ML20044C526

Summary of 930121 Meeting w/ABB-C-E in Rockville,Md Re Dser

ML20044C526
Person / Time
Site:	05200002
Issue date:	03/17/1993
From:	Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 9303230298
Download: ML20044C526 (25)

Text

/

o UNITED STATES 8

i NUCLEAR REGULATORY COMMISSION O

,E WASHINGT ON, D. C. 20555

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4

%.....o March 17, 1993 Docket No.52-002 APPLICANT: ABB-Combustion Engineering, Inc. (ABB-CE)

PROJECT:

CE System 80+

SUBJECT:

PUBLIC MEETING OF JANUARY 21, 1993, TO DISCUSS OPEN ISSUES FROM THE CE SYSTEM 80+ DRAFT SAFETY EVALUATION REPORT (DSER) i On January 21, 1993, a public meeting was held at the U.S. Nuclear Regulatory Commission (NRC), Rockville, Maryland, between representatives of ABB-CE and NRC. Enclosure 1 provides a list of attendees. is the material presented by ABB-CE. During the meeting, the staff and ABB-CE discussed three issues from the CE System 80+ DSER.

The first issue involved generic safety issue (GSI) 23, " Reactor Coolant Pump Seal Failures" (DSER Open Item 20.2-7).

GSI-23 addresses, in part, maintaining seal integrity under loss of seal cooling conditions (e.g.,

station blackout), thereby reducing the likelihood of a small-break loss-of-coolant accident (LOCA) from seal failure. The reactor coolant pump (RCP) shaft seal design for the System 80+ plant is a CE-KSB design. The design employs 3 cartridge-type, hydrodynamic seals, including 2 equally staged seals, and a third stage used as a vapor seal. Seal cooling is provided from component cooling water (CCW) and non-safety related seal injection from the chemical and volume control system (CVCS).

ABB-CE presented options for resolving GSI-23 for the CE System 80+ design.

ABB-CE stated that their preferred option was to conduct additional tests on the seals under loss-of-cooling conditions.

However, the staff noted that the agency has initiated rulemaking for GSI-23, and testing acceptance criteria would not be available for several months.

If the applicant decided to conduct further RCP seal tests, the staff would entertain ABB-CE's test results.

The second option called for a design modification of the System 80+ CVCS design.

Under this option, ABB-CE would add a highly reliable and diverse seal injection system. The diverse system would consist of an air-cooled positive displacement pump (PDP) that would be capable of being powered from either the emergency diesel generators (ED/Gs) or the alternate ac (AAC) source. The PDP would share some existing CVCS piping runs. During the interim between this meeting and the issuance of the associated meeting summary, ABB-CE decided to provide the diverse seal injection system in order to resolve the seal issue. ABB-CE will submit the details of the design modification in March 1993.

The second issue involved common mode failure (CMF) p'otential in digital i

systems and acceptable instrumentation and controls (I&C) diversity (DSER Open Item 7.2.2.2-1).

This issue addresses the potential for CMF of the System 80+

protective system software in conjunction with CESSAR-DC Chapter 15 design basis event initiators. ABB-CE had conducted a preliminary evaluation of the I

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issue and potential consequences of a CMF that renders all automatic response inoperable due to a pre-existing CMF of the protective system software.

ABB-CE's evaluation resulted in the need for additional analysis of 9 design basis events, the use of diverse instrumentation and controls (I&C) systems, and verification of reasonable operator response to provide adequate protection.

[

t for two of the nine events analyzed, ABB-CE requested use of the leak-before-l break (LBB) concept.

LBB would be applied to the large-break LOCA (LBLOCA) and the in-containment main steamline break (MSLB) events. Use of LBB criteria would result in a plant shutdown prior to significant pipe degradation that would yield a potential LBLOCA or in-containment MSLB event.

t The staff noted that the LBB methodology is under staff review for source term purposes, and LBB approval, in general, will influence the staff's decision to accept LBB application for CMF/1&C diversity purposes.

j The third issue discussed was interfacing system LOCA (ISLOCA) (DSER Open l

Item 20.2-14). ABB-CE stated that it was not their intention to upgrade the l

pressure handling capability of all CE System B0+ low-pressure systems to meet the ultimate rupture strength (URS) criteria.

