ML20212N155
| ML20212N155 | |
| Person / Time | |
|---|---|
| Issue date: | 08/18/1986 |
| From: | Paulson W Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8608280106 | |
| Download: ML20212N155 (29) | |
Text
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UNITED STATES p,
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August 18, 1986 LICENSEE:
B&W Owners Group (BWOG)
SUBJECT:
SUMMARY
OF JULY 24, 1986 MEETING WITH BWOG TECHNICAL SPECIFICATIONS COMMITTEE On July 24, 1986, the NRC starf met with representatives of the BWOG Technical Specifications Committee.
The purpose of the meeting was to discuss two recent BWOG topical report submittals:
" Justification for Increasing the Reactor Trip System On-Line Test Intervals," and "B&WOG Technical Specification Improvement Program." Enclosure 1 is a list of attendees. is a copy of the handouts provided by the BWOG.
The BWOG has proposed extending the reactor trip system instrument string on-line test intervals from one month (staggered) to every six months (staggered).
In addition, the Owners Group has proposed an unlimited allowable outage time for the fourth instrument string channel for testing and maintenancc.
In the l
B&W design, only one of the four channals can be bypassed (untripped condition);
hence, with an unlimited bypass time for one chanr.el, the trip logic would change from 2 out-of 4 to 2 out-of 3 while the bypass is in effect. The B&W0G indi-cated that they had not taken set-point drift into account in the analysis supporting tne proposed increase in test interval but that they were looking into this matter.
The Owners Group requested a six-month review schedule for I
the topical report and indicated that they would like to have periodic working meetings. The staff agreed to inform the Owners Group when a meeting would be appropriate.
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The B&W Owners Group indicated that the objectives of the technical specifi-I cation improvement program are (1) to develop a new, improved format and style i
of technical specification to address identified concerns with present standard and custom technical specifications; (2) establish the content of technical specifications to be consistent with existing regulations and the technical specification selection criteria; (3) improve the bases of technical specifi-cations by addressing identified deficiencies; and (4) improve technical aspects of individual requirements as is technically justifiable.
The Owners Group requested a timely decision by the staff regarding the accept-ability of the proposed format and content as presented in their topical report.
The example provided by the Owners Group in their submittal was the Technical Specification section on containment.
The staff indicated that it is ready to meet with the Owners Group any time to discuss the content of the proposed Containment sections.
The Owners Group stated they will contact the staff to g
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1 B&W Owners Group August 18, 1986 set up a meeting.
In conclusion, the staff pointed out that it needs a i
Commission statement on the Technical Specification Improvement Program i'
Policy Paper before a lot of staff resources can be devoted to this effort.
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/s/WPaulson Walter A. Paulson, Technical Assistant to the Assistant Director Division of PWR Licensing-B
Enclosures:
As stated i
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t EHCLOSURE 1 ATTENDANCE LIST JULY 24, 1986 MEETING NRC & B&W OWNERS GROUP TECHNICAL SPECIFICATION COMMITTEE NAME AFFILIATION W. Paulson NRR/PWR-B Sam Bryan NRR/TSCB Millard Wohl NRR/TSCB Don R. Lasher NRR/PAEI l
Brent Collins EG&G Idaho, Inc. (INEL)
Robert L. Ferguson NRR/PEICSB.
Hugh Clark Babcock & Wilcox David Distel GPU Nuclear-Courtney W. Smyth GPU Nuclear Patrick C. Rogers AP&L Robert A. Turner B&W Robert Gill Duke l
Robert Enzinna B&W i
Stanley Levinson B&W l
1 Daniel Gallagher SAIC i
Mark Rubin NRR/PWRB Patrick Milano I&E/VPB 1
Ivan Recarte NRR/TSCB Hukam Garg NRR/PEICSB
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J. S. Wermiel NRR/PEICSB C. F. McPhatter B&W David M. Porter FPC l
Dan Green FPC Ed Butcher NRR/TSCB Tom Dunning NRR/TSCB Bill Regan NRR/DPLB G. L. Plumlee, III NRR/DLPB David Langford NRR/TSCB i
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MEETING NOTICE DISTRIBUTION-i cket File / Central File NRC PDR i
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TA - W. Paulson ORAS H. Denton/R. Vollmer j
i OGC E. Jordan
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B. Grimes i
Receptionist l
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S. Donovan i
PPAS/TOSB i
F. Miraglia i
F. Schroeder W. Regan i
L. Marsh I
i NRC
Participants:
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S. Bryan 4
M. Wohl D. Lasher R. Ferguson M. Rubin i
P. Milano i
I. Recarte
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j H. Garg i
j-J. S. Wermiel L
E. Butcher i
l T. Dunning i
G. L.'Plumlee, III D. Langford 1
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e ENCLOSURE 2
,o NRC/B&WOG TECHNICAL SPECIFICATION COMMITTEE MEETING PHILLIPS BUILDING JULY 24,1986 AGENDA 9:00-9:10 OPENING REMARKS.............. WALT PAULSON 9:10-9:20 INTRODUCTION OF B&WOG EFFORT....... BOB GILL 9:20-10:30 PRESENTATION ON " JUSTIFICATION FOR INCREAS-
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ING THE REACTOR TRIP SYSTEM ON-LINE TEST INTERVALS"................
