ML20138M876

Forwards Updates to 850717 & 24 Responses to 850617 & 24 Ltrs Re 850609 Incident

ML20138M876
Person / Time
Site:	Davis Besse
Issue date:	10/18/1985
From:	Palladino N NRC COMMISSION (OCM)
To:	Markey E HOUSE OF REP., ENERGY & COMMERCE
Shared Package
ML20138M880	List: ML20138M876
References
NUDOCS 8511040463
Download: ML20138M876 (35)

Text

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[(#a nec%[o, UNITED STATES i

NUCLEAR REGULATORY COMMISSION i

r w Assimo TON. D. C. 20555 l

,[

Z October 18, 1985 CHAIRMAN i,

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1 The Hororable Edward J. Markey, Chairman i

Subcommittee on Energy Conservation and Power i

Committee on Energy and Comerce United States Hcuse of Representatives i

Washington, D.C.

20515 i

Dear Mr. Chairman:

In our letters dated July 17 and July 24, the Commission responded to your letters of June 17 and June 24 concerning the Davis-Besse incident. As we noted at the time, some of our responses were preliminary.

Further information is now available in a number of areas. We are providing the

)

anciosed updated responses in order to keep the Subcommittee currently i

informed in this area.

J Sincerely, C

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Nunzio J.JPalladino i

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Enclosures:

As stated cc: The Honorable Carlos J. Moorhead 1

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l 8511040463 851010 PDR COMMS NRCC l

CORRESPONDENCE PDR i

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ENCLOSURE 1 UPDATES To REPRESEtiTATIVE MARKEY'S GUEST 10NS OF JUNE 17, 1985

CUESTION 3.

HAD THE ELECTRIC DRIVEN PUMP NOT MANUALLY STARTED Dil51NG THE DAVIS-BESSEINCIbENT,ANDHADTHEAUXILIARY FEEDWATER SYSTEM NOT BEEN RESTORED, WOULD THERE HAVE BEEN A SEVERE CORE DAMAGE ACCIDENT.

IF YES, HOW LONG WOULD IT HAVE TAKEN BEFORE FUEL DAMAGE OCCURRED?

ANSWER SUPPLEMENTAL INFORMATION IS PROVIDED AS FOLLOWS:

CALCULATIONS ARE CURRENTLY EEING PERFORMED, USING ADVANCED, STATE-OF-THE-ART COMPUTER CODES, TO EXAMINE THE JUNE 9, 1985 DAVIS-BESSE EVENT.

THESE ANALYSES SIMULATE THE OPERATOR ACTION, AS SPECIFIED IN THE DAVIS-BESSE EMERGENCY PRCCEDURES, FOR THE SITUATION WHERE FEEDWATER IS NEVER RECOVERED.

lHE OPERATUM ACTIONS SIMULATED WERE OPENING THE PORV AND THE HIGH POINT VENTS, AND INITIATING FULL MAKEUP FLOW.

AS NOTED IN NUREG-1154, THE SHIFT SUPERVISOR DID NOT INITIATE MU/hPI COOLING AS SPECIFIED BY THE EMERGENCY PROCEDURES.

WHILE THE SHIFT SUPERVISOR WAS AWARE THAT MU/HPI COOLING MIGHT HAVE BECOME NECESSARY, HE WAITED FOR THE EQUIPMENT OPERATORS TO RECOVER THE AUXILIARY FEEDWATER SYSTEM.

SINCE AUXILIARY FEEDWATER WAS RECOVERED IN A TIMELY MANNER, MU/HP! COOLING WAS NEVER NECESSARY.

HOWEVER, NUREG-1154 DOES NOTE THAT THE SHIFT SUPERVISOR WOULD HAVE INITIATED MU/HPI COOLING IF "!T COMES TO THAT."

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CUESTION 3. (CONTINUED) IN PERFORMING TRE ANALYSIS OF THE DAVIS-BESSE EVENT, THE SPECIFIED OPERATOR ACTIONS IN THE EMERGENCY PROCEDURES WERE SIMULATED TO BE INITIATED AT VARICUS TIMES FOLLOWING STEAM GENERATCR DRYOUT.

THE RESULTS OF THE ANALYSES PERFCRMED TO DATE It!DICATE THAT THE OPERATOR HAD AT LEAST TWENTY MINUTES FOLLOWING STEAM GENERATOR DRYOUT TO FREVENT SEVERE FUEL DAMAGE.

DOCUMENTATION OF THE i

ANALYSIS RESULTS IS FROVIDED IN THE ATTACHED REFORT ENTITLED J

"RAFID-RESFONSE ANALYSIS OF ThE DAVIS-BESSE LcSS-OF-FEEDWATER l

I EVENT ON JUNE 9, 1985," SEPTEMBER 1985.

IN ADDITION, OUR FREV:GUS PESPONSE, WHICH WAS BASED UFON SIMPLIFIED MASS AND ENERGY CALCULAT!GNS, ESTIMATED FUEL DAMAGE AT AFFROXIMATELY ONE AND ONE-HALF (li) TO TWC (2) HOURS, IF l

EEDWATER WAS NEVER FECOVERED AND NO MITIGATI'/E OPERATCR ACTION WAS TAKEN.

PRELIMINARY COMPUTER CALCULATIONS INDICATE THAT CORE UNCOVERY WOULD HAVE CCCURRED AT AFFROXIMATELY EIGHTY MINUTE?.

WF ESTIMATE THAT SEVERE CODE DAMAGE WOULD CCCUR AFFRCXIMATELY THIRTY MINUTES LATER.

THUS, THESE COMPUTER CALCULATIONS CONFIRM CUR PREVIOUS EST! MATES.

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OUEST10N L1,

]ACCORDINGTOPPELIMINARY INFORMATION PROVIDED BY l

THE NRC STAFF, THE EMERGENCY CORE COOLING SYSTEM

-(ECCS.: AT DAv!S-BESSE IS UNABLE TO FUNCTION PROPERLY

)

WHEN THE PRIMARY COOLING SYSTEM !S PRES $URIZED IN i

EXCESS OF 1,600 POUNDS PER SQUARE INCH.

(IF T *S IS TRUE, WHY DID THE OPERATORS INITIATE THE ECCS DURING THE DAVIS-BESSE INCIDENT AND WHY DID THEY j

TERMINATE ECCS)?

WHAT OTHER PRESSURIZED WATER REACTORS (PWR) HAVE HIGH PRESSURE INJECTION PUMPS i

WHOSE SHUT 0FF HEAD IS BELOW THE SETPOINT OF THE CODE l

SAFETY VALVES?

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ANSWER, l

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IN S';PPLEMENT TO OUR PREVIOUS RESPCNSE, THE CPERATOR INtTIATED l

l ECCS FLOW BECAUSE REACTOR COOLANT SYSTEM PRESSURE WAS DECREASING i

AS A CONSECUENCE OF THE PE-INI*lATION OF AFW FLOW.

SHORTLY l

AFTER INITIATION OF ECCS FLOW REACTOR COOLANT PRESSURE WAS I

i RESTORED ABOVE THE 1830 PSIG WHICH IS PROVIDED BY THE ECCS t

l SYSTEM IN PIGGY-BACK OPERATION.

THEREFORE, THE OPERATOR i

TERMINATED OPERATION OF ECCS PUMPS.

THIS ISSUE IS DISCUSSED IN i

l MORE DETAIL AT PAGE 3-11 0F NUREG-1154.

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CUESTION 8, PR 7

OVIDE A HISTORY OF ANY PREVIOUSLY NCTED DIFFICULTIES OBSERVED WITH THE MAIN CR AUXILIARY JEEDWATER SYSTEMS AT DAVIS-BESSE S!flCE 1979 AND ANY ACTIONS TAKEN IN RESPONSE,

ANSWER, THE FOLLOWING IS PROVIDED AS AN UPDATE OF OUR PREVIOUS RESPONSE.

