ML20207G480

Summary of 880720 Meeting W/Bwr Owners Group MSIV Leakage Closure Committee in Rockville,Md Re Generic Methodology to Allow Increase in Leak Rate Limit & Elimination of MSIV Leakage Control Sys Requirements from Tech Specs

ML20207G480
Person / Time
Issue date:	08/17/1988
From:	Anand R Office of Nuclear Reactor Regulation
To:	Jocelyn Craig Office of Nuclear Reactor Regulation
References
NUDOCS 8808240128
Download: ML20207G480 (37)

Text

{{#Wiki_filter:O August 17, 1988 y, ilEMORANDUM FOR: John W. Craig, Chief Plant Systems Branch Division of Engineering and Systems Technology THRU: Jack Kudrick, Section Chief Plant Systems Branch Division of Engineering and Systems Technology 9 FROM: Raj Anand, Reactor Engineer Plant Systems Branch Division of Engineering and Systems Technology

SUMMARY

OF ltEETING WITli BWR OWNERS GROUP MSIV LEAKAGE CLOSURE COMllITTEE I. General On July (BWROG) Main Steam Isolation Valve (MSIV)presentatives of ti.e BWR Owners 20, 1988, the NRC staff met with the re Group Leakage Closure Committee in-Rockville, Maryland, to discuss a generic methodology to allow the increase of the MSIV Technical Specification (TS) leak rate limit and the elimination of the requirements for the MSIV leakage control system (LCS) from the plant TS. The conunittee also discussed how the results of Generic Issue C-8, "Main Steam Isolation Valve Leakage and LCS Failure" will be used in the proposed actions. The meeting followed the agenda provided in Enclosure 1 to this memorandum. is a list of meeting attendees. II. Meeting Highlights The staff noted that based upon the information provided before the meeting that no apparent safety benefits from the relief of allowable MSIV leakage rate limits, or the elimination of requirements for MSIV leakage control system from the plant TS had been identified. The staff requested the BWROG to define the safety benefits from the proposed changes, The BWR Owners Group began the discussion with a brief discussion of the proposed actions and described the recent BWR MSIV leakage history and the action required to allow credit via the isolation condenser. During the discussion, the staff stated that the BWROG approcch takes credit for the non-seismic piping between the second MSIY and the main condenser and takescreoitforfissionpreductattenuationinthemaincondenser.'Howevgr, the Liverncre studies indicated that the frequency of core melt is 2 x 10' per year becagse of internal events as compared to the core melt frequency of 0.8 x 10~ per year because of external events such as seismic events. It therefore seems imperative to show that the non-seismic piping and the condenser p will reuain intact due to this significant effect associated with the seismic event. I i OT g v 8008240128 880817 FDR TOPRP ENVGENE o'3 C PNU 'f

'o I John Craig ! The staff also noted that the design must be Seismic Category I as required by Appendix A to 10 CFR 100 if the system is used to mitigate 10 CFR 100 releases. The NRC staff also expressed concern regarding the assumptions made about unfiltered control room in-leakage. The BWROG presented a slide (Enclosure 3) which provided a comparison of BWROG's llSIV leakage contribution to the radiological dose calculations using NUREG-1169 results. The staff suggested that justification should be provided for each radiological assumption in the EWROG licensing topical report. The BWROG chairran stated that the topical report will be submitted to NRC for review in October 1988. The staff requested, at the close of the meeting that the committee should place more emphasis on the benefits of improved safety and the benefits received if relief from the ASME requirements were granted. The ASME requirements apparently requires extensive valve lapping with little derived safety benefit. cN M Raj Anand, Reactor Engineer l Plant Systems Branch Division of Engineering and Systems Technology

Enclosures:

1. Meeting Handouts l 2. List of Attendees 3. Slide DISTRIBUTION e P55ESTT1Tei PDRs PSB File Titartin JWermiel JXudrick CNichols AThadani LShao WHodges JCunningham i Ci!cCracken i I TMarsh ISpickler CGraves i RAnand ihm\\ SPLB: DEST SPLBf P RAnand;cf JXudrihk s 8/tf/88 8/p/88 ]

"r En dosufe. 1 o, BWR OWNERS' GROUP PRESENTATION TO THE NUCLEAR REGULATORY COMISSION MSIV LEAKAGE CLOSURE COMMITTEE INCREASING TECHNICAL SPECIFICATION ALLOWABLE MSIV LEAK RATE LIMITS AND ELIMINATING TECHNICAL SPECIFICATION REQUIREMENTS FOR LEAKAGE CONTROL SYSTEMS l l PREPARED BY GE NUCLEAR ENERGY I JULY 20, 1988 MSIV.LKG 1

r o, BWR OWNERS' GROUP PRESENTATION TO THE NRC 1. PURPOSE 2. BACKGROUND 3. NUREG-1169 CONCLUSIONS AND RECOMMENDATIONS 4. BWR MAIN STEAM SYSTEM DESIGN 5. RECENT BWR MSIV LEAKAGE HISTORY 6. ESTIMATE OF POTENTIAL BENEFITS FROM INCREASING ALLOWABLE MSIV LEAKAGE RATES 7. MSIV - LCS PERFORMANCE DATA 8. RADIOLOGICAL DOSF. CALCULATION TECHNIQUE 9.

