULATlON/ANALYS 5

REFERENCE:

ELECTRONIC FILENAME ELECTRONIC FILE FORMAT ELECTRON 10 FILE DESCRIP's.DN (C) WESTINGHOUSE ELECTRIC CORPORATION 1997 OWESTINGHOUSE PROPRIETARY CLASS 2 TNs document contains information proprietary to Westnghouse Electr6c Curpersu, it is subtrotted in confidence and is to be used solely for the purpose for wNch it is fumished and returned upon request This document and such informaton is not to be reproduced, transmitted, disclosed or used otherwise in whole or in part without prior wntten authonnhon of Westinghouse E.ectric Corporation, Energy Systems Business Unit, subject to the lyends contained hereof. OWESliNGHOUSE PROPRIETARY CLASS 2C This document is the property of and contains Proprietary Informabon owned by Westinghouse Electne Corporation and/or its subcontractors and supphers. It is transtnitted to you in confiderme and trust, and you agree to treat tNs document in stret accordance with the terms and condsbons of the agreernent under wNeh it was provided to you. [ WESTINGHOUSE CLASS 3 (NON PROPRIETARY) COMPLETE 1 IF WORK PERFORMED UNDER DESIGN CERTIFICATION QS COMPLETE 2 IF WORK PERFORMED UNDER FOAKE, 1 DDOE DESIGN CERTIFICATION PROGRAM GOVERNMENT LIMITED RIGHTS STATEMENT [See page 21 (%pyrl ht statement: A hcense la reserved to the U.S. Govemment under contract DE ACO3-90SF18495. 0 ODOE CONTRACT DELIVERABLES (DELIVERED DATA) Subject to specified exceptons, disclosure of thh data is restricted until September 30,1095 or Design Certfication under DOE contract DE-ACO3-90SF18495, wNchever is later, EPRI CONFIDENTIAL: NOTICE: 10 2 0 3 E 4 O s O CATEGORY: AEBOcODDeOFO '2 OARC FOAKE PROGRAM ARC LIMITED RIGHTS STATEMENT (See page 2) Copyright sta'ement: A license is reserved to the U.S. Govemment under contract DE FCO2 NE34267 and subcontract ARC-9#3 SC 001, DARC CONTRACT DELIVERABLES (CONTRACT A) Subject to specified exceptons, disclosurp(tNs data is re ncted ider ARC Subcontract ARC 93-3-SC-001, OAIGINATOR - G ATURE/ T-

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, NT c-J. A. JreSham r.M APPpop>L DATE f(/7/r

Approval of the roepunsible manager sagrvfios) pal cocument is complete, all required reviews are complete, electrorac ide is attached and document is-released for use, y

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AP600 DOCUMENT COVER SHEET Page 2 l Form ss2020(s/94) LIMITED RIGHTS STATEMENTS poE aovEnwufwr umf7Eo mouTs s1 ATEuENT (A) These Octa are submmed wth hmhed f6ghts under govemment contract No. DE ACo3 90SF18495. These data may be r oduced and used by 9.m govemment with the express hmitaten that they will rot, wtrout wr#tten permise6cn of the contractor, be for purposes of manuten'.turer for todosed outsede the govemment; except that the govemment may esciose these data outsede the goverrvient for the follmng purposes, if any, provided that the government :nakes such &sdoeure sutyect to prohibeton agemet further use and declosure. (I)) Ttys *Propr6etary Data' may be esdosed for evaluation purpose 9 under the teetnchons above. (II The 'Propnetary Data' may be declosed to the Electnc Power Rewarch Inshte (EPRI), e6ectnc utikty representattves and their ered consultants, exdudmg erect commeront compettors, and the DOE Netonal L.at, oratories under the p,&G and rootnctons above. 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WESTINGHOUSE NON PROPRIETARY CIASS 3 WCAP 14991 AP600 Multiple Steam Generator Tube Rupture Analysis J. H. Scobel November 1997 i l l l i eswp, house Electric Corporation 2 Energy Systems Business Ucit P.O. Box 355 Pittsburgh,PA 15230 C1997 Westinghouse Electric Corporation AllRights Reserved u\\3931.docit>11/11/97 l l

- lii - TABLE OF CONTENTS 1 INTRODUCTION.......................................................................................................... 1-1. 2 METHODOLOGY AND APPROACH......................................................................... 2-1 2.1 MAAP4 Benchmarking........................................................... 2-1 2.2 System Actua tion and Performance................................................................. 2-2 3 MAAP4 ANALYSIS RESULTS....................................................... 3-1 3.1 BaseCases............................................................................................................. 3-1 3.1.1 Case SG 1 - One Tube SGTR...................................................................... 3-1 3.1.2 Case SG2 through SG5 - Two through Five Tube M ul tiple-SGTRs.......................................................................................... 3-2 3.2 Sens i ti vi ty Ca ses....................................................................................................... 3-2 3.2.1 Case SG5b - Break Elevation Sensitivity.................................................. 3-3 3.2.2 Case SG5 max - Maximum PRHR Heat Exchanger Performance................................................................................................ 3-3 3.2.3 Case SG5 min - Minimum PRHR Heat Exchanger Performance..............................................................................................., 3-3 3.2.4 Case SG5op - Nonsafety-Related Injection Systems Only.................... 3-3 3.2 Case SG5p - Secondary PORV Failure to Open...................................... 3-4 3.2.6 Case SG5cvs - Operation of the CVS Injection with the Pa ssive Sys t e ms.......................................................................................... 3-4 3.2.7 Case SG5stk: Stuck Open Secondary System Safety Valve................ 3-4 3.3 Boron Dilu tion During ADS............................................................................. 3-6 3.3.1 Boron Concentration Calculation Method and Assumptions............. 3-6 3.3.2 Boron Dilu tion in Case SG5stk................................................................ 3-7 4 1UMMARY A ND CONCLUSIONS........................................................................... 4-1 l-5 REFERENCES................................................................................................................. 5-1 l l. i I t Table of Contents - Revision O. November 1997 or,\\3931 doc 1b.11/05/97

4 'e+d -e 40-> L~M4-b,4p.4L,skwik - at 5 m-A A 4 a*4& a iv LIST OF TABLES Table 3-1 AP_600 Multiple Steam Generator Tube Rupture MAAP4 Case Inpu t Assumptions................................................................................. - 9 Table 3-2 Case SG1 Anident Sequence Timing........................................................ : 3-10 Table 5-3 Case SG2 Accident Sequene. fiming......................................................... 3 ; Table 3-4 Case SG3 Accident Sequ,mce Timing....................................................... 3-12 Table 3-5 ' - Case SG4 Accident Sequence Timing............................................................ 3-13 " 5 Table 3-6 Case SGS Accident Sequence Timing.............................................................. 14 ' - Table 3-7, Case SG5b Accident Sequence Timing............................................................ 3 Table ".,-8 Case SG5 min Accident Sequence Timing...................................................... 3-16 Table 3-9 - Case SG5 max Accident Sequence Timing....................................................... 3-17 ....................... 3 l Table 3-10 Case SG5op Accident Sequence Timing...................... Table 311 Case SG5p Accident Sequence Timing............................................................. 3-19 Table 3 Case SG5cvs Accident Sequence Timing......................................................... 3-20 Table 313 - Case SG5stk Accident Sequence Timing.......................................................... 3-21 Introduction Revision 0, November 1997 cx\\3931,docit>11/5/97 -

~. 1 j -v r LIST OF FIGURES r Figure 11 AP600 Steam Generator Tube Rupture Multiple 1.4vels ofDefense.........u............................................................................................... ' 1-3 Figure 2-1 -- MAAP4 Passive RHR Model Best Estimate Heat Removal Benchmark...... 2-4 Figure 2 MAAP4 Passive RHR Model Maximum Heat Removal Benchmark............ 2-5

Figure 2-3 MAAP4 Passive RHR Model Minimum Heat Removal Benchmark............

2-6 Figure 3-1 AP6001 Tube Cold Side SGTR at Tubesheet - Base Case [ Tube Rupture Break Flow............................................................................ 3-22 ' - Figure 3 AP6001 Tube Cold Side SGTR at Tubesheet - Base Case - Pressurizer Wa ter I.evel...................................................................................... 3-23 i Figure 3-3 - AP6001 Tube Cold Side SGTR at Tubesheet - Base Case RCS and Secondary Systems Pressures........................................................... 3-24 Figure 3-4 AP6001 Tube Cold Side SGTR at Tubesheet - Base Case Steam Generator Downcomer Water Level................................................... 3-25 .-Figure 3-5 AP6001 Tube Cold Side SGTR at Tubesheet - Base Case - Faulted Steam Generator Pressure.................................................................... 3-26 Figure 3-6 AP6001 Tube Cold Side SGTR at Tubesheet - Base Caw CMT Wa ter Mass Flowra tes............................................................................. 3-27 Figure 3-7 AP6001 Tube Cold Side SGTR at Tubesheet - Base Case RCS and CMT Wa ter Temperatures............................................................... 3-28 Figure 3-8 AP6001 Tube Cold Side SGTR at Tubesheet - Base Case CMT W a ter Level.............................................................................................. 3-29 Figure 3-9 ' AP6001 Tube Cold Side SGTR at Tubesheet - Base Case PRHR Hea t Removal...................................................................................... 3-30 Figure 3 AP6001 Tube Cold Side SGTR at Tubesheet - Base Case RCS Wa ter Lev el................................................................................................ 3-31 Figure 3-11 AP600 2 Tube Cold Side SGTR at Tubesheet - Base Case - Tube Rup ture Break Flow................................................................................. 3-32 Figure 3-12. AP600 2 Tube Cold Side SGTR at Tubesheet - Base Case Press urizer Wa ter Level.................................................................................... 3-33 Figure 3-13 AP6002 Tube Celd Side SGTR at Tubesheet - Base Case RCS and Secondary Systems Pressures.......................................................... ' 3-34 Figure 3-14 AP600 2 Tube Cold Side SGTR at Tubesheet - Base Case Steam Generator Downcomer Water Level................................................... 3-35 ~ . Figure 3 AP600 2 Tube Cold Side SGTR at Tubesheet - Base Case - Faulted Steam Generator Pressure................................................................ 3-36 Figure 3-16 AP600 2 Tube Cold Side CGTR at Tubesheet - Base Case CMT Water Mass Flowrates........................................................................ 3 37 Figure 3-17 AP600 2 Tube Cold Side SGTR at Tubesheet - Base Case RCS and CMT Water Temperatures........................................................... 3-38 L List of Figures Revision 0, November 1997 o:\\39314oc1b.11/05/97 -

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LIST OF FIGURES (Cont.); Figure 3-18 AP600 2 Tube Cold Side SGTR at Tubesheet - Base Case CMT Wa ter Level..................................................................................... 3-39 iFigure 3-19 AP600 2 Tube Cold Side SGTR at Tubesheet - Base Case PRHR Hea t Removal.......................................................................................... 3-40 ' Figure 3-20 AP6002 Tube Cold Side SGTR at Tubesheet - Base Case .j RCS Wa ter Level..................................................................................... 3-41 i Figure 3-21 AP6003 Tube Cold Side SGTR at Tubesheet - Base Case - Tube Rupture Brea k Flow............................................................................. 3-42 Figure 3-22 AP6003 Tube Cold Side SGTR at Tubesheet - Base Case i Pressuri zer Wa ter lev el................................................................................. ' 3-43

Figure 3-23 AP6003 Tube Cold Side SGTR at Tubesheet - Base Case RCS and Secondary Systems Pressures.......................................................... 3-44

' Figure 3 24 AP600 3 Tube Cold Side SGTR at Tubesheet - Base Case Steam Generator Downcomer Water level................................................... 3-45 Figure 3-25 AP6003 Tube Cold Side SGTR at Tubesheet - Base Case Faulted Steam Genera tor Pressure................................................................ 3-46 Figure 3-26 AP600 3 Tube Cold Side SGTR at Tubesheet - Base Case CMT Wa ter Mass Flowra tes............................................................................. 3-47 1 Figure 3-27 -AP600 3 Tube Cold Side SGTR at Tubesheet - Base Case RCS and CMT Water Temperatures............................................................... 3-48 i Figure 3-28 AP600 3 Tube Cold Side SGTR at Tubesheet - Base Case - CMT Wa ter Lev el................................................................................................ 3-4 9 Figure 3-29 - AP600 3 Tube Cold Side SGTR at Tubesheet - Base Case PRHR Hea t Removal...................................................................................... 3-50 Figure 3-30 AP6003 Tube Cold Side SGTR at Tubesheet - Base Case RCS Wa ter Level.m.............................................................................................. 3-51 Figure 3-31 AP600 4 Tube Cold Side SGTR at T ubesheet - Base Case Tube Rup ture Break Flow................................................................................. 3-52 Figure 3 AP600 4 Tube Cold Side SGTR at Tubesheet - Base Case - Pressurizer Wa ter Level......................................................................................, 3-53 Figure 3-33 AP600 4 Tube Cold Side SGTR at Tube 3heet - Base Case RCS and Secondary Systems Pressures....................................................... 3-54 Figure 3-34 AP600 4 Tube Cold Side SGTR at Tubesheet - Base Case Steam Generator Downcomer Water Level................................................... 3 Figure 3-35 AP6004 Tube Cold Side SGTR at Tubesheet - Base Case Faulted Steam Generator Pressure.................................................................. 3-56 Figure 3 AP600 4 Tube Cold Side SGTR at Tubesheet - Base Case CMT Wa ter Mass Flowrates.................................................................. 3-57 Figure 3-37 AP600 4 Tube Cold Side SGTR at Tubesheet - Base Case L RCS and CMT Water Temperatures..................................................... 3-58 Introduction Rmsaon 0. November 1997 . o:\\3931. doc 1b-11/5/97

vii LIST OF FIGURES (Cont.) Figure 3-38 AP600 4 Tube Cold Side SGTR at Tubesheet - Base Case CMT Wa t e r Lev el.............................................................................................3-5 9 Figure 3-39 AP6004 Tube Cold Side SGTR at Tubesheet - Lase Case PRHR Hea t Removal....................................................................................... 3-60 Figure 3-40 AP6004 Tube Cold Side SGTR at Tubesheet - Base Case RCS Wa t e r Lev el.............................................................................................. 3-61 Figure 3-41 AP6005 Tube Cold Side SGTR at Tubesheet - Base Case Tube Rupture Break Flow....... ..............................................................3-62 Figure 3-42 AP6005 Tube Cold Side SGTR at Tubesheet - Base Case Pressurizer Water Ixvel= 3-63 Figure 3-43 AP6005 Tube Cold Side SGTR at Tubesheet - Base Case RCS and Secondary Systems Pressures......................................................... 3-64 Figure 3-44 AP6005 Tube Cold Side SGTR at Tubesheet - Base Case Steam Generator Downcomer Water Level................................................... 3-65 Figure 3-45 AP600 5 Tube Cold Side SGTR at Tubesheet - Base Case Faulted Steam Genera tor Pressure................................................................... 3-66 Figure 3-46 AP6005 Tube Cold Side SGTR at Tubesheet - Base Case CMT Water Mass Flowrates= .......................................................3-67 Figure 3-47 AP600 5 Tube Cold Side SGTR at Tubesheet - Base Case RCS and CMT Water Temperatures....................................... 3-68 Figure 3-48 AP600 5 Tube Cold Side SGTR at Tubesheet - Base Case CMT Wa ter Level................................................................................... 3-69 Figure 3-49 AP600 5 Tube Cold Side SGTR at Tubesheet - Base Case PRHR Heat Retnoval.......... ....................................................3-70 Figure 3-50 AP600 5 Tube Cold Side SGTR at Tubesheet - Base Case RCS Wa t er Le v el....................................................................................... 3-71 Figure 3-51 AP6005 Tube Cold Side SGTR - Break Elevation Sensitivity Tube Rup ture B reak Flo N.............................................................................. 3-72 Figure 3-52 AP600 5 Tube Cold Sido SGTR - Preak Elevation Sensitivity Press urizer Wa ter Le ve (................................................................................... 3-73 Figure 3-53 AP6005 Tube Cold Sid : SGTR - Break Elevation Sensitivity RCS and Second ary Sy tems Pressures.................................................... 3-74 Figure 3-54 AP600 5 Tube Cold Side SGTR - Break Elevation Se uitivity Steam Generator Downcomer Water Level............................................... 3-75 Figure 3-55 AP6005 Tube Cold Side SGTR - Break Elevation Sensitivity Faulted Steam Generatoi Pressure....................................................... 3-76 Figure 3-56 AP600 5 Tube Cold Side SGTR - B.eak Elevation Sensitivity CMT Wa ter Mass Flowra tes..................................................................... 3-77 Figure 3-57 AP6005 Tube Cold Side SGTR - Break Elevation Sensitivity RCS and CMT Water Temperatures....................................................... 3-78 List of Figures Revision 0, November 1997 o:\\3931.docib.11/05/97