AUXILI ARY FEEDWATER SYSTEM P!PE RESTRAINTS THE LICENSEE HAS ALMCST COMPLETED A WALKDOWN AND ANALYSIS OF THE AFWS PIPE RESTRAINTS. BASED Of4 A PARTIAL REVIEW OF THE FINDif4GS Ev PEGI0ft !!! AND sui 3E0 VENT DISCUSSIONS WITH THE LICENSEE, TED HAS EXPANDED ITS WALADOWN TO TWO OTHER SAFETY SYSTEMS SELECTED BY THE NRC.

THE PESULTS OF THIS EXPAf4DED WALKDOWf4 WILL BE EVALUATED BY THE NRC, MAIN FEEDWATE: SYSTEM AS PART OF THEIR INVESTIGATIOf4 0F THE JUNE 9 EVENT, THE INVEST!GATif4G TEAM IDENTIFIED A LIST OF EQUIPMENT FAILURES TO BE ADDRESSED BY THE LICEriSEE If4CLUD!f1G CONTROL PROBLEMS WITH THE MAIN FEEDWATER PUMPS (MFPS).

THE LICEflSEE HAS IDEllTIFIED Af!D CORRECTED THE EQU!PMEtli FAILUDE THAT CAUSED THE fluMBEP 1 MFP TO TRIP DUR!ftG JUf4E 9 (C0f1 TROL BOARD CIPCU!T FA! LURE).

THE LICEtJSEE IS C0f4TlfiUlf4G TO EVALUATE THE CVERALL RELI AE!LITY PPOBLEMS WITH THE MFW SYSTEM.

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CUESTION 9,

--WHAT ADE THE GENERIC IMPLICATIONS AND LESSONS LEARNED FROM THE DAVIS-BESSE INCIDENT?

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ANSWER, OUP PREVIOUS ANSWEP IS UPDATED, AS FOLLOWS:

{

THE NRC HAS DETERMINED THAT THERE ARE NO GENERIC ISSUES OF IMMEDIATE SAFETY SIGN!FICANCE RESULTING FROM THE DAVIS-BESSE f

INCIDEflT.

A COPY OF THIS DETERMINATION DATED AUGUST 19, 1985 1

FROM H. THOMPSON, JR. TO I, SPE!S IS PROVIDED IN ENCLOSUDE 3.

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SEVERA. ISSUES WERE IDENTIFIED AS CANDIDATES FOR NEAR-TERM i

j GENEPic ACTION AND THEY ADE CURPENTLY BEING EVALUATED BY THE i

STAFF TO DETERMINE IF LICENSEE ACTION, ON A GENERIC BASIS, IS NECESSADY.

IHESE ISSUES Ar~.

[

i (A)

POTENTIAL INAE!LITY TO REMOVE REACTOP DECAY HEAT DUE TO CUESTIONABLE RELIABILITY OF THE AUXILIAPY i

l FEED SYSTEM AS IT PELATES TO DISCHARGE VALVE FAILURES, DIFFICULTIES IN RECOVERING AUXILIARY l

l FEEDWATER PUMPS, OR FAILURES IN STEAM LINE BREAK MIT!GATI0tt SYSTEM.

)

(B)

ADEQUACY OF EMERGENCY PROCEDURES, OPERATOR TPAINING AND PLANT M0fl!TORING SYSTEMS FOR DETERMINING NEED TO i

l INITIATE FEED AND BLEED COOLING FOLLOWING t.0SS OF STEAM GENERATOR HEAT SINK; i

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QUESil0N 9, (G94TINUEDI

• l (C)

PHYSICAL SECURITY SYSTEM CONSTPAlf!TS WHICH COULD DENY L

TIMELY CPERATOR ACCESS TO VITAL ECUIPMEt4T AND lNHIBIT r

OPERATOP FC.CM PERFORMING LOCAL MANUAL OPERATI0t!S CALLED FOR IN EMERGENCY PROCEDURES.

t (D)

ADECUACY OF THE ENGINEEDING BASIS AND PROCEDURES FOR

[

SETTING TOROUE SWITCH AND TOROUE BYPASS SWITCH SETTINGS FCR SAFETY PELATED VALVES.

TWE STAFC is STILL EVALUAT!NG THE DAV.S-BESSE !NCIDENT TO CETEPMINE IF THEPE ASE POTENTIAL GENEPIC ISSUES OF A LONG-TERM i

NATURE.

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CUESTION 10:

jNLIGHTOFTHEDAVIS-BESSEINCIDENT,

!S THEPE ANY INFORMATION OF WHICH THE COMMISSICN IS AWARE THAT WOULD LEAD IT TO PECONSIDEQ ANY OF THE POSITIONS TAKEf! BY THE NPC e*AFF, OR [N ANY OF ITS OWN DECISIONS, IN THE TVI DESTART PROCEEDING" FOP EXAMPLE, IN THE TMI PFe* ART PROCEEDING.

THE NRC STAFF CONTENDED THAT A TOTAL LOSS OF CEEDWATER WAS BEY 0flD THE DES!GN BASIS AND, THEREFCPE, CAPABILITY TO ACCOMPLISH FEED AND BLEED WAS NOT CEQUIPED.

ANSWER.

THECE IS NO INFOPMATICN AS A DESULT OF THE " AVIS-EESSE INCIDENT OF WHICH THE !*AFF IS AWAFE THAT WOULD LEAD !T TO PEC0flSIDED Af'v 0F THE POSITIONS TAKEN BY THE STAFF THAT WCULD AFCECT COMM!**!P" DECIS10flS IN THE TMI FESTART PPCCEEDING.

A PDELIMINARY REVIEW CC THE CACT F:ND!?tG TEAM DEPnDT (NUREG-ll54) HA! FFCDUCED NO INFORMATIOff WHICH WOULD CHAf!GE THE STAFF POSITICf'.

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I QUESTION 11. -LIST THOSE IMI ACTION PLAN ITEMS DIRECTLY RELEVANT TO THE DAVIS-BESSE INCIDENT AND

. PROVIDE THE CURRENT STATUS OF COMPLIANCE, j

SPECIFICALLY, INCLUDED IN YOUR RESPONSE 1

SHOULD BE A DETAILED EXPLANATION OF WHAT ACTIONS i

WERE TAKEN AND WHEN IN RESPONSE TO THOSE TMI i

ACTION PLAN ITEMS CONCERNING THE AUXILIARY l

FEEDWATEP SYSTEM AND P! LOT OPERATED RELIEF VALVE, YOUR RESPONSE SHOULD CLEARLY IDENTIFY THOSE PELEVANT ACTION PLAN ITEMS THAT HAVE NOT BEEN FULLY IMPLEMENTED AND EXPLAIN WHEN EACH ITEM WAS ORIGINALLY SCHEDULED TO HAVE BEEN COMPLETED AND THE REASON IT REMAINS OUTSTANDING.

nswER.

ONE ITEM IN OUR PREVIOUS PEPORT IS UPDATED AS FOLLOWS:

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'l OUEST10N 11,_

-(CONTINUED) _

l.D.1 CONTROL-ROOM DESIGN CONSISTENT WITH CUP REVIEWS CONFIRMATORY ORDER ON SUPPLEMENT 1 TO NUREG-0737, THE LICENSEE I

SUBMITTED A

SUMMARY

REPORT AND PROPOSED A l

1 SCHEDULE FOR IMPLEMENTATION BY THE I

COMPLETION OF THE 7TH REFUELING OUTAGE ABOUT 4 YEARS FROM NOW.

THE i

SUEMITTALS WERE REVIEWED I

BY THE STAFF AND A PRE!MPLEMENTATION AUDIT WAS SENT TO THE LICENSEE NOTING A NUMBER OF DEFICIENCIES.