Rather, ABB-CE l

preferred to resolve the issue from a mechanistic approach that would i

demonstrate adequate pressure relief capacity through relief valves, sufficient pressure reduction in piping lines as a function of length and other line resistances (e.g., check valves, filters, oriface plates), and acceptable hoop stress levels during the pressure transient. ABB-CE will i

evaluate a spectrum of ISLOCA events on a case-by-ci.se basis and modify the plant design accordingly.

i The following commitments were made during the meeting:

l i

i (1) ABB-CE will evaluate use of diverse power sources to power the PDP such

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as use of a security diesel, a dedicated diesel, or the AAC power source (combustion gas turbine).

b (2) ABB-CE committed to evaluate why Amendment K for CESSAR-DC Table 3.2-1 l

revised classification of the RCP auxiliary components required for lubrication and cooling of the pump seals from " Quality Class 2" to "not subject to the quality assurance requirements of 10 CFR Part 50 Appendix B."

1 (3) For the ISLOCA issue, ABB-CE committed to identify system piping and j

components that are not designed to the URS criteria. ABB-CE will also provide an engineering assessment to support a departure from the URS criteria, and ABB-CE will provide a definition and justification for the t

test of practicality.

j (4) ABB-CE will provide a definition of a coolable core geometry.

In.

addition, ABB-CE will provide the time and temperature criteria (e.g.,

NUREG-0652) and supporting data for defining a coolable core geometry for the I&C diversity issue in conjunction with CESSAR-DC accident analysis.

5 I

)

i

-! March 17, 1993 (5) ABB-CE will quantify and justify operator response time for actions renuired to initiate safety injection and containment heat removal for the CMF issue.

(6)

ABB-CE will provide the appropriate list of parameters and displays for I&C diverse system indication.

(7) The staff will evaluate the proposed use of LBB for design basis events such as LBLOCA and in-containment MSLB scenarios within the context of i

the I&C diversity issue.

(8) ABB-CE will evaluate if a single pipe break location in the CCW system i

could render the entire system inoperable.

l t

(Original signed by) j Michael X. Franovich, Project-Manager' Standardization Project Directorate Associate Directorate'for Advanced Reactors and License Renewal Office of Nuclear Reactor Regulation j

Enclosures:

i As stated

{

l cc w/ enclosures:

j See next page j

DISTRIBUTION w/ enclosures:

Docket File PDST R/F MFranovich PDR RPerch, 8H7 PSha-

-i DISTRIBUTION w/o enclosures-TMurley/FMiraglia DCrutchfield WTravers RBorchardt WRussell ACRS (11)

JMoore, 15B18 GGrant, EDO JPartlow, 12G18 TWambach EJordan, MNBB3701 NSaltos,10E4 i

MMalloy AEl-Bassioni,10E4 DDiec, 8E23 MRubin, 8E23 MWaterman, 8H7 DTerao, 7H15 SSun, 8E23 SMagruder.

GBagchi, 7H15 JBrammer, 7H15 JJackson, RES SKShaukat, RES i

OFC:

LA:PDST:3DAR PM:PD {ADARSC:

T:ADAR NAME: PSheaa 0 MXF,2 tich:tz-RB ardt r

DATE: 03 9'3 03ffT 93 03// 7/93 l

OFFICIAL RECORD COPY: MSUM0121.MXF

ABB-Combustion Engineering, Inc.

Docket No.52-002 i

cc: Mr. C. B. Brinkman, Acting Director

'i Nuclear Systems Licensing Combustion Engineering, Inc.

1000 Prospect Hill Road Windsor, Connecticut 06095-0500 Mr. C. B. Brinkman, Manager Washington Nuclear Operations Combustion Engineering,-Inc.

12300 Twinbrook Parkway, Suite 330 Rockville, Maryland 20852 j

Mr. Stan Ritterbusch Nuclear Systems Licensing Combustion Engineering, Inc.