. ~.. - .i J u -- vill LIST OF FIGURES (Cont.)- l Figure 3-58 : AP600 5 Tube Cold Side SGTR - Break Elevation Sensitivi+y - CMT Wa ter hvel.......................................................................................... 3-79. Figure 3-59 AP6005 Tube Cold Side SGTR - Break Elevation Sensitivity PRHR Hea t Removal......................................................................................... 3-80 Figure H0 'AP600 5 Tube Cold Side SGTR - Break Elevation Sensitivity RCS Wa ter Level................................................................................................ 3-81 Figure M1 AP6005 Tube Cold Side SGTR'- Max PRHR Heat Removal Tube Rupture Break Flow............................................................................... 3-82 Figure H2' AP6005 Tube Cold Side SGTR - Max PRHR Heat Removal Pressurizer Wa ter imel.................................................................................... 3-83 . Figure M3. AP6005 Tube Cold Side SGTR - Max PRHR Heat Removal - RCS and Secondary Systems Pressures............................................................ 3-84 Figure 3-64 AP6005 Tube Cold Side SGTR - Max PRHR Heat Removal 2 . Steam Generator Downcomer Water Imel..................................................... 3-85 - Figure M5 - AP600 5 Tube Cold Side SGTR - Max PRHR Heat Removal Faulted Steam Generator Pressure................................................................... 3-86 Figure 3-66 AP6005 Tube Cold Side SGTR - Max PRHR Heat Removal CMT Water Mass Flowrates-................................................................ 3-87 Figure M7 AP600 5 Tube Cold Side SGTR - Max PRHR Heat Removal RCS and CMT Water Temperatures................................................................. 3-88 Figure M8 AP6005 Tube Cold Side SGTR - Max PRHR Heat Removal CMT Wa ter Lev el............................................................................................. 3-89 Figure M9 AP600 5 Tube Cold Side SGTR - Max PRHR Heat Removal PRHR Hea t Removal......................................................................................... 3-90 Figure 3 70 AP600 5 Tube Cold Side SGTR - Max PRHR Heat Removal RCS Wa ter Level.................................................................................................. 3-91 Figure 3-71 AP600 5 Tube Cold Side SGTR - Min PRHR Heat Removal Tube R up ture Break Flow................................................................................. 3-92 Figure 3-72 AP600 5 Tube Cold Side SGTR - Min PRHR Heat Removal Pressurizer Wa ter Level............................................................................... 3-93 Figure 3-73 AP600 5 Tube Cold Side SGTR - Min PRHR Heat Removal RCS and Secondary Systems Pressures........................................................... 3-94 - Figure 3-74 _ AP6005 Tube Cold Side SGTR - Min PRHR Heat Removal-Steam Generator Downcomer Water Level................................................... 3-95 Figure 3-75 : AFC05 Tube Cold Side SGTR - Min PRHR Heat Removal . Faulted Steam Generator Pressure............................................................ 3-% Figure 3-76 ' AP6005 Tube Cold Side SGTR - Min PRHR Heat Removal CMT Water Mass Flowrates.................................................................... 3-97 - Figure 3-77 AP6005 Tube Cold Side SGTR - Min PRHR Heat Removal RCS and CMT Water Temperatures........................................................... 3-98 j. Introduction - Revision 0, November 1997 cA3931.docib.11/$/97 -- en e v + w

ix : a LIST OF FIGURES (Cont.)l Figure 3 AP6005 Tube Cold Side SGTR Min PRHR Heat Removal CMT Wa ter Level.............................................................................................. 3-99 Figure 3-79 AP6005 Tube Cold Side SGTR Min PRHR Heat Removali PRHR Hea t Removal........................................................................................... 3-100 Figure 3-80. _ AP600 5 Tube Cold Side SGTR - Min PRHR Heat Removal RCS Wa ter level................................................................................................ 3-101 Figure 3-81 AP6005 Tube SGTR - CVS On with No Passive Systems - CVS Injection Flowra te..................................................................................- 3-102 Figure 3 - AP6005 Tube SGTR - CVS On with No Passive Systems Tube Rupture Break F1ow................................................................................... 3-103 Figure 3-83 AP6005 Tube SGTR - CVS On with No Passive Systems Pressurizer Wa ter Level.................................................................................. 3-104 Figure 3 AP6005 Tube SGTR - CVS On with No Passive Systems RCS and Secondary Systems Pressures......................................................... 3-105 Figure 3 85 AP6005 Tube SGTR - CVS On with No Passive Systems Steam Generator Downcomer Water level..................................................... 3-106 Figure 3 AP6005 Tube SGTR - CVS On with No Passive Systems Faulted Steam Genera tor Pressu re.................................................................. 3-107 Figure 3 AP6005 Tube SGTR - CVS On with No Passive Systems CMT Water Mass Flowrates............................................................................ 3-108 - Figure 3-88 AP6005 Tube SGTR - CVS On with No Passive Systems RCS and CMT Wa ter Tempera tures............................................................ 3-109 Figure 3-89 AP600 5 Tube SGTR - CVS On with No Passive Systems CMT Wa te r Level............................................................................................ 3-110 Figure 3-90 AP6005 Tube SGTR - CVS On with No Passive Systems PRHR Hea t Removal............................................... .......................................3-111 Figure 3 AP6005 Tube SGTR - CVS On with No Passive Systems RCS W a te r Lev el................................................................................................ 3-112 Figure 3-92 AP6005 Tube SGTR - SG PORV Failed Closed Tube Rupture Break Flow...................................................................... 3-113 Figure 3-93 AP6005 Tube SGTR - SG PORV Failed Closed Pressu rizer Water Level.................................................................................... 3-114 ' Figure 3 - AP600 5 Tube SGTR - SG PORV Failed Closed ' RCS and Secondary Systems Pressures......................................................... 3-115 - Figure 3-95 '.. AP6005 Tube SGTR - SG PORV Failed Closed-Steam Generator Downcomer Water Level............................. .................-3-116 Figure 3-% _AP6005 Tube SGTR - SG PORV Failed Closed. Faulted Steam Genera tor Pressure........................-........................................ 3-117 Figure 3-97 AP6005 Tube SGTR - SG PORV Failed Closed CMT Water Mass Flowrates........................................................................... 3-118 Ust of Figures Remion 0, November 1997 ' a:\\39314oc1b.11/05/97

~ 1 X' 1 i LIST OF FIGURES (Cont.) Figure 3 AP6005 Tube SGTR - SG PORV Failed Closed - RCS and CMT Water Temperatures........................................................... 3-119 j Figure 3-99 ' AP6005 Tube SGTR - SG PORV Failed Closed CMT Wa ter Level............................................................................................... 3-120 'I Figure 3100 -- AP600 5 Tube SGTR - SG PORV Failed Closed PRHR Hea t Remova1..................................................................................... 3-121 Figure 3-101' ; AP6005 Tube SGTR - SG PORV Failed Closed RCS Wa ter level -...................................................................................... 3-122 Figure 3-102 AP600 5 Tube SGTR - CVS with Passive Systems - - Charging Pump Injection Flowrate............................................................... 3-123 Figure 3-103 AP6005 Tube SGTR - CVS with Passive Systems Tube Rupture Break Flow.............................................................................. 3-124 Figure 3-104 AP600 5 Tube SGTR - CVS with Passive Systems. Pressurizer Wa ter Level.................................................................................... 3-125 Figure 3-105 _ AP600 5 Tube SGTR - CVS with Passive Systems RCS and Secondary Systems Pressures............................................................ 3-126 Figure 3106 AP6005 Tube SGTR - CVS with Passive Systems Steam Generator Downcomer Water Level..................................................... 3-127 -l Figure 3-107 AP600 5 Tube SGTR - CVS with Passive Systems j Faulted Steam Generator Pressure................................................................ 3-128 i Figure 3-108 AP6005 Tube SGTR - CVS with Passive Systems CMT Wa ter Mass Flowra tes............................................................................. 3-129 Figure 3-109 AP600 5 Tube SGTR - CVS with Passive Systems RCS and CMT Water Temperatures............................................................... 3-130 Figure 3-110 AP600 5 Tube SGTR - CVS with Passive Systems CMT Wa ter Level........................................................................................... 3-131 Figure 3-111 AP600 5 Tube SGTR - CVS with Passive Systems PRHR Hea t Re moval....................................................................................... 3-132 Figure 3-112 AP600 5 Tube SGTR - CVS with Passive Systems RCS Wa ter Level................................................................................. 3-133 Figure 3-113 AP600 5 Tube SGTR - Stuck SG Safety Valve with CVS On Tube Rup ture Break Flow............................................................................. 3-134 Figure 3-114. 'AP600 5 Tube SGTR - Stuck SG Safety Valve with CVS On CVS Injection Flowrate........................... .............................................. 3-135 Figure 3-115. AP600 5 Tube SGTR - Stuck SG Safety Valve with CVS On RCS and Secondary Systems Pressures.................................................. 3-136 - Figure 3-116 AP6005 Tube SGTR - Stuck SG Safety Valve with CVS On Pressurizer Wa ter Level................................................................................ 3-137 Figure 3-117 AP600 5 Tube SGTR - Stuck SG Safety Valve with CVS On

Startup Feedwa ter Flowrate..................................................................... 3-138 Introduction -

Revision 0, November 1997 o:\\3931. doc 1b.11/5/97

xi LIST OF FIGURES (Cont.) Figure 3-118 AP6005 Tube SGTR - Stuck SG Safety Valve with CVS On PRHR Hea t Removal...................................................................................... 3-139 Figure 3-119 AP6005 Tube SGTR - Stuck SG Safety Valve with CVS On CMT Wa ter Mass Flowra tes.............................................................................. 3-140 ' Figure 3-120 AP600 5 Tube SGTR - Stuck SG Safety Valve with CVS On CMT Wa t e r Level................................................................................................ 3-141 ~ Figure 3-121' AP600 5 Tube SGTR - Stuck SG Safety Valve with CVS On Steam Generator Downcomer Water Level..................................................... 3-142 Figure 3-122 AP6005 Tube SGTR - Stuck SG Safety Valve with CVS On Faulted Steam Generator Pressure................................................................ 3-143 Figure 3-123 AP600 5 Tube SCTR - Stuck SG Safety Valve with CVS On Accumula tor Injection Flowrate...................................................................... 3-144 Figure 3-124 AP6005 Tube SGTR - Stuck SG Safety Valve with CVS On RCS and CMT Wa ter Temperatures................................................................. 3-145 Figure 3-125 AP600 5 Tube SGTR - Stuck SG Safety Valve with CVS On Gravity Injection Flowrate= .............................................................3-146 Figure 3-126 AP600 5 Tube SGTR - Stuck SG Safety Valve with CVS On Con tainment Wa ter Level.............................................................................. 3-147 Figure 3-127 AP6005 Tube SGRT - Stuck SG Safety Valve with CVS On Long-Term Steam Loss through Open Safety Valve..................................... 3-148 Figure 3-128 Nodal Network for Boron Concentration Calculation................................. 3-149 Figure 3-129 AP6005 Tube SGTR - Stuck SG Safety Valve with CVS On Estimated AP600 Boron Concentrations - End-of Lift Initial Con d i tions....................................................................................................... 3-150 Figure 3-130 AP6005 Tube SGTR - Stuck SG Safety Valve with CVS On Estimated AP600 Boron Concentrations - Beginning-of-Life Ini tial Cond i ti ons................................................................................................ 3-151 I.ist of Figures Revnion 0, November 1997 ot\\3931.docib-11/05/97

11 1 INTRODUCTION This report provides an evaluation of the AP600 plant response to the rupture of multiple steam generator tubes. The analysis of multiple-steam generator tube ruptures (SGTRs) is prepared in response to the Nuclear Regulatory Commission's Containment Bypass issue as outlined in SECY-93-087, and request for additional information (RAI) numbers 440.27 (reference 1), 440.170 (reference 2) and 440.588 (reference 3). These sequences are beyond the design-basis of the AP600 and are performed with best-estimate MAAP4 evaluations of one through five tube multiple-SGTRs. The objective of the evaluations is to demonstrate that for steam generator tube rupture initiated events: the automatic depressurization system (ADS)is not actuated, the secondary safety valves do not open to create a potential containment bypass e

pathway, the AP600 provides defense-in-depth to unmitigated releases in the event of postulated e

sticking open of the safety valves. The core remains covered and cooled as the plant achieves a safe, stable condition. The AP600 provides passive safety-related systems to mitigate accidents. The passive systems provide a unique plant response to the SGTR initiating event with respect to conventional plants and mitigate the accident without voiding the reactor coolant system c,r overfilling the steam generator. The passive residual heat removal heat exchanger (PRHR) acts to reduce the RCS pressure below the pressure of the secondary system and shut off the break flow to the faulted steam generator. The heat is removed from the primary system from the PRHR instead of from the intact steam generator. Therefore, heat is transferred from the secondary system to the primary system to control the leak to the faulted steam generator. The core makeup tanks (CMTs) provide heat removal and coolant inventory makeup for shrinkage in the RCS. The CMTs inject water in recirculation mode, exchanging cold borated water for hot RCS water. The CMTs do not drain during recirculation injection, therefore ADS is not actuated. Additionally, nonsafety related pumped injection sources are also available to the operator to mitigate the accident without the operation of the passive systems. The safety-related passive systems and the non-safety related active systems provide a multiple layer steam generator tube rupture mitigation capability (see Figure 1-1). The automatic depressurization system is not actuated in either the passive or active responses, but provides accident management options for feed and bleed or full depressurization in the event of other system failures (see Figure 1-1). If a secondary system safety valve is arbitrarily postulated to stick open, the system responds to the SGTR-initiated accident as a small loss-of-coolant accident (LOCA). The loss of primary system coolant through the tube break and stuck-open valve eventually drains the CMTs, which actuates the ADS ar.d depressurizes the RCS in a controlled, staged manner. The safety-related passive injection systems, CMTs, accumulators and IRWST gravity injection provide introduction Revision 0, November 1997 oA3931. doc 1b-11/5/97

12 invenury makeup and boration throughout the depressurization. The core remains covered and cooled and achieves a safe, stable configuration. The depressurization mitigates the loss of inventory and the core remains covered and cooled without a release of fission products from the core. This report provides the bases for the following conclusions: The AP600 provides multiple defense-in-depth mitigation for releases of fission products for the beyond design basis steam generator tube rupture events, including rupture of up to five tubes. The operator can mitigate the accident with nonsafety-related systems without overfilling the steam generator or opening the secondary safety valve. In the case with no active systems, the passive systems prevent steam generator overfill and safety valve opening without any operator actions. The leak is terminated and the containment remains intact. No adverse system interactions between the pumped injection sources and the passive safety systems affect the success of the cooling. In case the PRHR heat exchanger fails, the ADS provides a third level of defense to mitigate the tube rupture. If the steam generator safety valve is postulated to be stuck open, defense-in-depth is achieved by depressurizing the RCS and maintaining reactor core cooling. No adverse boron dilution is predicted during or after the depressurization. Although the containment is postulated to be open to the atmosphere through the ruptured tubes and stuck-open steam generator safety valve, the fission products remain in the fuel and are not released to the envirorunent. Introduction Revision 0, November 1997 oA3931.docit>11/s/97

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2-1 2 METHODOLOGY AND APPROACH The Nuclear Regulatory Commission Staff has accepted the Westinghouse position on the multiple-SGTR issue documented in reference 4, which states, 'The multiple steam generator tube rupture scenario should not be a design basis event. This event should be explicitly treated only in the risk assessment domain where best-estimate analyses are used to assess plant re<ponse to scenarios beyond the design basis events." Toward this end, an analysis of the one-through five-tube multiple-SGTRs is performed using the MAAP 4.0 accident analysis code (refcrence 5) to model the best-estimate thermal hydraulic response of the AP600 design. The breale flow through the tube into the steam generator secondery system is calculated using the Henry-Fauske two-phase flow model, and the reactor coolant system response is modeled using 14 reactor vessel and loop nodes, and a one node 1600 ft' pressurizer. The stcam generator secondary system is modeled as a single node and the water level as a function of the secondary system volume is tracked. Best-estimate decay heat based on the ANS 1979 standard is used. Base cases are performed of the system response including the best-estimate passive RHR heat removal, and secondary power-operated relief system to prevent the opening of the safety valves. One through five tube SGTRs are analyzed to bound the range of break flow. Sensitivity analyses are performed on the five tube break to examine the effect of increased and decreased passive RHR capacity, operation of the charging system (CVS), break elevation uncertainty and the failure of the secondary PORV to open. A case with no passive systems is performed to show the adequacy of the active systems and the time available prior to the need for operator action to cooldown the RCS, Finally, an analysis assuming the opening and failure to close of the secondary safety valve is performed to demonstrate that the plant response will not uncover the core and release fission products to the environment through the unisolated secondary system. No operator actions are modeled in any of the passive system mitigation sequences. 2.1 MAAP4 BENCHMARKING For the modeling of the AP600 multiple steam generator tube rupture base cases, the important thermal-hydraulic phenomena modeled are the decay heat, CMT and passive RHR heat exchanger performance and tube rupture break flow. Since the RCS coolant is not predicted to saturate or void, two-phase modeling is not important. In the base cases, the PRHR best-estimate natural circulation heat removal is modeled. Sensitivity cases are performed to bound upper and lower estimates of the passive RHR performance. The MAAP4 passive RHR model is benchmarked against independent design calculations for the minimum, maximum and best-estimate passive RHR single-phase water natural circulation heat removal within the range of water temperatures expected in the multiple-SGTR cases. The results of this benchmarking are presented in Figures 2-1,2-2, and 2-3. The MAAF4 PRHR modeling shows good agreement with the designer's estimates of the passive RHR performance. Methodology and Approach Revmon 0, November 1997 oA3931.docib-11/s/97

22 l l The core makeup tanks also provide significant RCS heat removal capacity and inventory makeup. The MAAP4 core makeup tank behavior, as well as RCS thermodynamics and break flow modeling, are benchmarked in the MAAP4 /NOTRUMP benchmarking exercise performed in support of the resolution of the passive system reliability issue. The response of the case with the stuck-open safety valve is a small LOCA which is extensively benchmarked in the passive system reliability issue resolution documentation. Therefore, the overall benchmarking effort is not duplicated here. 2.2 SYSTEM ACTUATION AND PERFORMANCE Important setpoints for the actuation of systems in this analysis are: core makeup tank injection and reactor coolant p ump trip occurs due to low-2 pressurizer level,7 percent of span (1.87 m), reactor scram and turbine trip occur due to the CMT injection signal, e passive RHR heat exchanger (PRHR) is actuated on the same signal as the core makeup e tankinjection, pressurizer heaters are initiated on low pressurizer pressure, turn off on low pressurizer e water level and are tripped by the CMT injection signal, automatic depressurization (ADS) is actuated at core makeup tank level less than 13.1 feet e (3.99 meters) from the CMT bottom, secondary system PORVs are fail-closed valves which open at 1046 psia (7.21 MPa) and e are reset (closed) when the pressure falls 25 psi below the opening serpoint, secondary system three safety valves open at 1100,1130, and 1155 psia (7.58,7.79 and 7.96 e MPa), respectively, the secondary system automatic main steam isolation valve (MSIV) is actuated on low steamline pressure,600 psia (4.1 MPa), low-2 RCS temperature,515'F (541*K), hi-1 containment pressure,19.7 psia (1.4 bar), or low-2 steam generator narrow-range level, 28.5 ft (8.7 m)in the downcomer. All cases are assumed to begin from one hundred percent power. The PRHR and all trains of ADS and passive safety injection systems, CMTs, accumulators and gravity injection are available. Startup feedwater (SFW) provides two hundred gallons per minute flowrate to each steam generator with the level controlled. CVS injection flowrate is set to the maximum system flowrate of 170 gpm in cases in which steam generator overfill is an issue. CVS injection flowrate is set to the minimum system flowrate of 100 gpm in the case in which it provides inventory makeup and core cooling. Steam generator overfill protection automatically isolates 1 Methodology and Approach Revision 0, November 1997 c:W31. doc 1b.11/s/97

