ML20059A832

Summary of 931028 Meeting W/Representatives of BWROG in Rockville,Md to Discuss Current Schedule of ATWS Long Term Solutions & Concerns W/Proposed Emergency Procedures Guidelines Raised by NRR in Recent Simulator Exercise

ML20059A832
Person / Time
Issue date:	12/17/1993
From:	Ulses T Office of Nuclear Reactor Regulation
To:	Rosalyn Jones Office of Nuclear Reactor Regulation
References
NUDOCS 9401030150
Download: ML20059A832 (13)

Text

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December 17. 1993 MEMORANDUM FOR:

Robert C. Jones, Chief Reactor Systems Branch Division of Systems Safety and Analysis THRU:

Laurence E. Phillips, Section Chief Core Performance Section Reactor Systems Branch Division of Systems Safety and Analysis FROM:

Tony P. Ulses, Reactor Engineer Core Performance Section Reactor Systems Branch Division of Systems Safety and Analysis

SUBJECT:

NRC/BWROG MEETING DISCUSS ISSUES RAISED IN NRR SIMULATION OF PROPOSED EPG'S A meeting was held at One White Flint North in Rockville, Maryland on October 28, 1993 between representatives of the BWROG and NRR to discuss the current schedule of the ATWS Long Term Solutions (LTS) and the concerns with the proposed Emergency Procedures Guidelines's (EPG) raised by NRR in a recent simulator exercise.

The meeting began with a short presentation regarding the status of the plans to choose and implement the iTS.

Speaking en behalf of the owner's group, Mr.

Tom Rausch stated that some plants had already tentatively made their choice of which LTS to adopt and the remaining plants should be choosing shortly.

Mr. Rausch also outlined the proposed implementation schedule for options I-A and III. Attachment I contains the slides from Mr. Rausch's presentation.

Following this presentation, Mr. Taggart Rogers of OEI began discussing the owner's group response to the NRR letter. The issues raised in the NRR letter are as follows:

1.

RPV depressurization appears to be the only course of action following isolation in plants without high pressure injection 2.

The proposed EPG changes may lead to unnecessary isolations in plants without isolation key-1ock bypass 3.

The proposed EPG changes provide no guidance to maintain RPV water level above the isolation setpoint The owner's group responded to the first issue by stating the all plants have g n;; /,

I or are planning to have either motor-driven feedpumps, a key-lock bypass, or in excess of 95 in. between the operating water level and the MSIV isolation

,dj[ S setpoint.

The owner's group feels that this coupled with the fact that recent i

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' calculations suggest that baron in more effective than originally assumed show that the position of issue 1 is not true.

Regarding the second issue, Mr.

Roger's stated that the proposed EPG's do increase the probability of MSIV isolation, but most plants have either quick isolation bypass, feedwater spargers well above the isolation sctpoint, or, in the event of an isolation, sufficient high pressure injection to control water level.

In response to the third issue, Mr. Roger's stated that maintaining RPV water level above the isolation setpoint is not always appropriate, but its importance can be emphasized in training. Mr. Roger's slides are included as Attachment 2.

An attendance list is included as Attachment 3.

/s/

Tony P. Ulses, Reactor Engineer Core Performance Section Reactor Systems Branch Division of Systems Safety and Analysis SRXB:DSSA SRXB:DSSA*

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BWROG/NRC MEETING ON STABILITY LONG-TERM SOLUTION STATUS OCTOBER 28,1993

LTS STATUS o

OPTION SELECTION UNDERWAY SOME UTILITIES HAVE MADE COMMITMENTS DECISION PROCESS COMPLEX (MAY TAKE TIME TO COMPLETE)

STABILITY COMMITTEE REORGANIZED TO EXPEDITE DEVELOPMENT OF o

OPTION METHODOLOGY AND COMPLETION OF RELOAD REVIEW PROCEDURES GENERIC COMMITTEE (SINGLE POINT NRC INTERFACE)

DETECT & SUPPRESS METHODOLOGY OPTION III HARDWARE (ABB) C iiro#7g/gf OPTION I-A (HARDWARE & METHODS) (;gr OPTION I-D OPTION III COMBINED WITH POWER RANGE MONITOR UPGRADE (GE)