SUMMARY

OF BWROG CONCLUSIONS 10. SCHEDULE FOR BWR SUBMITTALS I MSIV.LKG 2

a-m-- t 1. PURPOSE 0 JUSTIFY INCREASING PLANT SPECIFIC ALLOWABLE MSIV LEAKAGE RATES. O JUSTIFY ELIMINATION OF MSIV LEAKAGE CONTROL SYSTEMS, O DETERMINE REQUIRED ACTIONS TO ALLOW TREATMENT VIA ISOLATED CONDENSER. 0 REVIEW SCHEDULE FOR SUBMITTALS. l i MSIV.LKG 3 )

'a 2. BACKGROUND 0 MSIV LEAKAGE COMMITTEE FORMED IN 1982 IDENTIFIED CONTRIBUTORS WHICH CAUSE MSIVs TO FAIL LLRTs BY LARGE MARGINS. DEVELOPED RECOMMENDATIONS TO MINIMIZE LEAKAGE. DEVELOPED LIST OF OPERATOR ACTIONS TO MINIMIZE LEAKAGE OR DOSE CONSEQUENCE WHEN MSIVs ARE KNOWN TO BE LEAKING. DEVELOPED REALISTIC CALCULATIONAL METH00 TO ESTIMATE DOSE RATES DUE TO MSIV LEAKAGE. O PNL EVALUATED BWROG EFFORT FOR THE NRC (RESULTS DOCUMENTED IN NUREG-1169). FAVORABLE REVIEW OF PROBABLE CAUSES AND RECOMMENDATIONS SOME CRITICISM OF BWROG REALISTIC DOSE ASSESSMENT METHODOLOGY (PNL DEVELOPED COMPUTER MODEL) 0 MSIV LEAKAGE CLOSURE COMMITTEE FORMED IN 1986 PROVIDED COMMENTS TO NRC ON NUREG-1169. REVISED BWROG RADIOLOGICAL DOSE CALCULATIONAL TECHNIQUE TO BE MORE CONSERVATIVE THAN PNL METHOD. COMPILED RECENT HISTORY OF BWR MSIV LEAKAGE WHICH CONFIRMED IMPROVEMENT. PREPARED TYPICAL LICENSING SUBMITTALS TO JUSTIFY INCREASING ALLOWABLE MSIV LEAKAGE AND ELIMINATING (WHERE APPLICABLE) REQUIREMENTS FOR LEAKAGE CONTROL SYSTEMS. IMPLEMENTATION WILL BE VIA PLANT SPECIFIC SUBMITTALS. MSIV.LKG 4 l

'o 3. NUREG-1169 CONCLUSIONS AND RECOMMENDATIONS RESOLUTION OF GENERIC ISSUE C-8 "AN EVALUATION OF BWR MSIV LEAKAGE AND THE EFFECTIVENESS OF LEAKAGE TREATMENT METHODS" 0 FINDING CLEARLY DEMONSTRATED THE POST-ACCIDENT DOSE REDUCTION POTENTIAL OF PROCESSING MSIV LEAKAGE THROUGH AN ISOLATED CONDENSER, VERSUS FILTERING IN AN ENGINEERED SAFEGUARD SYSTEM. j (NUREG ISSUED BECAUSE IT "MAY BE USEFUL GUIDANCE FOR j SOME LICENSEES CONTEMPLATING PLANT SPECIFIC CHANGE REQUESTS RU. LATED TO THIS ISSUE PENDING FINAL GENERIC RESOLUTIOY'. ) 0 RECOMMENDATIONS OF BWROG WERE REVIEWED AND FOUND REASONABLE. EFFECTIVENESS COULD NOT BE DETERMINEC DUE TO LIMITED AVAILABLE MSIV LF.AKAGE DATA. 0 OTHER AVAILABLE METHODS OF HANDLING THE POST-LOCA MSIV LEAKAGE ARE MORE EFFECTIVE THAN A SAFETY-RELATED LCS. OTHER METHODS "PRODUCE LOWER OFF-SITE DOSE CONSEQUENCES THAN LCS". OTHER METHODS ARE MORE RELIABLE THAN LCS (ISOLATED CONDENSER PATHWAY MAY BE PASSIVE). LCS IS NOT EFFECTIVE AT HSIV LEAKAGE GREATER THAN 100 SCFH PER LINE DUE TO DESIGN LIMITATION, I MSIV.LKG 5

P NUREG-1169 (CONTINUEDL 0 OVERALL RISKS FROM THE ACCIDENT SEQUENCES IN WHICH MSIV LEAKAGE IS A SIGNIFICANT FACTOR ARE LOW WITHOUT THE

LCS, OTHER METHODS AP.E MORE EFFECTIVE TRAN LCS.