I THE LICENSEE MUST NOW RESPOND TO THE STAFF PEPORT.

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CUESTION 14

- ACCORDING TO PRELIMINA Y INFORMATION PROVIDED BY R

_ THE NRC STAFF, THE LICENSEE HAS RESISTED NRC

, RECOMMENDATIONS TO IMPRCVE THE RELIABILITY AND CAPACITY OF THE AUXILIARY FEEDWATER SYSTEM AT CAVIS-BESSE.

IS THIS TRUE AND IF SO, WHY DID NRC NOT REQUIRE THAT IMPPOVEMENTS BE MADE?

ANSWER IN MODIFICATION CF GUR PREVIOUS PESPONSE, THE LICENSEE PAS INDICATED THAT STEPS FAVE BEEN TAKEN TO COMPLETE THE INSTALLATION l

OF THE NEW PUMP-ON AN ACCELERATED SCHEDULE, IHE LICENSEE'S TARGET IS TO COMPLETE THE WOPK PRICR TO RESTART, I

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QUESTION 16,

~ ACCORD: NG TO A JUNE 13, 1985 MEMORANDUM FROM WILLIAM J. DIRCKS, EXECUTIVE DIRECTOR FOR OPERATIONS, TO THE COMMISSION, THE LICENSEE FAILED TO PROVIDE ACCURATE INFORMATION TO THE NRC ABOUT THE DAVIS-BESSE INCIDENT.

THE MEMORANDUM STATES:

"IT BECAME CLEAR THAT THE INITIAL WRITTEN DESCRIPTION OF THE EVENT WAS INCOMPLETE AND THAT A NUMBER OF POTENTIALLY IMPORTANT DETAILS WERE NOT INCLUDED."

WHAT INFOPMATION WAS INCOMPLETE AND WHAT DETAILS WERE NOT INCLUDED IN THE LICENSEE'S INITIAL REPORT TO NRC?

WHAT IS THE REASON FOR THIS FAILUPE AND WHAT, IF ANY, REPORTING REQUIREMENTS WERE VIOLATED?

ANSWER.

AS A SUPPLEMENT TO OUP ORIGINAL PESPONSE, I/, ELE 3.1 CI NUREG-1154 PROVIDES A CHPON0 LOGICAL SEQUENCE OF EVENTS.

A COPY OF NUREG-1154 IS PROVIDED IN ENCLOSURE 3.

CUESTION 17,

-WHAT AC710r!S WILL NPC REQUIRE PDICR TO PESTAPT OF DAVIS-EESSE.

SPECIFICALLY, WILL NPC PECUIDE

.THAT THE JANUARY 1985 LICENSE Cor:DI?!ON COMMITT!f'G TO Afl ADDITIONAL AUY!LIARY FEECWATED PUPP SE FULCILLED PRIOR TO RESTAPT.

IF NOT, PLEASE EXPLA!!' WHY,

ANSWER, Or' AUGUST 14, 1985, THE STAFF PEOUESTED TCLEDO EDISOf! TO SUBPIT, PUPSUAf;T TO 10 CFR 50.54(F), PLAf!S AND PRCGPAMS TO RESOLVE STAFF CCf1CE NS PEL AT!NC-TO THI S EVEf!T.

INCLUDED IN THESE CCNCERNS IE THE NEED FCP A DIVERSE AFW CUMP.

THE STAFF WILL C0f! SIDED THE LICEf:SEE'S RESPONSE Pol 0R TO MAKING A DECIS!ON CONCERfiltG PCSTAPT OF THE DAVIS-EESSE FACILITY, WE UNDEPSTAND THAT THE LICENSEE IS MOVIt!G PAPIDLY ON THE ISSUE AND EXPECTS TO COMPLETE If!STALLATICfl 0F THE THIRD PUMP PRIOR TO PESTART.

A COPY OF THE AUGUST 14, 1985 10 CFP 50.54(F) LETTED IS PROVIDED IN ENCLOSUPE 3.

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CUESTION 18

_ LIST ALL PENDING REQUIREMENTS AND LICENSING

- ACTIONS RELATING TO SYSTEMS AND COMPONENTS

, INVOLVED IN THE DAVIS-BESSE EVENT.

i ANSWER l

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1 IN MODIFICATION OF OUR PREVIOUS ANSWER THE FOLLOWING

^ tAOyJO&T A.

R,ELIEF VALVE / SAFETY VALVE TESTING, NUPEG-0737, i m..

..J 1.

l THERE WERE NO MODIFICATIONS NECESSARY ON THE PORV AS A a

RESULT OF THE EPRI TEST PROGRAM.

MODIFICATIONS TO THE SAFETY VALVE (RELOCATION AND LOOP-SEAL) WERE COMPLETED IN 1982.

REGARDING THE POST-IMPLEMENTATION REVIEW, THE LICENSEE HAS SUBMITTED THE RECUIRED TESTING REPORTS.

THE LICENSEE f

HAS PARTIALLY RESPONDED TO CUR QUESTIONS AND A FULL RESPONSE l

IS EXPECTED IN THE NEAR FUTURE.

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LICENSEE CONDITION 2.C.3(T) TO OPERATING LICENSE, NPF-3.

IHE LICENSEE IS REQUIRED TO INSTALL A NEW, STARTUP FEEDWATER PUMP BEFORE STARTUP FROM THE NEXT REFUELING OUTAGE.

THE i

LICENSEE HAS ACCELERATED INSTALLATION OF THIS PUMP AND j

PRESENTLY ANTICIPATES COMPLETION PRIOR TO RESTART.

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i CUESTION 18, 4CONTINUECi l C.

AFW SYSTEM TECHNICAL SPECIFICATIONS THE LICENSEE HAS SUBMITTED PROPOSED TECHNICAL SPECIFICATIONS AS RECUIRED UNDER NUREG-0737, ITEM II.E.1.1.

IHESE HAVE BEEN PEVIEWED AND CERTAIN CHANGES (INVOLVING THE FLOW VERIFICATION TEST AND THE TEST AND OPERATING PROCEDURES) HAVE BEEN REQUESTED BY THE STAFF.

THE LICENSEE WILL PROVIDE A REVISED PROPOSAL BY THE END OF SEPTEMEER 1985.

D.

DETAILED CONTROL ROOM DESIGN REVIEW

SUMMARY

REPORT S*JPPLEMENT 1 TO NUREG-0737 REQUIRED A DETAILED CONTROL ROOM DESIGN REVIEW (DCRDR)

SUMMARY

REPORT TO BE SUBMITTED.

THE

SUMMARY

REPORT HAS BEEN REVIEWED EN THE STAFF AND A LIST OF DEFICIENCIES SENT TO THE LICENSEE.

(ALSO SEE ANSWER TO QUESTION 11).

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7LEASEPROVIDETHEFOLLOWINGINFORMATIONFOREACH P

QUESTION 20.

YEAR SINCE 1980:

E)

THE NUMBER OF ALL ENFORCEMENT ACTIONS INCLUDING A BRIEF DESCRIPTION OF THE i

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ISSUES, THE SEVERITY CLASSIFICATION AND 1

j ANY FINE LEVIED.

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j ANSWER.

IN ADDITION TO THE ENFORCEMENT CASES LISTED IN OUR PREVIOUS RESPONSE, ANOTHER ENFORCEMENT ACTION WAS ISSUED TO davis BESSE IN JULY, 1985.

A NOTICE OF VIOLATION AND PROPOSED I

IMPOSITION OF CIVIL PENALTY IN THE AMOUNT OF $100,000 WAS ISSUED TO TOLEDO EDISON COMPANY ON JULY 12, 1985 FOR VIOLATIONS INVOLVING 1) THE FAILURE TO FOLLOW A PROCEDURE THAT REQUIRED j

RESPONSIBLE INDIVIDUALS TO BE NOTIFIED AT THE TIME THE SECURITY AND FIRE PROTECTION COMPUTER WAS SHUT DOWN, 2) THE FAILURE OF A i

NON-LICENSED OPERATOR TO MONITOR PIPING STATUS IN THE AUXILIARY FEEDWATER PUMP AREA BECAUSE HE WAS SLEEPING AND

3) THE FAILURE TO LIMIT THERMAL POWER AS REQUIRED BY TECHNICAL SPECIFICATIONS WHEN THE REACTOR COOLANT FLOW RATE DECREASED.