1000 Prospect Hill Road Post Office Box 500 Windsor, Connecticut 06095-0500 l

Mr. Sterling Franks U. S. Department of Energy l

NE-42 Washington, D.C.

20585 Mr. Steve Goldberg Budget Examiner 725 17th Street, N.W.

Washington, D.C.

20503 l

Mr. Raymond Ng 1776 Eye Street, N.W.

Suite 300 Washington, D.C.

20006 f

Joseph R. Egan, Esquire Shaw, Pittman, Potts & Trowbridge 2300 N Street, N.W.

Washington, D.C.

20037-1128 i

e f

k MEETING ATTENDEES I

JANUARY 21, 1993 NAME ORGANIZATION M. Franovich NRR/PDST T. Wambach NRR/PDST W. Borchardt NRR/PDST M. Rubin NRC/DSSA A. El-Bassioni NRC/DSSA M. Waterman NRC/DRCH t

J. Jackson NRC/EIB/RES f

S. K. Shaukat NRC/RES/EIB S. B. Sun NRC/NRR/SRXB N. Saltos NRC/NRR/SPSB D. Diet NRC/DSSA G. Bagchi NRC H. Brammer NRC M. Cross ABB-CE I

S. Ritterbusch ABB-CE F. Carpentino ABB-CE R. Mitchell ABB-CE A. Hyde ABB/I&C h

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Enclosure.1 r

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NRC AND ABB-CE MEETING l

REACTOR COOLANT PUMP SEAL COOLING JANUARY 21, 1993 1

i OBJECTIVE:

TO PRESENT ABB-CE'S SEAL COOLING l

SYSTEMS i

]

TO DISCUSS TWO APPROACHES TO MEETING SB0 COOLING-i TO OBTAIN DIRECTION FROM THE NRC ON l

THE DESIGN APPROACH TO IDENTIFY AND UNDERSTAND AREAS j

WHERE MUTUAL AGREEMENT CANNOT BE i

REACHED l

l DISCUSSION:

ISSUE l

RCP SEAL INJECTION /.CVCS DESIGN ER RCP DEMONSTRATION TEST ALTERNATE'RCP SEAL INJECTION PUMP 4

1.

ISSUE P

r o

NRC DOES NOT PRESENTLY AGREE WITH PRESENT ABB-CE SEAL COOLING APPROACH 1

o SEAL COOLING APPROACH HAS REDUNDANT MEANS OF COOLING THE REACTOR COOLANT PUMP SEALS o

"NRC WANTS A SEAL ASSEMBLY THAT WOULD NOT

.i LEAK EXCESSIVELY DURING A STATION BLACK 0UT.

A SATISFACTORY RESOLUTION INVOLVES-A DEMONSTRATION TEST OR DIVERSE SAFETY GRADE SEAL-COOLING WHICH IS i

INDEPENDENT OF THE CVCS" i

I o

DSER QUESTIONS 9.3.4-1 AND 20.2-7 l

l l

I

i RCP SEAL INJECTION

/

CVCS DESIGN l

SEAL INJECTION (SI) PROVIDED BY TWO INDEPENDENT &

REDUNDANT CVCS DIVISIONS TO ASSURE RELIABILITY, REDUNDANCY AND AVAILABILITY.

L o

CHARGING /SI PORTION OF CVCS ASME III - SAFETY

)

CLASS 3 DESIGN o

TWO CENTRIFUGAL CHARGING PUMPS - SAFETY CLASS 3 DESIGN i

o CHARGING PUMPS POWERED FROM NON-SAFETY RELATED BUSES 0

EACH DIVISION CAN PROVIDE COMPLETE CHARGING FLOW j

RANGE (44-132 GPM) o FOR STATION BLACK 0UT (SBO) EVENT CHARGING PUMPS POWERED FROM ONSITE ALTERNATE AC -(AAC) POWER SUPPLY