) O SAFETY-GRADE LCS MAY NOT BE REQUIRED. USE ALTERNATE TREATMENT METHODS. TAKE CREDIT FOR FISSION PRODUCT ATTENUATIONS IN MAIN CONDENSER. O ALLOWABLE HSIV LEAK RATE CAN BE INCREASED. USE FISSION PRODUCT ATTENUATIONS FOR THE MAIN CONDENSER. REFLECT REALISTIC LEAKAGE RATES FOR LARGE VALVES. 0 NUREG-1169 IDENTIFIES POTENTIAL REGULATORY REQUIREMENTS AND CRITERIA TO BE CONSIDERED IN THE RESOLUTION OF GENERIC ISSUE C-8. i MSIV.LKG 6

'e 4. BWR MAIN STEAM SYSTEM DESIGN 0 ORIGINAL BWRs (CONSTRUCTION PERMITS ISSUED PRIOR TO RG 1.26) J MSIV PURPOSE WAS STRICTLY FOR STEAM SHUT 0FF ENTIRE SYSTEM B31.1 SEISMIC THROUGH THE MSIVs 0 RG 1.26 QUALITY GROUP CLASSIFICATION AND STANDARDS (FEBRUARY 1976. REVISION 3). ADDRESSES "SAFETY-RELATED COMPONENTS" OTHER THAN THE REACTOR COOLANT PRESSURE BOUNDARY. 3 ESTABLISHES "OUALITY GROUPS" A THROUGH D. REQUIRES MAIN STEAM PIPING UP TO TURBINE STOP VALVES TO BE QUALITY GROUP B (OR ALTERNATELY UP TO A THIRD SHUT 0FF VALVE). i l 4 MSIV.LKG (TAGFLM1) 7 1

4 O RG 1.29 SEISMIC DESIGN CLASSIFICATION (SEPTEMBER 1978. REVISION 3) SEISMIC CATEGORY 1 REQUIRES DESIGN TO REMAIN FUNCTIONAL IF THE SAFE SHUTDOWN EARTHQUAKE (SSE) OCCURS. INCLUDES MAIN STEAM PIPING UP TO, BUT NOT INCLUDING, TURBINE STOP VALVE IE ELECTRIC SYSTEMS PROVIDING POWER TO CATEGORY 1 SYSTEMS STRUCTURES (AND OTHER EQUIPMENT) WHICH COULD REDUCE FUNCTIONALITY OF CATEGORY 1 SYSTEMS EXTENDS TO FIRST SEISMIC RESTRAINT BEYOND DEFINED BOUNDARIES MSIV.LKG 8 1

'P i 0 BWR/6s AND SOME Ss NEGOTIATED ALTERNATE TO RG 1.26 AND 1.29 FOR SOME BWRs (SOME ARE SEISMIC UP TO THE STOP VALVES). INSTALL SHUT 0FF VALVE AFTER MSIVs. QUALITY GROUP B THROUGH SHUT 0FF VALVE AND ASSOCIATED SEISMIC RESTRAINT. DOWNSTREAM PIPING IS QUALITY GROUP D. l ADVANTAGE IS THAT THE TURBINE AND PIPING BEYOND THE RESTRAINT NEED NOT BE HOUSED IN A SEISMIC I STRUCTURE (INCLUDES TURBINE BYPASS PIPING). O PER NUREG-1169 BWR DESIGN PROVIDES HIGHLY RELIABLE ALTERNATE TREATMENT METHODS l ISOLATED CONDENSER WITH: i MAIN STEAM BYPASS VALVES OPEN i 1 OR l MAIN STEAM DRAIN LINES OPEN i l 0 BEST TO HAVE AUTOMATIC ALIGNMENT OF FLOW PATH TO CONDENSER i UPON CONTAINMF.if ISOLATION (NO OPERATOR ACTION) BUT 0 SOME PLANTS MAY ADMINISTRATIVELY OPEN EITHER THE BYPASS OR q j DRAIN LINE VALVES. l l MSIV.LKG 9

f 'd Con nment R*** Secondary Cpregiomspt, Turbine Bullding Remt Vuset. h' M SIV MSIV Turbine / 7 P V*%* C l IV BV SV lllll U Otisit: Dose d ' CV I N / F i l Stack SRV g l Discharge g p I l l Outboard l 1 jsiv.t.CS C9ndenser l i l ,Orl _ _ _ _ _ _ _ _ _s _ggI i inboard f SGTS MSiV.LCS J N[*g 1 Prirnary Containment Room Secendary g ~~ Containment Turbine Building i g RPV MS!v MSiv - ~ >4 - >4-- - q { sv. _) \\ I IV sy s gy (f Offsite Dese Drain 'CV \\ I \\ // i l SRV l f Discharge l e j I ~( w ---fk ) Condenser lQ

o 5. RECENT BWR MSIV LEAKAGE HISTORY 0 BWROG OBTAINED RECENT LEAKAGE RATE DATA 24 EWRs 329 MSIV LOCAL LEAK RATE TESTS 0 DATA

