ML20058A107
| ML20058A107 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 11/16/1993 |
| From: | Rooney V Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 9311300106 | |
| Download: ML20058A107 (43) | |
Text
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UNITED STATES i'
E NUCLEAR REGULATORY COMMISSION
- (+$ +/
i WASHINGTON, D.C. 20665-0001 November 16, 1993 Docket No. 50-423
/
LICENSEE: NORTHEAST NUCLEAR ENERGY COMPANY FACILITY: MILLSTONE NUCLEAR POWER STATION, UNIT 3
SUBJECT:
SUMMARY
OF OCTOBER 25, 1993, MEETING REGARDING PROPOSED REVISION TO TECHNICAL SPECIFICATIONS FOR THE SUPPLEMENTARY LEAK COLLECTION AND.
RELEASE SYSTEM On October 25, 1993, the NRC staff met with Northeast Nuclear Energy Company (NNECO) to discuss their proposed revision to 'the Technical Specifications (TS) for the Supplementary Leak Collection and Release System (SLCRS) and Auxiliary Building _ Ventilation System (ABVS) at Millstone Unit 3.
SLCRS and ABVS work together to draw down secondary containment.to a vacuum to reduce unfiltered post-accident radiation releases.
NNEC0 described the design of and the interaction between SLCRS and ABVS stressing the complexity of the control characteristics introduced by the lack of. independence between the systems.
Enclosure I is the list of individuals who participated in the discussion. is NNEC0's agenda and handout.
The following is a.
summary of the significant items discussed.
NNECO described the current plant status and the train of circumstances which identified problems with SLCRS/ABVS.
Startup has been delayed-because testing of SLCRS revealed possible problems in meeting;TS required vacuum drawdown times in certain post accident scenarios.
The Millstone 3Lreactor was expected to be able to startup October 27, 1993, from a refueling outage which began July 31.
NNEC0 has established a Task Force to concentrate intense efforts to' address SLCR/ABVS problems.
Failure modes and effects analysis characterized.
previo mly unrecognized weaknesses in the SLCRS/ABVS_ design..NNEC0 performe'd extensive testing and made modifications.under 50.59,: but nevertheless was unable to' meet the TS requirements.-
NNECO, therefore, requested by letter dated October 22, 1993,'a change'to1TS and enforcement discretion to permit plant operation. The. proposed TS extends.
the SLCRS drawdown time from 60. seconds to,150 seconds'and' compensates by,_
requiring tighter containment, so'that net post-accident dose rates are not.
increased.
NNEC0 further requested enforcement discretion to e'nter the startup mode (up to 5% power).for no longer _ than seven days, while the staff-processed the license' amendment.
NNEC0 supported this request for enforcement discretion by showing that post -
accident dose rates under these conditions would be. conservatively less than i
what had previously been accepted. - NNECO also presented-plausible support for the proposed amendment to extend the SLCRS drawdown time based on-reduction in required containment l_eak' rate ~
The staff orally granted. enforcement:
}i discretion for Millstone 3 to enter the'startup mode (up to 5% power) for no Jn2 Run Paha NHC flE CENTEfl COPY -
P' PDR
Northeast Nuclear Energy Company November 16, 1993 longer than seven days, with a confirmatory letter to follow. The licensee agreed to promptly revise the October 22, 1993 proposed TS change based on discussions during the meeting.
Original signed by:
Vernon L. Rooney, Senior Project Manager Project Directorate I-4 Division of Reactor Projects I/II Office of Nuclear Reactor Regulation
Enclosures:
As stated cc w/ enclosure See next page DISTRIBUTION:
Docket File NRC & Local PDRs PDI-4 Memo TMurley FMiraglia LCallan SVarga JCalvo VRooney SNorris OGC EJordan JStolz RLobel NWagner IAhmed RGoel JHayes R8arkley ACRS (10)-
-VMcCree LDoerflein, RI
_ f) s orricE LA:PDI-4 PM:PDIy4 A h DkI-4 SNY VRooney:bp JStoYb NAME DATE li/lb/93 0/de/93 iI /h/93'
/ /
/' /
OFFICIAL RECORD COPY i
Document Name: G:\\R00NEY\\l0-25TS. MET SLCRS MEETING OF OCTOBER 25. 1993 3
q i
Northeast Nuclear Energy Company November 16, 1993 i
longer than seven days, with a confirmatory letter to follow. The licensee agreed to promptly revise the October 22, 1993 proposed TS change' based on discussions during the meeting.
