IR 05000269/1987007

Enforcement Conference Repts 50-269/87-07,50-270/87-07 & 50-287/87-07 on 861222.Major Areas Discussed:Sequence of Events & Corrective Actions Re Emergency Condenser Circulating Water Sys Degradation

ML20211A715
Person / Time
Site:	Oconee
Issue date:	02/05/1987
From:	Burger C, Peebles T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
Shared Package
ML20211A655	List: IR 05000269/1987007 ML20211A650
References
50-269-87-07-EC, 50-269-87-7-EC, 50-270-87-07, 50-270-87-7, 50-287-87-07, 50-287-87-7, NUDOCS 8702190223
Download: ML20211A715 (11)

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ENCLOSURE 1 Report Nos.: 50-269/87-07, 50-270/87-07, and 50-287/87-07 Licensee: Duke Power Company 422 South Church Street Charlotte, NC 28242 Docket Nos: 50-269, 50-270, License Nos.: DPR-38, DPR-47 and DPR-55 and 50-287 Facility Name: Oconee Nuclear Station 1, 2, and 3 Enforcement Conference a the Region II Office: December 22, 1986 Inspector: ,, .

W/M j Af 7 C. lit;~ B'ufgeY Irate Signe~d

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Approved by: A P T ~7 T. A. Peebles, Section Chief Date Signed Division of Reactor Projects SUMMARY An Enforcement Conference was held on December 22, 1986, to brief NRC on the sequence of events and corrective actions regarding the Emergency Condenser ,

Circulating Water (ECCW) System being degrade Details of the event are described in NRC Inspection Report Nos. 50-269/86-33, 50-270/86-33, 50-287/86-33 and 50-269/86-26, 50-270/86-26, 50-287/86-26.

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Enclosure 1 2 REPORT DETAILS Personnel Attending Enforcement Conference Duke Power Company H. B. Tucker, Vice President, DPC M. S. Tuckman, Station Manager, Oconee N. Rutherford, System Engineer, Licensing R. B. Priory, Vice President, Design Engineering B. L. Peele, Principal Engineer, Design Engineering D. W. Murdock, Principal Engineer, Design Engineering F. E. Owens, Shift Supervisor, Compliance Nuclear Regulatory Commission J. N. Grace, Regional Administrator, RII M. L. Ernst, Deputy Regional Administrator, RII L. A. Reyes, Deputy Director, Division of Reactor Projects (DPR), RII V. W. Panciera, Deputy Director, Division of Reactor Safety (DRS), RII G. E. Edison, Deputy Director, Project Dire torate #6, NRR H. N. Pastis, Project Manager - Oconee/PWR-6/NRR T. A. Peebles, Section Chief, DRP, RII J. C. Bryant, Senior Resident Inspector - Oconee C. W. Burger, Project Inspector, DPR, RII L. J. Callan, Chief, Performance Appraisal Section, IE T. O. Martin, Inspection Specialist, IE G. R. Jenkins, Director, Enforcement Investigation and Coordination Staff, RII B. Uryc, Enforcement Specialist, RII L. Trocine, Enforcement Specialist, RII Event Discussion The NRC staff opened the discussions concerning the degraded ECCW System and the associated safety implications. Duke Power Company (DPC) provided a description of the sequence of events, sunenary, the significance and a conclusion. The meeting summary notes are described below. The event details are discussed in NRC Inspection Report Nos. 50-269,270,287/86-33 and 50-269,270,287/86-2 Sequence of Events DPC described the sequence of events from October 1, 1986 to December 22, 1986. Units 1 and 3 were at 100% power and Unit 2 was in

a refueling shutdown. A load shed test was in progress with the Low l Pressure Service Water LPSW for Units 1 and 2 on Unit 2. Approximately i

one hour into the test the LPSW flow became degraded. The same test was repeated with similar results. Subsequent evaluation of this data

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led to question the operability of Units 1 and 3 and the decision to

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Enclosure 1 3 shutdown the two unit Following various meetings with NRC Region II and a site visit, a successful gravity flow test on Unit 2 and then on Unit I was achieved. The ECCW System relies upon a siphon effect to lift water from Lake Keowee and then exit by gravity flow to Lake Hartwell at a lower elevation. Due to severe draught conditions during '

this time the elevation of Lake Keowee was below normal such that a pump flange was exposed to the air. A test was then performed on Unit 2 which did reveal a flange leak and confirmed the cause of the loss of siphon proble Sunnary The NRC discussed the event in detail with DPC and expressed concern that the load shed test had not been appropriately conducted in the past to ensure that the required gravity flow (which relies upon a siphon) for the ECCW System was available and effective upon deman The NRC advised DPC that a decision regarding this event would be forthcomin The NRC thanked DPC for their candid and comprehensive presentation, their extension actions taken during this event and their positive response to NRC concerns.