SUMMARY

TOTAL NO. OF PLANTS: 24 TOTAL NO OF ALL TESTS 329 NO. OF TESTS LESS THAN 11.5 SCFH 254 100 SCFH 295 0 774 LESS THAN 11.5 SCFH 0 90% LESS THAN 100 SCFH i 0 NO SIGNIFICANT DIFFERENCE IN LEAKAGE HISTORY DATA I BETWEEN MANUFACTURERS i 0 NOT GENERALLY DEPENDENT ON MSIV LOCATION (INBOARD VERSUS OUTBOARD) MSIV.LKG 11

RECENT BWR MSIV LEAKAGE HISTORY (CONTINUED) 0 COMPARISON OF PREVIOUS AND RECENT MSIV LEAKAGE PERFORMANCE PREVIOUS RECENT (PRE-1984) (POST-1984) i NUMBER OF TESid 586 329 PERCENTAGE OF TESTS LESS THAN 11.5 SCFH 62.2% 77% PERCENTAGE OF TESTS LESS THAN 100 SCFH 78.3% (1) 90% i (1) LESS THAN 90 SCFH PRE-1984 0 RECENT MSIV LEAKAGE PERFORMANCE HAS IMPROVED 15% LESS EXCEED THE 11.5 SCFH LIMIT 12% LESS EXCEED 100 SCFH 1 l MSIV.LKG 22

c, RECENT BWR MSIV LEAKAGE HISTORY (CONTINUED) 0 M3IV LEAKAGE AFTER REPAIR OR REFURBISHMENT LEAK RATE NUMBER PERCENTAGE AFTER REPAIR OF VALVES _OF TOTAL 0 TO 1 SCFH 32 51.6% 1 TO 2 SCFH 8 12.9% 2 TO 3 SCFH 2 3.2% 3 TO 4 SCFH 3 4.8% 4 TO 5 SCFH 7 11.3% 5 TO 6 SCFH 0 0% 6 TO 7 SCFH 2 3.2% 7 TO 8 SCFH 3 4.8% 8 TO 9 SCFH 0 0% 9 TO 10 SCFH 2 3.2% 10 TO 11 SCFH ] 4.8% 62 100% O LOW LEAKAGE OBTAINED AFTER REPAIR OR REFURBISHMENT. 52% LESS THAN 1 SCFH i 1 84% LESS THAN 5 SCFH 0 INDICATES MSIVs WHICH FAIL CURRENT LEAKAGE LIMITS ARE BASICALLY NON-DEFECTIVE. MSIV.LKG 13

ESJJfielE OF PC'.'ENTIAL BENEFITS FROM INCREASING MSIV LEAKAGE RATES (CONTINUED 1 4 0 BWR DATA l AVERAGE # AVG. OF REPAIRS TO 2 PLANI MAN-MAN REM EXPOSURES PASS LLRT AFTER liDDRS IfLBDARQ OUTBOARD INITIAL FAILURE COMMENT 1 165 1.03 0.36 1.7 1 $60K COST 2 530 1.55 0.77 l 3 275 9.00 1.25 4 1020 0.05 0.05 1.3 NEWER PLANT 1 5 240 0.04 0.03 1.0 NEWER PLANT 6 350 2.25 1.37 $20K COST 7 300 NEWER PLANT l 0 CONCLUSIONS i 350 MAH-HOURS PER VALVE 1 1 i AVERAGE EXPOSURE PER VALVE = 1.1 REM l I MSIV.LKG 15 I

i 6. ESIIMATE OF POTENTIAL BENEFITS ERQM INCREASING ALLOWABLE MSIV LEAKAGE RATES O LOWER DOSE EXPOSURE TO MAINTENANCE PERSONNEL (ALARA) O EXTEND EFFECTIVE SERVICE LIFE OF THE MSIVs EXCESS MACHINE LAPPING REDUCES SEAT THICKNESS WILL RESULT IN MAJOR REFURBISHMENT IN FUYURE YEARS O MINIMIZE OUTAGE EXTENSIONS i PROBLEM IDENTIFIED BY OUTAGE MANAGEMENT COMMITTEE ^ REPEAfE0 LOCAL LEAK RATE TESTING CAN CAUSE 'NChEASE IN OUTAGE DURATIONS O MORE REALISTIC LEAK RATE LIMIT WILL REDUCE MSIV REPAIR COSTS i 4 l j l 4 j MSIV.LKG 14

70 MSIV-IES PERFORMANCE QATA . ~. ' DECLARE SYSTEM TOTAL FAILURES INOPERABLE (LCO) PLANT SHUTDOWNS PIANT f PER YEAR PER YEAR OR START-UP DELAYS PERFORMANCE CC;.Edi-f1 NO DATA APPROX. 1 0 POOR PERFORMANCE, CRITICAL PATK DURING EVERY REFUELING OUTAGE.