2-3 the CVS and the SFW injection when the secondary level exceeds the 79% narrow range steam generator level. The MAAP4 code only models the secondary system to the MSIVs. The code does not couple the secondary system in the two steam generators with the steam header. Because of the MAAP4 modeling, the MSIV closure is assumed at the time of turbine trip in the analpes. The code cannot model the heat removal through the steam condenser, a diverse, redundant alternative to the opening of the secondary PORV. In the SGTR accident, the automatic MSIV closure setpoints are not reached. However, as the heat removal in the AP600 is through the passive RHR and CMTs on the primary system side, the secondary system pressure is essentially equivalent in the two steam generators, regardless of the status of the MSIVs, provid!ng the operator significant time to close the MSIV and isolate the faulted steam generator. Therefore, this modeling does not limit the applicability of the results. Methodology and Approach Revision 0, November 1997 o:\\3931.docibit/5/97

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g. 1 Mo. 8 9. 53 'WAAP4 Passive RHR Modei M i n irrum 'H e o t R emo s o l' Benchmork f[ MAAP4 Minimum d> Min PRHR m1 BE PRHR 2g. ---Max PRHR _ '5 0 m: 's m 40 - - 40 = m _,. ~ " _ _ _. [ O [ ~# - ~~ ~,... - -- 3 0 - g { 30 -- e x = - 20 -- - 20 0 x 10 - - 10 x I x y ct 0i i, .,iii,, O-l g.- g-530 540 550 560 570 580 590 y PRHR Inlet Wcter Temperature (K) Iri

u 3 MAAP4 ANALYSIS RESULTS This section presents the results of the MAAP4 analyses for the multiple tube rupture cases and the sensitivity and uncertainty analyses. The system availability assumptions for all the cases are presented in Table 3-1. 3.1 BASE CASES This section presents the description of the MAAP4 code results from the analyses of one-through five-tube multiple-steam generator tube rupture safety cases. The base case assumes that 2 CMTs,2 accumulators, PRHR heat exchanger, ADS and 2 IRWST injection lines are available for operation. No other injection sources, such as CVS, are credited. No operator actions are credited. A summary of the base case accident sequence timing is presented in Tables 3-2 through 3-6. In each case, the secondary power opented relief valve (PORV) or steam condenser and the RCS heat removal via the PRHR heat exchanger and CMTs maintains the pressure in the secondary system below the minimum safety valve setpoint. The heat removal capability of the passive RHR heat exchanger and the core makeup tanks equilibrates the pressure between the reactor coolant system and the secondary system, shutting off the break flow and terminating the accident without voiding the RCS or CMTs, and without actuating the automatic depressurization system. The plant equilibrates to a safe, stable condition without operator actions. 3.1.1 Case SG1 - One Tube SGTR The AP600 single tube SGTR case, SG1,is a double-ended guillotine break of one cold-side steam generator tube at the tubesheet elevation. The MA AP4 results for case SG1 are presented in Figures 3-1 through 3-10. Event timing is summarized in Table 3-2. At time zero, the tube rupture occurs, relieving primary system water into the broken steam generator (Figure 3-1). The pressurizer level (Figure 3-2) and RCS pressure (Figure 3-4) decrease and the reactor scrams and the turbine trips due to an CMT injection signal on a low-2 pressurizer level. The steam generator maia feedwater system is isolated and startup feedwater is initiated on the reactor scram. The faulted steam generator water level (Figure 3-4) increases due to the break flow addition, but does not overfill. The faulted steam generator pressure (Figure 3-5) increases to the setpoint of the secondary PORVs valves which relieve secondary system steam to the environment. The pressure remains below the lowest safety valve opening pressure. The core makeup tank injection line valves are cpened to the RCS and the reactor coolant pumps are tripped on the CMT injection signal. The CMT injects (Figure 3-6) in recirculation mode due to the density difference between tne cold CMT water and the hot RCS water. As the cold CMT water injects into the RCS, an equal volume of hot RCS water is drawn into the CMT. The CMT water temperature increases (Figure 3-7) allowing the CMTs to act as heat sinks for the RCS During recirculation injection, the CMTs inject without decreasing the water level in the tank (Figure 3-8). l MAAP4 Analysis Results Revision 0, November 1997 o:\\3931. doc 1b-11/s/97

i 3-2 'Ihe passive RHR heat exchanger is actuated by the CMT injection signal. The heat removal by the PRHR (Figure 3-9) and CMT reduces the primary s/ stem.md faulted steam generator pressure below the secondary system relief valve setpoints. The two pressures are essentially - equalized, stopping the loss of coo ant from the primary system. The flow between the primary and se:ondary systems fluctuates around zero (Figure 3-1), and the primary system water level !s mainitained throughout the transient (Figure 3-10). The secondary safety valves never open since the pressure in the faulted steam generator remains below the safety valve actuation pressure throughout the entire accident scenario (Figure 3-4). The water level in the core makeup tank (Figure 3-8) does not decrease d ae to the recirculation mode injection and the RCS remains subcooled throughout the transient (Figure 3-7). 3.1.2 Case SG2 through SG5 - Two through Five Tube Multiple-SGTRs The MAAP4 res da of cases SG2, SG3, SG4, and SG5 are presenied in Figures 3-11 through 3-50. The event fming s"mmaries are presented in Tables 3-3 through 3-6, respectively. The results are essentially the same as case SG1 with differences in the timing attributed to the increasing . break sizes. No vo'dng of the RCS or draining of the CMT is predicted in any case. The ADS is not actuated. The stea w generator does not overfill and the safety valves do not open. 3.2 SE14SITIVITY CASES The cases presented in this section examine variations in the initial conditions and in the PRHR modeling to demonstrate that the base results of the analysis are robust. The cases examine the sensitivity of the results to break elevation, and variations in the effectiveness of the PRHR heat removal. Each sensitivity case is based on the SG5 base case as it is most challenging for steam generator pressurization and overfill. Additionally, several cases are examined with various system interactions: the time available prior to the need for operator action to cooldown the primary system e with auxiliary sprays in the active system only case, SG5op, failure of the secondary PORV to open is presented in case SG5p, e successml CVS injection interaction with passive systems case is presented in case e SG5cvs. the case in which the CVS injects, secondary PORV fails to open, and the safety valve is postulated to stick open when it is actuated is presented in case SG5stk. The final case, SG5stk, demonstrates the AP600 defense-in-depth using the ADS mitigation of the accident. MAPP4 Analysis Results Revision 0, November 1997 o:\\3931. doc 1b 11/s/97

3-3 3.2.1 Case SG5b - Break Elesation Sensitivity-Case SG5b is the same as base case SG5 with the break elevation increased to the top of the tube bundle. In the base case, the break was assumed to occur on the cold side at the tubesheet. The results of the MAAP4 analysis are presented in Figures 3-51 through 3-60. Event timing is presented in Table 3-7. As in the base case, the CMTs remain full of water throughout the transient, The CMTs and PRHR heat removal stops the loss of coolant though the break. No ADS actuation is predicted. The pressure in the faulted steam generator remains below the safety valve actuation pressure throughout the entire accident scenario. The overall resulta are not sensitive to break elevation. 3.2.2 Case SG5 max - Maximum PRHR Heat Exchanger Performance Case SG5ma S the ame as base case SG5 except the passive RHR heat removal is increased from best-estimate to the maximum performance. The madmum PRHR performance is 'modeled as benchmarked in section 2. The MAAP4 results of the ana4 sis are presented in Figures 3-61 through 3-70. Event timing is presented in Table 3-8. As in the base cases, the CMTs remain full of weter throughout the transient. The CMTs and the PRHR heat removal stops the loss of coolant through tne break. No ADS actuation is predicted. The pressure in the faulted steam generator remains below the safety valve actuation pressure throughout the entin accident scenario. The overall results are not sensitive to increased PRHR heat exchanger performance. 3.2.3 Case SG5 min - Minimum PRHR Heat Exchanger Performance Case SG5 min is the same as base case SG5 except the passive RHR heat removal is decreated from best-estimate to the minimum performance. The minimum PRHR performance is modeled as benchmarked in section 2. The MAAP4 results of the analysis are presented in Figures 3-71 through 3-80. Event timing is presented in Table 3-9. As in the base cases, the CMTs remain full of water throughout the transient. The CMTs and the PRHR heat removal stops the loss of coolant through the break. No ADS actuation is predicted. The pressure in the faulted steam generator remains below the safety valve actuation pressure throughout the entire accident seenario. The overall results are not sensitive to decreased PRHR heat exchanger performance. 3.2.4 Case SG50p - Nonsafety-Related Injection Systems Only Case SG5cp is a five-tube multiple SGTR with the assumed failure of the passive RHR and CMTs. The MAAP4 results are presented in Figures 3-81 through 3-91. Event timing is presented in Table 3-10. The CVS is assumed to be 5jecting at 100 gpm at time zero (Figure 3-81), the minimum injection flowrate. SFW is available and injection is controlled on the steam generator level. The run is terminated at 1530 seconds when CVS and SFW are isolated at the steam generator water level of 79 percent of the narrow range span. The analysis demonstrates that at the lowest expected flowrate of the CVS, the core remains covered, I MAAP4 Analysis Results Revision 0. November 1997 c:\\393140citw11/s/97 I. (

3-4 allowing the operator sufficient time to cool the RCS with the intact steam generator and to align the CVS injection to the pressurizer sprays, depressurize the RCS to stop the leak. 3.2.5 l Case SG5p - Secondary PORY Failure to Open Case SG5p is the same as the base case SG5 except the secondary system PORY is assumed to not open when the pressure exceeds the opening setpoint. The MAAP4 results are presented in Figures 3-92 through 3-101. The event sequence timing is presented in Table 3-11. As in the base case, the CMT remains full of water throughout the transient. The CMTs and PRHR heat removal stops the loss of coolant through the break. No ADS actuation is predicted. The pressure in the faulted steam gener. tor exceeds the PORV setpoint, but remains below the safety valve actuation pressure throughout the entire accident scenario. 3.2.6 Case SGSevs - Operation of the CVS Injection with the Passive Systems Case SG5cvs is the same as base case SGS except the CVS system is assumed to be injecting at the time the break occu;s. The CVS injection rate is 170 gpm, the maximum injection allowed by the cavitating venturi in the system. The SFW system injects 200 gpm into the steam generators and is not throttled by the level control system. CVS and SRV inject imtil the steam generator water level reaches 79% of the narrow range level (totallevel of 14.5 meters above the tubesheet) when they are automatically terminated. The MAAP4 results for case SG5cvs are presented in Figures 3-102 through 3-112. The sequence timing is presented in Table 3-12. Tha tube rupture occurs at time zero and tl.e loss of coolant from the RCS exceeds the CVS injection. The pressurizer heaters actuate on low pressure. The heaters are not effective due to low water level in the pressurizer. CMT actuation occurs due to a drop in pressurizer level. The signal actuates the CMTs and PRHR, and trips the reactor, the turbine, the reactor coolant pumps and the pressurizer heaters. The CVS injection maintains the RCS and faulted secondary pressure at the setpoint of the secondary system PORV for an extended duration. At 1929 seconds the secondary water level exceeds the hi-2 steam generator narrow range level and the CVS and SRV are terminated. Shortly after the CVS injection stops, the secondary PORV closes and the primary and faulted secondary system pressures are equilibrated, terminating the break flow. The CMTs do not drain and the RCS is not voided. Therefore, the ADS is not actuated. The plant achieves e safe, stable condition without uncovering the core. However, the results suggest that in the event of the condenser and PORV failure, the secondary system would pressurize to the safety valve opening pressure prior to the isolation of the CVS and SMV. Therefore, either the non-safety turbine bypass or PORV opening function is required to prevent the safety valve from opening in the event of CVS injection or unthrottled SFW injection. 3.2.7 Case SG5stk: Stuck Open Secondary System Safety Valve Wis section presents the results of case SG5stk in which the CVS injects, SFW is unthrottled, turbine bypass and PORV fail to open and the secondary system safety valve is postulated to MAPP4 Analysis Results Revision 0, November 1997 oA3931. doc 1b 11/5/97 l

3-5 stick fully opan. The assumption that the safety valve sticks is highly conservative since the plant automatically prevents steam generator overfill and the valve does not relieve water. A five tube double-ended break is assumed to occur at the steam generator tubesheet. The PRHR and all trains of ADS, CMTs, accumulators and gravity injection are available. The CVS system is assumed to be injecting to the RCS at the time of the break. The secondary system PORV is assumed to not open, thus failing to control the pressure on the secondary side. As the accident progresses, the secondary,ystem is pressurized to the opening pressure of the safety valves by the SAV and CVS injection through the break, and die valve is assumed to stick open at this time. No operator actions and no nonsafety-related systems are credited with mitigating the accident. The non-safety CVS and SRV are modeled since they have the adverse effect of overfilling and overpressurizing the steam generator. The CVS and SRV injections are automatically isolated on the hi-2 steam generator signal at 79% of the narrow rage span. The MAAP4 results are presented in Figures 3-113 through 3-127. The event timing is presented in Table 3-13. At time zero, the five steam generator tubes are assumed to fail at the steam generator tubesheet, and primary coolant is lost into the secondary system (Figure 3-113). The CVS is injecting 170 gpm at the time the break occurs (Figure 3-114). The loss of coolant causes the RCS pressure (Figure 3-115) and the pressurizer level (Figure 3-116) to fall, and at 81 seconds, CMf injection is initiated due to low level in the pressurizer. On the injection signal, the reactor scrams, and the turbines and main feedwater trip, Startup feedwater (Figure 3-117) and passive RHR (Figure 3-118) are initiated. The CMT injection (Figure 3-119) trips the reactor coolant pumps and the pressurizer heaters. The CMT injects in recirculation mode without reducing the water level in the tank (Figure 3-120). The RCS and faulted steam benerator pressure (Figure 3-115) are essentially equalized, and coolant is lost from the primary side to the secondary side at approximately the injection rate of the CVS. The increase in the steam generator level (Figure 3-121) due to the CVS and SRV injection compresses the steam bubble in the secondary and increases the system pressure. The turbine bypass to the condenser and the secondary PORVs are assumed to fail to open, so the pressure continues to increase to the safety valve opening pressure (Figure 3-122). One safety valve opens and is assumed to stick open. The pressure in the secondary system falls due to the loss thmugh the safety valve. The break flowrate through the broken tubes increases and the RCS pressure is reduced. The decrease in pressure allows the accumulators to injact (Figure 3-123), temporarily stalling the CMT injection and increasing the pressurizer water level. The water level in the faulted steam generator dips slightly due to flashing at the time that the safety valve sticks open, but continued break flow and SFW injection cause it to increase again. At 2979 seconds, the hi-2 steam generator narrow range level is reached and the CVS and SRV inje ion are isolated. The accumulator water is depleted at 4335 seconds, and the injection of non-condensable nitrogen into the RCS is assumed to fail the PRHR heat removal. The loss of heat removal causes the RCS to begin to saturate (Figure 3-124), and at 12100 seconds, the CMTs begin to drain. The low-1 CMT level is reached at 12629 seconds and ADS is actuated. The RCS pressure is approximately 100 psia at the time ADS is actuated. Stages 1,2 and 3 ADS MAAP4 Analysis Results RevWon 0, November 1997 oA3931.du:lb-11/s/97

) w . lines are opened by a timer following ADS system actuation causing water to flood into the - . pressurizer. J i Stage 4 ADS is opened on a low-2 CMT level at 13300 seconds. Stage 4 ADS allows gravity injection of IRWST water (Figure 3-125) into the reactor vessel. He IRWS1 water fills the - t containment (Figure 3126) and at 23637 seconds, the gravity recirculation lines ar-opened by a l low IRWST level. The containment water level reaches the maximum elevation in the flooded ' volumes at the 108-foot elevation. Coolant inventory is lost from the system as steam through the stuck open safety valve at a rate of approximately 5 lbm/sec (Figure 3-12_7), As this rate ) decreases over time with decay heat, long-term cooling can be maintained for more than 3 days without adding makeup water to the containment. The fourth stage depressurization of the RCS reverses the break flow from the secondary into the primary system. Secondary water flashing in the primary system does not affect the passive system' performance. The passive RHR and CMTs have completed their funcions prior to depressurization, and ADS is designed to depressurize the system from much higher pressures and flowrates than predicted at the time of reverse flow in the SGTR. Adverse boron dilution from the reverse flow is not expected and is addressed specifically in the next section. ~ 3.3 BORON DILUTION DURING ADS The potential dilution of RCS boron during ADS initiated by a multiple-SGTR en issue discussed in SECY-93-087. The dilution is postulated to occur due to reverse flow of cold, ' unborated secondary system water to the RCS when the pressure drop through the break reverses. The scenario is postulated to result in positive reactivity in ertion in the core. This section estimates the effect of the reverse flow during depressurization on the boron concentration in the RCS. The MAAP4 cc de does not track the boron concentration, therefore, the boron concentration calculation is performed post-process, using water mass and flow data generated by the MAAP4 code.- 3.3.1 Baron Concentration Calculation Method and Assumptions A five node model is used to track boron in the MAAP4 calculations. The nodalization and the flow links between them are presented in Figure 3-128. The nodes arenodeled as lumped masses and are assumed to be well-mixed. . The boron is tracked in the following control volumes: i reactor coolant system - faulted secondary system - +- core makeup tank 1 L core makeup tank 2 IRWST and containment sump Two constant boron concentration injection sources are also modeled: the accumulators and the CVS.- Best-estimate boron concentrations are assumed for all the water sources. CMTs have an .- MAPP4 Analysis Results. Revision 0, November 1997 o:\\3931. doc 1b-11/5/97 1 s ..,. -. ~,. - -.. - - m...',m.,