THE LICENSEE PAID THIS PROPOSED CIVIL PENALTY ON AUGUST 12, 1985.

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i ENCLOSURE 2 UPDATES To REPPESENTATIVE MARKEY'S CUESTIONS OF JUtiE 27, 1985 f

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l QUEST!nN 7

__AT THE BEGINNING OF THE DAVIS-EESSE INCIDENT ON JUNE 9, 1985, HOW MANY OPERATORS AND WHICH ONES WERE IN THE CONTROL ROOM?

DURING THE INCIDENT i

HOW MANY OPERATORS WERE OUTSIDE THE CONTROL ROCM OR STATIONED POST, WHAT WERE THEIR TITLES, i

WHY DID THEY LEAVE THE CONTROL ROCM OR STATICNED POST, AND SPECIFICALLY WHAT ACTIONS WERE ACTUALLY ACCOMPLISHED OUTSIDE OF THE CONTROL i

ROOM.

111 LIGHT OF THOSE ACTIONS THAT NEEDED TO i

f BE'TAKEN FROM OUTSIDE THE CONTROL ROOM, IS DAVIS-BESSE MEETING GENERAL DESIGN CRITERION 19 I

WHICH STATES:

'A CONTROL ROOM SHALL BE PROVIDED FROM WHICH ACTIONS CAN BE TA<EN TO OPERATE THE f4UCLEAR POWER UNIT SAFELY UNDER NORMAL C0tIDITIONS AND TO Malt 4TAlti IT IN A SAFE CONDITION UNDER ACCIDENT CONDITIONS...."

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ANSWER.

UPDATED ltlFORMATION IS PROVIDED, AS FOLLOWS:

AN NRC INVESTIGATING TEAM WAS SENT To THE DAVIS-BESSE PLANT TO INVESTIGATE THE JUNE 9, 1985, INCIDENT.

THE REPORT OF THIS TEAM WAS ISSUED IM JULY 1985 AS NUREG-1154, " LOSS OF MAlti AND AUXILIARY FEEDWATER EVENT AT THE DAVIS-BESSE PLANT ON JUNE 9, l

1985."

DETAILED INFORMATION REGARDING OPERATOR LOCATIONS AND 1

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GUESTION 7,

_(CONTINUED) _

ACTIONS DURING,THE EVENT IS PROVIDED IN CHAPTERS 3 AND 6 0F NUREG-1154, AND IS BRIEFLY SUMMARIZED BELCW.

AT THE TIME OF THE DAVIS-BESSE INCIDENT ON JUNE 9, 1985, THERE WERE 10 MEMBERS OF THE OPERATING SHIFT ON DUTY AT THE PLANT.

THESE INDIVIDUALS ARE AS FOLLOWS:

1 SHIFT SUPERVISOR (LICENSED SENIOR OPERATOR) 1 ASSISTANT SHIFT SUPERVISOR (LICENSED SENIOR OPERATOR) 1 PPIMARY-SIDE OPERATOR (LICENSED OPERATOR) 1 SECCNDARY-SIDE OPERATOR (LICENSED OPERATOR) 4 EOL'!PMENT OPERATORS (UNLICENSED) 1 AUXILIARY UPEPATOR (UMLICENSED) 1 ADMINISTRATIVE ASSISTANT IN ADDIT!CN TO THE PEGULAR SHIFT MEMBERS NCTED ABCVE, A SHIFT IECHNICAL ADVISOR (SIA) ALSO WAS PRESENT AT THE PLANT, BUT NOT AS A .EMSER OF THE SHIFT CREW.

IHE SIA WORKS A 24-HOUR SHIFT AT DAVIS-3 ESSE AND IS TO EE AVAILABLE WITHIN 10 MINUTES TO PR0vlDE ADVICE TO THE OPERATING CREW.

THE INCIDENT INITIATED AT 1:35 A.M.

AT THAT TIME THE POSITIONING OF THE SHIFT PERSONNEL AND THE STA WAS AS FOLLOWS:

SHIFT SUPERVISOR - IN HIS OFFICE ADJACENT TO THE CONTROL ROOM.

_ _. - =

I CUESTION 7,

__ (CONTINUED) __

ASSISTANT, SHIFT SUPERVISOR - HAD JUST RETURNED TO THE CONTROL ROCM FPOM THE KITCHEN.

1 PRIMARY-SIDE OPERATOR - AT THE OPERATOR'S DESK IN THE CONTROL ROOM.

I SECONDARY-SIDE OPERATOR - IN THE KITCHEN ON A BREAK.

EaulPMENT OPERATOR - IN THE KITCHEN ON A BREAK, 3 EculPMENT OPERATCRS - AT STATIONS IN THE PLANT.

AUXILIARY OPERATOR - AT STATION IN THE PLANT.

ADMINISTRATIVE ASSISTANT - IN HER OFFICE ADJACENT TO THE CONTROL ROOM.

SHIFT IECHNICAL ADVISOR - ASLEEP IN THE QUARTERS PROVIDED FOR ON-DUTY STAS.

4 THE INCIDENT BEGAN WITH A TRIP OF THE NO. 1 MAIN FEEDWATER PUMP TURBINE.

THE " WINDING DOWN" 0F THE TURBINE AS IT DECREASED SPEED PROVIDED AN AUDIBLE SIGNAL TO SHIFT PERSONNEL THAT SOMETHING WAS NOT NORMAL.

THE SHIFT SUPERVISOR AND THE ADMINISTRATIVE f

ASSISTANT IMMEDIATELY LEFT THEIR OFFICES AND ENTERED THE CONTROL i

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00ESTION 7.

-(CONTINUED) _

i POCM.

THE SECONDARY-SIDE OPERATOR PAN TO HIS STATION IN THE i

CONTROL POCM.

TWO OF THE EQUIPMENT OPERATORS PROCEEDED DIRECTLY TO THE CONTROL ROOM AND WERE JOINED THEPE BY A THIPD EQUIPMENT CPERATOR.

THE ADMINISTPATIVE ASSISTANT NOTIFIED THE STA CF THE INCIDENT BY TELEPHONE.

THE STA ARRIVED IN THE CONTROL 000M ABOUT 15 MINUTES AFTER EVENT INITIATION, THUS, AT 1:35 A.M. WHEN i

THE INCIDENT BEGAN, THE ASSISTANT SHIFT SUPERVISOR AND THE PRIMARY-SIDE OPEPATOR WEPE IN THE CONTROL ROOM PROPER.

WITHIN I

SECONDS OF THE INCIDENT INITIATION, THE SHIFT SUPERVISOR, THE SECONDARY-SIDE OPERATOR AND THE ADMINISTRATIVE ASSISTANT WERE ALSO IN THE CONTROL ROOM.

THEY WERE JOINED SEVERAL MINUTES LATER BY THREE OF THE EQUIPMENT OPERATOPS AND ABOUT 15 MINUTES LATER EY THE SHIFT IECHNICAL ADVISOR.

ABOUT 30 SECCNDS AFTER THE TRIP OF THE NO. 1 MAIN FEEDWATEP PUMP TUPBINE, BOTH OF THE MAIN STEAM ISOLATION VALVES CLOSED.

THIS SHUT OFF THE STEAM SUPPLY TO BOTH OF THE MAIN FEECWATER PUMP TURBINES AND THE NO 2 MAIN FEEDWATER PUMP TUPBIFE BEGAN T0 i

COAST DOWN.