1. 2 NO DATA ABOUT 80%

LCS AVAILABILITY . #3 NO DATA NO DATA 44 APPROX. 5 APPROX. 5 2 POOR PERFORMANCE. 64 SURVEILIANCE TEST FAILURES & 250 MAINTENANCE ITEMS SINCE INSTALLA-! TION IN 1975 (13 YEARS)

1. 5 APPROX. 12 APPROX. 1 1

POOR PERFORMANCE; NEW PIANT. f6 APPROX. 3 APPROX. 1 0 TESTING CAUSES HIGH SUPPRESSION CHAMBERS AT, HAS CAUSED ESF ACTUATIONS. NOTE: SURVEILIANCE TESTINGS TO SATISFY TECH SPEC: 18 MONTHS SYSTEM FUNCTIONAL TEST 18 MONTHS VALVE LEAKAGE TEST QUARTERLY VALVE STROKE TEST MONTHLY SYSTEM IDGIC TEST MSIV. HOR 16

~ ~ 7. MSIV-LCS PERFORMANCE DATA (Continued) EQUIPMENT REPLACEMENT LLRT RELIABILITY PART INBOARD MAINTENANCE DOSE PLANT f PROBLEMS PROBLEM TEST PROBLEMS COST / YEAR EXPOSURES f1 NO DATA NO DATA NO DATA $60K-$80K NO DATA

1. 2

REIAYS, RELAY NO PROBLEM

$50K-$100K APPROX. 1 MAN REM /VEAR

HEATERS, REPLACEMENT, (APPROX. 10

SWITCHES, EQ PROBLEMS MAN MONTHS)

SPRING PACKS f3 FIDW TRANS-BLOWER MOTORS NO PROBLEM $15K (1987) < 50 MILLIREM / YEAR MITTERS (EQ) FLOW ELEMENTS (RE-DESIGN) f4 FIDW TRANS-HEATERS (EQ) NO PROBLEM $40K-$50K NO DATA

MITTERS, HEATERS FLOW ELEMENTS (RE-DESIGN)

1. 5 FIDW TRANS-FIDW ELEMENTS YES HIGH IDW l

MITTERS (RE-DESIGN) (OUT-OF-SERVICE (NEW PLANT) FOR 68 HOURS)

1. 6 VALVE IDGICS

( MSIV.HCR I 17 c

^ 's MS.IV-LCS PERFORMANCE

SUMMARY

(6 BWRs) DOSE EXPOSURE: APPROXIMATELY 1 MAN REM PER YEAR. MAINTENANCE COST: $15K TO $100K PER YEAR (NOMINAL $50K PER YEAR). I MAINTENANCE REQUIREMENTS: 1) SYSTEM HAS EXTENSIVE LOGIC & INSTRUMENTATION. 2) HIGH NUMBER OF SURVEILLANCE TESTS (RE-CALIBRATION FREQUENTLY REQUIRED). LIMITING CONDITION OF OPERATION: ABOUT ONE PER YEAR PER PLANT. i CRITICAL PATH MAINTENANCE: OCCURS FREQUENTLY. PLANT SHUTDOWNS OR PLANT HAS OCCURRED AT 2 0F 6 PLANTS IN STARTUP DELAYS: SURVEY. MAJOR EQUIPMENT PROBLEMS: A) INBOARD FLOW ELEMENTS CAUSE SYSTEM TO TRIP (RE-DESIGN IN PROGRESS). B) FREQUENT RE-CALIBRATION 1 0F PRESSURE TRANSDUCERS. i l MAJOR REPLACEMENT PART PROBLEM: BLOWER MOTORS, HEATERS, FLOW ELEMENTS (PROBLEM IN PURCHASING EQUIPMENT THAT MEETS EQ REQUIREMENTS). 4 MSIV.LKG 18 i

l 8. RADIOLOGICAL DOSE CALCULATION TECHNIQUE i i l O BWROG TECHNIQUE USES TURBINE EQUIPMENT TO MITIGATE CONSEQUENCES OF LEAKAGE. 0 SIMILAR TO NUREG-1169 RECOMMENDATIONS. RESULTS MORE CONSERVATIVE THAN PNL RESULTS CONSERVATIVELY EVALUATES DOSE CONTRIBUTION TO CONTROL ROOM PERSONNEL AND THE GENERAL PUBLIC FROM BWR MSIV LEAKAGE 0 EMPLOYS STEAMLINES AND CONDENSER AS TREATMENT PATH FOR MSIV LEAKAGE. ASSUMES PLATE OUT OF IODINE IN THE STEAMLINES AND ) CONDENSER 1 DECAY OF FISSION PRODUCTS IN TRANSIT j l 4 } I MSIV.LKG 19