3-7 initial boron concentration of 3400 ppm which changes over the transient as RCS water mixes in the CMT. The IRWST has an initial boron concentration of 2600 ppm which changes very little as the water mass is so large. The accumulators inject water with a constant 2600 ppm boron concentration, and the CVS injects water with a constant boron concentration equal to the RCS concentration prior to reactor scram. After scram, the CVS water boron concentratien increases to 4300 ppm. Unborated startup feedwater injects to tl.e secondary system. The secondary.- system water is not initially borated. The RCS water boron concentration ranges from 1600 ppm at the beginning-of-life to 0 ppm at the end-of-life. Calculations are performed for both beginning-of-life and end-of-life to bound the range of RCS boron concentration. The water masses in each node and flows between nodes during each time step are calculated by MAAP4 and are saved to a file that is input to the boron calculation. The boron calculation tracks the boron mass in each of the flows based on the upstream boron concentration and calculates the boron concentration in control volumes at each time step. In this calculation it is assumed that: boron is carried in water flow at the snurce concentration, steam flow does not carry boron, a the boron instantaneously mixes in the receiver control volume, e The SG5stk case, which activates ADS due to coolant loss through a stuck-open secondary safety valve, is analyzed for the boron dilution after ADS injects until the IRWST injection is established. 3.3.2 - Baron Dilution in Case SG5stk The thermal-hydraulic details of case SG5stk are presented in section 3.2.7 and Figures 3-113 through 3-127. The event timing in the case is presented in Table 3-13. The boron concentration for the RCS and secondary systems are presented in Figure 3-129 for the end-of-life and Figure 3-130 for the beginning-of-life initial conditions. In the end-of-life case, the boron concentration in the RCS and the secondary system begin at 0 ppm. The initiation of the CVS boration and the CMT recirculation injection at the time of reactor scram increase the concentration in the RCS and decrease the concentration in the CMT as RCS water is mixed in the CMT The boron concentration in the secondary system increases slightly until the time that the safety valve sticks open and the break flow fcom the RCS increases. The loss of clean secondary water as steam through the stuck-open valve accelerates the increase in boron concentration in the secondary water. As the RCS water saturates, the ' RCS boron concentration increases slightly due to the loss of water as steam. The secondary water boration rate increases as there is more boron in the break flow. The CMT boron concentration decreases due to the condensation of unborated steam from the RCS balance line. At ADS, the RCS and secondary system boron concentrations are approximately the same. The - RCS boron concentration peaks due to flashing of water during depressurization, and the secondary boron concentration becomes constant as the break flow reverses from the secondary system to the primary system. As the IRWST water injects, the RCS boron concentration equilibrates to the IRWST boron concentration. MAAP4 Analysis Results Revision 0, November 1997 o:\\3931. doc 1b-11/5/97

3-8 The beginning of life boron concentration transient response is approximately the same as the end-of life transient, except the overall concentrations are higher prior to gravity injection. The , secondary system concentration is significantly higher than it is in the end-of-life case as more

boron is in the break flow and collected there from the beginning of the transient. After gravity injection, the boron concentration in the primary system equilibrat.es with the IRWST boron concentration.

No adverse boron dilution of the RCS water occurs due to the boradon of the secondary water - to the RCS boron concentration which occurs over the course of the transient. l ,MAPP4 Analysis Results. Revision 0, November 1997 c:\\3931.docib 11/5/97 .. ~.

3-9' Table 3-1 AP600 Multiple Steam Generadr Tube Rupture MA AP4 Case Input Assumptions ~ System Availability - Case Failed CVS SFW PRHR CMTs ADS / Gray Sec PORV/ Comments Tubes Inject Condenser SG1 1 No . 200 gpm ' Best Est Yes Avail / NA - Yes Safety Cases SG2 2 No 200 gpm Best Est Yes Avail / NA Yes SG3 3 No 200 gpm Best Est Yes Avail / NA Yes SG4 4 No 200 gpm Best Est Yes Avail / NA Yes' SGS - .5 No 200 gpm Best Est Yes Avail / NA Yes SG5b 5 No ' 200 gpm Best Est Yes Avail / NA Yes ' SG5 min ' 5 No 200 gpm Min Yes Avail / NA Yes ,SG5 max 5 No 200 gpm Max Yes Avail / NA Yes SG50p 5 100 gpm - 200 gpm Failed Failed Avail / NA Yes No passive system available SG5p 5 No 200 gpm Best Est Yes Avail / NA Failed SG5cvs 5 170 gpm 200 gpm Best Est Yes Avail / NA Yes SFW unthrottled SG5stk 5 170 gpm 200 gpm Best Est Yes Yes Failed SFW unthrottled Sx SV sticks fully open MAAP4 Analysis Results Reviskm O, November 1997 <x\\3931 doc 1b-11/5/97

____..-_._.m.___ f S-10 i Jable 3 2 Case SGI Accident Seeuence Tisnina Tiene Events I O rupture of 1 stearn generator tube f 8 pu heaters on 143 pu heaters uncovered l 5 347 CMT in}ection signal on low pressurizer level [ Rx scrarn, turbine trip, MFW trip PRHR on,SFW on CMT on, RCP trip,pzt heaters trip j 550 secondary PORY opens accumulators begin toinject hi 2 NR water level in faulted steam genernur CVS and SFWisolated 5 - accumulator water depleted j PRHR heat removal assumed failed by NC gas 1 CMTs begin todrain a: Iow.1 CMTlevel ADS netuated i stage 1 ADS open i + Jtage 2 ADS open + stage 3 ADS open t low 2 CMTlevel stage 4 ADS open i gsarityinjection begins i low IRWST waterlevel gravity recirculation valves opim [ e l 1 r _f -l 1 MAAP4 Analysis Results Revwon o, November 1997 .l - oA3931.docib 11/5/97 - i l ,_..,1 s..,,., ,,._,__......4_.__.-...

3 11 Table 3 3 Case SG2 Accident Sequence Timing Time 'ivents (seconds) 0 rupture of 2 steam generator tubes 4 pzr heaters on 79 pzr heaters uncovered 180 git injection signal on low pressurizer level Rx scram, turbine trip, MRV trip PRiiR on,SRV on CMT on, RCP trip, pzt heaten trip 274 r.econdary PORV opens accumulators begin toinject hi-2 NR water levelin faulted steam gene; ator ' YS and SRV irolated accumulator water depleted PRiiR heat removal assumed failed by NC gas GiTs begin to drain low 1 CMTlevel ADS actuated stage 1 ADS open stage 2 ADS open stage 3 ADS open low 2 CMTlevel stage 4 ADS open gravity injection begins low 1RWST water level gravity recirculation valves open MAAP4 Analysis Results Revision 0, November 1997 c:\\3931.docit*13 /5/97

3 12 Table 3-4 Case SG3 Accident Sequence Timing Time Events (seconds) 0 rupture of 3 steam generator tubes 2 pzt heaters on 54 per heaters uncovered 121 CMT injection signal on low pressurizer level Rx scram, turbine trip, MFW trip - PRHR on,SFW on 1 CMT on, RCP trip,pzr heaters trip j 192 secondary PORY opens accumulators begin toinject h! 2 NR water level in faulted steam ger.erator l CVS and SFWisolated accumulator water depleted PRHR heat removal assumed failed by NC gas CMTs begin to drain i low.1 CMTlevel ADS actuated stage 1 ADSopen stage 2 ADS open stage 3 ADS open low 2 CMTlevel stage 4 ADS open gravity injection begins l low 1RWST waterlevel gravity recirculation valves opca i i c MAAP4 Analysis Resultw Revtuon 0, November 1997 a\\3931.docib 11/5/97 4-w,, -s--e--aear-.. m+---.,--se w-,. r-s*v---*w.-r...- eww ,w

-o ms-,e

--w--a v~e-.--+,,,--a .m.,, w...

3 13 Table 3 5 Case SG4 Accident Sequence Timing Time Events (seconds) 0 rupture of 4 steam generator tubes 2 pzt heaters on 41 pzt heats uncovered 94 CMT injection signal on low pressurizer level Rx scram, turbine trip, MRV trip PRHR on, SRV on CMT on, RCP trip,pzr heaters trip 159 secondary PORV opens accumulators begin toinject hi 2 NR water level in faulted stcam geneator CVS and SRV isolated accumulator water depleted PRHR heat removal assumed failed by NC gas CMTs begin to drain low.1 CMTlevel ADS actuated stage 1 ADS open stage 2 ADS open stage 3 ADS open low.2 CMTlevel stage 4 ADS open gravity injection begins low IRWST wa6er level gravity recirculation valves open MAAP4 Analysis Results Revision 0, November 1997 oA3931 doc 411/5/97

S 14 Table M Case SGS Accident Sequence Timins Time Events (seconds) j i 0 rupture of 5 steam generator tubes l 2 pzt heaters on [ t' 33 pzt heats uricovered 75 CMT injection signal on low pressurizer level j Rx scram, turbine trip, MFW trip PRHR on,SFW on CMT on, RCP trip,pzr heaters trip 134 secondary PORV opens [ accumulators begin toinject hi 2 NR water level in faulted steam generator l CVS and SFWisolated accumulator water depleted PRHR heat removal assumed failed by NC gas CMTs begin to drain 1 low 1 CMTlevel ADS actuated ' stage 1 ADS open ' stage 2 ADS open stage 3 ADS open low 2 CMTlevel i stage 4 ADS open gravity injection begins-low IRWST water level gravity recirculation valves open. k MAAP4 Analysis Results Rah 0,Novemter 1997 a\\393tdocib 11/5/97 - ~. ..2 ..a

3 15 Table 3 7 Cane SGSb Accident Sequence Timing Time Events (seconds) 0 rupture of 5 steam generator tutes 2 pzr heaters on 33 pzt heaters uncovered 75 CMT injection signal on low pressurizer level Rx scram, turbine trip,MFW trip PRIG on,SFW on CMT on, RCP trip,pzt heaters trip 134 secondary PORV opens actumulators begin toinject hi 2 NR water level in faulted steam generator CVS and SFW isolated necumulator w'4 r depleted PRHR heat ts ava !*med failed by NC gas ...c,,...~. CMTs begin to ar.w low 1 CMTlevel ADS actuated stage 1 ADS open stage 2 ADS open stage 3 ADS open low 2 CMTlevel stage 4 ADS open gravity injection begins low IRWST water level gravity recirculation valves open MAAP4 Analysis Results g,visiono,Nov,md,:),7 oA3931. doc 1h11/5/97 i w

.- -.. _ ~ 3 16 Table 3-8 Case EG5 min Accident Seevence Timina Time Events (seconds) _ j I 0 rupture of 5 steam generator tubes 2 pzt heaters on 33 par heaters uncovered l 75 CMT injection signal on low pressurizer level { Rx scram, turbine trip, MIW trip - PRHR on,SIW on CMT on, RCP trip, pzr heaters trip f 134 secondary PORV opens accumulators begin toinject l hi 2 NR water level in faulted steam generator f CVS and SFW isolated j accumulator water depleted l PRHR heat removal assumed failed by NC gas i CMTs begin to drain j ~t low.1 CMTlevel ADS actuated j i stage 1 ADS open stage 2 ADS open stage 3 ADS open L low 2 CMTlevel stage 4 ADS open j gravity injection begins low IRWST water level gravity recirculation valves open 4 i t i [ MAAP4 Analysis Results. m o,w % 39,7 a\\39314cc:Ib 11/5/97 y t ~ _,.. .m.__,

~_ _ _.._ _. _ _ _ _ _.. _ _ - _ _ _ _ _ _ _._ _ _ _. _ _ 3 17 Table 59 Case SG5 mas Accident Sequence Timina j Time Events i (seconds) 0 rupture of 5 steam generator tubes 2 pu heaters on 33 pu heaters uncovered 75 CMT injection signal on low pressurizer level Rx scram, turbine trip,MFW trip PRHR on, SFW on. CMT on, RCP trip,pu heaters trip 134-secondary PORV opens accumulators begin toinject hi 2 NR water level in faulted steam generator CVS and SFW isolated - accumulator water depleted PRHR heat removal assumed failed by NC gas CMTs begin to drain low.1 CMTlevel ADS actuated stage 1 ADS open stage 2 ADS open stage 3 ADS open low.2 CMTlevel stage 4 ADS open gravity injection begins low 1RWST waterlevel gravity recuculation valves open . MAAP4 Analysis Results Revision O. November 1997 a:\\3931. doc 1b 1I/S/97

__ _.m 11.s Table 310 Case SG50p Accident Sequence Timing Time Events (seconds) O rupture of S steam generator tubes r CVSinjecting 100 gpm 2 pzr heaters on f 33 pzr'neaters uncovered l 78 CMT injection signal on low pressurizer level Rx scram, turbine trip, MFW trip SFW on,RCP trip, pzr heaters trip 133 secondary PORV opens accumulators begin toinject 1530 hi 2 NR water level in faulted steam generator CVS and SFW isolated accumulator water depleted PRHR heat removal assumed faued by NC gas CMTs begin to drain low.1 CMTlevel ADS actuated stage 1 ADS open stage 2 ADS open stage 3 ADS open-low.2 CMTlevel stage 4 ADS open gravity injection begins low 1RWST waterlevel gravity recirculation valves open L j 4 MAAP4 Analysis Results Revision 0, November 1997 c:\\393140cib11/5/97 4,-_ , _.. _. ~ .. -... ~.. _ _, - -.._

.m. _.m 3 19 Table M1 Case SG5p Accident Sequence Timing Time Events (seconds) i 0 rupture of 5 steam generator tubes i 2-pzr heaters on 33 pzt heaters uncovered 75 CMT injection signal on low pressurizer level - Rx scram, turbine trip,MFW trip PRHR on,SFW on CMT on, RCP trip,pzt heaters trip secondary PORV opens accumulators begin toinject hi 2 NR water level in faulted steam generator CVS and SFW isolated accumulator water depleted PRHR heat removal assumed failed by NC gas CMTs begin to drain low 1 CMTlevel ADS actuated stage 1 ADSopen stage 2 ADS open stage 3 ADS open low-2 CMTlevel stage 4 ADSopen gravity injection begins low IRWST waterlevel gravity recirculation valves open i MAAP4 Analysis Results Revision 0, November 1997 oA39314cc1b 11/5/97 - . ~.. ._;________...__..__...______.._.,a._...

..-.. _.. _ _ _ - - - ~.. _ - _ _ _. _.. _ _ _ _. _ _ _. _ _ _ _ _ _... _ _. _. - ! 3 20 t Table 312 Case SG5cvs Accident Sequence Timing - Time Events l ' (seconds) O rupture of 5 steam generator tubes CVSin}ecting 170 gpm 2 pu heaters on l 35 pu heaters uncovered 82 CMT injection signal on low pressuriser level - i Rx scram, turbine trip, MFW trip PRHR on,SFW on CMT on, RCP trip,pu heaters trip 414 secondasy PORY opens accumulators begin toinject 1929 hi 2 NR water level in faulted steam generator CVS and SFW isolated accumulator water depleted PRHR heat removal assumed failed by NC gas CMTs begin to drain low 1 CMTlevel l ADS actuated stage 1 ADS open l stage 2 ADS open stage 3 ADS open low 2 CMTlevel stage 4 ADS open gravityinjection begins low IRWST weterlevel gravity recirculation valves open L i MAAP4 Analysis Results % o, %.,% 39,y' . o:\\303140 cit >11/$/97 - B T -~w ..m -v-6-wm-e, w e--, +s --m -r ,, e e +

- ~. ) i 3 21 r i Table 313 Case SG5stk Accident Sequence Timing Time Events (seconds) 0 Ruptureof 5 Tubes t CVSinjecting 170 gpm 2 pzt heaters on 33 pzr heaters uncovered i 81 CMT injection signal on low pressurizer level Rx scram, turbine trip, MFW trip PRHR on,SFW on CMT on, RCP trip, pzt heaters trip 768 secondary SV Sticks open 825 accumulators begin toinject 2978 hi 2 NR water level in faulted steam generator CVS and SFWisolated 4335 accumulator water depleted PRHR heat removal assumed failed by NC gas 12100 CMTs begin to drain 12629 low.1 CMTlevel ADS actuated 12694 stage 1 ADS open 12809 stage 2 ADS open 12929' stage 3 ADS open 13299 low 2 CMTlevel stage 4 ADS open gravity injection begins 25637 low IRWST water level gravity recirculation valves open MAAP4 Analysis Results Revhion 0, Novemic 1997 o:\\3931.docit>11/5/97 -1 1 J~.,. , +, - *, y :_. -. -... -. ~. e.- - -.---- ~ - - - +

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.?4 w> w> E2 hk c .AP600 l' Tube C o l d' S i d e SGTR ot Tubesheet - Base Case Qi Pressurizer Water Level ex 3 5 - 15 e 4-n ~ E m 3-- - 10 " y U ~ C I j. cn 2 - I- ~ c cn r i e -5 C S 1-l l i y 0 l i 0 l: 0-1000 2000 300a 4000 Time (sec) a S E e y i U ,,,,--n, ..~

