ML16341F568

Summary of 900130 Meeting W/Util in Rockville,Md Re License Amend Request to Disable One Pressurizer Safety Valve in Event of Valve Leak

ML16341F568
Person / Time
Site:	Diablo Canyon
Issue date:	02/22/1990
From:	Rood H Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 9003010158
Download: ML16341F568 (50)

Text

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February 22, 1

'I Docket Nos.

50-275 and 50-323 LICENSEE:

PACIFIC GAS AND ELECTRIC COMPANY (PG&E)

FACILITY:

DIABLO CANYON NUCLEAR POWER PLANT, UNITS 1

AND 2

SUMMARY

OF MEETING ON JANUARY 30, 1990 TO DISCUSS LICENSE AMENDMENT REQUEST (LAR) TO PERMIT DISABLING ONE PRESSURIZER SAFETY VALVE (PSV)

IN THE EVENT OF A VALVE LEAK On January 30, 1990 the NRC staff met with PG&E in Rockville, Maryland to discuss the above subject.

Attendees at the meeting are given in Enclosure l.

Selected viewgraphs used by the licensee are given in Enclosure 2.

Following two previous meetings with PG&E on this same subject, held July 20 and December 5, 1989, PG&E submitted a License Amendment Request (LAR) by letter dated January 25, 1990.

The LAR would permit disabling one of the three PSVs in the event of a leak in the associated loop seal.

The technical issues involved in this amendment request had been addressed in previous meetings and discussions.

Some were addressed further here, particularly those associated with meeting the requirements of the ATWS rule, and assurance that the two remaining operable PSVs would have adequate blowdown capacity.

Additional assurance against a small break LOCA resulting from gagging a

PSV with leaking loop seal was discussed, and documentation supporting this and related issues was identified and presented (see ).

The LAR of January 25, 1990 does not specify a time limit on reactor operation with one disabled PSV.

PG&E stated that it is the intent that reactor operation would continue in the condition only until the first outage of sufficient duration to restore valve operability. It was agreed that a few words should be added to the TS to not leave it open-ended.

Jones said a more deterministic basis to show ATWS rule is met would be helpful.

PG&E said they would think about that, but they believe the current submittal/

analysis goes beyond what should be needed.

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Enclosures:

As stated

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SUMMARY

DISTRIBUTION 55 555 NRC

& LPDRs CTrammell JSniezek RBevan DRSP/PD5

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HRood NRC Participants OGC ACRS (10)

EJordan H.B. Clayton

(,(Y'riginal signed by Roby Bevan Roby Bevan, Project Manager for Harry Rood, Senior Project Manager Project Directorate V

Division of Reactor Projects - III, IV, V and Special Projects Office of Nuclear Reactor Regulation

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Docket Nos.

50-275 and 50-323 UNITEDSTATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 February 22, 1990 LICENSEE:

PACIFIC GAS AND ELECTRIC COMPANY (PG&E)

FACILITY:

DIABLO CANYON NUCLEAR POWER PLANT, UNITS 1 AND 2 SUBJECT-:

SUMMARY

OF MEETING ON JANUARY 30, 1990 TO DISCUSS LICENSE AMENDMENT REQUEST (LAR) TO PERMIT DISABLING ONE PRESSURIZER SAFETY VALVE (PSV)

IN THE EVENT OF A VALVE LEAK On January 30, 1990 the NRC staff met with PG&E in Rockville, Maryland to discuss the above subject.

Attendees at the meeting are given in Enclosure 1.

Selected viewgraphs used by the licensee are given in Enclosure 2.

Following two previous meetings with PG&E on this same subject, held July 20 and December 5, 1989, PG&E submitted a License Amendment Request (LAP,) by letter dated January 25, 1990.

The LAR would permit disabling one of the three PSVs in the event of a leak in the associated loop seal.

The technical issues involved in this amendment request had been addressed in previous meetings and discussions.

Some were addressed further here, particularly those associated with meeting the requirements of the ATWS rule, and assurance that the two remaining operable PSVs would have adequate blowdown capacity.

Additional assurance against a small break LOCA resulting from gagging a

PSV with leaking loop seal was discussed, and documentation supporting this and related issues was identified and presented (see ).

The LAP. of January 25, 1990 does not specify a

with one disabled PSV.