BOB ENZINNA 10:30-11:30 PRESENTATION ON "B&WOG TECH SPEC 1
M O D E LS".................
BOB GILL 11:30-12:00 DEFINE NEXT ACTIONS...........
WALT PAULSON/
BOB GILL 12:00 ADJOURN m
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OBJECTIVES OF THE RTS PRESENTATIQN 1.
PROVIDE A TECHNICAL OVERVIEW OF BAW-10167 TO JUSTIFY THE INCREASE IN RTS INSTRUMENT STRING TEST INTERVALS AND ALLOWED OUTAGE TIMES (AOT) 2.
OBTAIN STAFF FEEDBACK ON METHODOLOGY AND RESULTS 3.
IDENTIFY MAJOR OPEN ITEMS / OBSTACLES THAT COULD INTERFER WITH THE TIMELY IMPLEMENTATION OF NEW TEST INTERVALS AND AOT's 4.
ESTABLISH SCHEDULE FOR COMPLETING RESPONSES TO STAFF QUESTIONS / CONCERNS 5.
ESTABLISH SCHEDULE AND AGENDA FOR NEXT MEETING WITH THE STAFF
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I OBJECTIVES OF THE TECHNICAL SPECIFICATION SESSION 1.
DESCRIBE THE ELEMENTS OF THE B&WOG TECHNICAL SPECIFICATION IMPROVEMENT PROJECT 2.
OBTAIN STAFF COMMITMENT TO FINALIZE " FORMAT AND CONTENT" EARLY 3.
PRESENT B&WOG SCHEDULE FOR PROVIDING OUTPUT TO THE STAFF 4.
OBTAIN COMMITMENT FROM STAFF FOR TIMELY REVIEW OF TECHNICAL CONTENT 5.
IDENTIFY MAJOR OPEN ITEMS / OBSTACLES THAT COULD INTERFERE WITH THE TIMELY COMPLETION OF THE B&WOG EFFORT 6.
ESTABLISH SCHEDULE ANO AGENDA FOR NEXT NRC/B&WOG TECH SPEC MEETING I
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JUSTIFICRTION F0R INCRERSING THE RERCT0R T R. I P
SYSTEN ON-LINE TEST INTERVRLS Presented by BSW Owners Group to Nuclear Regulatory Commission 4
July 24, 1986
- Bethesda, Maryland I
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PURPOSE
- Justification for extension of RTS instrument string on-line test intervals from one month to six months
- Justification for extension of the ACT limit for the fourth instrument string channel EXISTING PROPOSED Instrument String Monthly Every six months Test Interval Staggered Staggered Instrument String Varied Unlimited for the AOT fourth channel in bypass Sensors /RTMs/SCRs/
Breakers Test
unchanged -----------
Interval /AOT
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RTS TEST INTERVRL EXTENSION l
l PR0GRRH 0VERVIEW CALCULATION OF RTS RELIABILITY AT VARIOUS TEST INTERVALS PRA EVALUATION ASSESS RESULTS TO DETERMINE h
AND DOCUMENT NET CHANGE OF IN TOPICAL CORE MELT REPORT FREQUENCY CALCULATION OF SPURIOUS TRIPS DUE TO TESTING
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C0NFIGURRTION i
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- Oconee and Davis-Besse models account for major configuration differences
- Breaker and SCR arrangement 1
- ARTS interface 1
- Analysis bounds minor plant specific differences r
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RELIRBILITY BL0CK DIRGRRM NODELING Codes IRIS workstation for reliability analysis FTAP
- cut set generator from RBDs PACAAT - FRANTIC-like code for time-dependent calculations SAMPLE - Monte Carlo simulation uncertainty analysis Dynamic Modeling
- Effects of changes in system configuration for testing and maintenance (channel bypass)
- Demonstrates effects of staggering
- Time-dependent model Results
- Average unavailability over time interval
- Instantaneous failure probability (shows changes in reliability with time due to configuration changes)
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ISSUES RDDRESSED l
- This analysis addressed the important test-related issues identified in NRC generic letter 83 28.