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Faulted SG U n t a u l^t e d SG 160 m

140 - 2 o - 2000 -- = _o 120 - j - 1500 100_ t a) 80 - ~ - 1000 a 60 -;; _ _, m m 3 m 40 - U3 i - 500 m a> 20 - l o_ u 5 0 l l 0 i 0 ,C

1000 2000 3000 4000 y

Time (SeC) if

n. 3waI . f -AP600 1 ' Tube Cold Side SGTR ot Tubesheet Bose Cose ~ L .51 Steam Generotor Downcomer W e t~e r Level s s-4g Faulted SG

UnfaultedSG 11.6

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E foulted SG ey

Safety Valve Setpoint PORY Setpoint i

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1 35 1 r 55 .i [ 2 .y i I !. AP600 1 Tube Cold Side SGTR at Tube' sheet - Bose Case i 54 CMT Water Moss Flourotes sw Ag .Dischoge Line ~ -E

Balance line

\\ -w F t 20 l m ~ ^^ r . o, ( 40

E l

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6_. b b. !I l e. AP600 1' Tube Cold Side SGTR o 't Tubesheet'- Bose Case j} RCS and CMT Water Temperatures 4M RCS Core Water 2 g

CMT Wo.t e r t

Tsat 650

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3 .M h- . ! g. Ze. -AP600 '1 Tube C o l d -S i d e SGTR ot Tubesheet Base Case 54 CMT Water Level f"Wg 7 a 6-h - 20 .l n E5-v K 4-v m ~ _c '"3- : < C c "' 2 -: a2 ) -5 1- [ 0 l l 0 g 0 1000 2000 -3000 4000 o f 1 'z T+ime i s e c >l g r T

w E2hi E{ AP600 1' Tube Cold Side SGTR ot Tubesheet - Bose Case Rr PRHR Heat Removo! E PRHR Cs

Decay Heat 1

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i hh at g. "i 5& .AP600-1 Tube Cold Side SGTR at Tubesheet Bose Case -36 RCS Woter Level b ac if 25 r - 80 I a 20 - I i - ^ m - 60 5 h 4 m 15-V 1 4 a r ~. - 40 m o ~ cn 10 - W c-CD c_ - 20 i 5-i w i e n t t t t t t i f f f f 9 i f i f f f 0 h U 5 3 5 E D 1000 2000 3000 4000 ~o 3 T.ime sec ) z t a i 3 [ 4 .~n.- +. --,e

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S'&: M2l'; .fk AP600 2 Tube. Cold Sid'e SGTR ot Tubesheet - Bose Case Q. Steam Generator Downcomer Water Level -4 F Faulted SG E

Unfoulted SG e

11.8 11.6 - i - 38 w m ^ E 11 4 -: ~ _37" v 11.2 - v y _c 11 - - 3 6 _c ~ & 10 G-l c t i

)

10.6 - - 35 c 'i e) a - - - - - -. - ~ -. - - - - - a 10.4 - - it _ 34 - Il [ 10.2 l i g 0 1000 2000 3000 4000 j Time (seC) 1 s Yd 6 .. ~ -

n Y M- .e f*- .pt - :5 AP600 2 Tube Cold Side SGTR ot Tubesheet Bose Case Ei! Foulted Steam Generotor. Pressure i Foulted SG C s

Safety Volve Setpoint

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- 1140._ o.78 - m O I - 1120 a. -] v y 76- :--------------------- - 1100 e u - 1080 74 - 2 3

m

~ - 1060

m
72 -:

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Balance Line z

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o

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F

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i >w 2:ha

0. g

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F I

5 - 15 4 -- m n 2! 3__ - 10 " g c _c L ~ ~ .o2-w c -5 __.a 1-0 T l' l 0 ~ ' ^ ^ ' I !~ 0 1000 2000 3000 4000 C h Time sec s 3 r i i

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y t:

e 80 - r- - 1000 m s 60 - -1 3 m. m 40 - : - 500 m -S o 20 - e o_ [ 0 ~ ' l l l 0 g 0 1000 2000 3000 4000-T.ime ( s e c 'i f 3 'z R9 k a _, e- -e - + - -

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- 38 ^ m E **~~ 3 _37* v

l 11.2 - -

E ~ c 11 -

_ 3 6 _c.

~ ~ cn 10. 8 - C - 35 c 1 0.' 6 - : o __J. ,( 10.4 - _ 34 [ 10.2 l -i 0 1000 2000 3000 4000 .o (sec-) r y T.ime 3 I

Y* 3 M Eb.ilI Base Case $3 AP600 3 Tube Cold Side SGTR at Tubesheet E i-Faulted Steam Generator Pressure

y foulted SG Solety Volve Setpoint

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.gr .b

0. g ES AP600 3 ' T u b'e Cold Side SGTR at Tubesheet - Bose Case E E.

CMT Water Moss Flowrote's O f3 Disch'oge Line 80Ionce Line 20 I ~ -40" cn E x .a ] - ss'/ gs t. 15 - v _30" 21 8 \\<sb\\ O v'sa

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m-

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M E

5 AP600 3 Tube Co l d -S i de SGTR ot Tubesheet.- Bose' C o s'e 5% CMT Woter Level s u. .n y E 7 E 6- - 20 m ^ E5-3 ~

v 5.

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n 15 --

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Faulted SG Unfoulted SG l

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t. e v e l -

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1 0. 6 -- -

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74 --

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CMT Water 600-

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a v-F .j$ E .d k

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I k a _ Au Eg ' $4 AP600 4 Tube Cold S i de SGTR at Tubesheet Base Case E E-PRHR Heot Removof i

[

PRHR h

Decoy Heat 60 2E+09 s

s m 50 - s m s ' c 3 .15E+09 N s g" 2 40 - 's 3 s 's v g ~~ m 30 - u .1E+09 v a) 3:. 2 0 - O .5E+08 o_ 35 10 -- o-G- F ~ 0 ;''l 0 k 0 1000 2000 3000 4000-P f i [ I.lme (SeC) B T 5 l 1 l 4

S" tt { s

3. 2

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B s w E 8 - P >. g Ey. AP600 5 Tube Cold Side SGTR at Tubesheet Bowe' Case 3 " u' Tube Rupture Break Flo'w - eg E. ^ 140 - 300 ^ m N 120 - l x _7 - 250 E 100 -- v - 200 " 5 80 - e ~ 3 - 15 0 -. y 60 - O Z m 40 -1 - 100 D o O u-20 -2 - 50 l ~ m g lffff ~^ O~: v -0 O g 2 ~ i s g -20 l i e i l q 0 1000 2000 3000 4000. Time (sec) l [ 8

v.. kh Eh Er 1 e. AP600 5 Tube Cold Side SGTR at Tubesheet - Bose Case j) Pressurizer Water Level ~

y l

5 - 15 4-- m ^ E v - 10 v m 3__ a.! c c r ~ & 2 -- m c C _5 a> a, .__s a 1 -- [ 0 -y' 'r"M 0 9~ 0 1000 2000 3000 4000 / \\ 'z I*lm0 (SeC) O !s a . _ = _ - _ _

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l..

0 1000 2000 3000 4000 i; T T,n e (sec,J 2 3 E

av $k E2 d i Bose Case AP600 5 Tube Cold Side SGTR at Tubesheet E E-Steam Generator Downcomer Water L,e v e l

y foulted SG y

Unfoulled SG 12

- 39 1 n i ^ E 11.5 - j' s v -37v 1 11 - - 36 r

r

~ ~ cn C" - 35 c-5 ~ ~ - - - - ' - ' - - - - ~ ~

10. 5 --I

-I, ' - 34 __,. g ~ [ 10 l 8 0 1000 2000 3000 4000 i Time (Sec) e 3 ? w P

' 9 k 3 E2 AP600 5 Tube Cold Side SGTR ot Tubesheet ' Bose Case G Fev' i Steam Generctor Pressure tw

sg Foulteo aG g

- - - - S a f e t.v Valve Setpoint

PORV Setpoint 80 1160 n

2 O - 1 1 4 0.._ o 78 - D m - 1120 ct E U g 76 -:--------------------------- - 1100 G) - 1050

u 74 -

u 2 s m - 1060 1 m m

72 ~

- 1040 u a2 L f - 10 2 0 n_ 1 4 70 e i 0 1000 2000 3000 4000 i P f T y T*ime (sec) 93 t i I l t w er - - - - + -, n.- ,n-

'S 3 . [2 Z AP600 5 Tube Cold ~ Side SGTR at Tubesheet - Base Cose 51.1 CMT Water Moss Flowrote~s s ~ My D i s c h a g e-'L i n e g

Bolonce Line

_ 20 i x - 4 0 x,, E x n y %it'16 e - -30 v s<.Lt ' s ', _,* 2 \\

s ~ v.

a 10 - o -w_- a: - 2 0 cr p ~ o u-5- - 1 0 "- v3 v. 44 WB C O g 0 l l 0 l 2 i 0 I N ~ 1000 2000 3000 4000 l Time (secI x a E o 4

.g M A 3..s It AP600 5 Tube Cold Side SGTR ot Tubesheet - Bose Case Q RCS and CMT Water Temperot~ures 4F RCS Core Water E

CMT Water Tsot 650

^ - 700 ^ x c W v 600 -:s - 600 "

\\

2 550 - I ~ ~ ~ ~ - - - - ~ ~ - - ^ - - ' - - - - - - " g e - 500 e ' 500 - ; i o - 400 ~ 450 - o ~ ~ _ _ _. o - 300 u u i e 400 -5 e i ca. - 200 E 350 - 2 E e e ~' y " 300 i i'i' 2 I O 1000 2000 3000 - 4000 p f 1 I.lme l SBC i z 3 t 2

If 3> E2 i f e. _A P 6 0.0 5' Tube 'Cold Side SGTR at Tubeshest Bose Case c4 'CMT Water Level e s- - 4x g E 7 a 6- ~~ 'O l ^ ^ . E5-4 m v t i 4-t j' { _c 2 3_ : -10. ~ cn cn + C C of 2_ 3 -5 _a t 1- [ 0 'l l o E O 1000 T 300 3000 4000 'o f 1 z ^ Time i Sec E a t 4 E .T s ~ 4 i W ,v w n y- .v-N s,.. m ,n~-y- .e,.rm ,oc, y .pr,, v% .,..m... .-e ,,et m m ---e

i\\ Ilij

llll lI s'cN"~mv

-

5o_o 3

e 9 s 9 0 9 8 a 0 + 0 0 C + E + + E 5 E E e 2 1 1 5 0 0 s a 0 ~ 0 B 4 t e e h~ s 0 0 e 0 l b a 3 u v T o ) m c t e o R e s R t 0 T a 0( G 0 e S 2 H e e m R d H ~ i i R S ~ T P ~ d t s 0 l a 0 o e ~ 0 C H 1 s e y b R a u H c ~ T R e s PD s' 5 s 0 0 0 6 0 0 0 0 0 0 0 P 6 5 4 3 2 1 A n3Ov u y3o _

E o

i; r* lKk. N&E $ci ((yt5 f 3bb $ E." l

l i g k; ~ .ft,_ AP600-5 Tube Cold Side SGTR at'.Tubeshees.t - Bose Case 51 RCS Water Level- .y. my E 25 - 80 a b m i -2 0 - - 60 ~ E v 15 - y C E -40 r & 10 - ~- c. c a). l a - 20 5-- [ g o B 0 000 2000 3000 4000 1 o ] Time (sec)- s E

9% Y d 2 %. E. V N [=$ = AP600 5 Tube Cold Side SGTR - Break Elevation Sensitivity E Tube Rupture Break Flow sp r ^ 140 - 300 ^ l .w. m N 12 0 -~ N - 250 E .ca u - 100 -- -i v - 200 i ~ 80 - l m e } ~ ^ ~ - 150 $ Y 60 -- o = a: m - 100 40 - m i o o l u 20 -j - 50 u_ i j 0- [/(( { ,- = = ~yyv-- -O m m m m { -20 l l s e 1000 2000 3000 4000 l 8 0 if T.ime (secJ B E 3 l l L L

. ij >k wE2 8pi AP600 5' Tube Cold Side SGTR - Break Elevation Sensitivity t{w E Pressurizer Woter Level. 87 s 5 ? - 15 4- ^ t m E v 3-- - 10 " 3 'A ~ i a _c ? -c ~ ~ cy, 2 - - ~ g 1 c 5 e t.- - i F 0 P' '""t l 0 [ 0 1000 2000 3000 4000 ? Time (SCC) 2 3 4 ? v U 9 ~ .n.-

r 3 W an.2 b !I [3 AP600 5 Tube Cold Side SGTR - Break Elevation Sensitivity _gy RCS and Secondary Systems Pre'ssures 4p RCS

Faulted SG

- - - - U r. f o u l t e d SG 11 .160 m m - 2000.o 140 - u a m

n

_a i20 - 1 c. v - 1500 v 100 - t.5 o 80 - I 7 1000 r a 60 - a m m m 40 - : - 500 m o S 20 - M 1 u i E 0 l 0 1 0 1000 2000 3000 4000 y \\ 2 ~ -[.lme i SeC) 3 h i l m

y c .w .g .g ik AP600!5 Tub 3 Colt' Side SGTR - Breek'Elevotion Sensitivity x1 S t e orn G e n e r o t o r Dosacomer Weter Levei . !k# Foulted-5G ~ F l E. --- Un f ou I t e d SG a .12 - 39 l n ~ - 38 i E I I 5 -- ~

n v.

[ ] - 37 v y i E . _c 11 - -36_c j i w .c -35" i c i 2. ____.._.._________~_______ 10.5 -4 e _s .I, < - 3 4 __; ^ i. -t t i - 33 i -y 10 i i i 1 i I O 1000 2000 3000 4000 t j 'P y Time' (f.secJ l 1 i l 9 i. E. i t i i {.-. 'y.m-y.... .. ~. y, ,r._.. ,,,,,_.,,,..._.4 c.

o Y g M a w AP600 5 Tube Ccid Side SGTR - Break Elevation Sensitivity i RE Foulted Steam Generator Pressure-4W Foulted SG g Safety Valve Setpoint r PORV Setpoint 80 1160 n I - 1140,o ~ o 78 - _o m v - 1120 a_ 1 i g 76 - - 1100 a> u - 1080 74 - 3 a m - 1060 m m .v 72 - - 1040 a) 1 u u o_ !f ~. - 10 2 0 CL i i i e 70 8 0 1000 2000 3000 4000 -P y b if Time (f S e C >I 9 I i i i 4 ar.

h l ,:et i,>

r.

i[ i it i,irl!

l- !Ii riT_

y4 n, sE o. e o:a mo ' amO2 y 0 0 0 0 t 4 3 2 1 0 0 i 0 v 0 i 4 t i s n e S n o ~ 0 i ,0 t a 0 s s 3 v e e t t l s Eo ~ t r w k C o t a C l e F s r .S t B 0 s ,0 s t t 0 o 2 M R s e t s T m r i G e t S . l t o I a 'e t We r d n e i . ~ T.i n t S MLi 0 C L ,t 0 'd t, 0 e ,i l o ge 1 g C oc t t r h n M e' c o t b sl t 'u .i a ,s T DB t t n 5 t

g 0

0 0 6 0 5 0 5 0 P 2 1 1 'A m.,x6 x y e o:

O a

u umO2 m v* l~- I>2 e We.4r gEc fgs,2a3$ $ 5w2 l~ '<a. !i-j' 4 jil it; 4 i< !:';>lI. 1); !4i .ii

O Y M E2 h{ i AP600 5 Tube Cold Sidw SGTR - Break Elevation Sensitivity Sw RCS and CMT Water Temperatures

"xa RCS Core Water I

CMT Water Tsat 650 n

- 700 n x t i.a_ v 600 -9 - 600 " _g I 550 -I ~ - - ~ ~ - - - - - - - - ~ - - - ~ ~ ~ - - - ~ - - ' - - ~ - ~ - ~ ~ - - ' - ' - i e - 500 e f b 500 - s - 4 0 0." 450 -5 o o u - 300 u e 400 -- e ~ o- - 200 E l E 350 - ; a) e F H -100 6-- t 300 -8, 0 1000 2000 3000 - 4000 l (sec,i if T.ime i g i k i j i I

,,i... . g ' = ?g t I r. 'AP600 5 Tube Cold Side SGTR.- Break Elevation Sensitivity - t ~4 CMT Water Level tw ap 1 .: 7 a I! + 6- _: - 20 1 1 n m .E5-v - 15 m i v 4_ I. y c _c i 8 i 3_: ' -+' m r C c

2-I e.