,,/' ] / / _
f',
/
/
Vernon L. Rooney, enior Project Manager Project Directorat I-4 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation
Enclosures:
As stated cc w/ enclosure See next page L
( -
Mr. John-F. Opeka Millstone Nuclear Power Station Northeast Nuclear Energy Company Unit 3 cc:
Gerald Garfield, Esquire R. M. Kacich, Director Day, Berry and Howard Nuclear Licensing Counselors at Law Northeast Utilities Service Company City Place Post Office Box 270 Hartford, Connecticut 06103-3499 Hartford, Connecticut 06141-0270 J. M. Solymossy, Director J. P. Stetz, Vice President Nuclear Quality & Assessment Services Haddam Neck Plant Northeast Utilities Service Company Connecticut Yankee Atomic Power Company Post Office Box 270 362 Injun Hollow Road Hartford, Connecticut 06141-0270 East Hampton, Connecticut 06424-3099 Kevin T. A. McCarthy, Director Regional Administrator Monitoring and Radiation Division Region I Department of Environmental Protection U.S. Nuclear Regulatory Commission 79 Elm Street 475 Allendale Road Post Office Box 5066 King of Prussia, Pennsylvania 19406 Hartford, Connecticut 06102-5066 Allan Johanson, Assistant Director First Selectmen Office of Policy and Management Town of Waterford Policy Development and Planning Division Hall of Records 80 Washington Street 200 Boston Post Road Hartford, Connecticut 06106 Waterford, Connecticut 06385 S. E. Scace, Vice President P. D. Swetland, Resident Inspector Millstone Nuclear Power Station Millstone Nuclear Power Station Northeast Nuclear Energy Company c/o U.S. Nuclear Regulatory Commission Post Office Box 128 Post Office Box 513 Waterford, Connecticut 06385 Niantic, Connecticut 06357 F. R. Dacimo, Nuclear Unit Director M. R. Scully, Executive Director Millstone Unit No. 3 Connecticut Municipal Electric Northeast' Nuclear Energy Company Energy Cooperative Post Office Box 128 30 Stott Avenue Waterford, Connecticut 06385 Norwich, Connecticut 06360 Burlington Electric Department David W. Graham c/o Robert E. Fletcher, Esq.
Fuel Supply Planning Manager 271 South Union Street Massachusetts Municipal Wholesale '
Burlington, Vermont 05402 Electric Company Post Office Box 426 Nicholas S. Reynolds Ludlow, Massachusetts 01056 Winston & Strawn 1400 L Street, NW Washington, DC 20005-3502
.~
SLCRS MEETING OF OCTOBER 25. 1993 ATTENDANCE LIST NAME ORGANIZATION Vernon Rooney NRR/DRPE/PDI-4 John Stolz NRR/DRPE/PDI-4 Jose Calvo NRR/DRPE Richard Lobel NRR/DSSA Norman Wagner NRR/SPXB Iqbal Ahmed NRR/HICB Raj Goel NRR/PRPB John J. Hayes NRR/PRPB Richard Barkley RGI R. G. Joshi Northeast Utilities (NU)
G. R. Pitman NU R. M. Kacich NU F. R. Dacimo NU E. A. DeBarba NU Ray Crandall NU Sunil Weerakhody NU Gilbert Olsen NU Cliff Ashton NU Arnold Roby NU R. J. Mcdonald NU
A Mr., John F. Opeka Millstone Nuclear Power Station Northeast Nuclear Energy Company Unit 3 cc:
Gerald Garfield, Esquire R. M. Kacich, Director Day, Berry and Howard Nuclear Licensing Counselors at Law Northeast Utilities Service Company City Place Post Office Box 270 Hartford, Connecticut 06103-3499 Hartford, Connecticut 06141-0270 J. M. Solymossy, Director J. P. Stetz, Vice President Nuclear Quality & Assessment Services Haddam Neck Plant Northeast Utilities Service Company Connecticut Yankee Atomic Power Company Post Office Box 270 362 Injun Hollow Road Hartford, Connecticut 06141-0270 East Hampton, Connecticut 06424-3099 Kevin T. A. McCarthy, Director Regional Administrator Monitoring and Radiation Division Region I Department of Environmental Protection U.S. Nuclear Regulatory Commission 79 Elm Street 475 Allendale Road Post Office Box 5066 King of Prussia, Pennsylvania 19406 Hartford, Connecticut 06102-5066 Allan Johanson, Assistant Director First Selectmen Office of Policy and Management Town of Waterford Policy Development and Planning Division Hall of Records 80 Washington Street 200 Boston Post Road Hartford, Connecticut 06106 Waterford, Connecticut 06385 S. E. Scace, Vice President P. D. Swetland, Resident Inspector Millstone Nuclear Power Station Millstone Nuclear Power Station Northeast Nuclear Energy Company c/o U.S. Nuclear Regulatory Commission Post Office Box 128 Post Office Box 513 Waterford, Connecticut 06385 Niantic, Connecticut 06357 F. R. Dacimo, Nuclear Unit Director M. R. Scully, Executive Director Millstone Unit No. 3 Connecticut Municipal Electric Northeast Nuclear Energy Company Energy Cooperative-Post Office Box 128 30 Stott Avenue Waterford, Connecticut 06385 Norwich, Connecticut 06360 Burlington Electric Department David W. Graham c/o Robert E. Fletcher, Esq.