^

o FOR SB0 EVENT CONTINUED SEAL COOLING ASSURED BY SI 1

AND AAC l

0 CVCS/SI-SYSTEM DESIGN MEETS-DRAFT RG 1008 REQUIREMENTS FOR AN INDEPENDENT POWERED SYSTEM i

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RCP SEAL INJECTION l

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CCWS DESIGN i

COOLING WATER IS PROVIDED BY THE NON-ESSENTIAL COOLING WATER HEADER.

o CCWS CONSISTS OF 11J0 TRAINS i

o EACH TRAIN SUPPLIES ESSENTIAL AND NON-ESSENTIAL COOLING WATER o

EACH TRAIN INCLUDES REDUNDANT CCW PUMPS o

ESSENTIAL CCW-LOOP IS COMPOSED OF SAFETY CLASS 3 PIPING AND COMP 0NENTS o

THE NON-ESSENTIAL CCW LOOP IS COMPOSED OF NON-NUCLEAR SAFETY PIPING AND COMPONENTS l

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SYSTEM 80+

RCP SEAL DESCRIPTION o

SEAL SYSTEM CONSISTS OF THREE HYDRODYNAMIC SEAL.

STAGES ARRANGED IN SERIES o

EACH STAGE IS CAPABLE OF OPERATING AT FULL SYSTEM PRESSURE o

FIRST TWO STAGES BREAK DOWN APPR0XIMATELY 84% OF SYSTEM PRESSURE (42% EACH) o THIRD STAGE BREAKS DOWN REMAINING 16% OF SYSTEM-PRESSURE AND ACTS AS A VAPOR SEAL o

SEAL SYSTEM HAS FOUR YEAR SERVICE LIFE (EPRI /

ALWR REQUIREMENT) s l

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SEAL COOLING-o SEAL COOLING PROVIDED BY INDEPENDENT AND REDUNDANT COOLING SYSTEMS SEAL INJECTION (SI) WATER (6.6 GPM EACH PUMP AT 120*F) INTRODUCED INTO SEAL COOLING l

CIRCUIT.

i COMPONENT COOLING WATER (CCW) WHICH COOLS SEAL WATER BY.HIGH PRESSURE SEAL COOLER (HPSC) AND THROTTLE SEAL COOLERS-(TSC).

i o

SEALS CAN OPERATE INDEFINITEL'i WITH:

LOSS OF SEAL INJECTION (SI) WATER WITH COMPONENT COOLING WATER AVAILABLE.

d LOSS OF CCW WITH SI AVAILABLE.

1 1

1 1

1

dSEAL LEAKAGE P01 - SEAL CAVITY PRESSURE PC2 a lNTERMEDIATE PRESSURE CB0 PC3 = BACKUP PRESSURE n

... FLOW Y

RESTRICTOR CCW RIGIO COUPLING HIGH PRESSURE COOLER I

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THIRD SEAL (EACKUP SEALJ THROTTLE n

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SECOND SEAL P02 a

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FIRST SEAL P01 l

T02 CYCLONE AUXILIARY ~"? I 7 i

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JOURNAL BEARING JET PUM)P S

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OSEAL IMPELLER INJECTION Figure 2 Flow Diagram for Hydrodynamic Shaft Seal System.

Normal Operation - with CCW & SI e

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i RCP DEMONSTRATION TEST o

DEMONSTRATION TEST MAY BE POSSIBLE FOR STATION BLACK 0UT 0

REGULATORY GUIDE 1008 IS BEING REVISED TO INCLUDE TEST ACCEPTANCE CRITERIA o

ACCEPTANCE CRITERIA HAS NOT BEEN FINALIZED BY NRC 0

ABB-CE PREPARED DRAFT ACCEPTANCE CRITERIA'SENT TO THE NRC FOR THEIR CONSIDERATION o

A DEMONSTRATION TEST IS NOT A VIABLE OPTION l

WITHOUT A DEFINITIVE ACCEPTANCE CR.ITERIA-i ll l

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System 80+ toss of RCP Seal Coolino Test Proaram l

A.

Station Black Out (SBO) Test Proaram Loss of cooling water and loss of seal injection water, pump stopped at hot reactor coolant system operating conditions.

1.

Basis For station blackout event seal leakage limited to an a.

acceptable value. The RCP does not have to operate after a SB0 and seals can be replaced if necessary 2.