-J -5 .J 1-2 i [ 0 ~ '-l l l 0 f 0 1000 2000 3000 4000 o r 1 ) ) T.ime (secJ t i i t t 4 Y 2 3-t 4 j a .l ...-m .c... r .. ~. - _ ,, ~.....,...... - ~.,.,....a ..,_,,,..,,-__..,,,-ew-m.,...yy.,,m-_.,.,,y.-#_-#,

4 P r h l -.gg

8 Y

Breek Elevation Sensitivity AP600 5 Tube Cold Side SGTR r -x35 PRHR Hoot Removal i E{ PRHR }

Decay Heat

[ 60 .2E+09 l s m l 50 - c i ~ s .15E+09.N y s ,1 s ~ ~ K 2 40 - i v ~, Y ~ m 4 30 - ~~~_' -.1E+09 g i v .,i-m O m 20 - O o_. 5E+08 f 5 10 - o' 4 n_ t f ~ t t t t e 0 i, i, i, 0 t t t e i t t I t i i 1 F 0 1000 2000 3000 4000 i P 1 l' { I'i m e (f SeC/ 1 = 1

AP600.5' Tube Cold Side SGTR - Broek ~ Elevation' Sensitivity T G RCS Weter' Level ~ tw 4g ~' E 25 - 80 s 4 1 2 m n - 60 t E V ^ ~

n 15 -

3 ~ v I -40 c' .x t ~ y & 10-C- 4 c v e - 20. J F 5 '- 4 4-j i i t 1 i f i t t i I I f f 1' t i i 1 0 I O 1000 2000 3000 4000 f 1 .o p Teime (sec) I I .h h 4 1 ~ i _...i.....,.,, _r..;_ -...,._#,.,y.. .,_,._,.,m.., ,,,,.,,_,.,,,.,,_~..,_..m.,,.

i 9E 'r' M5 5 .E2 E 3:q AP600.5 Tube CoId Side SGTR - Mox PR:lR Heot RemovoI gE Tube Rupture Break F l o's. sp 1 140 ^ - 300 ^ w m N 120 - I N - 250 E x .o 100 - v

n e:

80 - { - 200 " e e 5 - 150 - .o 60 - o y g a:: 40 - - 100, o u-20 - - 50 \\ m - r

~

~ 0[f((DfWW i ~* g -20 ~ 2 2 i l i 0 1000 2000 3000 4000 I I.lme SeC .k i a 3 i .Lr 3 i m

.gv Mk E2 $ N E& AP600 5 Tube Cold Side SGTR Max PRHR Heat Removal i-Pressurizer Water Level g%' ~ 2 E 5 4- ~ E v 3- - - 10 " S 0.c3 9 E 1 ,o ~ cn 2 - - O c ~ e. -5 C e i a 1- -8 a w '~'- ' ' t 0 i" 0 z 8 0 1000 2000 3000 4000 } Time (sec)= ak 5 . m u ,,n,.,n..,. ,n. ,-r.-

A l h5 5 =g - [ r =x AP600 5 Tube Cold Side SGTR - Max PRHR Heat Removal i!E RCS and Secondary Sy' stems' Pressures E RCS h Fou'ited SG - --- - U n f a u l t e d SG 4 L i 160' i ^ m j l ' 140 - ~ - 2 0 0 0. __ o .n .o 120 - ~ t o_ t v [ 100 - g - 1500 v l i e 80 - i i L e) =, m - 1000 t a 60 - ;;c, 3 i m t i m 40-m t i - 500 m a> ap - i. 20-e u a_ t k. i t 0 ~ 1 i i 1 i f I t i I i t i i I t t t t O t t I 3 0 1000 2000 3000 4000 i if Time (sec) ~ a t E i i i i 1 ._... -. -... _., _,., _.....,,.............. ~. _.... - _. _... _ _.,

e Sh 3> E2 rr[ AP600 5' Tube Cold Side SGTR - Max PRHR Heat Removal E% Steam Generator Downcomer W o t -e r Level

w 3x faulted SG j

(

Unfaulted SG 12

- 39 - 3 8 ^" ^ 11.5 - - ~ 5 v r j -37v i t Y E _c 11 -. - 3 6 _c ~ t W c - 35 c , 10.5_ _- e J 'l ' - 3 4 __. i r -I ~ 33 [ 10 F 0 1000 2000 3000 4000 l Time (sec) 8 .T. ~ e

3 'r' 3 R -g. Y w AP600 5 Tube' Cold Side SGTR - Max PRHR Heat Removal EE Faulted Steam Generator Pressure ex 3 faulted SG E.a

Safety Valve Setpoint PORY Setpoint 80 1160 m

'o - 1 1 4 0.__ o 78- ~ 1 - 1120 w [ 76 - - 1100 e u - 1080 *- 74 - a m - 1060 m i w c) 72 - - 10 4 0 e u ~ i t i t i i f I t f I f f I f f. I e 70 i. l [ 0 1000 2000 3000 4000 if Time (sec) 15I 5

hh e2; k.- "W f e. AP600 5 Tube Cold Side SGTR i Mox PRHR Heat Removal 54 CMT Water Wass Flowrotes .sw 4 F Dischage Line ~ .j

Bolonce Line 20 m

- 4 0 s,, s o. E x O '. lin - m g,'w - 30 I 1

nsh 2

- <\\

f,, e vN gg 10 - \\"^'s~s-o = - 20 m ~ m I-O ~ o m u. 5- - 10 ' I i m m m M U-O f 2 I t t t t t i t f I I t t t I t 2 i g 0 t, ,i i, 0 8 0 1000 2000 3000 4000 o 3 'z I.lme SBC l s i 3 .E. t 3 g i s l

e Y 3 3 E2 $ !!i $5 AP600 5 Tube Cold Side SGTR - Max PRHR Heat Removal Re RCS and CMT Water Temperatures 4y RCS Core Water 4

CMT Wa t e r Tsat 650

^ - 700 m y e u_ v 600 - -\\ - 600 " I 550 -[ ~ g - 500 as 5 500 - h 3 - 400 450 - a o a) 400 - u - 300 u o_ i - 200 ~ E 350 - 2 E i 5 ', - 100 s-x s 2 300 i i I O 1000 2000 3000 4000 l o h I.lme SeC r s 4 1 s k m.- .,y m. ,n,.-

e 3.x gg t I' AP600 5 Tube Cold-Side SGTR:- Mox PRHR Heat N CM! Water Level ^ Removel- ~ Eg i e. r .7 p 6 '- l - 20 ] j n l .E 5 - - ~ v -.n v g 4-Y _C C-g; 3_ : : ~ w C C i

2-

-5 --.s i 1-4 1 F 0-t 0 l l 8 0 1000 2000 3000 4000 if Time (-sec) j 5 T y 3 s i i

or w $h I "2 g }4& AP600 5 Tube Cold Side SGTR Max PRHR Heat Removal

=$

PRHR Heat Removal PRHR .h

Decoy Heat 60 s

.2E+09 \\ m 50 - \\ l ^ s _c !!!c -.15E+09 N s 2 40 -- 's 3 1 ~ g ,v ~ ~ I 30 -- ~_ -.1E+09 v ~ m s 20 - s 5E+08 . o_- 10 - 7 o a_ l y 0 O g s 0 1000 2000 3000 4000 .o f 1 i T+ime (sec) I E

?G5 e u T - EM AP600 5 Tube Cold Side SGTR - Max PRHR Heat-Removal 5 E RCS Water Level s ee 3 E.* 25 - 80 ~ 20 -- m n - 60 E v m m y 15 - a l k C 1 -40 _c ~ & 10 - C i c h _a - 20 5-4 k j' ~ 0 l l l o [ 0 1000 2000 3000 4000 i ) Time l' s e c 'l 2 s k w 1 ,y- -n ._,,.u.

l' .? 3 g + 3}g 5 AP600 5 Tube C ol d Side SGTR Min PRHR Heat Removal Tube Rupture Breok FIow E. I 140 - 300 ^ m un N 120 - : N 1 m -250 E- .x ..o 100 - v - 200

3 80 -

~ i e 3 t 1 y .o - 150 - a 60 - o l - 100 m 40 - a O' ~_ o - 50 { L.. '20-I \\ (y ^ ^"n-m ^- -0 m m i 0-1 m o o y s -l e s g -20 l .o 0 1000 2000 3000 4000 [ r 3 z Time I S B C >i 8 3 a I s . ~

T- =. c b.hl 24 AP600 5 Tube Cold Side SGTR - Min PRHR Heat Removal EE Pressurizer Water Level 83' E. c 5 - 15 1 ~ E v 5 g 3 -- - 10 " ~ 'g ~ cn 2 - - C e -5 C o 1 -- 8 e p \\, _ m _ 1 0 0 0 1000 2000 3000 4000 l [ Time ( s e c )- i w y 8 l i

i 1[ a f, g. r e. t1 AP600 5 Tube Cold Side SGTR - Min PRHR Heot Removal 5% RCS and Secondary' Systems Pr~essures l, .RCS faulted SG Unfaulted SG I e ISO .m O 140 - ~ -2000.__ s-- l o m w. ~ _o 120 - g o v - 1500 v 100 - e 80 - as , =. _ _ _. _ _ _ _. _. _. _. _. _. _. _. _. _. _. _. _. _. _ - 1000 6 0 ;[- - u m a 3 m m m 40 - : - 500 m .1 a) 20 s-m. [ a_ l l l 0 i g 0 ~ 1000 2000 3000 4000 s 0 Time Sec z S 3 X t t 3 u

.g g -: l. L8 $ .E2 k ET AP600 5 Tube Cold Side SGTR - Min PRHR Heat.llemovat jF Steam Generator Downcomer Water Level .f Foutted SG G

Unfaulted SG 12.5 4

- 40 ^ 12 - E ~ w. w - 38 v 11.5 -- y 2

_c

~ 11 - - 3 6 ' m. o c O [ g ' - - - - - ~ - - -J 10 5 - - 3 4 __J -ir .o ~ 10 j! o 1000 2000 3000 4000 [ Time (Sec-) 3~ m Y

n y .h. b. $l 54 AP600 5 Tube' Cold Side SGTR - Min PRHR Heat R e m o v a l'.-. Faulted Steam Genetclor Pressu,re %( foulled SG

Safety Volve Setpoint

PORV Setpoint

~ 80 1160 ^ ~ m o - 1 1.4 0.. __ o 78 - .m i ~ - 1'120 o_ a v v -u 76 -: -- - - - - 1100-u. - 1080 74 - i-o a m - 1060 m m

72-

- 10 4 0 e m 1 I f I i 1 3 1 f I I f I f I ~ 1_ 70 f. i i 0

100t, 2000 3000

-4000 If Time- (sec) G I 5

e.m ...p R hu k{N Min PRHR Heot. Removal -AF600 5 Tube CoId Side SGTR er CMT Water Mass Flowrotes 4 :e .a .Dischoge Line } Balorce mine 20 m m - 4 0 (m-EE -) cn l o a l 15 -- t' b I \\ st' vg,,,1/ sg l - 30 2! 1 \\' ' e \\ r, s, f N es f ,~_,'"-s-o ~ 10 - - 20 m o o u_ 5- _10 w .~ m w m m O O 0 l 0-T 2 I o 1000 2000 3000 4000 0 ~ Time (sec) S 3 X 8 ~

e Y 3 a b. 8 g. IE .AP600 5 Tube Cold Side SGTR - Min PRHR Heat-Removal 54 RCS and CMT Water Temperatures su yg RCS Core Watcr E

CMT Water a

Tsoi 650 - 700. 'M (~ .v600- -s 31 - 600 v 550 - T ^ - ^ ~ ^ ~ ~ ~ ' - * ' ~ ~ - ' ~ ~ ~ ~ ~ ~ - - - - - - - - - - - - - - - 3 3 - 500 e ] ' 500 -- - 400 u-s 3 i 450 - -~_ c O - 300 u-e 400 - G) O. ~ - 200 E 350 -: E a3 - 100 s [ 300 l l l i, o 1000 2000 3000-4000 j Time.(sec) 9 k

3 3 g FI AP600 5 Tube C o l d -S i d e SGTR - Min FRHR Heat Removal ET . R or CMT Water Level ng e. 7 a 6-5 - 20 .n n E5-j ~ ~ ~ - 15 ' v g;- 4_ g Q, c u _c 3-cn C I ~ O c.- S ~ -5 i_ [ 0 0 0 1000 2000 3000 4000 ,s T.ime sec z a B !I 3 y j ~ i l l

9 Y 8 s E b i $E AP600 5 Tube Cold Side SGTR.- Min PRHR Heat Removal El-PRHR Heat Removal

f PRHR h

Decoy Heat

~ 60 g .2E+09 \\ ^ l s 50 - s ^ s _c ^ 15E+09 N 3i: s wi { E 40 - 's, s w ~, b 30 -: _ _ _ ~. ..ic og w ~ -. c) sa: 20 - m o 5E+08 a 10 - o. 5 $'l ( 0 l l 0 [ 0 1000 2000 3000 4000 i Time (sec) 1i

4. s nr GF w> ~2 Ig i I e. AP600 5' Tube CoId' Side SGTR - Min PRHR-Heot RemovaI- ^ RCS Water Level 8l' 3 ^ A 25 80' ~ .l 20 - m ^ E - 60 v w 15 - 1 l c g - 40 _c cn 10 - + C Cn .c O g a - 20 5- .g i ~ n .i } 0 l 'l 0 ^ s 0 1000 2000-3000 - 4000 o (sec) b T.rme 1 I ? v Q 1- -4 ... 4

3 8 e b h{i AP600 5 Tube SGTR - 'C V S On with no Possive Systems R 5-CVS Injection Flowrote. ax 3 E. a 7 n n m - 14 N E m6- .x - 12 _o v 5-e - 10 \\ o e n - -0 o o a e m 3-l m -6 O O l - -4 w m 1- -2 w o I 3 s0 ,,,iiiiiiiiiii'''''''''''' 0 i i i i i i i )1 0 -200 400 600 800 1000 1200 1400 1500 Time (sec)~ 3 E

.R $E. E V $E AP600'5 Tube SGTR -~CVS On with no Possive Systems N Tube R u p't u r e Break Flow

F b

140 - 300 ^ m m \\ N c"120-E u - 250 " v m-100 -- - 2 0 0 => g 80 -- o-n x y - 150, ~ o 60 - o ~ - 100 ' l I w 40 - t 2 \\\\0\\\\N\\d\\\\((\\(k\\\\\\\\WW(i'gg'g y,, m m ~ \\ m o ~ l o - 50

s

[ 20 ll!ll l H~ 0 200 400 600 800 1000 1200 1400 1600 i j Time (sec) a Y a E l

n v. E E E h{k AP600 5 Tube SGTR '- CVS On with no Possive Systems "r Pressurizer Water L e v e'l 4F E if 5 ~ - 15 m n ~ E4-v v e 3--{ - 1 0 __ g a E o _a 2-Q) _ g e o 1-3 o 3 [ ~ 0 i''ll 'lll 0 8 0 200 400 600 800 1000 1200 1400 1600 a (sec) r ) T.ime a X 5

' M k" S 'E2 B. L AP600 5 Tube SGTR - CVS On with no Possive Systems EE RCS and Secondary Systems' Pressures

F RCS h

Faulled SG -- - U n f o u t i e d ' S G 160 n

140 -

.2000.__ .u _a 120 -2 - 1500 100 - v2 a). 80 - D e m vvne< m xva<-<.,-v-~, , ~we em _;ggg u o 60 -i_' m 40 - 3 - 500 m e 20 -2 m Q-o_ [ 0 l';ll!ll 0 g 0 200 400 600 800 1000 1200 1400 1600 er Time SeC Br; Y

J 9 Y 5 E2 E U AP600 5 Tube SGTR - CVS On with no Possive Systems iEE-Steam Generator Downcomer Wa tter Level 43' f o u l'.t e d SG ~ h

Unioutled SG 15 n

E ~ ~ 14 -- t -45" 9 l I

13 -

Y o> a> ~ o> l J - 40 12 - u q) jj_ ~ - 35 o 3 g, ,uus,-- es- -u y [ 10 llllll.!. i' 0 200 400 600 800 1000 1200 1400 1600 P f 8 y I=lme (SOC) B E

R7 B. R AP600 5 Tube'SGTR - ~CVS On with no Pcssive Systems EE Foutled Steam Generator Pressure

[

Faulled SG h Solety Volve Setpoint - - --- P O R V Setpoint 80 1160 m ~ o 78 -1 - 1 1 4 0 '-- - 112.0 $

d f

76 - _1100 m u - 1080

74 -

2 m 1 - 1060 fI 72 - - 1040 g -iO2 m l 70 i i i i i i 0 200 400 600 800 1000 1200 1400 1600 [ Time (sec) I e a n

n y $g 5 g E'd Ey AP600 5 Tube SGTR ~CVS On with no Passive Systems j u~ CMT Water Moss Flowrotes Dischoge Line E. 7 1- ^ ^ m -2 m N N cn ~ E .x .o 5- -1 v v w I,, e 0 -0 o x ~ m 'O ~ o_ w S- --1-u_ m m m m o _ _2 o t' s i ii iii,iiiii .iiiiii s t -1 i i i i i i i~ 0 200 400 600 800 1000 1200 1400 1600 (sec) g p T.ime T 5

~ 1 h~5 k 'AP600 5 Tube SGTR - CVS On with no.Possive Systems 9 'RCS and CMT Water Temperatures ~w Ex RCS Core Water aE

CMT Woter

.Tsot 650 - 700 m m x c ~ 600 - 's v s .600.v n

n 550 -2

] ~ - 500 ie. e ' 500 - ; 2 - 400 D. ~ 450 - o o 2 - 300 u e 400 -i v. Q-o _- - 200 E 350 - ; E e e H - 100 H 300 , i i i i.,,,iiiii,,,,,,i, i g' O 200 400 600 800 1000 1200 1400 1600 { Iime (S8C) p i w 2. Y 3 s

9 Y 5 E,,. b 3I [4 'AP600 5 Tube SGTR CVS On with no Possive Systems E E-CMT Water Level l 4x { a 7 ^6-- -20^ E ~ v 5- - 15' 2! ] a, 4 - - S a ~ ~ G) gy a3- --10 a u u G' 2^ - a> ~ -5 o 31-o g 1, 0 0 i i i..,,........... i 0 200 400 600 800 1000 1200 1400 1600 i Time (sec) ~ e k 5 t

3 3Em Z E. AP600.5 Tube SGTR' .CVS.On vith no Possive Systems . al PRHR Heal Removal t 3 P PRHR }

Decoy Heal 60 2E+09 s

N m. N. 50 - 's ~, ..z-

g.