Fuel Supply Planning Manager -
271 South Union Street Massachusetts Municipal Wholesale Burlington, Vermont 05402 Electric Company Post Office Box 426 Nicholas S. Reynolds Ludlow, Massachusetts 01056 Winston & Strawn 1400 L-Street, NW Washington, DC 20005-3502 l
s SLCRS MEETING 0F OCTOBER 25. 1993 ATTENDANCE LIST NAME ORGANIZATION Vernon Rooney NRR/DRPE/PDI-4 John Stolz NRR/DRPE/PDI-4 Jose Calvo NRR/DRPE Richard Lobel NRR/DSSA Norman Wagner NRR/SPXB Iqbal Ahmed NRR/HICB Raj Goel NRR/PRPB John J. Hayes NRR/PRPB Richard Barkley RGI R. G. Joshi Northeast Utilities (NU)
G. R. Pitman NU R. M. Kacich NU F. R. Dacimo NU E. A. DeBarba NU Ray Crandall NU Sunil Weerakhody NU Gilbert Olsen NU Cliff Ashton NU Arnold Roby NU R. J. Mcdonald NU F
9 MILLSTONE UNIT NO. 3 SUPPLEMENTARY LEAK COLLECTION AND RELEASE SYSTEM / AUXILIARY BUILDING VENTILATION SYSTEM OCTOBER 25,1993
MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System 1.
INTRODUCTION F. R. DACIMO II.
OVERVIEW G. R. PITMAN lil.
SLCRS/ABVS DESCRIPTION R. J. MCDONALD IV.
ACTIONS TO MAKE SLCRS/ABVS OPERABLE A. DESIGN CHANGES G. M. OLSEN B. FAILURE MODES AND EFFECTS ANALYSIS S. D. WEERAKKODY C. PERFORMANCE ASSURANCE PROGRAM A.R.ROBY V.
REQUESTED REGULATORY ACTIONS R. M. KACICH VI.
RADIOLOGICAL CONSEQUENCE EVALUATION R. A. CRANDALL Vll.
CONCLUSION E.A.DeBARBA.
b o
MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System PARTICIPANTS E.A.DeBARBA VICE PRESIDENT, NUCLEAR, ENGINEERING SERVICES F. R. DACIMO DIRECTOR, MILLSTONE 3 R. M. KACICH DIRECTOR, NUCLEAR LICENSING G. R. PITMAN MANAGER, NUCLEAR PROJECT SERVICES A.R.ROBY MANAGER, ELECTRICAL AND I&C ENGINEERING R. J. MCDONALD ENGINEER, MILLSTONE 3 ENGINEERING G. M. OLSEN SUPERVISOR, NUCLEAR PROJECT SERVICES R. A. CRANDALL SUPERVISOR, RADIOLOGICAL ENGINEERING S. D. WEERAKKODY SENIOR ENGINEER, PRA C. J. ASHTON SENIOR ENGINEER, SYSTEM ENGINEERING R.G.JOSHI PRINCIPAL ENGINEER, NUCLEAR LICENSING -
MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System 1.
INTRODUCTION CURRENT PLANT STATUS MEETING PURPOSE REVIEW PROPOSED AGENDA l
l l
t t
! l
MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System II.
OVERVIEW OBJECTIVES o
DEVELOP A FULL UNDERSTANDING OF DESIGN BASIS o
COMPLETE AN EVALUATION OF THE SYSTEM TO IDENTIFY DEFICIENCIES o
COMPLETE A FAILURE MODES AND EFFECTS ANALYSIS TO ENSURE ELIMINATION OF ALL SINGLE FAILURE VULNERABILITIES o
INCORPORATE MODIFICATIONS TO CORRECT IDENTIFIED SYSTEM DEFICIENCIES o
DEVELOP AND CONDUCT PERFORMANCE ASSURANCE PROGRAM.
MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System II.
