05000269/LER-1982-017, Forwards LER 82-017/01T-0.Detailed Event Analysis Encl

Forwards LER 82-017/01T-0.Detailed Event Analysis Encl

ML20063M151
Person / Time
Site:	Oconee
Issue date:	09/03/1982
From:	Tucker H DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20063M153	List: 05000269/LER-1982-017, Forwards LER 82-017/01T-0.Detailed Event Analysis Encl 05000269/LER-1982-017-01, /01T-0:on 820820,station I&C Batteries 1CA,1CB & 3CA Declared Inoperable Due to Failure to Take Corrective Actions on Deficiencies Identified During Monthly Surveillance.Caused by Personnel Error
References
NUDOCS 8209100165
Download: ML20063M151 (4)

LER-1982-017, Forwards LER 82-017/01T-0.Detailed Event Analysis Encl

Event date:
Report date:
2691982017R00 - NRC Website

text

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DUKE POWEn Gonnov I*.O. Isox 331ftO CIIAHLOTTI!. N.C. Mil 242 II AI.11. TUCKI:13 TE LE PftOM E vo il am-4sas u....,.,

September 3, 1982 mu,... : 4 -

Mr. James P. O'Reilly, Regional Administrator U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 Re: Oconee Nuclear Station Docket No. 50-269 w

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Dear Mr. O'Reilly:

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nn yz Please find attached Reportable Occurrence Report R0-269/82-17. This rfport ZW is submitted pursuant to Oconee Nuclear Station Technical Specificatiorfo

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6.6.2.1.a(2) which concerns an operation subject to a limiting condition for

'?O operation which was less conservative than the least conservative aspecEjof d,'

the limiting condition for operation established in the Technical SpeciMcationsJ and describes an incident which is considered to be of no significance with

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respect to its effect on the health and safety of the public.

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Very truly yours, Hal B. Tucker JFK/php Attachment L

cc: Document Control Desk U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Mr. W. T. Orders NRC Resident Inspector Oconce Nuclear Station Records Center Institute of Nuclear Power Operations 1820 Water Place Atlanta, Georgia 30339 Mr. Philip C. Wagner Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555 4

iMFFICIAL COPY

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8209100165 820903 a

PDR ADOCK 05000269 6

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r-3, DUKE POWER COMPANY OCONEE NUCLEAR STATION Report Number: R0-269/82-17 Report Date: September 3, 1982 Occurrence Date: August 20, 1982 Facility: Oconee Nucicar Station, Seneca, South Carolina Identification of Occurrence:

Station Instrument and Control Batteries inoperable Conditions Prior to Occurrence: Oconee 1 - 100% FP Oconee 2 - 100% FP Oconee 3 - Cold Shutdown Description of Occurrence: On August 20, 1982, five of six station instrument and control batteries (ICA,1CB, 2CB, 3CA, and 3CB) were declared inoperable as a result of failure to take corrective actions on deficiencies identified during monthly surveillance. Various cells on these batteries had specific gravity or individual cell voltage out of tolerance. This determination was made based on a review of completed surveillance procedures.

Apparent Cause of Occurrence: The apparent cause of this incident was personnel error in that the personnel taking the readings did not follow established pro-cedures to identify the out of tolerance conditions and take appropriate corrective actions, and this deficiency was not identified in the documentary review of the completed procedure.

Analysis of Occurrence:

Each Oconee unit has a 125 Volt DC system to provide a reliable source of continuous control and instrumentation power for normal operation and for orderly shutdown. For each unit, two independent and physically separated 125 Volt DC batteries and DC buses are provided for the 125 Volt DC Instrumentation and Control Power System. Three battery charges are also supplied, with two serving as normal power supplies to the bus sections with the associated 125 Volt DC battery floating on the bus. Each of the three battery chargers are supplied from the redundant 600 Volt AC Engineered Safeguards motor control centers of each unit.

The 125 Volt DC Instrumentation and Control Power System and the 120 Volt AC Vital Power System are des'igned such that upon loss of power supplied no inter-actions exist between Reactor Protection Systems, Engineered Safeguards Protection I

Systems, and control systems that would preclude these systems f rom performing their respective functions. Also, any interactions between units as a result of the loss of power supplies does not preclude the safety and control systems of any unit from fulfilling their function. This is verified by safety analyses and described in Chapter 8 of the FSAR. Each battery is sized to carry the con-tinuous emergency load for a period of one hour in addition to supplying power for the operation of momentary loads during the one-hour period.

A Service Test Discharge is performed on a battery to demonstrate the capability i

of the battery to meet the safety-related design requirements of the system to which it is connected. For the instrument and control batteries, this test places a 600 Amp load on the batteries for one hour.

The 600 Amps requirement i

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Report No R0-269/82-17 Page 2 l

l is a conservative estimate of accident condition battery loads, assuming single failure of one of each unit's batteries. The ICA, ICB, 2CA, and 2CB instrument and control batteries had test discharges completed satisfactorily during July 1982. A satisfactory test discharge was completed on the 3CB instrument and control battery on August 29, 1982. The 3CA instrument and control battery was charged on August 20, 1982. A review of the data on the 3CA instrument and control battery has determined that this battery would have performed its intended function.

It is felt that although five of the six instrument and control batteries were inoperable as a result of failure to perform the required corrective action following identification of the out of tolerance conditions, that the batteries were capable of performing their safety-related function. This determination is based on IEZE Standard 450-1980 which states that the items checked on periodic surveillance " indicate conditions that, if allowed to persist for extended periods, can reduce battery life. They do not necessarily indicate a loss of capacity."

This is further substantiated by the fact that test discharges completed satis-factorily on the Oconee batteries with out of tolerance cells demonstrated that the battery capacity was not degraded. Thus, the health and safety of the public were not affected by this incident.

Corrective Action

A shutdown was initiated on Units 1 and 2 at approximately 1700 on August 20, 1982. The out of tolerance conditions were corrected on the 3CB battery at approximately 1918 on August 20, 1982, and Unit 2 returned to full power.

The out of tolerance conditions were corrected on the ICA battery at approximately 2300 on August 20, 1982, and Unit 1 returned to full power.

The 3CA battery was charged on August 20, 1982, and declared operable. The 2CB battery was charged on August 25, 1982, and declared operable. The ICB battery was charged on August 28, 1982 and declared operabic, at which time all six instrument and control batteries were operable. A test discharge was satis-factorily completed on the 3CB battery on August 29, 1982.

The completed surveillance procedures for the Keowce instrument and control batteries and the 230 KV station batteries were reviewed for similar problems and none were found.

An evaluation of the I6E process for review and approval of completed procedures has been completed and shows no indication of a generic problem in this process.

The individuals involved in this incident have been counselled and have received appropriate disciplinary action. This incident will be reviewed by all appropriate station personnel by September 10, 1982.

l The battery surveillance procedures will be revised to clarify the requirements for initiation of corrective actions.

This revision will be completed by September 21, 1982.

The Station Manager has requested a Quality Assurance audit to ensure that all requirements of Section IV of the Technical Specifications are incorporated in appropriate procedures, that surveillance items required by the Technical Spec-ifications are being performed as stated, and that corrective actions are being taken, when appropriate, as a result of these surveillances. This audit is currently in progress.

Report No. R0-269/82-17 Page 3 Management control and audit of station work activities is being evaluated to ensure that the manager's scope of responsibility and assigned workload are such that time is available to perform effective evaluations of station activities.

Corrective actions will be taken where deemed necessary by this evaluation.

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