Question 4.5.3:
- common mode failure / human error of sensors and strings
- common mode failure / human error of breakers
- uncertainties in random and common mode failure rates
- reduced redundancy (testing bypass)
- Wear out, also identified in NRC generic letter 83.28, is not significant for electronic components J
DRTR S0URCES
Emphasizes Operating Experience
Emphasizes Common Mode Failures Electronics
- NUREG/CR-3289 (Common Cause Failure Rates for Instrumentation and Control Assemblies by Atwood)
- Based on LERs
- Includes human error in common cause failure rate Breakers
- BSW and CE operating experience evaluated from LERs
- NPRDS, Nuclear Power Experience, NUREG-1000
- Includes common cause failure i
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Figure 8-2 Best Estimate & SRMPLE Rasults (95%)
RTS Unavai1 ability versus Test Interval T
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Oconee, 95%
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Oconee, B'est Estimate
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Instrument String Test Interval (months)
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MISSION SUCCESS
- Power is removed from ALL safety and regulating rod groups
- Mission success criteria is:
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- Conservative for ATWS
- Appropriate for evaluating tech specs
- Penalizes Oconee configuration - requires safety and regulating rods to be inserted
> Oconee:
SCRs trip regulating rod groups only
> Davis Besse:
SCRs trip all rod groups
- Operator manual trip - not included
- ICS rod drive in - not included 1
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RERS0NS F0R HIGH RTS RELIRBILITY
- Diversity:
- SCRs and breakers
- Shunt trip and undervoltage trip i
- Four channel system with installed bypass
- Testing in tripped mode, (except for instrument strings)
- Most components fail-safe /de-energize to trip
SPURIOUS TRIP RRTE
'S U M M R R Y-Test Interval (months) 1 4
6 Spurious trip rate caused
.50
.31
.29 by RTS surveillance (scram /
plant / year)
Spurious trip rate caused
.25
.063
.042 by instrument string testing (scram / plant / year)
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UNRVRILRBILITY VS SPURIOUS TRIP: -
RISK TRRDEOFFS RFFECTED BY THE TEST INTERVRL Quantified Effects
- Time in bypass (reduced redundancy) decreases
- Failures remain undetected for a longer time
- Risk from spurious trips decreases Intangible benefits
- Reduced challenges to operators and technicians T
- Reduced challenges to safety systems
- Reduced operator distractions
- Diversion of resources
INCREMENTRL RISK RSS0CIRTED
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HITH EXTENSI0N OF INSTRUMENT STRING INTERVRL T0 SIX M0NTHS l
CASE NET INCREMENTAL RISK (core melt / reactor year)
Davis-Besse
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-7.55 x 10
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95 Percentile
-1.33 x 10 l
l Oconee
_g Best Estimate
-7.71 x 10
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95 Percentile
-4.71 x 10 1
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i C0NCLUSIONS 1
- Overall change in risk due to test interval increase is small
- Incremental risk is negative for all test intervals L
l up to six months l
'Best' in terms of risk is six month staggered interval
- Acceptable reliability demonstrated with unlimited A0T for fourth instrument string channel l
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B & W CMERS GROUP TEOiNICAL SPECIFICATION IffROVBfNT PROGRAM JULY 1986
OBJECTIVES e DEVELOP A EK IfMOVED RR%T AND SlYLE OF TEONICAL SRCIFICATION TO ADDRESS IDENTIFIED CONCERNS WITH PRESENT STANDARD AND CUSTOM TEONICAL SKCIFICATIONS.
e ESTABLISH TE CONTENT OF TEONICAL SRCIFICATIONS TO BE CONSISTDIT Willi EXISTING REGul.ATIONS AND THE TEONICAL SRCIFICATION SEECTION CRITERIA.
e IfMOVE TE BASES OF TEONICAL SKCIFICATIONS BY ADDRESSING IDENTIFIED DEFICIBICIES.
e IffROVE TEONICAL ASPECTS OF ItalVIDUAL REQUIRE?DITS AS IS TECHNICALLY JUSTIFIABLE.
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ETHODOLOGY e DEVELOPED TEOi SRC INFORMATION MANAGBER PROGRAM - A LIBRARY OF IDENTIFIED CONCERNS /PROBEMS WITli EXISTING TE0flICAL SPECIFICATIONS.
e CREATED A RtitxENCE LIBRARY OF PRESENT TECH SPECS /FSAR's 0F EACH B&W OPERATING PL M e CREATED, TliROUGH AN ITEPATIVE PROCESS, A tDDEL SET OF TECHNICAL SPECIFICATIONS, SURVEll1ANCE, BASES FOR A SINGLE SECTION (I.E. C0hTAltfENT SfSTEMS) e EXTB4SIVE If4Plff/ REVIEW BY OPERATORS, LICENSING ENGINEERS, HtPAN FACTORS ENGINEERS, STATION PERSONNEL CORPORATE INDIVIDUALS, NSSS ENGINEERS.
e CREATED A WRITERS GUIDE TO DESCRIBE THE STYUE, FORMAT.
s CREATED A DOCLIER TO DESCRIBE TliE BACKGR0lt0 AND TECHNICAL JUSTIFICATION FOR WHAT WAS DONE.
e FURRE APPLICATION TO REMAINDER OF TEOfilCAL SWCIFICATIONS TO CREATE ENTIE DOCitENT.