PG&E stated that it is would continue in the condition only until the duration to restore valve operability. It was be added to the TS to not leave it open-ended.

time limit on reactor operation the intent that reactor operation first outage of sufficient agreed that a few words should Jones said a more deterministic basis to show ATWS rule is met would be helpful.

PG&E said they would think about that, but they believe the current submittal/

analysis goes beyond what should be needed.

Enclosures:

As stated Roby Bevan, Project Manager for Harry Rood, Senior Project Manager Project Directorate V

Division of Reactor Projects - III, IV, V and Special Projects Office of Nuclear Reactor Regulation

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Mr. J.

D. Shiffer Pacific Gas and Electric Company Diablo Canyon CC:

NRC Resident Inspector Diablo Canyon Nuclear Power Plant c/o U.S. Nuclear Regulatory Commission P. 0.

Box 369 Avila Beach, California 93424 Dr. R.

B. Ferguson Sierra CLub - Santa Lucia Chapter Rocky Canyon Star Route Company Creston, California 93432 Ms. Sandra A. Silver 660 Granite Creek Road Santa Cruz, California 95065 Bruce Norton, Exq.

c/o Richard F. Locke, Esq.

P. 0.

Box 7442 San Franci sco, Californi a 94120 Managing Editor The Count Telegram Tribune 13 1 Jo nson Avenue P. 0.

Box 112 San Luis Obispo, California 93406 Chairman San Luis Obispo County Board of Supervisors Room 270 County Government Center San Luis Obispo, California 93408 Richard F. Locke, Esq.

Paci fic Gas

& Electr ic Company Post Office Box 7442 San Francisco, California 94120 Mr. John Hickman Senior Health Physicist Environmental Radioactive Mgmt. Unit Environmental Management Branch State Department of Health Services 714 P Street, Room 616 Sacramento, California 95814 Regional Adminstrator, Region V

U.S. Nuclear Regulatory Commission 1450 Maria Lane, Suite 210 Walnut Creek, California 94596 Mr. Peter H. Kaufman Deputy Attorney General State of California 110 West A Street, Suite 700 San Diego, California 92101 Ms. Nancy Culver 192 Luneta Street San Luis Obispo, California 93401 Michael M. Strumwasser, Esq.

Special Assistant Attorney General State of California Department of Justice 3580 Milshire Boulevard, Room 800 Los Angeles, California 90010

ENCLOSURE f NRC/PG&E MEETING - JANUARY 30, 1990 LAR 90-01 DISABLING OF A PSV NAME Roger Johnson James Tomklns Anthony M. Sicari Alan Nicholson Tien P.

Lee B.S.

Lew Roby Bevan Don Katze Y. Gene Hsii Y. (Renee)

Li R. Jones ORGANIZATION PG&E PG&E Westinghouse PG&E PG&E PG&E NRC/NRR RSB/NRR NRC/NRR NRC/EMEB NRC/SRXB

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fgGL>2uRE 2 AGENDA PG&E -

NRC MEETZNG JANUARY 30, 1990 ROCKVXLLE, MARYLAND PRESENTATXON OF LAR 90-01 (DATED JANUARY 25, 1990)

TO OPERATE DXABLO CANYON 'MXTH ONE PRESSURXZER SAFETY VALVE DXSABLED 1.

8ACKGROUND PG&E INTRQDUcTXQN AND PURPosE QF LAR

SUMMARY

OF PREVIOUS MEETXNGS OVERvxew OF LAR t

2.

ORGANXZATXON AND DESCRXPTXON OF LAR PG&E 3.

ANALYTXCALRESULTS AND STATUS OF Rel.ATED Issues 4.

SUMMARY

5.

NRC COMMENTS AND DXSCUSSXON PG&E NRC/

PG&E Paclllo Oaa.and Electric Company

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INTROD CTION AND PURPOSE OF LAR 1.

PURPOSE OF LAR ALLOW OPERATXON WITH ONE PSV INOPERABLE AND DXSABLED JUSTIFY THAT Two PSVs:

Q PROVIDE SUFFXCXENT PRESSURE RELXEF Q

MEET ASME/SRP REOUXREMENTS O

MEET FSAR CRITERIA AT LEAST ONE PORV AVAXLABLEWHEN PSV DXSABLED ADDRESS NRC COMMENTS REGARDXNG ATWS ADDRESS NRC GENERIC PSV CONCERNS AFFECTED BY PROPOSED TECH SPEC CHANGES 2.