HOWEVER, IT STILL PPCVIDED ADEQUATE FEEDWATEP FLOW FOR ANOTHER 4i MINUTES.

IHE OPEPATORS THEN TOCK ACTION TO PLACE THE AUXILIARY FEEDWATEP PUMPS IN SERVICE, BUT BOTH PUMP TUPBINES TRIPPED ON OVERSPEED.

ALSO, THE AUXILIAPY FEEDWATER SYSTEM CONTAIMMENT ISOLATION VALVES FAILED TO RE-OPEN AFTEC BEING INADVERTENTLY CLOSED DUE TO AN OPERATOR ERPOR.

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CUESIION 7.

-- ( C ONT I N UED) :

AFTER DELIBERATING THIS PROBLEM FOR SEVERAL MINUTES, AT ABOUT 9 MINUTES INTO THE INCIDENT, TWO OF THE EQUIPMENT OPEPATORS WERE SENT TO THE AUXILIARY FEEDWATER PUMPS TO MANUALLY RESTORE THE PUMPS TO SERVICE; TWO OTHER ECUIPMENT OPERATORS WERE DIPECTED TO MANUALLY OPEN THE AUXILIARY FEEDWATEP ISOLATION VALVES; AND THE AUXILIARY OPERATOR WAS DIRECTED TO PLACE THE AUXILIARY STEAM BOILER IN SERVICE.

AT THIS SAME TIME, THE ASSISTANT SHIFT SUPERVISOR LEFT THE CONTROL ROOM TO PLACE THE START-UP FEEDWATER PUMP IN SERVICE, i

A* ABOUT 16 MINUTES It1TO THE It4CIDENT, THE START-UP FEEDWATER PUMP BEGAtt SUPPLY!flG FEEDWATER.

IWO MINUTES LATER, THE NO. 2 AUXILI APY FEEDWATER TRAlf4 BECAN SUPPLYING FEEDWATER, FOLLOWED 1 MINUTE LATER BY THE NO. 1 AUXILIARY FEEDWATE7 TRAlti.

CONTROL OF THE NO. 2 AUXILIARY FEEDWATER PUMP WAS TAKEN OVEP BY THE C0tlTROL ROOM UNDER MANUAL C0tlTROL RATHER THAN AUTOMATIC.

THE NO. 1 AUXILIARY FEEDWATER PUMP WAS CPERATED LOCALLY BY THE ECUIPMEf1T OPERATOPS WHO WERE IN COMMut11 CATION WITH THE CONTROL ROOM, BY 2:04 A.M., ABOUT 30 MINUTES AFTER THE INITIATION 0F THE INCIDENT, THE PLANT CONDITIONS WERE ESSENTIALLY STABLE.

THE STAFF EVALUATION OF THE INCIDENT AtlD THE ADEOUACY OF THE CONTPOL POOM INSTRUMENTATIOM AtiD CONTROLS HAS NOT YET BEEN COMPLETED.

THUS, WE ARE UNABLE AT THIS TIME TO PROVIDE A DEFINITIVE RESPONSE REGARDING WHETHER OR NOT DAVIS-BESSE MEETS t

QUESTION 7

-(CONTINUED) GENERAL DESIGN. CRITERION 19. HOWEVER, THE PRELIMINARY STAFF EVALUATION IS THAT DAVIS-3 ESSE IS IN CONFORMANCE WITH GDC 19.

THE DIFFICULTIES EXPERIENCED DURING RESPONSE TO THE INCIDENT APPEAR TO HAVE BEEN DUE TO OPERATOR ERROR, BASIC HUMAN FACTORS DEFICIENCIES IN THE CONTROL ROOM DESIGN, AND EQUIPMENT MALFUNCTIONS, t

i i

l i

CUESTION 8.

kCCORDINGTOTHENRCSTAFF, FEED AND BLEED PROCEDURES FOR EMERGENCY COOLING WERE INITIATED dURING THE DAVIS-BESSE INCIDENT.

NUMEROUS NRC MEMORANDA STATE THAT FEED AND BLEED EMERGENCY COOLING IS NOT CAPABLE OF AVERTING CORE DAMAGE AT DAvlS-BESSE.

WHY THEN ARE FEED AND BLEED PROCEDURES PART OF THE NRC APPROVED EMERGENCY OPERATING PROCEDURES FOR THIS PLANT?

IN RESPONDING j

TO THIS QUESTION, PLEASE STATE WHETHER SUCH A PROCEDURE WOULD LENGTHEN THE TIME BEFORE CORE UNCOVERING AND DAMAGE (AND IS SO BY HOW MUCH) AND WMtlhtR UNDERTAKING SUCH AN EFFORT IS DESIRABLE GIVEN OTHER PRIORITIES FACING THE OPERATORS.

s a

ANSWER.

i i

SUPPLEMENTAL INFORMATION i

AS NOTED IN OUR PREVIOUS ANSWER, THE FEED AND BLEED COOLING MODE IS A BACKUP MEASURE, AVAILABLE TO PLANT OPERATOF.S, TO KEEP THE CORE COOLED WHILE MEASURES ARE TAKEN TO RESTORE FEEDWATER.

THE I

PREVIOUS RESPONSE ALSO STATED THAT THE LIMITED MAKEUP PUMP FLOW AT DAVIS-BESSE WOULD Al LEAST HAVE SUBSTANTIALLY EXTENDED THE TIME BEFORE CORE DAMAGE WOULD OCCUR.

4 l

4 1

QUESTION 8.

ChNTINUED 2-i 4

i AS NOTED IN OUR SUPPLEMENTAL RESPONSE TO QUESTION 3 TO THE JUNE l

17, 1985 RESPONSES, COMPUTER CALCULATIONS INDICATE THAT DAVIS-BESSE WOULD HAVE STARTED TO UNCOVER THE CORE IN APPR0XIMATELY EIGHTY MINUTES IF FEEDWATER WAS NEVER RECOVERED AND NO MITIGATIVE OPERATOR ACTION WAS TAKEN.

IN CONTRAST, THE COMPUTER CALCULATIONS i

DOCUMENTED IN THE ATTACHED DRAFT REPORT ENTITLED " RAPID-RESPONSE ANALYSIS OF THE DAVIS-BESSE LOSS-OF-FEEDWATER EVENT OF JUNE 9, 1985" SHOWS THAT MAINTAINING FLOW FROM JUST ONE MAKEUP PUMP DELAYS CORE UNCOVERY UNTIL APPROXIMATELY TWO AND ONE-HALF (Zi) HOURS.

3ASED ON THAT ANALYSIS, WE JUDGE THAT ESTABLISHMENT OF FLOW FROM l

BOTH MAKEUP PUMPS WOULD HAVE PREVENTED CORE LNC0VERY.

l THUS, THE STAFF HAS CONCLUDED THAT INCLUSION OF THE FEED AND I

j BLEED MODE OF CORE COOLING IN THE EMERGENCY PROCEDURES IS PRUDENT f

AND EXPECTED TO BE SUCCESSFUL IF INITIATED IN A TIMELY MANNER.

i WE ALSO BELIEVE THAT IMPLEMENTATION OF FEED AND BLEED DOES NOT PLACE AN UNDUE BURDEN ON THE OPERATORS BECAUSE THE OPERATOR ACTIONS ARE SIMPLE TO INITIATE AND CAN BE READILY PERFORMED FROM THE CONTROL ROOM.

I I

ADDITIONAL STAFF COMMENTS ON OUR PREVIOUS RESPONSE ARE AS FOLLOWS:

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q CUESTION 8.

hbNTINUED.

i A)

IHE FIRST SENTENCE OF THE FIRST PARAGRAPH ON PAGE 4 0F THE RESPONSE TO QUESTION 8 SHOULD BE CLARIFIED TO READ:

j

" PLANT-SPECIFIC TECHNICAL GUIDELINES (BASED ON GENERIC GUIDELINES) FOR WRITING EMERGENCY PROCEDURES HAVE BEEN DEVELOPED BY TOLEDO EDISON COMPANY BASED ON THE ANALYSES DESCRIBED ABOVE."