3 RADIOLOGICAL DOSE CALCULATION TECHNIQUE (CONTINUED). O LIMIT ON MSIV LEAKAGE RATE DETERMINED BY THE DOSE AT THE SITE BOUNDARY AND/0R THE CONTROL ROOM. O CONTROL ROOM DOSE IS TYPICALLY LIMITING DUE TO ITS PROXIMITY TO THE RELEASE POINT. O ADDITIONAL "NEW" DOSES FROM ANCREASED MSIV LEAKAGE ADDED TO FSAR LOCA DOSE (EXTREMELY CONSERVATIVE) 0 PLANT UNIO.UE ANALYSES USING THIS MODEL SHOW THAT HIGHER MSIV LEAKAGES DO NOT EXCEED REGULATORY DOSE LIMITS. MSIV.LKG 20

RADIOLOGICAL DOSE CALCQLATION TECHNIQUE IN VESSEL %QQiL 4 O INTENT IS TO MODEL EVENTS USED IN NUREG-1169. I LARGE BREAK LOCA AIRBORNE ACTIVITY DEFINED BY RG 1.3 i FOR PLATE OUT IN CONDENSER AND TURBINE BUILDING THE IODINE WILL BE ASSUMED PARTICULATE (ADDITIONAL DISCUSSION LATER IN THIS SECTION). O CORE UNCOVERED, VESSEL DEPRESSURIZED THROUGH THE BREAK O INSTANTANEOUS FISSION PRODUCT RELEASE TO CONTAINMENT i 0 ACTIVITY REENTERS VESSEL THROUGH THE BREAK AND IS AVAILABLE ) FOR TRANSPORT VIA MSIV LEAKAGE. i I MSIV.LKG 21

l RADIOLOGICAL DOSE CALCULATION TECHNIQUE l PLANT TRANSPORT i \\ 0 EVALUATES TRANSPORT AND DECAY AND REMOVAL OF RADIONUCLIDES FROM RPV TO ENVIRONMENT AND CONTROL ROOM TOTAL RELEASE OF ACTIVITY TO ENVIRONMENT FOR OFF-SITE DOSE CALCULATIONS INTEGRATED ACTIVITY IN CONTROL ROOM O MODEL SEPARATES PLANT INTO FOUR (4) COMPARTMENTS l 1 1 - PRIKARY CONTAINMENT 2 - TURBINE / CONDENSER 3 - TURBINE BUILDING l 4 - CONTROL ROOM i j MSIV LKG 22 1

RADIOLOGICAL DOSE CALCULATION TECHNIQE DOSE MODEL j i 1 0 METHOD COMMONLY USED IN DBA ANALYSIS 0 ASSUMES SEMI-INFINITE CLOUD MODEL l 0 WHOLE BODY AND BETA DOSE RESULTS ARE SKIN DOSE j 0 THYROID DOSE COMMITMENT RESULTS FROM IODINE INHALATION I l i 1 1 ] MSIV.LKG 23 4

COMPARISON OF BWROG TO NUREG 1169 (PNL) ASSUMPTIONS 1 XEY ASSUMPTIONS NUREG 1169 BWROG 1 1. TYPE OF EVENT RG 1.3 LOCA RG 1.3 LOCA 2. STEAM LINE FLOW COMPLEX FLOW 8X PLUG FLOW RATES MODEL 3. PLATE-0VT FIPST NONE NONE 48 HOURS 4. EFFLUENT TREATMENT STEAM LINES & STEAM LINES & EQUIPMENT CONDENSER CONDENSER 5. SETTING AEROSOL 0.44 TO 10.8 0.68 DECAY CONSTANT 6. BAROMETRIC PRESSURE .00058 ATMOSPHERE / .00058 ATH0 SPHERE / CHANGE HOUR HOUR 7. PERCENT APPROACHING 100% 33% CONDENSIBLES IN THE MAIN CONDENSER ) j 8. TURBINE BUILDING LEAK 2400% l RATES ] (PERCENT PER 24 HOURS) i i MSIV.LKG 24 .1

i ASSUMPTION REGARDING IODINE REMOVAL MECli&N15]i1 0 NEDC 30259 (REVISION 0) USED WASH 1400 METHOD FOR 10 DINE DEPOSITION APPLICABLE FOR ELEMENTAL AND ORGANIC IODINE. O NEDC 30259 (REVISION 1) EMPLOYS SLIGHTLY DIFFERENT APPROACH. O USES APPROPRIATE REMOVAL TERMS FOR ELEMENTAL AND ORGANIC I0 DINE PER RG 1.3 AND WASH 1400 IN THE STEAM PIPING. l SIGNIFICANT FLOW DOWN THE PIPE HIGH TEMPERATURES SIGNIFICANT FRACTION IS NON-CONDENSIBLE STEAM LINE REMOVAL PROCESS TURNED OFF FIRST 48 HOURS (CONSERVATIVE) O EMPLOYS PARTICULATE IODINE REMOVAL PROCESSES IN CONDENSER (NATURAL DEPOSITION). VERY LOW FLOW RATES j LARGE SURFACE AREAS TEMPERATURES BELOW THOSE NEEDED TO MAINTAIN GASEOUS j ELEMENTAL IODINE l 1 1 SIV.LKG (TAGFLM1) 25/26