LAR PROVXDES CAPABXLITXES THAT ARE IMPORTANT TO SAFETY DXSABLXNG PREVENTS INADVERTENT PSV OPENING AND POTENTXAL SMALL BREAK LOCA Pacltlc Oae and Electric Coapany

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SUMMARY

OF PREVIOUS MEETINGS WITH THE NRC Q

JULY 20, 1989 TECHNXCAL MEETXNG INXTXAL"PGLE PROPOSAL SAFETY EVALUATXON VALVE PERFORMANCE IMPROVEMENTS NRC COMMENTS REGARDXNG ATWS 0

DECEMBER 5g 1989 TECHNXCAL MEETXNG IMPROVED VALVE PERFORMANCE EFFORTS OYERYXEw DF ATWS ANALvsxs PROPOSED TECH SPEC CHANGES RECENT UNXT 1 BEAUMONT TEST RESULTS NRC COMMENTS AND GENERXC QUESTXONS 0

JANUARY 9, 1990 MANAGEMENT MEETXNG LAR SUBMXTTAL PLANS ISSUES AND BENEFXTS TO BE ADDRESSED MEETXNG wxTH NRC AFTER SUBMXTTAL Paclflc Oae and Electric Company

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OYERYIEW OF LAR o

PRDFDSED TECH SFEc CHANGEs o

BACKGRouND o

JUSTXFXGATXDN o

SAFETY EvALUATxoN 0

No SxGNxFxcANT HAzARDs EYALUATxoN 0

NRC GENERxc SAFETY CCNcERNs Faclfle Oae and Etectrlc Coapany

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n ORGANIZATION AND DESCRIPTION OF LAR O

PROPOSED TECH SPEC CHANGES (PAGE 1)

ALLOW OPERATXON WXTH ONE PSV INOPERABLE ALLOW 24 HOURS TO DXSABLE INOPERABLE PSV REQUIRE ONE PORV OPERABLE XN AUTOMATIC MODE WITH BLOCK VALVE OPEN REQUIRE PLANT SHUTDOWN WITH TWO PSVS INOPERABLE Pacltlc Oaa and Elactrlc Company

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REA TOR COOLANT SYSTEM OPERATING LIMITING CONDITION FOR OPERATION 3.4.2.2 All pressurizer Code safety va'Ives shall he OPERABLE with a lift setting of 2485 psig i 3X.~

APPLICABILITY:

HODES l, 2 and 3.

ACTION:

duo Mith ewe pressurizer Code safety valve inoperable, be in at least HOT STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in at least HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

c.P.

The provisio'ns of Specification 3.0.4 aay be suspended for up to 18 hours2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br /> per valve for entry into and during operations in MODE 3 for the purpose of setting the pressurizer Code safety valves under ambient (hot) conditions provided a preliminary cold setting was made prior to heatup.

SURVEILLANCE RE UIREMENTS 4.4. 2. 2 No additional requirements other than those required by Specifica-tion 4.0.5.

a.

Kith one pressurizer Code safety valve inoperable, within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> ensure the inoperab1e valve is disabled and at least one pressurizer power-operated relief is OPERABLE and its associated block valve is open.

Otherwise, be

$ n at least HOT STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and at least HOT SHUTDOHN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

"The liftsetting pressure shall correspond to aILbient conditions of the valve at nominal operating temperature and prcssure.

OIABLO CANYON " UNITS 1 8 2 3/4 4-8

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REACTOR COOLANT SYSTN ES VALVES (Contfnued) va1ves fs Iteatar than the aaxfaw late loss of load assuaging no Reactor trfp tel Trfp Setpofnt fs reached (f.e., no credft fp on the loss-of-load) and also assefng no relfef valves r ste dump valves.