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ENCLOSURE 2 OCONEE MEETING HAND 0UTS t

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I OCONEE NUCLEAR STATION EMERGENCY CONDENSER CIRCULATING WATER SYSTEM

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OCTOBER, 1986 INCIDENT l

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6 SEQUENCE OF EVENTS 10/1/86 -

UNIT 1 & 3 AT 100% POWER

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UNIT 2 AT REFUELING SHUTDOWN

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LOAD SHED TEST IN PRO-GRESS

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LPSW FOR UNITS 1 & 2 ON UNIT 2

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LPSW FLOW DEGRADED AFTER 1 HOUR

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PLANT RESTORED TO NORMAL

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TEST REPEATED WITH SIMILAR RESULTS

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NRC REGION II NOTIFIED 10/2/86 -

EVALUATION OF DATA LED TO QUESTION OF UNITS 1 & 3 OPERABILITY

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UNIT 1 & 3 SHUTDOWN INITIATED

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NRC REGION II APPRAISED OF ACTION 10/3/86 -

REPAIRS BEGUN ON CCW PUMPS (BELIEVED CAUSE OF FAILURE)

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10/4/86 -

NRC SITE VISIT BY REGION II 10/8/86 -

NRC REGION II MEETING IN ATLANTA 10/9/86 -

SUCCESSFUL GRAVITY FLOW TEST ON UNIT 2 10/13/86 -

SUCCESSFUL GRAVITY FLOW TEST ON UNIT f

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NRC MEETING IN BETHESDA

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CONCURRENCE TO START-UP OCONEE RECEIVED

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SEQUENCE OF EVENTS (CONTINUED)

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10/14/86 -

SUCCESSFUL GRAVITY FLOW TEST

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UNIT 1 & 2 START-UP 10/22/86 -

UNIT 3 START-UP 12/22/86 -

MEETING WITH NRC REGION II IN ATLANT .

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A SUMMARY OF PROBLEM

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EMERGENCY CONDENSER CIRCULATING WATER SYSTEM (ECCW) RELIES UPON A SIPHON TO LIFT WATER FROM LAKE KEOWEE TO CCW PIPING AND THEN GRAVITY FLOW TO LAKE HARTWELL

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DUE TO DRAUGHT, LAKE KEOWEE ELEVATION WAS LESS THAN 792' (FULL POND 800').

AT THIS ELEVATION A PUMP FLANGE IS EX-POSED TO THE AI OUT LEAKAGE FROM THE FLANGE WAS IDENTI-FIED IN THE FALL OF 1985 AND A TEST PERFORMED ON UNIT 3 TO DETERMINE IF SIPHON WAS AFFECTE IT DID NOT APPEAR TO AFFECT SIPHO TEST ON UNIT 2 IN OCTOBER 1986 REVEALED FLANGE LEAK DID CAUSE PROBLEMS WITH SIPHO ROOT CAUSE OF EVENT WAS INAPPROPRIATE DESIGN OF THE PUMP AND FAILURE OF TEST-ING TO REVEAL THIS INADEQUAC .

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s CORRECTIVE ACTIONS

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CCW PUMP FLANGES HAVE BEEN MODIFIED

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GRAVITY DRAIN TESTS HAVE BEEN PERFORMED

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TESTS OF ALL SYSTEMS THAT SUPPORT THE ECCW SYSTEM HAVE BEEN PERFORMED

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PROCEDURES HAVE BEEN UPGRADED FOR OPERA-TION, MAINTENANCE AND TESTING OF THE ECCW SYSTEM

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PERSONNEL HAVE BEEN TRAINED ON THE IM-PORTANCE AND CHANGED TO THE ECCW SYSTEM

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OTHER SYSTEMS WHICH COULD BE INFLUENCED BY ECCW HAVE BEEN REVIEWED AND CORRECTIVE ACTION TAKEN

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A SIGNIFICANCE OF PROBLEM

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OCONEE TECHNICAL SPECIFICATION 3. REQUIRES ECCW SYSTEM TO BE OPERABLE

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FOR PERIODS WHEN LAKE KEOWEE ELEVATION WAS LESS THAN 792' OCONEE DID NOT MEET THIS SPECIFICATIO THE SPECIFICATION IS PROVIDED ONLY FOR LOSS OF OFF-SITE AND ON-SITE POWER (STATION BLACKOUT)

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THIS SCENARIO IS UNIQUE TO OCONEE

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THE REASON FOR ECCW IS DUE TO RELATIVELY SMALL TECHNICAL SPECI-FICATION VOLUME OF EFW SUPPLIES

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THE ' ' N ORMA L ' SUPPLIES OF EFW ARE ADEQUATE TO SUSTAIN BLACKOUT WITHOUT ECCW

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OCONEE HAS VERY RELIABLE ON-SITE POWER SOURCES

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ALL OTHER SCENARIO'S RELY UPON CCW PUMPS

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LOCA WITH LOSS OF OFF-SITE POWER

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LOCA WITH LOSS OF OFF-SITE POWER AND SINGLE FAILURE OF ON-SITE POWER -

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LOSS OF OFF-SITE POWER

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LOSS OF OFF-SITE POWER WITH SINGLE FAILURE OF ON-SITE POWER

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CONCLUSION

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PROBLEM WAS IDENTIFIED BY STATION PERSONNEL

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EXTENSIVE ACTIONS TAKEN TO RESOLVE PROBLEM PROMPTLY

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ACTUAL SAFETY IMPACT WAS NOT A SIGNI-FICANT DEGRADATION

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VERY LOW PROBABILITY EVENT (STATION BLACKOUT)

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UNIQUENESS OF EVENT TO OCONEE FSAR

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SIGNIFICANT LEARNING EXPERIENCE

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