UN0FFICIAL POLL OF UTILITY PREFERENCE TAKEN o

OPTION III (ABB & GE) 9-11 OPTION II 2

OPTION I-A 4-5 f

OPTION I-D-4 UNDECIDED 2

ALL UTILITIES PARTICIPATING TO DATE, MAY TAKE SEVERAL VOTE o

CYCLES TO COMPLETE BWROG OPTION SELECTION j

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LTS STATUS o

SOME UTILITIES REQUIRE FINAL GENERIC LETTER BEFORE COMMITTING TO A PROGRAM OF THIS SIZE PUC PRUDANCY CONSIDERATIONS SOME UTILITIES PROCEEDING AT RISK AMBIGUITY OF DRAFT GENERIC LETTER REGARDING POSSIBLE LONG-TERM USE OF ICAs i

i ELIMINATION OF INTERIM CORRECTIVE ACTIONS (ICAs)

FOLLOWING LTS IMPLEMENTATION ESSENTIAL TO UTILITY COMMITMENT (INCLUDING TECH. SPEC. REMOVAL WHERE APPLICABLE) o UTILITY CONSIDERATIONS INCLUDE COST / BENEFIT AND COMPETITION FOR LIMITED RESOURCES o

BWROG IS WORKING TO FACILITATE OWNER RESPONSES TO FINAL GENERIC LETTER IMPROVED INTERIM ACTIONS OPTION-SPECIFIC DESIGN AND INSTALLATION SCHEDULES l

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LTS SCHEDULE INFORMATION 40/93 STABILITY COMMITTEE ORGANIZED INTO FUNCTIONAL GROUPS 40/93-10/94 DEVELOP UTILITY RESPONSE TO NRC GENERIC LETTER OPTION I-A ACTIVITIES 40/93 INITIATE DESIGN WORK 10/94 SELECT LEAD PLANT (S) 10/94 PROVIDE SPDATE ON ANALYSIS /KARDWARE SCHEDULE FOR NRC (INCLUDE I & C STAFF) 1994 NRC STAFF INVOLVEMENT IN DESIGN, TEST PLAN, ETc.

i 10/94 SUBMIT OPTION I-A METHODOLOGY TOPICAL REPORT SUPPLEMENT 10/95 SUBMIT OPTION I-A HARDWARE TOPICAL REPORT 1995 OPTION I-A READY FOR INSTALLATION AT LEAD PLANTS DURING OUTAGES 1996 OPTION I-A READY FOR INSTALLATION AT ALL PLANTS

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DURING OUTAGES OPTION III ACTIVITIES (A88)-

10/94 INITIATE DESIGN WORK

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i 2-30/94 MEETINGS W/NRC ON SOFTWARE DEVELOPMENT PROCESS f

l 40/94 SELECT LEAD PLANTS i

40/94 DETECT & SUPPRESS TOPICAL REPORT (FIRST TIME APPLICATION AND RELOAD REVIEW) 10/95 OPTION III KARDWARE/ SOFTWARE TOPICAL REPORTS 10/95 FABRICATE AND TEST PROTOTYPE 40/95-10/96 OPTION III READY FOR INSTALLATION AT LEAD PLANT OPTION III AVAILABLE FOR INSTALLATION AT.ALL 1997 PLANTS DURING OUTAGES (ASSUMING SUCCESSFUL LEAD PLANT, SCHEDULE TO BE DEFINED BY UTILITIES /NRC)

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Concerns identified in NRC ATWS Simulator Exercises i

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I BWR Owners' Group 1

October 28,1993

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BWR Owners' Group Response RPV depressurization is not expected to be required to control RPV waterlevelin HPCS plants because:

5/7 HPCS plants have motor-driven feedpumps 2/7 HPCS plants have quick isolation bypass 6/7 HPCS plants have feedwater spargers > 95 in. above the MSIV isolation setpoint All HPCS plants have either motor-driven feedpumps, quick isolation bypass planned or installed, or i

significant water level margin to isolation 1

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1 BWROG Response (continued)

The proposed EPG changes do increase the probability of MSIV isolation, but:

Most plants have either quick isolation bypass or feedwater spargers well above the isolation setpoint All non-HPCS plants have sufficient high pressure injection to control RPV water level after MSIV isolation Requiring that RPV water level be maintained above the isolation setpoint is not always appropriate, but its importance can be emphasized in training i

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