B)

AS DISCUSSED IN THE RESPONSE TO QUESTION 8, THE REVIEW OF' Dt. ANT-SPECIFIC GUIDELINES AS PART OF THE PROCEDURES GENERA-4 TION PACKAGE FOR DAVIS-3 ESSE IS PROGRE55ING BUT NO NEW l

MILESTONES HAVE BEEN REACHED.

AS IS TFE CASE OF ALL PROCE-DURES GENERATION PACKAGES FOR OPERATING B&W PLANTS, THE GUIDELINES FOR DAVIS-3 ESSE HAVE BEEN AUTHORIZED FOR IMPLEMENTATION PRIOR TO COMPLETION OF FORMAL STAFF REVIEW (NUREG-0737, SUPPLEMENT NO. 1, SECTION 7.2.B).

THE STAFF REVIEW IS SCHEDULED FOR COMPLETION BY MAY 30, 1986.

IT SHOULD BE NOTED THAT FEED AND BLEED WAS NOT INITIATED i

DURING THE JUNE 9 EVENT.

THIS IS DISCUSSED IN SECTION 6 0F NUREG-1154.

t i

- ~ - - __.

QUESTION 9.

-- GIVEN THE DEMONSTRATED LIKELIHOOD OF A TOTAL LOSS f

0F FEEDWATER AT B&W REACTORS, WHY DOES THE NRC

- CONSIDER THIS TYPE OF INCIDENT TO BE BEVOND THE DESIGN BASIS?

WHAT IS THE TECHNICAL BASIS FOR CONSIDERING A POTENTIAL FAILURE OR ACCIDENT SEOUENCE AS A DESIGN BASIS EVENT?

l

ANSWER, l

SUPPLEMENTAL INFORMATION IS PROVIDED, AS FOLLOWS:

IN NUREG-1154, " LOSS OF MAIN AND AUXILIARY FEEDWATER EVENT AT THE DAVIS-BESSE PLANT ON JUNE 9, 1985," SEVERAL ITEMS ARE IDENTIFIED AS CONTRIBUTING TO THE TOTAL LOSS OF AUXILIARY FEEDWATER.

THESE APE:

i 1.

OPEPATOR ERROR INVOLVING MANUAL INITIATION OF THE STEAM AND FEEDWATER LINE RUPTURE CONTROL SYSTEM (SFRCS).

THIS l

ERROP, WHICH WAS THE RESULT OF THE OPERATOR INADVERTENTLY PUSHING THE WRONG TWO BUTTCNS, RESULTED IN THE ISOLATI0'l 0F AUXILIARY FEEDWATER TO BOTH STEAM GENERATORS.

2, FAILURE OF THE AUXILIARY FEEDWATER ISOLATION VALVES TO OPEN AFTER THE OPERATOR ERROR DESCRIBED ABOVE WAS CORRECTED, THIS RESULTED IN THE NEED TO LOCALLY OPEN THE ISOLATION VALVES j

l LATER IN THE EVENT IN ORDER TO RESTORE FEEDWATER.

l l

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J QUESTION 10

- L: ST EVERY REGULATION, REQUIREMENT, RECOMMENDATION, GENERAL DESIGN CRITERIA, STANDARD REVIEW PLAN [ TEM,

. BRANCH TECHNICAL POSITION, CONFIRMATORY ACTION LETTER ITEM, LICENSING COMMITMENT, TMI ACTION PLAN ITEM, NUREG-0667 RECOMMENDATION, OR ANY OTHER ITEM THAT DAVIS-BESSE WAS NOT IN FULL AND COMPLETE COMPLIANCE WITH ON JUNE 9, 1985, f

I ANSWER.

SUPPLEMENTAL INFORMATION IS PROVIDED, AS FOLLOWS:

i AS STATED IN THE DAvlS BESSE SER THE STAFF BELIEVED, AT THE TIME 0F LICENSING, THAT THE TWO AUXILIARY FEEDWATER TRAINS WERE CAPABLE OF SUSTAINING A SINGLE ACTIVE FAILUDE.

SUBSEQUENTLY, AS A RESULT OF THE NRC INVESTIGATIVE TEAM'S RE20RT, NUREG-1154, THE STAFF WAS MADE AWARE THAT THE CONCLUSION REACHED REGARDING THE SINGLE FAILURE CAPABILITY IS NOT INCLUSIVELY TRUE, THE TEAM FOUND THAT THE STEAM AND FEEDWATER LINE RUPTURE CONTROL SYSTEM l

(SFRCS) INTERACTION WITH THE AUXILIARY FEEDWATEP (AFW) SYSTEM

'l DOES NOT MEET THE SINGLE FAILURE CRITERION AND IS NOT IN COMPLIANCE WITH GENERAL CESIGN CRITERION (GDC) 34 AS DEFINED s

BY THE CURRENT STANDARD REVIEW PLAN (SRP) SECTION 10,4,9.

SPECIFICALLY, IN THE EVENT OF A STEAM LINE BREAK, A SINGLE FAILURE WITHIN THE SFRCS OR IN THE AFW SYSTEM (MOTOR OPERATED CONTAINMENT ISOLATION VALVE FAILS TO OPEN), COULD RESULT IN THE FAILURE TO DELIVER AFW TO THE INTACT STEAM GENERATOR, 4

i

l QUESTION 10.

( CONTI FLUED) l SHOULD BE NOTED THAT AT THE TIME OF LICENSING GDC-3I4 AS DE INED BY THE CURRENT SRP SECTION 10.4.9 DID NOT APPLY TO THE AFW SYSTEM AT 38W OPERATIflG PLANTS AS THE AFW SYSTEM WAS NOT CCNSIDERED/REGUIRED TO BE A SAFETY RELATED SYSTEM.

C0fdPL I Af!CE WITH GDC-34 IS NOT CURRENTLY A REQUIREMENT F00 AFW SYSTEMS AT OPERATING PLANTS, If!CLUDING DAVIS-BESSE, BECAUSE IT HAS NOT BEEF!

SACKFITTED.

HOWEVER, Ifl THE SAFETY EVALUATION PEPORT FOR THE OPERATIf;G LICENSE REVIEW 0F DAVIS-BESSE, THE AFW SYSTEM WAS REVIEWED TO SINGLE ACTIVE FAILURE CRITEPIA BECAUSE THE LICENSEE.

1 j

HAD It! STALLED A SAFETY GPADE AFW SYSTEM EVEfl THOUGH THEY WERE fl0T "ECUIRED TO DO S0.

Ifl EITHEP CASE, THE LICEflSEE IS PROPOSIflG TO MAKE MODIFICATIONS TO THE SFRCS SYSTEM TO ELIMIt! ATE THE POTENTIAL FOR SINGLE FAILUPE WHICH HAS BEEN IDENTIF!:D l

I I

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3 4

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l

OUESTION 15.

AFTER CONCERNS WERE RAISED BY COMMISSIONER GILINSKY AND THEN REGION III IN 1983, TcLEDO EDISON PLEDGED TO TAKE STEPS TO IMPROVE ITS REGULATORY PERFORMANCE AND MANAGEMENT.

ACCORDING TO THE NRC STAFF, THESE MEASURES WERE INEFFECTIVE.

WHY DIDN'T THE NPC TAKE ACTION TO REQUIRE EFFECTIVE IMPROVEMENTS AND HAS THE NRC DETERMINED WHY THOSE ACTIONS THAT WERE TAKEN WERE NOT EFFECTIVE?