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sutoe rate resultfng froa a c untf1 the ffrst Reactor Trfp 5 fs taken for a dfrect Reactor t operatfon of the yeet operated e~

Ceeonstratfon of the safety valves'fft settfngs All occur only durfng shut~

and ofll be performed fn accordance vfth the ptovfsfons of Sectfon XI of the AQ% Sof let and Pressure Code.

tn the event that no safety valves ate KERAILE, an operatfno NHR loop, con-nected to tha RCS, provfdes ovorptessure relfef capabflfty and will prevent RCS overpressurfxatfon.

in addftfon, the Ovorpressure trotectfon Systae (relfef valves) prcvfdos a dfvarsa oaans of protactfon aoafnst RCS ovarprsssurfzatfon at lac teeperatures.

ok W~o f<<ss~--e C Jc f<<v ives <<~ <<de reseat tao RCS froa befog Orossorfsee above fts Safety Weft of S7SS SsSS.pto cesbfned rel fef capac of Hfth one pressur1zer Code safety valve fnoperable, operatfon may continue prov1ded that the fnoperable valve 1s 1ncapable of openfng and one pressurfzer PORV 1s OPERABLE and 1ts assoc1ated block valve 1s open.

For th1s techn1cal spec1f1cat1on, the pressur1zer PORV 1s OPERABLE ff 1t fs capable of opentng automat1cally.

Thfs requ1rement 1s conservat1ve 1n that the accfdent analysfs does not assume operat1on of the PORYs.

3/a.i. i RELIEF vALvE The peer-operated telfef valves (PORVs) and stem hobble functfon to relfave RCS pressure durfng all desfyn ttansfents up to and fncludfng the design step load Cscrease Qth stean dump.

Operatfon of the year-operated rel fef valves sfnfaf1es the undesfrable openfnQ of the sptfng loaded pressutfzer Code safety valves.

Each KNf has a teaote1y operated block valve to provfde a posftfve shutoff capabflfty should ~ telfef valve hecoee fnoperable.

The NRVs performs a safety. related functfoa by provfdfno an KS deptas-surfzatfon path durfng certafn event recovery sequences.

The capabf1fty of the PORVs to perfore thfs functfon fs based on aanual actuatfon and does not tequfre the pressure satpofnt functfon of the valve to be OPBAbLE fn order to Neet fts lfaftfng condftfon for opatatfon.

OIASLO CANYON NITS 1 C 2 I 3/l I-2 AMENDMENT 805.

27 ANO 26 January 5,

1988

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o BACKGRoUNn (PAGE 2)

RECENT PSV TEST RESUl.TS MG INVESTXGATXONS INDUSTRY EXPERXENCE MXTN PSVS PSV DxsABLXNG METHOD 0

JUSTXFXCATXON (PAGE 3)

DXSABLXNG PREVENTS SMALL BREAK LOCA TWO PSVS PROVXDE SUFFXCXENT PRESSURE RELXEF ASME CODElSRP REGUXREMENTS AND FSAR CRXTERXA ARE MET PORV OPERABxLxTY PRovxDEs ADDXTxoNAL CONSERVATXSM Paclflc 0 ~I and Electric Company

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9 SAFETY EYALUATXQN FOR TMO PSVS (PAGE 4)

TMO NON-LOCA ACCXDENTS ARE LXMXTXNG PEAK PRESSURES

< 1104 ATMS TARGET CMF OF 1E-5 MKT FOR ONK PSV DXSABLED AND NO PORVS POTENTXAL FOR 1NADVERTENT PSV OPENXNG 0

DXSABLXNG PSV PREYENTS INADVERTENT OPENXNG 0

NO SXGNXFXCANT HAZARDS EVALUATXON (PAGE 7)

THREE 50.92 STANDARDS ARE MET PIclflc Ohl ahd

'Kl~ CttlC CoÃlPlhg

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O NRC GENERXC SAFETY CONCERNS (ENCLOSURE 2)

PSV UNCERTAXNTIES, INCLUDING SET POINT SNIFT BEsT WAY To SET PSVs ACCOUNTING FOR LOOP SEAL CLEARXNG XN ANALYSIS DETECTXNG LOSS OF LOOP SEAL INPAGT 0F L00P SEAL Loss oN LOCA ANALYsxs (TMI ITEN II.K.3. 2}

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DISABLED VALVE

SUMMARY

OE ANALYTICALRESULTS 0

DETERNxwlsTlc o

ATMS - MEsTxwGHousE o

ATMS -

PG&E o

NRC CowcEaNs Pacltlc Oaa and Electric Company

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DETERMINISTIC ANALYSIS PREvxousLY DxscussED wxTN NRC AT JULY 20, 1989 MEETxNG ANALYZED LOSS OF LOAD, LOCKED ROTOR EVENTS O

FSAR ASSUMPTXONS 0

OVERPRESSURE PROTECTXON RESULTS 1104 DESIGN PRESSURE LXMXTS MET (LOSS OF LOAD) 1204 DESXGN PRESSURE LXMXTS MET (LOCKED ROTOR)

VALXDXTY OF RESULTS CONFXRMED RELATXVE To MCAP-10105

,12 Pacltlc Oaa and Electric Company

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PGRE CONFIRMATION PRE"XMXNARY ANALYSXS ASSUMXNG:

TWO SAFETY VALVES AVAXLABLE NOMXNAL SETPOXNT PLUS 14 1 '

SEC.