15E+09 N ~ ~

n v

1 40 -i 3 9 v co 30 -i .1E+09 v u e 5 20 - o .5E+08 o_ 10 - o o_. i [ 0 ~ ' ' ' ll;;;;; 0 8 0 200 400 600 800 1000 1200 1400 1600 t P (secJ 3 i T.ime s k Y = 3 ~

l l L l 'n v g !u> vg El AP600 5 Tube SGTR - CVS On with no Possive Systems' j RCS Water' Level E.5 25 80 ^ L 'E 2 0 -- ~ - 60 v. l { e 15 - e. y

s e

- 4 0-o

~

l _s l 10 - u e - 20 ' o 5-- o l 5 i e' t ie e 1 1 1 t t t iiI t I I t i1 I t t t I 0 a, I, I, I, 0-g 0 200 400 600 800 1000 1200 1400 1600 l ,o l f Time (sec) s E 5

n GS A.s. k AP600 5 Tube SGTR SG PORV F.a i.l e d Closed R Tube Rupture Break Flow

BY

~ ^ 140. - 300 ^ m m N 120 - I' N - 250 E x .o - 100 - - 200 " 80 -- e 5 e - 150 -

g o

60 - o y e a m 40 -; - 10 0,. o o ~ l u_ 20 -g , 50 %/ 0- = = ~ y vy-, 2 ~ 'l l 2 -20 0 .1000 2000 3000 4000 g g Time (sec) i v s E l

.a / .g E2 8 e AP600 5 Tube SJTR SG PORV Foiled Closed i2 E-Pressurizer Water Level $p E.5 5 i - 15 4_ m m E '7 ~ i { 3- - 10 " c. ~ p2_ ~ G C ~ ~ ~ as .5 -C a a) 1- _.J 6 4 ~ l' 0 '--- m - ~ M 2 0 g-0 1000 2000 3000 4000 iF Time (SeC) O i

e I

k 5 1 l

Sr 'M c g kk AP600 5 Tube SGTR SG PORV F'i' led Closed o H. RCS and Secondary Systems P.r e.s s u.r e's-1[ RCS h - - - - F o u'l t e d SG Unfoulted SG 160 n o 140 - .2000.__ O

n a 12 0 -

a } - 1500 v 100 - 2 'e 80 - -L =- - 1000 u s 60 - ;q. m 3 m .40 -: - 500 m-m m o e u 20 - : m 1 g,

0 l

l l 0 I o 1000 2000 3000 4000 Time. (sec) t B T y u 'I k =- .~a a

B M E E E it b. AP600 5 Tube SGTR SG PORV Foiled C'l o s e d Ee . Steam G e.n e r a t o r Downcomer W'a t e r Level F rouited sc h

Unfoutted SG 12

- 39 ^ -38~ E 11. 5 - .:n v ..d, -37v _c 11 - - 3 6 _c ~ ~ c - 35 5 ~ ~ ~ ' l

10.5 - -I ir,-

l -8 - 3 4 __, I ~ 33 l 10 l i l. g 0 1000 2000 3000 4000 g T.ime sec z a a E i 3 l l

SK Ms E2 h AP600 5 Tube 'SGTR Ew[ SG PORV Foiled Closed Foulted Steam Generator Pressure $f foulted SG Sofety'Volve Setpoint s.

PORY Setpoint 80 1160 m

^ u o - 1140._ 78 - _a m 7 - 1120 'o_ g v 76 - g - 1100 m u - 1080 74 -- u 2 ~ m - 1060 m m j7- - 10 4.0 e m o u m - 10 2 0 a_ I I I I t t I I i t i I I I I t t 7 i 0 1000 2000 3000 4000 P T.ime g (secJ T } 0 s

3e r Ek 5 u E AP600 5 Tube SGTR SG PORV F.oiied Closed EU CMT Water Moss Flowrotes f Dischoge Line-l 's --,- Balance Line ~ 20 m w m m L s - 40 x cn E y .43 15 -- k - 4. e.*f s, g ' \\ li ~ v

n

- 3 0 ee ns a ' t ~ r, e " 10 - f % _, # ~ ~ -' ' ~ c s c_ o - 20 m m O ~ o + w 5- - 10 ' m m m m O Y 2 O 0 .0- ,k i 0 1000 2000 3000-4000 J I.lme (SCCf hi

ar $5 .ch Er AP600 5 Tube SGTR SG PORV F. oiled Closed Ee RCS and CMT Water Temperatures G lP i RCS Core Water ~ E. n

CMT Water

_.- - - T s o i 650 - 700 m x c u_ 600 --s v - 600 " -\\ I - ~ - ~ -'-~^~~ - -~- - -~-~- - -'-~~ -'-~-~-- 550 - 3 - 500 m e E 500 - 5 s - 400 " ~ ~ 450 - : a a - 300 u u e 400 -: e o- - 2 0 0. " E E 350 - a) o - 100 - l' 300 l l l g 0 1000 2000 3000 4000 a 'z T.ime sec~ s a 5 a a

a v 3' n o c. E t . [{ AP600 5 T u'b e SGTR SG PORY Failed Closed R5 CMT Water Level-S ilP E 7 6-j ~ - 20 E5-2 - 15 v m j 4.-i I e .c ~3- :. C e o2- _.J - _a 1-i ( 0 l l l 0 s 0 1000 2000 3000 .4000 f 1 P p T*ime (sec) B E b

1 e s w Eg t g SG P O R V. Foiled Closed-A'P600.5 Tube SGTR ^

E-P R H R li e a t RemovoI-f PRHR E

Decoy Heat-60

_.2E+09- _ ( m m s . _ 'c 50 - s .:1 5 E + 0 9 N 3C s { CE 40 - 3-s- s ~ s ~ ' ' ' m 8 ' 3 0 -- .1 E +0 9 * -m D ~ y 20 -- u- ~ .5E+08 S , i O i 1 'l l l 0 [ 0 g 0 1000 2000 3000 4000 3 'z I.lme SeC l ^ f o e a r 5 e.

i 9f g u E2 a V 3:3 AP600 5 Tube SGTR SG PORV F.2 i i e d Closed ij g RCS Water Level s. 1 5 25 80 20 - i m m E - 60 v

n v

15 - i I y C I - 40 g _c ~ cn 10 - ~ cn C G) C a - 20 5-t i F p g o l 0 1000 2000 3000 4000 .o r 3 i T.ime (sec) a l 5 l h l J ._m, ,.,-..--.--,-_<-r ,ww ,-~~v.. ..e,,,--<-e-u-- . = -

i 1 EE i - 35 12N h 2AP600 5 Tube SGTR CVS with Possive' Systems j Chorging' Pump injection F~l o w r o t e E. 5 12 m m - 25 m m N t x & -10 _ i_ E i .a x v g-t L e e -15

I 6-o i

i n x l - 10 m o 4-o LA- ~ La i -5 l 1 e 2- = i. u> m o o t t t t t e t t e t t t t i 2 f 2 ~ g 0 A, a, a, t,. O 8 0 2000 4000 6000 8000 10000 ~ r t if I.lme I,SeC/ 3 i T 3 U f r ..., ~.... _ - =..

9 t v = a R-95 ET AP600 5 Tube SGTR CVS with Possive Systems .sg Tube Rupture Break Flow E" _ 140 - 300 ^ w m N 120 - ~ N i e' ~ - 250 E .x o 100 -. v - 200 " 5 8 0 -- } e e ] - 150 - y 6 0 -- o g g x - 100 i 4 0 -- = 0 o 20 -g - 50 u_ I m IL m 0-: r 0 m o [ o I =s ~ -20 9 2000 4000 6000 8000 10000 if ~ Time (seci t E 5 1

35 5 4 s Es l- ?g AP600 5 Tube SGTR CVS with Pa.ssive Systems EE Pressurizer Water Level 49 s.a 5 - 15 4- ~ m ^ g v { 3- - 10 " r .c .= 2 c w2-C O ~ e -5 C c ]- J 4 [ 0 M^^~ ; 0 1 0 2000 4000 6000 8000 10000 ) Time (sec) i E. y b n. m v.n- .,,w, ~

i o y .!(g E I .g. vt .Ej AP600 ~5 Tube SGTR CVS with Possive Systems RCS cnd Secondary Systems Pressures ~ 'jg f RCS 5

Favited sc

- -~- U n f o u t t e d SG i 160 ^ m I40 - : - 2 0 0 0.__ o '5 o 120 -- l o-v Y 100 -. - 1500 v l 3 a> 80 - - - 1000

t

~pt =

= -

. _. _ _ _. _. _. _. _ _. -. _. _ ~ ~ ~ ~ ~ ~ ~ " - u o 60 - r 2 p g m 40 l - 500 m v. ~. s> b -u f f .y .o_ e 0 'l l 0 [ 0 2000 4000 6000 8000 10000 i t 3 . 'I I.lme ( S O C )' 3 i i I

S5h

s. a ab

$q AP600'5 Tube SGTR'- CVS with Possive Systems M Steam Generator Downcomer W a t. e r. Level N Foulted SG .h

Unioutled SG i

15 n m 14 - E - 45 m ^ w ~ Q. i3-E c - 4 0.c a 12 - w / w C / c e 1 e -s 11 - - 3 5 __ r/ ~( i 'l l f 10 l 4000 6000 8000 10000 0 2000 .a Iime (SOC) J i T y t: g

F M E.k M E l CVS with Possive Systems E& AP600 '5 T u b'e SGTR

E Faulted Steam Generator P'ressure il z 3

-Foulted SG

Sofety Valve Setpoint PORV Setpoint 1!60 80 m

n o - 1140._ O 78 I-m _a - 1120 o_ T v v _1100 { 76 -______________________________ G) - 1980 u 5-74 -- a ~ - 1060 m m w e 72- / ~ ~ - 1040 as i u u - 1020 o_ I 1, 70 g 8 0 2000 4000 6000 8000-10000 Time (SCC)~ .o { i ? 3

9" sh 'E2 D CVS with Possive Systems $4 AP600 5 Tube S G-T R ~

E-CMT Water Moss Flowrotes II:e g

Dischoge Line E

Bolonce Line j

30 m - 6 0 x. a,. s E s c" 2 5 - o x v ' I m 1 20 - L g - 40 a ~ S O 15 - - 3 0 a: O n o 10- ~~' - 20 _o u-u_ m 5- _ 10 m O O I 0 l l l l 0 2 8 0 2000 4000 6000 8000 10000 1 P I.lme i (f SeC) 9 ? ? Y;s ~ l e I 'N-----"-N'-ii'"*'"'"''

v n7 8 GS E>2 w Eg CVS with P o.s s i v e Systems AP600 5 Tube SGTR Ex EE RCS and CMT Water Temperatures 3 /: 3 RCS Core Water E.

CMT Water E

_.----- Tsot n - 700 m 650 v 600 -k - 600 " M m i.___ _._ _. _ _._ _ _ _ _ _ _. _ _ _ _ i! 550 - - 500 m a , e y m 5 500 -~ - 400 o 450 - : o - 300 u m e 400 - - 2 0 0 [" o_ E 350 --,' s, -i00 - y 300 i i i i B' 0 2000 4000 6000 8000 10000 t r k T.ime I sec o t a 3 5

a s2 I CVS wiih Passive Systems f AP600 5 Tube SGTR El CMT Water Level sw 3 7. f 20 l 6-l m I ~ 2 E5- : - 15 ' v v y y 4_ Y .c ~ C y 3-w CD C c a) 2- -2 5 6 e 4 0 f 0 ~ f f f f f f f f f f f f f f f f f f f t i f f B' 0 2000 4000 6000 8000 10000 e (sec,.)- T.ime e p tr 0 x 3

r ?" 0 se E> Ei AP600 5 Tube SGTR CVS with Possive Systems r= PRHR Heot Removal (( PRHR g 8

Decoy Heat 60 2E+09 n

1 u s 50 - s a n \\ -.15E+09 N 3 3 T

E 40 _.

s 3 s .v CD s 30 -- 's -.1E+09 v ~ 20 -- l o 5E+08 3: Q_ o 10 - o_ h 0 l 'l 'l l 0 I i 0 2000 4000 6000 8000 10000 (sec,J e i T.ime f.

1 h5 m2 3 l.; if AP600 5 Tube SGTR --CVS with'Possive Systems J 'EE RCS Water Level

f 1

a E 25 - 80 20 - m ^ - 60 E v v { 15 - E ^ - 40 c _c ~ m 10 - g. C c. o> a - 20 5-0-[' l l l 0 i 0 2000 4000 6000 8000 10000 i Time (se.c;). P .a T y i E' -_=-

3 w r un. 2 hs . Ed AP600 5 Tube SGTR - Stuck SG Sofety Voive with CVS On gg Tube Rupture Break Flow a E. 5 140 - 300 ^ m m N,2 0 -- N cn - 250 E ~ .x o 100 - v - 200 " 80 - j g - 150 - a, a ~ 60 - o x - 100 5 40 - O o ~ u_ 20 - 11, - 50 u_ ~ m k m 0-0 m m 0 0 y } JE ~ -20 l i 0 ~10000 20000 30000 40000 z a ime I deC l g t i r2 i .i i

1 i 3r -g g [2 AP600 5 Tube SGTR - Stuck SG Sofety Volwe sith CVS On EE CVS-injection Flourate ny h

il 2 m

- 25 m l m N: N & jo_ E a .o t o v i 8-

n a>.

..} ~ ~ - 1 5 l Z 6- -o n: - 10 m o 4-o L g -5 m 2-m i m m 1 0 ~ O i } 0 l l l 0 f s 3 8 0 10000 20000 30000 40000 ,o (f SSC) 1 y I.lme 1 i T i y 4 l i t I r k { --s. ~.

$r mE E2 8> 9[ w AP600 5 Tube SGTR - Stuck SG Safety Volve with CVS On D E-RCS and Secondary Systems Pressures E RCS I h

Foulted SG Unfaulled SG

'160 ^ ^ o 140 - : - 2 0 0 0. __ u o w _o 120 - n a g v v 100 - 2 - 1500 v i vi e 80 - e

r. ' - -

- 1000 m o 60 - t 3 m 40 - ~ .._.._~~ w m i - 500 m j 1: a> 20 - - \\ L r U- , r, ct y 0 O t E O 10000 20000 30000 40000 f 1 P p T*ime ( s e c j-E i Lr 5 I

n$ w 2: q b. N Stuck SG Sofety Voive with CVS On AP600 5 Tube SGTR Pressurizer Water Level E E-ax 3 N 8 - 25 ^ g E v6-- - 20 C M i - 15 e as 4- _e a - 10 u ~2-o -5 'l 3' 0 0 4 d 10b00 20b00 30$00 .40000 I O p (sec,) e T.ime s 5 e

e Y 5 '4 - p d 24 AP600 5 Tube SCTR - Stuck SG Safety Volve with CVS On D E-Startup Feedwoter Flourate hx a cif 20 m m M M i-N ~ - 40 x en E l x .o 15 - v v ~ - 30 ~ m ] 10 -- o 4 - 20 m o o u-5- - 10 ' m m V) in O y O g. 2 2 0 0 [ 0 10000 20000 30000 40000 l i Time (sec)~ l L } ? l

G5 E> w 2 8 >a AP600 5 Tube SGTR - Steck SG Safety Valve mith CVS On .EE P R:;d Heat Removal PRHR h

Decay Heat 60 2E+09 L

n 7 ~ 50 - t n .c i .15E+09 N 3c -~g T JE 40 - - g ~ v y \\ co i 30 - s 1E+09 v u s a) '.s ' y 20 - : ~_ .5E+08 o o_ 10 - o O_ i 5 0 ~ ' l ;''l 0 i 0 10000 20000 30000 40000 P I.lme I SeC l t 8 ? t i 3 I s. 4 C 4 e

1lll iI1 %8 _"NEo._m o:

o w

mUOE 1 3 a n 0 O 0 0 0 0 0 1 8 6 4 2 0 0 0 S 0 V 0 C 4 h t i w e v 0 0 l s 0 o e 0 V t 3 o y r t w ) e o C f l a F e S 0 S s G 0( s 0 S o 0 M k 2 e c m r u e t i t S T a e W n k i T 0 R L M 0 T 0 C G e 0 S g 1 o ~ h e c b s u i T o 5 0 ~- ~'~ o 0 6 0 0 0 0 0 0 P 5 4 3 2 1 A n _"Nca

~
o _ u_ mO0s

( y3Q, ::* 5sPhTa'FI "k yiE(iX 5 YEj

.os .3 a k Eg AP600 5 Tube SGTR - Stuck SG Sofety Voive'with CVS On EE CMT Water Level

F I

7 -20^- ^6-E i l v v 5- ~ - 1 5 __ i } e >4_ E o 3_: - 1 0 _, a __J u e2-e ~ -5 o o D1-3 F t 0 a i 0 i i i I O 10000 20000 30000 40000 T.ime s e c >l z a 3 5 ? 5 0

w n ~r h. S SI Stuck SG Sofety Volve with CVS On AP600 5 Tube SGTR !!g Steam Generator Downcomer Wat&r Level ~ ~ s-

y Foulted SG h

Unfouited SG 18 n

~ ^ E - 55 _ 1 16 - 3 . l 2 e O s u - 45 o ~ v 14 - J g -). ,~ ___________s w x _ 49 u x e

12 - 4

/ e / o o Ei: f - 35 g [ 10 l l f 0 10000 20000 30900 40000 i Time (sec) 3 T 5

3 e b. '$g It 'AP600 5 Tube SGTR'- Stuck SG Safety Volve with CVS On 55 Faulted Steam Generator Pressure . s G. 4 ;lP Faulied SG .h

Sofety Volve Sc r uint

-:--PORY Setpoint 80 1160 m o - 1 1 4 0. __ o 78 - m m .o - 1120 a_ I. v v 76 -- 1100 M a) u - 1080 7 4 -- 3 a m - 1060 m m a2 72 - - 1040 $ u L o_ !r - 1020 o_ e 70 B 0 10000 20000 30000 40000 t -) Time (sec) a g t 3 e i i

o G 5 t a b.

b. g AP600 5~ Tube SGTR --Stuck SG Safety Volve with CVS On Es Accumulator injection Flowrote 4R i

E ir 250 m m m m x - 500 x cn E a 200 -- o m - 400 v

150 -

1 - 300 - a Y o G o i m i 100 - l o - 200

1 o

u_ m 50 - m - 100 m m m o

q'''''''''''''

o l [ s 0 0 E o 10000 20000 30000 40000 e (sec,) i ~ T.ime !i i T 5 l l l l

BE w>4 Sa b i Stuck SG Sofety Volve with CVS On Ta AP600 5 Tube SGTR l 5]. RCS and CMT Water Temperatures 4p RCS Core Water ")