ADDITIONALLY, WHAT MEASURES DOES THE COMMISSION PLAN TO TAKE NOW TO ASSURE REGULATOPY AND MANAGEMENT IMPROVEMENTS AND HOW WILL THEY DIFFER FROM THOSE TAKEN OVER THE PAST TWO YEARS?

ANSWER, SUPPLEMENTAL INFORMATION IS PROVIDED, AS FCLLOWS:

IN JULY 1985, A PROPOSED CIVIL PENALTY OF S100,000 WAS ISSUED TO TECO AS A RESULT OF CONTINUING NRC CONCERNS WITH INTEPNAL COMMUNICATICN PROBLEMS AT TED AND LACK OF PROMPT IDENTIFICATION AND CCPRECTION CF REGULATORY PP0BLEMS. IHE LICENSEE PAID THIS CIVIL PENALTV CN AUGUST 12, 1985.

MORE DETAILS REGARDING THIS ENFORCEMENT ACTION ARE PROVIDED IN THE UPDATED RESPONSE TO QUESTION NO, 20 0F YOUR JUNE 17, 1985 LETTER.

l i

CUESTION 15 _. (CONTINUED,

NEW MANAGERS WERE ASSIGNED TO THE FOLLOWING POSITIONS TO EFFECT MANAGEMENT IMPROVEMENT AT THE DAVIS BESSE FACILITY, ALL WERE OBTAINED FROM OUTSIDE THE COMPANY AND HAVE NUCLEAR EXPERIENCE.

SENIOR VICE PRESIDENT, NUCLEAR PLANT MANAGER MAINTENANCE SUPERINTENDENT PLANNING SUPERINTENDENT INSTRUMENT AND CONTROL ENGINEER REGION lli WILL CONTINUE TO BE INVOLVED IN MONITORING THE NEW MANAGEMENT, i

I i

l

OUESTION 18, __SHOULD COST-BENEFIT ANALYSIS BE USED TO DECIDE WHETHER TO REQUIRE DAVIS-BESSE TO INSTALL A THIRD AUXILIARY FEEDWATER PUMP WHEN IT DOES NOT MEET THE STANDARD REVIEW PLAN RELIABILITY AND WHEN NO OTHER U.S. REACTOR HAS THE SAME DESIGN VULNERABILITY OF ONLY TWO STEAM DRIVEN PUMPS?

ANSWER, SINCE OUR RESPONSE TO THE JUNE 27 CUESTION 18, A STAFF COST-BENEFIT ANALYSIS OF THE DESIRABILITY OF ADDING A THIRD, DIVERSE PUMP TRAIN TO THE EXISTING DAVIS-BESSE TWO TURBINE-DRIVEN AUXILIARY FEEDWATER TRAINS HAS BEEN COMPLETED.

THE ANALYSES ARE SUMMARIZED IN THE EXECUTIVE

SUMMARY

OF THE STAFF REPORT (MEMORANDUM FOR H. DENTON FROM T. SPEIS, "ADE00ACY OF THE AUXILIARY FEEDWATER SYSTEM AT DAVIS-BESSE," JULY 23, 1985), SEE ATTACHED COPY, COMPLETE MEMO IS IN ENCLOSURE 3.

Davis-Sesse AFW Anaijsis EXECUTIV: " vr.MA R Y Ine reliability of the auxiliary fee:-ater syster at Davis-Besse, a.1d its ef fECt on Core melt frequency and public risk, have been examined usir.g the techniques of probabilistic analysis.

In particular, the desirability of a: ding a third, diverse (i.e. motor-driven) train to the two existing

~

turoine-driven trains was investigated.

Inere is no PRA availatie for the Da.is-Eesse plant.

Therefore, PRA calculations for Oconee 3 were adapte: for tne Davis-Besse plant.

Altncughallhme usual uncertainties of PRA are present, it appears that the addition of a tnird, diverse train would avert rougnly 10 4 core melts per year.

Cost effectiveness over the remaining life of the plant appears to be in the range of 100 to 4C0 collars per cerson-rer averted.

In terms of re::: tion of core relt frecuen:y, tne ac:ition of a tnird train is highly desirable, particularly sin:e tre FRA analysis is casec largely on

eneric data.

Tne large number of LERs on file for the Davis-Besse auxiliary fee -ater syster suggests that tne ana'ysis of the present situation may well ce oserly optiristic.

Inis -cui: make a third train still more valuatie, an: implies inr. 3:re at; 3:i ng of two evisting trr-:

might be in arcer.

In terms of cost effectiveness, tne addition of a third train appears to te cuite cost effective, but the ce:ision is not atsolutely clear De:ause ;f the uncertainties involved.

However, tnis analy5is considered only two, some-nat ny;othetical designs.

't is likely inat a still more

st ef fe:tive syste cou e te ::s gned.

t in sur.macy, the a::ition of a tnir tr31r c' au iliar, fee =ater at Davis-Besse appears to be juftified.

1 l

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ENCLOSUPE 3 1

i 1.

NUREG-1154, LcSS cF MAIN AND AUXILIAPY FEEDWATER EVENT AT THE DAV!S-BESSE PLANT

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2.

TITLE 10 CFR 50.54(F) LETTER FPOM H. DENTON TO TOLEDO EDISON, DATED AUGUST 14, 1985 3.

MEMO: SHORT IERM GENERIC ACTIONS AS A REtulT OF THE 4

1 DAvtS-BESSE EVENT, H. THOMPSON, JP, TO T. SPE!S,

.1 AUGUST 19, 1985 4

MEM0; ADEQUACY OF THE AUXILIAPY FEEDWATER SYSTEM AT DAVIS 3 ESSE, I. EPEIS TO H. DEf! TON, JULY 23, 1985 j

i.

5.

OEPCFT; RAPIP DESPCflSE ANALYSIS OF THE DAVIS-CESSE LOSS-CF-FEEDws.TE:'

EVENT cv JUNE 9, 1985 J

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ps* ** c v UNITED STATES

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wasmNoTON D C. 20555 EN 14 W Docket No. 50-346

~

Toledo Edison Company ATTN: Mr. Joe Williams, Jr.

Senior Vice President Nuclear Edison Plaza 300 Madison Avenue Toledo, Ohio 43652

Dear Mr. Williams:

On June 9, 1985. Toledo Edison Company's Davis-Besse Nuclear Power Plant was operating at 90% power when it experienced an event that involved the loss of-all feedwater. Af ter the complete loss of main feedwater, an operator error, malfunctions of two containment isolation valves in the safety-related auxiliary feedwater system, and overspeed trips of both steam turbine-driven auxiliary feedwater pumps resulted in the loss of all sources of feedwater to the steam generators. Recovery from this event involved operator actions outside the control room, the addition of feedwater from the (non-safety related) startup feedwater pump, and restoration of feedwater from the two steam turbine-driven auxiliary feedwater pumps.

The NRC subsequently investigated the circumstances of this event and documented its conclusions in NUREG-1154 (Loss of Main and Auxiliary Feedwater Event at the Davis Besse Plant on June 9,1985). An advanced copy of that report was sent to you on July 26, 1985. The investigation concluded that the underlying causes of this event were: (1) the lack of attention to detail in the care of plant equipment; (2) a history of perfaming troubleshooting, maintenance and testing of equipment, and of evaluating operating experience relating to equipment in a superficial manner and, as a result, the root causes of problems were not always found and corrected; (3) the engineering design and analysis effort to address equipment problems was frequently either not utilized or was not effective; and (4) that equipment problems were not aggressively addressed and resolved.

These underlying causes are indicative of significant programatic and manage-1 ment deficiencies. Accordingly, we have identified the following general areas of concern which must be addressed in your response to this event:

1.

Completion of the investigation of the June 9,1985 event, including analysis of the equipment failures, determination of the root causes, detemination of the implications for other equipment, and completion of corrective actions.

b 'IO[

2.

The plant-specific findings regarding this event.

3.