Test Reovirements P

Tests consist of three separate single stage cartridge tests a.

for up to eight hours each at full RCS temperature and pressure. For a SB0 event, controlled bleed off flow is isolated so last or top seal sees full pressure and potentially S50*F.

Therefore, use of a multi-stage cartridge is not necessary.

Separate tests provide for repeatability of SB0 conditions and address any concerns about variabilities in seal material properties.

b.

Tests performed with new seal assemblies because seals experience relatively little wear or thermal damage during a fuel cycle.

i i

All seal parameters measured and recorded, i.e., seal c.

pressure, temperature and seal leakage.

d.

Seals disassembled after test and inspected.

l

=

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l 3.

Acceptance Criteria a.

Seal leakage through last or top seal assembly shall not exceed 40 gpm which is maximum acceptable leakage for each RCP without uncovering reactor core.

b.

Seal face thermal damage acceptable as long as seal leakage criteria is not exceeded.

c.

Seal elastomer damage acceptable as long as seal leakage criteria is not exceeded.

I B.

Other loss of Seal Coolina Events RCP seal integrity has been demonstrated by test for the following loss of seal cooling events. The test data has been forwarded to NRC staff on May 14, 1992 (DCTR 12).

1.

Loss of cooling water, seal injection water available, pump stopped.

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2.

Loss of seal injection water, cooling water available, pump stopped.

3.

Loss of cooling water, seal injection water available, pump running.

4.

Loss of seal injection water, cooling water available, pump running.

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ALTERNATE RCP SEAL i

INJECTION PUMP o

LOCATED IN PARALLEL WITH CHARGING PUMP i

o POSITIVE DISPLACEMENT PUMP i

o POWERED FROM EMERGENCY DIESEL

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o REMOTELY. OPERATED VALVES AND APPLICABLE INSTRUMENTATION POWERED FROM SAME SOURCE AS THE ALTERNATE RCP SEAL-INJECTION PUMP l

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ALTERNATE RCP SEAL INJECTION PUMP - SAFETY CLASS 3 i

DESIGN l

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1 ALTERNATE RCP SEAL INJECTION LETDOWN O

Q VOLUME j'-h-CONTROL

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i MEETING i

NRC AND ABB-CE i

i SYSTEM 80+

1 INTERSYSTEM LOCA j

1 1-21-93 a

OBJECTIVE:

TO PRESENT ABB-CE'S DESIGN APPROACH FOR THE-ISLOCA ISSUE TO OBTAIN AGREEMENT Fn0M THE NRC ON THE DESIGN APPROACH (I.E., SYSTEMS INVOLVED; i

HANDLING OF FLANGES, VALVE PACKING, ETC.; EVALUATION PROCESS)

TO IDENTIFY AND' UNDERSTAND AREAS WHERE MUTUAL AGREEMENT CANNOT BE REACHED l

DISCUSSION:

SCOPE FOR ISLOCA l

ISLOCA EVALUATION PROCESS.

SYSTEM'80+ DESIGN IMPROVEMENTS AFFECTING l

ISLOCA

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l SCOPE FOR ISLOCA l

1 o

APPLIES TO SYSTEMS CONNECTED TO THE RCS AND EXTENDED OUTSIDE THE CONTAINMENT BOUNDARY j

o CE NPSD-741-P PRESENTS SYSTEM 80+ EVALUATION o

SYSTEM 80+ SYSTEMS INCLUDE:

i SAFETY INJECTION SYSTEM SHUTDOWN COOLING SYSTEM l

CHEMICAL AND VOLUME CONTROL SYSTEM 1

PROCESS SAMPLING SYSTEM j

o SCOPE OF EVALUATION INCLUDES PIPING AND ISOLATION VALVES IN THE INTERFACING. SYSTEMS 0

SCOPE OF EVALUATION DOES NOT INCLUDE COMPONENT OR SUBCOMPONENTS SUCH AS FLANGES, PACKING ASSEMBLIES AND PUMPS.