DELAY TO CLEAR LOOP SEAL 0.1 sEC.

DELAY F0R FULL OPEN THE PEAK PRESSURE XS 2745 PSXA FOR VANTAGE 5 FUEL l3 Pacltlc Oaa!nd Electric Company

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WESTINGHOUSE ANALYSIS ATWS RULE COMPLIANCE CONCLUSIONS TARGET XS TO HAVE ATWS CDF NEAR OR BELOW 1 X 1Q 5 CDF CALCULATED WXTH 2 OF 3 SAFETY YALVES AVAXLABLE (NO CREDXT FOR ANY PORVS)

MEETS THXS GOAL O

BASXS FOR ATWS RULE XS SATXSFXED Pacltlc Oaa and Elactrlc Company

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PG&E ATMS ANALYSIS USrNG LTSP DCPRA NOBEL 0

ONE SAFETY VALVE DlSABLED, NO PORVS

~ 0 SMALL LOCA FOR RCS PRESSURE

< 3200 lSX CORE DAMAGE FOR RCS PRESSURE

>> 3200 PSX 0

ATWS CORE DAMAGE FREQUENCY 1.6 E-6 15 paclflc Oae and Electric Coepany

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NRC CONCERNS FROM DECEMBER 5, 1989 MEETING (ADDRESSED IN ENCLOSURE 2)

SUMMARY

WHAT ARE THE UNCERTAXNTXES AFFECTING SAFETY VALVE PERFORMANCE, INCLUDING THE RECENT SETPOlNT SHIFT REPORTED BY WESTINGHOUSE?

LIFT POINT PRESENCE OF LOOP SEAL UP TO 84 VARXATXON 16 Paclflc Oaa and Elacfrlc Company

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WHAT XS THE BEST MAY TO SET SAFETY VALVES>

ACTUAL LIFTING OF YALVE WITH APPROPRXATE MEDIUM IDENTXCAL CONFIGURATION IDENTXCAL ENVIRONMENT BEAUMONT TEST FACXLITY 17 Paclllc Gaa and Electric Coepany

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HOW SHOULD THE OVERPRESSURE ANAl.YSXS DEAL MXTH CLEARING OF THE LOOP SEALS.

WESTINGHOUSE EVALUATXONS CONSERVATXVE MANNER WCAP-10105 EXPLxcxTLY TREATED LOOP SEAL DELAY WCAP-10105 SHOWED OVERPRESSURE REOUXRENENTS MET RESULTS VALID FOR DISABLED SXTUATION P68(E ANALYTxcALCQNFIRMATIQN 18 Peclflc Oae an(f Etectflc Col(pany

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flOW CAN THE LOSS OF lOOp DETECTED (HIGH TAIl. pIpE TEMPERATURE OCCURS AFTER THE LOOP SEAL IS LOST)?

SONIC ALARMS HIGH TAIL PIPE TEMPERATURE PRT LEVEL CHANGES RCS PRESSURE CHANGES 19 Paclflc Oaa and Electric Company

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WHAT XS THE IMPACT OF LOOP SEAL LOSS ON THE LOCA ANALYSXS REQUIRED TO SATXSFY TMI ITEM II.K.3.2 POTENTIAL INCREASED PROBABXLITY oF SBLOCA DISABLING DXRECTLY REDUCES THIS PROBABXLXTY 20 Paclflc Oaa and Electric Company

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LAR JusTXPXES OPERATxoN wxTN QNF.

PSV IN0PERABLE" ANn DxsABl.ED ANALVSES ADDREss FSAR CNAPTER 15 ANn ATWS CQNsxDERATxoNs LAR PROVXDES IMPORTANT SAFETY CAPABXLXTXES 21 Paclflc Oao and Eltctrlc Company

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