OVERVIEW SLCRS TASK FORCE OVERVIEW o-THE TASK FORCE LEADER WAS ASKED TO TEMPORARILY LEAVE THE HADDEM NECK PLANT CORPORATE ENGINEERING MANAGER POSITION, IN PART, TO ENABLE A FRESH OUTLOOK ON THE SYSTEM o
IT WAS READILY APPARENT THAT THE-SUPPLEMENTARY LEAK COLLECTION AND RELEASE SYSTEM (SLCRS) IS SIMPLE, FULLY REDUNDANT AND INDEPENDENT o
SATISFACTION OF THE SLCRS FUNCTION, HOWEVER, BECOMES COMPLEX WITH THE INTRODUCTION OF THE NEED FOR AUGMENTATION BY THE AUXILIARY BUILDING VENTILATION SYSTEM (ABVS) o THE ABVS IS VERY COMPLEX, ESPECIALLY WHEN CONSIDERING OPERATIONAL RESTRICTIONS AND THE NEED TO MAINTAIN THE VITAL EQUIPMENT COOLING FUNCTION WITH OUTSIDE AIR ALL-THE-WHILE THE SLCRS FUNCTIONAL REQUIREMENT TO DRAW A VACUUM ON SLCRS VOLUMES CO-EXISTS o
BASED ON THE ABOVE, IT WAS CLEAR THAT A MULTI-TALENTED TEAM WOULD BE NEEDED TO IMPROVE THE COMBINED SLCRS/ABVS SLCRS/ABVS TASK FORCE ORGANIZATION J
GEORGE PITMAN (Eng.)
ucENSING ISSSUES MANAGER Ravl Joshi I
I I
i SCHEDULNG DESIGN TEAM TESTTEAM Bill Temple (Lic.)
Bob Kozul (C&S)
Cliff Ashton (Mech /HVAC)
Arnold Roby Ray Crandat (Rad. Engr}
Gil Olsen (l&C)
(ECal Eng. Mgr.)
I I
i 1
I I
I I
TEAM #1 TEAM # 2 FAILURE ANALYSIS /
DAYTEAM NIGHT TEAM Dan Aube (l&C Eng.)
Mike Scanlon (HVAC)
DESIGN BASIS 7 A.M.-7 P.M.
7 P.M.-7 A.M.
Bob Mcdonald (Sys Eng.)
Bob Brourtier (Sys. Eng )
- John Dibartolomeo (t&C)
- John Rothert (PRA)
- Bob Grebasch (Test)
- Bernie Jwaszewsk (Sys. Eng.)
- Cal MoreN (l&C)
- John Chunis (DBDM)
- Steve Brown (1&C)
- John Serdechny (Test)
- Les Pasura (HVAC)
- Mike Siebert (Ops)
- Wondal Moore
- George Timm (HVAC)
- Mech /HVAC Designers
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MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System II.
OVERVIEW ABVS SYSTEM CHARACTERISTICS o
THE SYSTEM DESIGN BASIS ROLE IS TWO-FOLD 1)
PROVIDE COOLING TO VITAL EQUIPMENT HOUSED IN THE AUXILIARY BUILDING UNDER NORMAL AND POST-ACCIDENT CONDITIONS, AND 2)
AUGMENT THE SLCRS IN COMPLETING ITS ENCLOSURE AND ANCILLARY BUILDING VACUUM DRAWDOWN DESIGN REQUIREMENT o
THE ABVS IS REDUNDANT IN TERMS OF ACTIVE COMPONENTS, BUT LACKS INDEPENDENCE SINCE FAILURE OF ONE TRAIN OF EQUIPMENT MUST BE POSITIVELY DETECTED PRIOR TO STARTUP OF THE STANDBY TRAIN o
SYSTEM TIMING, UNDER WORST CASE FAILURE AND POSTULATED ACCIDENT AND LOSS OF POWER CONDITIONS SUFFERS WHILE A DETERMINATION OF OPERATIONAL STATUS OF EACH OF THE ABVS TRAINS IS AUTOMATICALLY MADE MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System II.
OVERVIEW ABVS SYSTEM CHARACTERISTICS - cont.
o THIS IS QUITE UNLIKE CONVENTIONAL REDUNDANT EQUIPMENT TRAINS WHEREIN BOTH TRAINS AUTO-START ON ACCIDENT, AND BOTH RUN QUITE OBLIVIOUS TO THE OTHERS OPERATIONAL STATUS o
THE NET RESULT IS THAT THE ABVS IS COMPLEX AND SLOW IN RESPONSE, IN A ROLE REQUIRING RELATIVELY RAPID RESPONSE o
ADDITIONALLY, THE SYSTEM BECOMES COMPLEX TO ANALYZE, INTRODUCING THE REQUIREMENT TO GO BEYOND NORMAL MEANS TO THOROUGHLY PROVE DESIGN FEATURES AND DEVICE COORDINATION l
o POSITIVE MEANS FOR ONE ABVS TRAIN TO DETECT OPERATION OF THE OTHER, i
AND VICE-VERSA, BECOME CUMBERSOME AND INTRODUCE UNDESIRED TIME l
DELAYS l
1 l
~
MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System II.