The programatic and management issues that have contributed ig (

to this event and more generally to the recent performance N of Davis-Besse.

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Mr. Joe Williams, Jr..

Additional infomation on these general areas of concern are identified in the enclosure to this letter.

Pursuant to 10 CFR 50.54(f), ycu are requested to furnish, under oath or affinnaticn, no later than 30 days froin the date of this letter, your plans and programs to resolve the concerns identified above and in the enclosure.

The plans and programs should specify those actions to be completed prior to restart of Davis-Besse and include a schedule for any longer term actions.

We are prepared to meet with you in our office in Bethesda, Maryland to discuss your plans and program prior to the submittal of your written response and as soon as your program is sufficiently well-defined to make such a meeting useful.

Over the past few years we have identified deficiencies through enforcement actions, Perfomance Appraisal Team (PAT) inspections, and Systematic Appraisal of Licensee Perfomance (SALP) evaluations, as well as through more routine inspection and licensing contacts.

In late 1983 Toledo Edison initiated a Perfomance Enhancement Program (PEP) to improve regulatory perfomance at Davis-Besse. Modifications to this program were made in response to the most recent Systematic Assessment of Licensee Performance (SALP) and, more recently, Toledo Edison made management changes to strengthen perfomance. Prior to the availability of NUREG-115a, you outlined in a July 18, 1985 letter, an initial program to identify and implement those measures necessary to return Davis-Besse to safe cperation. While these programs for responding to the June 9, 1985 event and for improving your performance may have considered some of the cencerns in NUPEG-1154, they should be reexamined in accordance with the above request.

As you,are aware, on June 10, 1985, the NRC Region III Office issued a Confimatory Action Letter documenting actions you have taken or will take o

regarding this event. This letter supersedes that letter, as lead responsibility o

for NPC staff actions relating to facility restart has been assigned by the Executive Director of Operations to NRR. Consistent with your discussion with Region III on June 10, 1985, it remains our understanding that you will not restart the Davis-Besse facility without NRC approval.

Sincerely, l

Harold R. Denton, Director Office of Nuclear Reactor Regulation

Enclosure:

Areas of Concern Relating to the June 9, 1985 Loss of Feedwater Event cc w/ enclosure:

See next page

Mr. J. Williams DISTRIBUTION Docket File JPartlow ERossi NRC PDR ACRS-10 EHolahan L PDR R!ngram SBurns ORBd4 Rdg ADe Agazio JKeppler HThompson Gray File JTaylor OELD EBrach DEisenhut EJordan F0rnstein HDenton BGrimes WPaulson RWessman GEdison

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• See previous white for concurrences.

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GHolahan 8/12/85 8/12/85 8/12/85 8/12/85 8/9/85 8/12/85 OELD*

AD/OR:DL*

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D/RIII IE*

SBurns*

Glainas FThompson JKeppler*

JTaylor 8/9/85 8/9/85 8/12/85 8/9/85 8/13/85 DD/NRR*

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8/13/85

// 85

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t

Mr. J. Williams Davis-Besse Nuclear Power Station Toledo Edison Company Unit No. I CC:

Donald H. Hauser, Esq.

Ohio Department of Health The Cleveland Electric ATTN: Radiological Health Illuminating Company Program Director P. O. Box 5000 P. O. Box 118 Cleveland, Ohio 44101 Columbus, Ohio 43216 Mr. Robert F. Peters Attorney General Manager, Nuclear Licensing Department of Attorney Toledo Edison Comoany General Edison Plaza 30 East Broad Street 300 Madison Avenue Columbus, Ohio 43215 Toledo, Ohio 43652 Mr. James W. Harris, Director Gerald Charnoff, Esq.

Division of Power Generation Shaw, Pittman, Potts Ohio Department of Industrial Relations and Trowbridge 2373 West 5th Avenue 1800 M Street, N.W.

P. O. Box 825 Washington, D.C. 20036 Columbus, Ohio 43216 Paul M. Smart, Esq.

Mr. Harold Kohn, Staff Scientist.

Fuller & Henry Power Siting Comission 300 Madison Avenue 361 East Broad Street P. O. Box 2088 Columbus, Ohio 43216 Toledo, Ohio 43603 Mr. Robert B. Borsum President, Board of Babcock & Wilcox Ottawa County Nuclear Power Generation Port Clinton, Ohio 43452 Division Suite 200, 7910 Woodmont Avenue Bethesda, Maryland 20814 Resident Inspector U.S. Nuclear Pegulatory Comission 5503 N. State Route 2 Oak Harbor, Ohio 43449 Regional Administrator, Region III U.S. Nuclear Regulatory Comission 799 Roosevelt Road Glen Ellyn, Illinois 60137

ENCLOSURE AREAS OF C0'lCERN RELATING TO THE JUNE 9,1985 LOSS OF FEEDWATER EVENT I.

Coroletion of the Event Investigation A.

Completion of the investigation of the equipment malfunctions and operator errors that occurred during the June 9,1985 event.

B.

Determination of the root causes of the malfunctions and errors that occurred during the event and the implications to the rest of the plant.

C.

Corrective actions needed to assure the reliability of the systems which can mitigate loss of feedwater events.

II. Concerns Directly Related to the June 9,1985 Event A.

Concerns identified in NUREG-1154:

1.

The adequacy of the analyses for loss. of feedwater events, including time margins and consequences of alternative sequences.

2.

The adequacy of the design and operation of the SFRCS, including spurious actuations, seal-in features for SFRCS-actuated equipment, and single failures.

3.

The potential adverse effect of plant physical security and administrative features (locked doors, locked ecuipment, etc.) on the operator's ability to gain timely access to equipment to mitigate accidents.

4 The availability of and role for the Shift Technical Advisor assistance during complex operating events.

5.

The reliability of the Auxiliary Feedwater (AFW) containment isolation valves and other safety-related valves.

6.

The adequacy of Toledo Edison Company's procedures and training for raporting events to the NRC Operations Center.

7.

The reliability of the AFW system and turbine-driven pumps, including the need for a diverse pump.

8.

The reliability of the PORY.

t

__ 9.

The adequacy of control room instrumentation and

~

controls.

10. The acceptability of the provisions which resulted in the inability to place the startup feedwater pump in service from the control room.

11. The resolution of those equipment deficiencies listed on Table 5.1 of NUREG-1154 and not addressed by other items, above.

12. The adequacy of plant operating procedures including verification that plant procedures involving " drastic" action are sufficiently precise and clear to ensure timely implementation.

13. The adequacy of safety system testing including verification that safety systems are tested in all configurations required by design basis analysis.

B.

Additional NRC concerns:

1.

Adecuacy of procedures, equipment and training for quickly and efficiently starting or restarting equipment for loss of feedwater mitigation.

2.

Adequacy of programs to minimize the likelihood of inadvertent isolation of AFW to both steam generators (including training of the plant operators and human factors aspects of the SFRCS control room equipment).

3.

The plans and program for the installation of the new startup feedwater pump in accordance with the license condition of January 8,1985.

4.

Adequacy of other engineered safety features, including design considerations, in light of the single failure vulnerabilities identified in the SFRCS and auxiliary feedwater system.

III. Management and Programatic Concerns l

A.

Adequacy of management practicy

,r A %ig control of l

maintenance programs, use of operational experience, degree of engineering involvement, testing, root cause detennination of equipment misoperation, licensed and non-licensed operator training, and post trip reviews.

B.

Adequacy of the maintenance program, including maintenance backlog, maintenance procedures and training, vendor interface and correction of identified deficiencies.

C.

Adequacy of the implementation of the Performance Enhancement Program (PEP) and any other ongoing corrective action programs.

D.

Adequacy of the resources committed to the Davis-Besse facility for investigation of the event, resolution of the findings and conclusions prior 'to restart, and implementation of longer term measures to improve overall performance.

O

/

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