REQUIREMENTS IMPOSED IN THE COMPONENT DESIGN / EQUIPMENT SUPPLY PROCESS WILL ASSURE INTEGRITY fi l

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3-T INTERSYSTEM LOCA EVALUATION PROCESS i

I DENTIN SYSTDA l

REV!EW PARTS OF SYSTDd DESGN f

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MEETS RCS DESGN PRESSURE ES OR URS

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i mTDEON i

NO j

CONTMNWENT LOCADON IN n

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iS OVERPRESSURE PROTECDON PROVDED YES

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NO EVENT RESULTANT YES PRESSURE W:THN 0-LP. DESGN t

i N0 i

I DESGN TO RCS YES

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PRESSURE OR URS DUTER:0N l

l NO a

NUWBDt OF FNLUPIS MAKES THE

-YES PROBAINUTY OF AN ISLOCA u< LOW U

NO i

- NEID NDEPENDENT MC REDUNDANT p

WEANS OF iSOLAVON i

DESGN TO

- NEID DVERPRESSURE PROTECDON-RCS PRESSURE

- NEID PDUODIC LEAK TESTING OF

' l OR URS ISOLAVON VALE.S DUTDCON

- NEID PRESSURE NSTRUMENTAVON WTH NDICAVON AND ALARW N CONTROL ROOM l

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p-DESW SAVSFIES ISLOCA REQUIRDdENTS (SECY-90-016) l J

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SYSTEM 80+

DESIGN IMPROVEMENTS AFFECTING ISLOCA 1

o 4 HIGH PRESSURE SAFETY INJECTION PUMPS (ELIMINATION OF LOW PRESSURE' SAFETY INJECTION PUMPS) o SHUTDOWN COOLING SYSTEM DESIGN PRESSURE INCRE/SE TO 900 PSI (RCS URS CRITERION) o CVCS INTERMEDIATE PRESSURE SYSTEM DESIGN PRESSURE l

INCREASE o

CVCS LETDOWN HIGH TEMPERATURE LINE INSIDE CONTAINMENT o

RWST LOCATION INSIDE CONTAINMENT

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I&C DIVERSITY

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IMPACT ON TRANSIENTS & ACCIDENTS l

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PRELIMINARY EVALUATION INDICATES NORMAL CONTROL f

SYSTEMS AND THE ALTERNATE PROTECTION SYSTEM (APS) i PROVIDE ACCEPTABLE LEVEL OF PROTECTION.

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. 1/21/93 i

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.I&C DIVERSITY ISSUE EVENTS FOR EVALUATION r

1.

LOSS OF AC (LOSS OF RCS FLOWRATE) j i

f 2.

LOCKED ROTOR 3.

SHEARED SHAFT l

1 4.

CEA EJECTION l

5.

LETDOWN LINE BREAK 6.

STEAM GENERATOR TUBE RUPTURE i

7.

MAIN STEAM LINE BREAK 8.

FEEDWATER LINE BREAK 9.

LOSS OF COOLANT ACCIDENT l

i i

1/21/93 EVALUATION METHODS BEYOND DESIGN BASIS EVENTS o

BEST ESTIMATE EVALUATION ASSUMPTIONS 1.

EVENT & CHF (No ADDED SINGl.E FAILURES).

2.

NOMINAL OPERATING PARAMETERS.

J.

CONTROL SYSTEMS PROVIDE AUTO AND MANUAL MITIGATION / REC 0VERY ACTIONS.

4.

ALTERNATE PROTECTION SYSTEM PROVIDES HPP RX TRIP AND EFAS.

5.

LEAK-BEFORE-BREAK LIMITS LOCA AND MSLB BREAK SI7_ES.

o BEST ESTIMATE ACCEPTANCE CRITERIA 1.

RETAIN C00LABLE GE0 METRY FOR ACCIDENTS USE " TIME-AT-TEMPERATURE" TO ENSURE NO FUEL FAILURE.

2.

MEET 100% OF 10CFR100 FOR LOSS OF AC o,

i 1/21/93' I

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LOSS OF RCS FLOWRATE i

i Rx TRIPS WITHIN 4 SECONDS FOLLOWS A LOSS OF AC.