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- 0 OkU M. STRUCTURE o OWNERS GROUP DOCIM NTS TOPICAL PEPORT (BAW - 1921)
VOUJE I - GENERIC TEONICAL SRCIFICATIONS '
VOLifE II - GENERIC SURVElllR4CE Pl#4/GBERIC BASES
- .e TEONICAL REPORT (BAW - 1922)
GENERIC F0RRR TE01 SNCS - SElfCTED LICENSEE C0fEITTPENTS JUSTIFICATION AND BACKGROLED DOCLPENT (BAW - Im_3) e LICB1SEE DOCitENTS PlMT SKCIFIC TECH SRCS EASED ON TOPICAL I'EPORT V0L I PLMT SRCIFIC SURVEILIANCE AND BASES (ADMINISTRATIVE 1.Y CONTROLLED)
BASED ON TOPICAL REPORT WL II Pl#T SKCIFIC SELECTED LICENSEE C0ftITTFENTS (ADMINISTRATIVELY CONTR0llED)
BASED ON OWNERS GROUP REPORT
TECHNICAL SRCIFICATIONS CHAPTER 1.0 - DEFINITIW S SME AS PESBiT EXCEPT SURVEILIR4E REl.ATED RELOCATED TO SECTION 4.0 CHAPTER 2.0 - CON 1ENT TO BE DElERMINED CHAPTER 3.0 - LIMITING CONDITI0tS FOR OPERATION
- NBi SlYLE, FORMAT
- SECTIONS IN FSAR CHAPTER ORDER
- LSS?st INCLUDED IN APPROPRIATE LCO
- STE INCLUDED IN APPROPRIATE LC0
- CON 1Bir BASED W APPLICATION OF SELECTION CRITERIA
- ONE TO ONE C0rXLATION BERG! DEGRADED CONDITION, EQUIED ACTION, IND C0iPLET10N TIE CHAPTER 4.0 - SURVElllRIE REQUIREPH.TS
- ESTABLISHES AN ADMINISTRATIVELY MAINTAINED SURVEILl#E PLAN
- ONE TO ONE CORRELATION Will! LC0's
- ESTABLISHES PROCESS TO FMINTAlt! SURVEILLANE Pl#1
-tBlSTYLE,FORf%T
- SURVEILLANE REQUIPBelT, FREQlE1CY, SAE AS PESBfT FOR NST ITEMS CHAPTER 5.0 - DESIGN FEATURES MINIMAL CHANGES FROM EXISTItG CHAPTER 6.0 - ADMINISTRATION MINIMAL CHANGES FROM EXISTItG
SURVEILLANCE PLAN FOR TECH SKCS e ADMINISTRATIVELY f%INTAINED PLAN e TIED TO TE01 SKCS CPAPTER 4.0 e TE0hlCAL CONTEhT ESSEhTIALLY LIiORNGED FROM PKSEhT REQUIRENNTS e EW FORI%T BASES OF EOi SKCS e ADMINISTRATIVELY fMINTAINED e DEFINITIVE UNTENT OF EA01 BASES e NB1 FORi%T e EXPLRMTION OF 'W1Y" e BASIS FOR " VALUES" 0F PARA TTERS e TABULAR LISTIfES INCLUDED e REFERENCES INCLUDED
SELECTED LICENSEE C0fEITTWhTS (FORffR TECH SKCS) e INCLUDES PRESENT TECH SKCS NOT SELECTED BY CRITERIA e REFORmTED PRESENTATION CONSISTENT WITH TOl EONICAL SKCIFICATIONS, SURVEILLMICE, AND BASES FORmTS e MINIFAL TECHNICAL CHANGES e ADMINISTRATIVELY CONTROLLED #iD MAINTAINED e PLANT SKCIFIC-IfPLEKNTATION VIA INCLUSION IN FSAR (CHAPTER 16)
AND DUPLICATED IN A DOCliTNT LOCATED WITH TE0i SKCS, SURVEILLN4E NO BASES (FOR 0 RATOR CONT 41ENCE) c-7 n-
JUSTIFICATION AND BACKGROUf0 DOCitelT f
e NRC QUESTIONS AND ANSWERS e BWOG WRITERS GUIDES 4
.i e FATRIX OF TE01 SRCS - WHERE IT WAS; WHERE IT IS e HISTORICAL ECORD 4
1 s TRAINING FlNCTION 4
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