OVERVIEW SLCRS TASK FORCE CONCLUSIONS o
GENERAL THE SLCRS FUNCTION CAN BE RELIABLY ACCOMPLISHED WITH THE EXISTING
- SYSTEM, AS RECENTLY MODIFIED BASED ON THIS TASK FORCE'S RECOMMENDATIONS THE ABVS WILL NOT BE PRGNE TO SINGLE FAILURES RESULTING IN RENDERING INOPERABLE BOTH TRAINS OF EQUIPMENT THE ABVS REQUIRES GREATER THAN AVERAGE PREVENTIVE MAINTENANCF ^ND SURVEILLANCE GIVEN ITS IMPORTANCE TO THE SLCRS AUGMENTATION ROLL' (ND THE VERY NATJRE OF VENTILATION
- SYSTEMS, IN GENERAL.
TLINING OF CONTROLLER
- RESPONSE, BALANCING OF DAMPERS AND THE INCLUSION OF SYSTEM SETPOINTS BsSED ON SYSTEM CHARACTERISTICS DERIVED UNDER TEST A
PROPERLY OPERATING SLCRS/ABVS
- ALONE, CANNOT ENSURE TECHNICAL SPECIFICATION COMPLIANCE -- SLCRS BOUNDARY MAINTENANCE IS A MUST MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System II.
OVERVIEW SLCRS TASK FORCE CONCLUSIONS o
SPECIFIC INCREASE SURVEILLANCE FREQUENCY AND TEST OBJECTIVES TO ENABLE EARLY DETECTION OF SYSTEM COMPONENT DRIFT AND TO BUILD CONFIDENCE IN SYSTEM COMPONENTS BASED ON RESULTS OF INCREASED AND MORE COMPREHENSIVE SURVEILLANCES, IDENTIFY THOSE COMPONENTS HAVING LOWER RELIABILITY, AND SCHEDULE FOR REPLACEMENT COMPLETE AND PROVIDE QUALITY DOCUMENTATION FOR THE FMEA RECENTLY PERFORMED ON THE SYSTEM -
MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System 111.
SLCRS/ABVS DESCRIPTION
. SYSTEM DESCRIPTION SYSTEM HISTORY OCTOBER 1992 CURRENT-REFUELING OUTAGE
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MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System IV.
ACTIONS TO MAKE SLCRS/ABVS OPERABLE A.
DESIGN CHANGES FIRST DESIGN CHANGE Re-powered loss of flow detection switches. Uninterruptible 120 vac safety related power sources (flow switches associated with Fans 13/14 & Fan 68)
SECOND DESIGN CHANGE Reduced time delay setting from 20 seconds to 10 seconds for Fans 14A and 14B.
Modified the fan 6A failure detection circuit (30 second) timer. Initiate timer immediately upon receipt of an accident signal.
Revised flow switch setpoints to respond without excessive time delay.
Operate both trains (14/13A & 14/13B) in automatic (control switches placed in " Auto").
THIRD DESIGN CHANGE Removed time delay for Fan 6B control circuit. Allows Fan 6A to start first on receipt of an accident signal.
DUAL TRAIN LOP / SIS SLCRS DRAWDOWN WITH TRAIN "A" DIESEL FAILURE-
~.-
INITIAL CONDITION: FANS 14A/13A RUNNING
- TIME IN SECONDS.
SIS o
10 20 30 40 50 60 70 80 90
- PREVIOUS
. FN 128
- DESIGN START
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START TIME)
(FANS 14A/13A--
.FN6B COASTDOWNTIME 24 START AND 10 SECOND TIME DELAY) 39 (5 SEC PLENUM PRESSURE INCREASE AND 10 SEC-DAMPER STROKETIME)
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MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System IV.
ACTIONS TO MAKE SLCRS/ABVS OPERABLE B.
FAILURE MODES AND EFFECTS ANALYSIS METHOD:
ANSI /IEEE STD 352-1987 "SECTION 4.1 IEEE GUIDE FOR GENERAL PRINCIPLE OF RELIABILITY ANALYSIS OF NUCLEAR POWER GENERATING STATION SAFETY SYSTEMS - FAILURE MODES AND EFFECTS ANALYSIS" PURPOSES
=
PREPARA TORY STEPS
=
PROCEDURES
=
REGULATORY GUIDE 1.53 " APPLICATION OF THE SINGLE-FAILURE CRITERION TO NUCLEAR POWER PLANT PROTECTION SYSTEMS" REFERENCE TO IEEE STD 379-1972
=
ANSI /IEEE STD 379-1988 "lEEE STANDARD APPLICATION OF THE SINGLE FAILURE CRITERION TO NUCLEAR POWER GENERATING STATION SAFETY SYSTEMS" ANSI N658-1976 "AMERICAN NATIONAL STANDARD SINGLE FAILURE CRITERIA FOR PWR FLUID SYSTEMS" f
ANSI /ANS.58.9-1981
" SINGLE FAILURE CRITERIA FOR LIGHT WATER REACTOR SAFETY-RELATED FLUID SYSTEMS"
- 19 ~ -
MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System IV.