• o COW ARISON OF BWR OWNERS' GROUP MS!V LEAL' AGE DOSE CALCULATIONS FOR "BASE CASE" BWR TO NUREG 1169 RESULTS i

l S BWROG .T t O - BWROG - WB ,d v O i S " NUREG - T 4 5 .i h$7 s NUREG - WB S 5 i

1. ,w a

l >= f s,,. ', 1 8 / s l t / p S / / 3 / / / / / // / n 'e.% 2 i 4 Y 2 0 200 400 600 800 1000 SCFH PER STEAM LINE THYR 0!D (T) LIMIT = 300 REMS WHOLE BODY (WB) LIMIT = 25 REMS 27 i 4 ---ea-c w --g ._g +

,s o SENSITIVITY STUDY PERFORMED TO EVALUATE AFFECT ON CALCULATED DOSE RATES SENSITIVITY SENSITIVITY SIGNIFICANT SIGNIFICANT VARIABLES STUDIED FOR WB DOSE FOR THYROID DOSE 1. DRYWELL VOLUME 2. CONTAINMENT PRESSURE X 3. CONTAINMENT TEMPERATURE 4. STEAM LINE FLOW XX ASSUMPTIONS 5. PIPING PLATE-0UT TIME XX 6. PERCENT CONDENSIBLES X XX 7. BAROMETRIC PRESSURE CHANGES 8. CONDENSER PLATE-0VT FACTOR XX 9. TURBINE BUILDING LEAK RATE X X = SOME SIGNIFICANCE XX = MAJOR SIGNIFICANCE MSIV.LKG 28

,,'s ,e 9.

SUMMARY

OF BWRQG_C.ONCLUSIONS 0 ESTABLISHES RATIONAL BASIS FOR ALLOWABLE MSIV LEAKAGE RATES 0 INCREASE IN ALLOWABLE MSIV LEAKAGE RATE DOES NOT DEGRADE VALVE ISOLATION PERFORMANCE. VENDOR STATES THAT UP TO 200 SCFH LEAKAGE CAN OCCUR WITHOUT PRESENCE OF SPECIFIC DEFECTS CONFIRMED BY REPAIR EXPERIENCE OF LEAKING MSIVs 0 INCREASED LEAKAGE RESULTS IN AN INSIGNIFICANT INCREASE TO DOSE EXPOSURES PREVIOUSLY CALCULATED FOR DESIGN BASES LOCA. O INCREASING MSIV IT.AK RATE LIMITS AFF(9DS SIGNIFICANT BENEFITS AVOIDS UNNECESSARY DOSE EXPOSURE EXTENDS SERVICE LIFE OF THE MSIVs REDUCES PLANT OUTAGE TIME REDUCES REPAIR AND REFURBISHMENT COSTS 0 REVIEW 0F RECENT MSIV LEAKAGE DATA VERIFIED IMPROVEMENT IN REDUCING ACTUAL MSIV LEAKAGE, SIV.LKG (TAGFLM1) 29

10K_7.Y OF BWROG CONCLUSIONS (CONTINUED) l 0 USE OF ALTERNATE EQUIPMENT TO TREAT MSIV LEAKAGE ALLOWS ELIMINATION OF THE SAFETY RELATED LEAKAGE CONTROL SYSTEM (LCS) ALTERNATE METHODS ARE MORE RELIABLE AND EFFECTIVE LCS NOT EFFECTIVE FOR LEAKAGE > 100 SCFH PER STEAM LINE 0 ELIMINATION OF LCS RESULTS IN SIGNIFICANT BENEFITS l REDUCES NUMBER OF CONTAINMENT ISOLATION VALVES REDUCES SURVEILLANCE AND LOCAL LEAK RATE TESTING REDUCES LCOs AVOIDS UNNECESSARY DOSE EXPOSURE AND COST FOR TESTING AND MAINTENANCE REDUCES CRITICAL PATH OUTAGE TIME ELIMINATES PLANT STARTUP DELAYS AND PLANT SHUTDOWNS BECAUSE OF LCS FAILURES SIV.LKG (TAGFLM1) ao