CMT Water Isat l

650 - 700 m x u_ v 600 - - 600 " n K 550 - - 500 e e E 500 -- - 400 ~' i ~' ~ ~ 450 -i 's o o - 300 u u e 400 -i' t, e f - -- -- = = = _. = = _. - a ) 4 - 200 .______.._z E E 350 -; e o - 100 s [ " 300 g 0 10000 20000 30000 40000 'z T.ime sec o a. m i a

?" 1 8 E2 k{# AP600 5 Tube SGTR - Stuck SG Safety Valve with CVS On Gravity injection Flowrote gg E. _ 200 m 5 m m x - 400 x w E .O x 150 -- P v v - 300 e i .m o 100 -- - 2 0 0 a: y m o o u. 50 -- - 100 ' ~ m LO En O 2 0 'l 0 I 2 li 0 10000 20000 30000 40000 i Time (sec) a i k

S' i-pf Stuck SG Sofety Volve with CVS On AP600 5 Tube SGTR ~ 3EI Containment Water Level

y (measured from 83' elevotion)

E. a 8 - 25 m n E "6- - 20 m m 1 e 3 ~ - 15 e 'tg e 4 -- --.s - 10 u o> 2 o> a -5 o 3 y [ 0 l l 0 8 0 10000 20000 30000 40000 e (sec,) l P T.ime 6 E w 1 __ _

3 148 (s/wqi) ajog molj sson c o o o c o o o m o i f f f g 3 o O _# 2* o o -e w O o >e m ~~ ~o ^ o E o O=,= o m oO o w l .a ,C o ~o m i E U =m .m* + o M ~! ,E E .o "

~,1 m=

C O '; 0 o s = 0 m ~ o a. (S/6 M) alog molj sson Figure 3-127 htAAP4 Analysis Results Revision 0, Novemte 1997 a:\\3931.docib11/5/97

h M A P4 A = n c4a a l s h s i R F = e i s g u u l i r S e 3 12 E 8 No d a l N e t w alC o r k fo n r B o ron p u C o n c e n tra n t io = n C a lcu i la t i R o e i n v s oi g n ,0 = = N ov m 1s e b e 3 r 1 9 1 9 4 7 9 1

B. 5 'T 55 8-E2 8 ? ' A, iB i!- AP600 5 Tube SGTR - Stuck SG Safety Volve with CVS On 4W Estimated AP600 Boron Concentrations i End-of-Life initiet Conditions RCS

Foulted SG CMT

+ +000 4000 m E' y a c j 3000 - 1 - 3000 e Y _s ,o .\\ / x ~._ _ _ _ - _._ _ _. N - 2000 I 'O 2000 - e ~ u a o / ~ / - 1000 o 1000 - e o ~ s o / I 0 l l l 0-G 0 5000 10000 15000 2U000 i 3,ime (r SBC 1 2 s Lr m. amm mm - ..m -...- m-.

S M I" Yh ^ i AP600 5 Tube SGTR - S' tuck SG Sofaty Volwe with CVS On 3)p Estimated AP600 Boron Concentrot. ions g Beginning-of-l.ife initiol Conditions 5 RCS ---Foulted SG CMT .,.5000 ~ 5000 e a m a ] ~ 4000 -: - 4000 g = c g 3000 -? s._ ']- - 3000 o ,y C

2000 -

- 2000 i / ~ e O l u / 1000 -- -1000 c o

/

f a '~ = r 0 l l 0 F 0 5000 10000 15000 20000 i { Time (sec-) z 3 5

4-1 4

SUMMARY

AND CONCLUSIONS The analysis examines beyond design-basis steam generator tube ruptures. The objective of these beyond design basis analyses is to show that the multiple-SGTR event does not lead to unmitigated release of fission products to the environment. This is accomplished in a defense-in-depth manner by demonstrating that the AP600 provides multiple levels of defense to mitigate single / multiple tube rupture, e including active sy Mems with operator actions to cooldown and depressurire the RCS, automatic passive systems response with no ADS, as well as passive systems with ADS. diverse, redundant systems prevent the oring of the steam generator safety valve during the multiple-SGTR event, and if the safety valve is postulated to be opened and stuck-open during a tube rupture, the e plant achieves a safe, stable state in which the reactor core is shutdown and cooled throughout the accident. One-through five-tube multiple steam generator tube rupture cases are analyzed with MAAP4 without crediting any operator actions. These base cases show that the heat removal by the passive RHR and CMTs stops the loss of coolant from the primary and secondary systems, and the CMT level is ma'ntained throughout the transients since there is no cold leg voiding to break the siphon in the balance line. The CMTs inject in recirculation mode due to the density difference between the hot RCS water and cold CMT water. There is no reduction in CMT level, and no automatic ADS signal is generated by a low level in the CMT. In each case, either - a turbine bypass valve to the condenser or the secondary system PORV opens, and the pressure in the faulted steam generator remains below the secondary side safety valve opening setpoint. The secondary system safety valve remains closed throughout the analyses. The sensitivity analyses presented in section 4 show that the conclusions are also valid considering high and low variations in passive RHR heat removal capacity and location of the tube rupture. Case SG5p, an accident sequence with the failure of the secondary condenser and PORV to - open, demonstrates the operation of these systems is not required to prevent the opening of the secondary safety valve. However, case SG5cvs shows that if the nonsafety-related CVS system injects, which is very likely, the secondary PORV or condenser must operate to prevent the safety valve from opening. The steam generator overfill protection isolates the CVS and SFW systems at a' water level which prevents the secondary PORV and safety valves from passing two-phase flow. In case SG5stk, with CVS injection and the failure of the turbine bypass valves and PORV to open, the secondary system safety valve opens and is conservatively assumed to stick fully open, although it does not pass water in the scenario. This case is presented to show that even if the secondary safety valve is postulated to stick open, the plant is able to provide defense-in-depth by achieving a safe, stable condition with no fission product release, assuming no operator actions and crediting only safety-related systems. The continuous loss of coolant Summary and Conclusions Revision 0, November 1997 oA3931. doc 1b-11/s/97

4-2 through the stuck-open safety valve eventually leads to the voiding of RCS and CMTs, and the ADS is actuated. The RCS and secondary pressures an. significantly reduced and essentially equilibrated at the time of ADS. Some reverse flow is predicted from the secondary side to the primary side. The secondary water is borated to the RCS boron concentrat'.n during the transient through the break and by the loss of clean water inventory as steam through the eiuek-open valve. No boron dilution in the RCS is predicted during or after ADS. Once depressurized, gravity injection keeps the core cooled. Loss of water inventory through the stuck-open valve is minimal once the plant is depressurized, and no makeup is required for rc. ore than 2.5 days. The core is never uncovered, remains cooled, and there is no large release of fission products which may be postulated to bypass the containment through the stuck open valve. Therefore, the AP600 mitigates the potential for smisolatable containment bypass that may be postulated for steam generator tube rupture events. Diverse, redundant systems are provided which isolate the break, prevent the overfihmg of the st-am generator and prevent the opening of the secondary safety valve. Heat removal from passive systems isolates the break and prevents voiding of the RCS. Postulated boron dilution from reverse flow from the secondary to the primary system is prevented as automatic depressurization does not occur. In the event of a postulated stuck open safety valve, the AP600 demonstrates defense-in-d 9th to the contairunent bypass by mitigating the accident and achieving a safe, stable condition without uncovering the core. Postulated boron dilution does not occur as the secondary water is borated to the RCS boron concentration prior to ADS by the addition of borated water through the break and loss of clean water as steam through the stuck-open safety valve. I Summary and Conclusions Revision 0, November 1997 oA3931.docib-11/s/97

51 5 REFERENCES - 1. Letter, Thomas J. Kenyon (NRC) to Nicholas J. Liparulo (Westinghouse), Dated. September 23,1992.; 2. - Letter, Thomas J. Kenyon.(NRC) to Nicholas J. Liparulo (Westinghouse), Dated June 1,1994. 3. - Letter, William C. Iluffman (NRC) to Nicholas J. Liparulo (Westinghouse), Dated - January 21,1997. 4. Ietter ET-NRC-92 3748, N.J. Liparuto to Dr. Ivan Selin dated September 17,1992.. 5. EPRI Research Project. Number 3131-02, "MAAP4 - Modular Accident Analysis Program for LWR Power Plants Computer Code Manual." i References Revision 0, November 1997 c:\\3931. doc:1b-ll/5/97

i to Westing souse Letter DCP/NRCli30 November 11,1997 u% ept

NRC REQUEST FOR ADD 'ONAL INFORMATION -- v w - Question 440.683 (OITS #5707) The analysis report did not appear to provide sufficient argument with respect to the measures to prevent the lifting of safety valves in the event of MSGTR. or the mitigating features in the event of a stuck open safety valve. to address the MSC..R/ containment bypass issue. a. For a more realistic calculation with the assumptions that the CVS actuated at low pressurizer pressure or level, and the turbine bypass steam dump system available until the MSIV closure, a loss of off4ite power, or a loss _of condenser vacuum, would the steam pressure reach the safety valve setpoints, and at what time? Would there be sufficient time for operator actions (such as diagnosis of a SGTR event, isolation of CVS iniection, realignment of the CVS for pressurizer spray) to prevent safety valve lifting if PORV fails to open? - b. - Since the AP600 PORV is a non safety related system, what design features and other measures are there to ensure the PORV will automatically open on demand to prevent safety valve from opening in a MSGTR event? What is the probability of PORV failure on demand? It is stated (page 8 of the repo.1) that the assumption of safety valve sticking open is highly conservative c. since the safety valve will not relieve water with the AP600 steam generator overfilling protection design of automatic isolation of CVS and SFW at 79% SG narrow range. What available data are there to support that safety valve will not stick open for steam release? d. What measures are there in the AP600 design to mitigate the consequence of a stuck-open safety valve?

Response

He capacity of either the steam dump system or the PORV are sufficient to prevent the opening of the a. steam geneutor safety valves. Therefore, if either the steam dump or the PORV operates successfully, the steam gener.itor safety vahes will not open. As discussed in the response to RAI 440.681, the operation of the CVS makeup pumps during a multiple steam generator tube rupture event does not significantly affect the timing that pressure relief is required from the steam generator secondary side. The AP600 ERGS for a steam generator tube rupture event directs the operator to isolate the feed flow to the ruptured steam generata. Dis manual action, if performed successfully, will increase the time until the safety valves would lift. However,if the CVS makeup pumps continue to operate and the PORV is failed, the steam generator safety valves would eventually lift. The ERGS direct the operator to isolate the faulted steam generator, but do not instruct the operator to isolate the CVS makeup pumps for the purpose of preventing the steam generator safety valves from lifting. CVS makeup pump operation is controlled based on pressurizer water level. i 440.683-1 M iligt10U38 ,m a ..,-4 n

NRC REQUEST FOR ADDITIONAL INFORMATION +m I b. Since the AP600 secondary side PORVs have a safety-related function to close, they are tested (exercise full stroke) quarteriy (Table 3.9.6-16 of AP600 SSAR). They are also tested for operability every 10 years. The quarterly test period is a typical time period for valves for a safety system in current plants and assures opening as well as closing funetionality of the PORVs. Hus, the PORV reliability to open is expected to be as good as those PORVs in current plants. - The PORV failure probability to open is 5.0E-03/ demand, as given in the AP600 PRA data section. Ec value is taken from the ALWR URD, Chapter 1. Appendix A (Revision S&6,12/93). c. Failure of safety valves to reclose after steam release is addressed in the AP600 data base for pressurizer safety valves.- The failure probability quoted in the data analysis section is 5.0E-C3/ demand and is from the ALWR URD. Chapter I, Appendix A (Revision 5&6,12/93), his value is supported by 0 failures in 153 demands for three plants, as quoted in he URD. He secondary side safety valves are identical in design (spring loaded) and in operation.o those of the pressurizer; thus the same failure probability is used for the secondary side safety relief valves. d.' Case SG5stk in the MSGTR report presents the AP600 response to a stuck open safety valve. The multipic SGTR with a stuck open safety valve scenario is a beyond design basis event. Mitigation is defined as limiting the 24 hour TTDE dose to less than 25 r:m at the site boundary. Given that the secondary system cannot be isolated due to the stuck'open valve, mitigation of a large release is accomplished by not meh6g fuel rods and maintaiaing the fission products in the fuel matrix. The AP600 responds to a stuck open safety valve as it responds to any design basis small LOCA. The loss of coolant through the safety valve eventually causes the CMis to start to drain and actuate the ADS system. The RCS is depressurized, and gravity injection and recirculation provide long-term cooling. The core does not uncover and there is no release of fission products from the fuel matrix. Boron dilution of the RCS during the depressurization does not occur since boric acid accumulates in the steam generator water prior to the ADS actuation. The release of radiation to the environment is limited to the reactor coolant activity. This release is well within the large release goal and is considered :o be mitigated. 440.683 2 W Westinghouse _J

Q NRC REQUEST FOR ADDITIONAL INFORMATION

n:

P A telecon was held on October 16,1997 between Westinghouse (C. Haag, J. Scobel) and NRC (W. Huffman, G. Hsii) to discuss an NRC September 16,1997 fax (see Attachment 440.6831) which contained a summary of the staff's MSGTR issues. It was agreed during the telecon that item 2.d of the NRC fax would be answered as part of this RAI response. The item from the September lo fax is: 2.d Even if the MSSV fails to resca. after it is actuated, the SGTR scenario turns into success through automatic ADS actuation, and core damage would not occur, as shown in case SGS-stk. The maximum total release would he limited to the initial activity in the RCS. Provide an estimate of total release if the safety valve is stuck open, and the core melt does not occur. The response to item 2.d is as follows: In the event of a multiple SGTR, the RCS is depressurized and long term core cooling is provided by gravity injection and passive recirculation. The core does not uncover and there is no release of fission products from the fuel matrix. The release of radioactivity to the environment is limited to the inventory in the reactor coolant As this is an accident that is beyond the design basis, the analytical assumptions u. sed are not as conservative as used for design basis events. The amount of activity in the reactor coolant system is based on a fuel defect level of 0.05 percent (this is one fifth of the design basis level of 0.25 percent) and assumes a pre-existing iodine spike that raises the steady state iodine concentration from 0.08 pCi/g to 4.8 pCi/g Dose Equivalent 1131. The primary coolant noble gas activity associated with 0.05 percent fuel defect level is 30 pCi/g Dose Equivalent Xe.133. With 3.6E5 lb of primary coolant, the activity available for release is 785 Ci Dose Equivalent 1-131 and 4900 Ci - Dose Equivalent Xe-133. The site boundary atmospheric dispersion factor for design basis accident analyses is 1.0E-3 sec/m', but for a beyond desigr. basis accident, a realistic value of 1.25E-4 sec/m'is used. Assuming that all of the activity in the primary coo; ant is released (no credit for iodine partitioning) during the first two hours of the accident, the site boundary dose is determined to be 1.1 rem IIIDE which is well below the dose guideline of 25 rem TEDE. SSAR/PRA Revision: None,

- 3 3 w womeoou

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S 9 .RESOLiff!ON OF MSGTR-ISSUR 1. Respond to RAI 440.575 regarding MAAP4 benchmark: 4 Provide 4 summary of MSGTR scenarios and import &Rt phenomena, and a susenary of MAAP4/NOTRUMP benchmark and results that can be used to arfue that isportant phenomena during a MSGTR can be reasonably analysed with MAAP4. On the 80 secondary side, there may not be a MAAP4 benchmark. It would be necessary to discuss the sisplified one-node model, the-fundamental equations and constitutive models used to conservatively analyzed the secondary side, and discuss _why this is appropriate. 2. The argument for resolution of the issues

a. Even for 5-tube rupture case, the secondary pressure never reaches the safety valve setpoints as long as the PORY is i

operable and open to relieve the pressure. This is evidenced in case SGE-cvs.

b. The probability of the PORY fails to open is low though it is a non-safety related systems Provide the PORY design features and measures to ensure the PORY

- will sutomatically open on demand, and provide an estimate of its failure probability. (RAI 440-CO3 b) In [he low probability event that the PORV fails to open, the

c. MasVs will open at a higher pressure.

The SG overtill protection l automatically trip the CVs and eru on hi 2 SG narrow range level, and the M88V will release steam only. Therefore, the probability of M88V failure to ressat is smail: The scenario is similar to SG5=cvg. except that the MSSV open at higher pressure than the PCRV. However, this case was not analyzed. The 805-stk case-assumes the MSSVs fail to reclose once it open, and the result shows the SG overfill even after the f CVS and SFW are isolated at 50 minutes on hi 2 SG narrow range / level. However, the analysis results showed that the SG is filled with water after about 2 hours, and therefore water is release through the MSSVs. (A) Provida (1) an analysis (similar to case SGS-cvs except that the PORV is assumed to fail to open), or (2) an argument based on similar results from case SGS-cvs except for higher set pressure of the safety valves, to demonstrate that even if the PORV fails to open, the safety relief valve will open at a higher pressure than the PORV would, and will release steam and reclose as SG pressure declines. (B) provide-available data to support the argument that the l safety valve will not stick open with steam release. (440.603 c)

d. Even if the MCSV fails to resent after l't is acutated, the SGTR scenario turns into a through hutomatic ADS actuation, and no core damage would not occur, as shown in case SG5 stk.

The maximum total release would be limited to the initial activity in the RCs. ~ l k,- l SEP 16 '97 12: 49 PAGE.002 440.683-5 4

4-l

. Provide an estimate of total release if tM safety valve is stuck open, and.the core malt dose not. occur, J e 4 .I. j r. [ SEP 16 '97 12:49-PAGE.003 440.683-e ..}}

ML20199C002

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REFERENCE:

SUMMARY

Response

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