ACTIONS TO MAKE SLCRS/ABVS OPERABLE B.
FAILURE MODES AND EFFECTS ANALYSIS SCOPE:
ALL--ABVS COMPONENTS (FANS, FILTERS, FLOW SWITCHES, PRESSURE SWITCHES, RELAYs...) IMPACTING SLCRS PERFORMANCL EXAMINED SIGNIFICANT EMPHASIS ON COMPONENTS AND LOGIC THAT DEFEAT INDEPENDENCE OF SYSTEM (FANS 13A/B,14A/B, 6A/B, FS 52A/B, FS 98A/B, FS 278, PS 104A/B)
TYPICAL SINGLE FAILURE ASSUMPTIONS (E.G.
EXCLUDED NON-HARDWARE RELATED COMMON CAUSE FAILURES, PASSIVE FAILURES, AND NON-CREDIBLE FAILURES)
DETAILED ANALYSIS OF SUPPORT SYSTEMS FOR SINGLE FAILURES (DC, VITAL AC)
WAS PREVIOUSLY COMPLETED NO OPERATOR ERRORS OF-COMMISSION CONSIDERED OPERATOR ERRORS OF OMISSION CONSIDERED ON A LIMITED BASIS.
MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System IV.
ACTIONS TO MAKE SLCRS/ABVS OPERABLE B.
FAILURE MODES AND EFFECTS ANALYSIS SUCCESS CRITERION FOR SYSTEM:
AVAILABILITY OF A SINGLE TRAIN OF ABVS AND FILTRATION FANS WITH THE DAMPERS IN APPROPRIATE POSITIONS WITHIN A PRESCRIBED DURATION (derived from negative pressure requirement).
MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System IV.
ACTIONS TO MAKE SLCRS/ABVS OPERABLE B.
FAILURE MODES AND EFFECTS ANALYSIS IDENTIFICATION OF FAILURE CRITERIA:
(What constitutes a failure of the system?)
NOT HAVING A SINGLE TRAIN OF FANS WITH DAMPERS IN APPROPRIATE POSITIONS WITHIN A PRESCRIBED DURATION (relatively more complex for this system compared to typical systems)
HAVING-MORE THAN ONE SUPPLY FAN (14A/B)
HAVING MORE THAN ONE FILTRATION FAN (6A/B) OPERATING CONCURRENTLY SUBSEQUENT TO SIS /CDA/ LOP TOO MUCH FLOW INTO ABFS INLET PLENUM SUBSEQUENT TO SIS /CDA/ LOP TOO MUCH FLOW INTO MISSILE HOOD EXCEEDING DESIGN PRESSURE OF INLET PLENUM TOO LOW PRESSURE OF INLET PLENUM.
MILLSTONE UNIT-NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation-System
~
IV.
ACTIONS TO MAKE SLCRS/ABVS OPERABLE B.
FAILURE MODES AND EFFECTS ANALYSIS CONCLUSIONS:
NO ADDITIONAL SINGLE FAILURE OF ABVS COMPONENTS THAT CAN IMPAIR SLCRS FUNCTION WERE FOUND CONFIRMED ALREADY IDENTIFIED SINGLE FAILURES CONFIRMED THAT DESIGN CHANGES DO NOT INTRODUCE NEW SINGLE FAILURES MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System l
l IV.
ACTIONS TO MAKE SLCRS/ABVS OPERABLE C.
PERFORMANCE ASSURANCE PROGRAM I
ABVS/SLCRS PERFORMANCE ASSURANCE PROGRAM IS BASED ON:
1)
IDENTIFICATION OF ALL OF THE VARIOUS COMBINATIONS OF POWER TO THE SYSTEM, TOGETHER WITH ALL COMBINATIONS OF OPERATIONAL ALTERNATIVES, 2)
EVALUATION OF EACH CASE FOR EXPECTE,D SYSTEM RESPONSE AND TIME LINES PREPARED FOR EACH RESPONSE, 3)
SELECTION OF CASES TO BE TESTED (WOULD BE BOUNDING FOR THE CASE (S)
WHICH WOULD NOT BE TESTED),
4)
IDENTIFICATION OF TESTED CASES WHICH WOULD INCLUDE MULTIPLE DRAWDOWN CASES TO DEMONSTRATE SYSTEM PERFORMANCE, 5)
PREPARATION OF FULL SCOPE TESTING PROCEDURE IDENTIFYING ALL ACTIONS AND PREREQUISITES FOR THE TESTED CONDITION, TOGETHER WITH A FULL REVIEW OF REQUIREMENTS, PRIOR TO' IMPLEMENTATION, 6)
COLLECTION OF TESTING INFORMATION AND EVALUATION AT COMPLETION OF EACH TEST WITH FULL RECONCILIATION OF DISCREPANCIES BEFORE PROCEEDING TO OTHER TESTS,.