SUMMARY

OF BWROG CONCLUSIONS (CONTINUED) 0 MSLs AND ISOLATED CONDENSER EXPECTED TO BE AVAILABLE FOLLOWING ACCIDENTS AS SEVERE AS DESIGN BASIS LOCAs. LIVERMORE STUDY SEISMIC QUALIFICATION UTILITY GROUP (50VG) DATA BASE l CONFIRMS NUREG-1169 CONCLUSIONS 0 PROPOSED CHANGES NOT EXPECTED TO INVOLVE A SIGNIFICANT HAZARD CONSIDERATION. O RESULTING DOSE EXPOSURES DO NOT EXCEED REGULATORY LIMITS. MSIV.LKG/TAGFLM1 31

eSb .t :- 10. BWROG MSIV LEAKAGE CLOSURE COMMITTEE SCHEDULE FOR BWR SUBMITTALS 0 NEDO 30259 REVISION 1 MID-AUGUST RADIOLOGICAL CALCULATION TECHNIQUE O RECENT MSIV LEAKAGE HISTORY MID-AIJGUST 0 HOPE CREEK SUBMITTAL MID-AUGUST (MSIV LEAKAGE RATE INCREASE) 0 ADDITIONAL SUBMITTALS SEPTEMBER-0CTOBER (INCLUDES ELIMINATION OF LCS) MSIV.LKG 31

h ,[t BWR OWNER'S GROUP MEETING WITH THE NRC ON JULY 20, 1988 REGARDING MSIV LEAKAGE ISSUES Name Organization _ Telephone Number Raj Anand NRC/NRR/SPLB 301-492-0805 John Craig NRC/NRR/SPLB 301-492-0873 Jack Kudrick NRC/NRR/SPLB 301 492-0871 Frank Witt NRC/NRR/ECEB 301-492-0823 Irwin Spickler NRC/NRR/PRPB 301-492-1147 L. Jay Cunningham NRC/NRR/PRPB 301-492-1111 P. J. Fulford NUS/LIS 301-258-8692 Charles Graves NRC/RES/PSIB 301-492-3557 Richard Verbus Cleveland Electric Illum. 216-259-3737 Norman Peterson Iowa Electric 319-851-7595 Pat Simpson SERI 601-984-9216 Tom Elwood Illinois Power 217-935-8881 David Rothberg Stone & Webster 609-482-3408 Paul Allen Stone & Webster 609-482-3156 Joseph Rutbery NRC/0GC 301-492-1532 Colleen Woodhead HRC/0GC 301-492-1525 Timothy Colburn NRC/NRR/PD33 301-492-1369 Pat Powell Wasington Public Power 509-377-2298 Robert Binz PSE&G 609-339-3739 Richard Beckwith PSE&G 609-339-5234 Cynthia Tully Georgia Power Company 404-52C-3543 Lloyd Burns GE Nuclear Energy 408-925-6596 Bill Drews Niagara Mohawk 315-342-2007 Mary Haughey NRC/NRR/PD11 301-492-1439 John W. Power Nuclear Safety Consultant NMP 315-428-7501' Larry Crocker NRC/NRR/PD23 301-492-3049 J. D. Heidt GPC Licensing Mgr. Hatch 404-526-4530 George Rivenbark NRC/NRR/PD12 301-492-1422 Bob Samworth NRC/NRR/PD5 301-492-1364 Gubin Shelb Commonwealth Edison 312-294-8849 Gary Hawner NRC/NRR/EMEB 301-492-0919 Louis Lee GE Nuclear Energy 408-925-1882 Tom Green GE Nuclear Energy 408-925-1308

Emdosure 3 (i. COMPARISON OF BUR OWNERS' CROUP NSIV LEAK CONTRIBUTION TO THE

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^ RADIOLOGICAL DOSE Calf,UIATIONS TO NUREC 1169 RESULTS (ALL VALUES IN REM) Plant Limits IAak Rate Calculated Domes CFPH/ Exclusion Boundary LPZ Boundary Steamline 2 Hours at 30 Days Control Roome hole Wole Wole Thyroid Body Thyroid Body Thyroid Body _ 3g13., Dose Limits 300 25 300 25 30 5 30/75 3agt_Cann 11.5 0.0 0.0 1.2E-3 1.7E-2 3.8E-7 5.2E-3 0.12 25 0.0 0.0 4.6E-3 4.7E-2 1.5E-6 1.4E-2 0.33 g, 50 0.0 0.0 4.4E-2 0.12 1.2E-5 3.7E-2 0.85 pc 100 0.0 0.0 0.22 0.32 6.0E-5 0.10 2.3 8 250 0.24 1.2E-3 2.09 1.2 6.0E-4 0.40 8.9 h t 500 1.88 5.1E-3 7.5 3.0 2.2E-3 1.0 22.7 4 1000 3.3 2.1E-2 28.0 6.4 8.0E-3 2.4 51.5 NUREC 1169 Results l For Isolated Steamitne 11.5 8.9E-4 7.8E-4 Not Celeulated I and Condenser with Open Bypass Lines 1000 0.41 6.6F,-2 Not Calculated I i j

• control Rooms X/Qs not available for Hanford 2; values for a typical BUR are assumed (see 3ase Case).

It should also be noted that this plant has a large rectreulation filter system in the control room that reduces the thyroid l dose in the control room. f =}}