REALISTIC THERMAL MARGIN AND RCP BEST ESTIMATE C0ASTDOWN MINIMIZE FUEL DAMAGr.

t DOSES SHOULD REMAIN BELOW 100% 10CFR100.

l LOSS OF AC REQUIRES RECOVERY USING MANUAL-CONTROL 0F EFW AND ADV'S.

THE DGs AND AAC ARE.AVAILABLE l

TO OPERATE THE SCS.

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I 1/21/93 LOCKED ROTOR & SHEARED SHAFT REALISTIC THERMAL MARGIN OFFSETS REDUCED CORE FLOWRATE TO MINIMIZE FUEL DAMAGE.

MARGIN IS REDUCED BUT ADEQUATE AT THE FINAL REDUCED 3 PUMP FLOWRATE (70-75%).

CORE C00 LABILITY SHOULD BE ASSURED...PARTICULARLY IF DEFINED VIA " TIME AT TEMPERATURE."

" TIME AT TEMPERATURE" HAS BEEN ACCEPTED

• FOR DEMONSTRATING COOLING WILL NOT BE LOST DUE TO FRAGMENTATION OF EMBRITTLED CLADDING FOR NON-LOCA EVENTS.

REFERENCES:

(1)

ST. LUCIE SSER #1, PARAGRAPH 4.2.3.3(A)

FOR MSLB, LR & CEAE.

(2)

CESSAR SSER#1, PARAGRAPH 4.2.3.3(A) FOR MSLB, LR & CEAE.

t

i 1/21/93' CEA EJECTION j

THE APS PROVIDES A HPP RX TRIP. THIS TRIP IN-CONJUNCTION-WITH REALISTIC THERMAL MARGIN SHOULD t

MINIMIZE FUEL DAMAGE.

1 CORE C00 LABILITY SHOULD-BE ASSURED...PARTICULARLY IF DEFINED VIA " TIME AT TEMPERATURE."

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1 1/21/93 t

I LETDOWN LINE BREAK THIS EVENT IS MITIGATED VIA MANUAL ACTIONS AT 30 MINUTES TO ISOLATE THE BROKEN LINE AND TRIP THE REACTOR.

PZR (RCS) INVENTORY CONTROL PROVIDED BY CHARGING PUMP (PLCS).

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1/21/93-STEAM GENERATOR TUBE RUPTURE THIS EVENT IS MITIGATED BY CONTROL ACTIONS:

PLCS CHARGING FLOW / LETDOWN MINIMIZED j

PZR HEATERS PPCS MFW REDUCTION l

FWCS SBCS SG VENTS T0 CONDENSER i

THE RX CAN BE MANUALLY TRIPPED AFTER IS+ MINUTES 1

WITHOUT DRAINING PZR OR OVERFILLING SG.

i a

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1/21/93-i 1

MAIN STEAM LINE BREAK i

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LBB ELIMINATES LARGE BREAKS REDUCING HSLB TO THE i

EXCESS LOAD TYPE OF EVENT ALLOWING TIME FOR MANUAL MITIGATION (RX TRIP, B0 RATION VIA CHARGING AND MSIV CLOSURE).

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1/21/93 i

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FEEDWATER LINE BREAKS THE APS PROVIDES HPP RX TRIP AND AFAS.

THE PPCS WILL HELP MITIGATE PEAK PRESSURE VIA NORMAL PZR 1

i SPRAY.

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i LOSS-OF-COOLANT ACCIDENT-LBB ELIMINATES LARGE BREAKS.

SMALL BREAKS 1

ACCOM)DATE MORE TIME FOR MANUAL MITIGATION.

l REACTIVITY FEEDBACK FROM VOIDING'SHOULD SHUTDOWN CORE.

CHARGING SHOULD-ASSIST REACTIVITY AND l

INVENTORY CONTROL.

l RCS HEAT REMOVAL AND PRESSURE CONTROL FOR SMALLER l

BREAKS MAINTAINED BY MAIN FEEDWATER AND STEAM BYPASS CONTROLS.

i

'I 1

e i

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