MILLSTONE UNIT NO. 3 o
Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System IV.
ACTIONS TO MAKE SLCRS/ABVS OPERABLE C.
PERFORMANCE ASSURANCE PROGRAM 7)
INTEGRATED REVIEW OF ALL TEST DATA (INCLUDING DRAWDOWNS ACHIEVED) TO SUPPORT PROPER SYSTEM PERFORMANCE IN ACCOMPLISHING
RESPONSE
OBJECTIVES, 8)
A TOTAL OF 18 CASES IDENTIFIED, OF WHICH 11 WERE DEMONSTRATED BY TEST.
(A FULL DRAWDOWN TEST WAS PERFORMED FOR MOST CONSERVATIVE CASES),
- AND, 9)
ONLY-2 TESTED CASES DEMONSTRATED ANY NECESSITY FOR SETPOINT OR OTHER ADJUSTMENTS. THESE WERE EARLY IN THE PROGRAM AND WERE CORRECTED SO THAT OTHER TESTS INCLUDED THESE CHANGES..
MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System IV.
ACTIONS TO MAKE SLCRS/ABVS OPERABLE C.
PERFORMANCE ASSURANCE PROGRAM CONCLUSIONS:
THE PROGRAM DEMONSTRATED OPERATION IN ACCORDANCE WITH DESIGN TO ACHIEVE NEGATIVE 0.4 INCHES W.G. IN LESS THAN 150 SECONDS.
THIS WAS ACHIEVED WITHOUT ANY INDICATIONS OF INSTABILITY OR POTENTIAL FOR UNAVAILABILITY-AS A RESULT OF CASES CONSIDERED. _ _ _ _ _ -
e ABVS & SLCRS POWER SUPPLIES 4 kV BUS A 480 V TRAIN A SLCRS
~
')( ()
OFFSITE O ^svs ^
PD%ER TRAIN B O SLCRS DGB O ^8vs 8 4kV BUS B 480 V TRAIN A
A SLCRS SLCRS A
B TRAIN B
l I
OFFSITE DG'A' DG'B' OFFSITE OFFSITE DG'A' DG'B'
MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System V.
REQUESTED REGULATORY ACTIONS EXISTING TECHNICAL SPECIFICATION REQUIREMENT SLCRS IS REQUIRED TO DRAW A NEGATIVE PRESSURE OF 0.25 (NCHES-WATER GAUGE IN THE ANNULUS WITHIN 50 SECOND OF START SIGNAL QCTOBER 22,1993 SUBMITTAL EMERGENCY LICENSE AMENDMENT REQUEST o
INCREASE THE TIME TO DRAW A NEGATIVE PRESSURE OF 0.25 INCHES WATER GAUGE WITHIN THE SECONDARY CONTAINMENT BOUNDARY FROM 50 SECONDS TO 150 SECONDS, AND, REDUCE THE ALLOWABLE INTEGRATED CONTAINMENT LEAKAGE RATE (L )
FROM 0.65 WT% TO 0.30 WT% (PER DAY)
-OR-ENFORCEMENT DISCRETION ASSOCIATED WITH THE ABOVE LICENSE AMENDMENT o
-OR-ENFORCEMENT DISCRETION THAT WOULD ALLOW MILLSTONE 3 TO PROCEED TO o
MODE 2 FOLLOWING-THIS REFUELING OUTAGE.
MAXIMUM TIME THAT PLANT WOULD BE ALLOWED TO REMAIN IN MODE 2 IS SEVEN DAYS
MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System V.
REQUESTED REGULATORY ACTIONS JULY 29,1993 SUBMITTAL THE PROPOSED AMENDMENT, IF APPROVED, WILL PERMIT MILLSTONE 3 TO o
OPERATE WITH THE POTENTIAL FOR THE UPPER ELEVATIONS OF THE ENCLOSURE BUILDING TO BE AT A SLIGHTLY POSITIVE PRESSURE AT CERTAIN TIMES DURING THE YEAR (INFO NOTICE 88-76)
SUPPLEMENTAL SUBMITTAL ANTICIPATED ON OCTOBER 25,1993 o
SLCRS WILL PRODUCE A NEGATIVE PRESSURE OF GREATER THAN OR EQUAL TO 0.4 o
INCH W.G. IN THE AUXILIARY BUILDING AT 24'-6" ELEVATION WITHIN 150 SECONDS APPROVAL REQUESTED BY-OCTOBER 31,1993 o
ACTUAL SYSTEM PERFORMANCE SLCRS WILL PRODUCE A NEGATIVE PRESSURE OF GREATER THAN OR EQUAL TO 0.4 o
INCH W.G.
IN THE - AUXILIARY BUILDING AT 24'-6" ELEVATION WITHIN 150 SECONDS
- 29 '-
MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System VI.
RADIOLOGICAL CONSEQUENCE EVALUATION TWO CASES CONSIDERED REVISION TO DRAWDOWN TIME TO 2.5 MINUTES AND ALLOWABLE CONTAINMENT LEAK RATE REDUCTION TO 0.3 WT%/ DAY (EMERGENCY LICENSE AMENDMENT)
NO CREDIT FOR FILTRATION IF THE PLANT PROCEEDS TO MODES 4, 3, AND 2 (ENFORCEMENT DISCRETION)
FOR BOTH CASES FULLY COMPLY WITH DBA ASSUMPTIONS AS REQUIRED BY THE STANDARD REVIEW PLAN RESULT IN DOSES LESS THAN OUR CURRENT DOCKETED LOCA ANALYSIS Ventilation Vent 1
95 %
Secondary Containment or Auxiliary Building
- Filter Efficiency L
Filtered Leakage '
N 0.6222%/ day (from both s aray,ed and unsprayee regions) e l
t Unsprayed Region Spr Reg,ay ion Bypass Leakage m
0.0278%/ day (from both sprayed and m
r
. unsprayed regions)
I Containment Sump 50 % I Leak Rate = 104cc/hr L 10% I Flash For conservatism, ailleak e thatis filtered is assumed to ESF Building originate-in the Auxiliary Building and is thus discharged via'the
. ventilation vent. Leakage into the secondary containment -
po to SLCRS and to Unit 1 stack. MP1 stack releases would result in lower doses.
q MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System VI.
RADIOLOGICAL COfJSEQUENCE EVALUATION FOR MODES 2,3,4 CHANGE (ENFORCEMENT DISCRETION)
SLCRS/ABFS NOT REQUIRED FOR DBA DOSE CALCULATION COMPLIANCE LOSS OF FACTOR OF 20 CREDIT FOR FILTERS FOR IODINES MORE THAN COMPENSATED FOR BY:
1) 80 DAY DECAY OF IODINES GIVES.001 X T = 0 INVENTORY 2)
NO PRODUCTION OF FISSION PRODUCTS IN MODES 3 AND 4 3)
EQUILIBRIUM MODE 2 (5% POWER) CONCENTRATION 1/20 OF FULL POWER SOURCE 4)
WILL NOT REACH EQUILIBRIUM IN 7 DAYS 5)
GROUND RELEASE ASSUMPTION NOT CHANGED 6)
LIMITED TO CYCLE 5 STARTUP,
MILLSTONE UNIT NO. 3 Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System VI.
RADIOLOGICAL CONSEQUENCE EVALUATION FOR 2.5 MIN. DRAWDOWN CHANGE (EMERGENCY LICENSE AMENDMENT) o REANALYZED USING TACT-ill CODE FOLLOWING CHANGES IN ASSUMPTIONS FROM DOCKETED CALCULATION:
1)
L FROM 0.65%/ DAY TO 0.3% DAY 2)
CORRESPONDING REDUCTION lN LONG-TERM BYPASS LEAKAGE FROM 0.0278%/ DAY TO 0.0128%/ DAY 3)
UNFILTERED CONTAINMENT LEAKAGE FOR T = 0 TO 2.5 MIN.
PREVIOUSLY FACTOR OF 20 REDUCTION APPLIED TO THIS TIME PERIOD._.
a MILLSTONE UNIT NO. 3
\\.
Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System VI.
RADIOLOGICAL CONSEQUENCE EVALUATION 2.5 MINUTE DRAWDOWN CHANGE DOSE RESULTS (REM)
LOCATION / DOSE TYPE FSAR MEW EAB 0-2 HR 150 146.5 THYROID EAB 0-2 HR 19.5
.5 WHOLE BODY LPZ 30 DAY
'O O'
THYROID LPZ 30 DAY WHOLE BODY CONTROL ROOM AND TECHNICAL SUPPORT CENTER DOSES WOULD ALSO DECREASE.
MILLSTONE UNIT NO. 3 s
Supplementary Leak Collection And Release System / Auxiliary Building Ventilation System Vil.
CONCLUSION SLCRS/ABVS UNIQUENESS COMPLEXITY FMEA / DESIGN BASIS REVIEW / FUNCTIONAL TEST ASSURANCE SAFETY CONSEQUENCES MINIMAL AND WELL UNDERSTOOD SYSTEM WILL PERFORM INTENDED SAFETY FUNCTION MILLSTONE UNIT 3 READY TO RETURN TO SERVICE REQUEST PROMPT STAFF RESPONSE l
, i
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