05000277/LER-1981-037, Forwards LER 81-037/01T-0.Detailed Event Analysis Submitted

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Forwards LER 81-037/01T-0.Detailed Event Analysis Submitted
ML20030D554
Person / Time
Site: Peach Bottom Constellation icon.png
Issue date: 08/21/1981
From: Cooney M
PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To: Grier B
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20030D555 List:
References
NUDOCS 8109010525
Download: ML20030D554 (3)
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LER-1981-037, Forwards LER 81-037/01T-0.Detailed Event Analysis Submitted
Event date:
Report date:
2771981037R00 - NRC Website
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text

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4 LCA PHILADELPHIA ELECTRIC COMPANY 2301 M ARKET STREET P.O. BOX 8699 PHILADELPHIA. PA.19101 1881 - Icell 1215)841-4000 August 21, h

SR>s Mr. Boyce H.

Grier, Director 9

1 9

Officti of Inspection and Enforcement [S

q/.

s Region I

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/(b US Nuclear Regulatory Commission 9

j 631 Park Avenue E

King of Prussia, PA 19406 f

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SUBJECT: LICENSEE EVENT REPORT NARRATIVE DESCRIPTION

Dear Mr. Grier:

The following occurrence was reported to Mr. Cowgill, Region I, Office of Inspection and Enforcement on August 10, 1981.

Reference:

Docket No. 50-277 Report No.:

LFR 2-81-37/1T-0 Report Date:

August 21, 1981 Occurrence Date:

August 8, 1981 Facility:

Peach Bottom Atomic Power Station RD #1, Delta, PA 17314 Technical Specification Reference:

Technical Specification 3.7.D.2 requires in part that if any isolation valve becomes inoperable, reactor power operation may continue provided at least one valve in each line having an inoperable valve shall be in the mode corresponding to the isolated condition.

Technical Specification 3.7.D.3 requires in part that if 3.7.D.2 cannot be met, an orderly shutdown shall be initiated.

T6.0 Description of the Event 3

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l With the Unit operating at 97.5% power, an operator observed, during a front panel cneck, that the normally open HPCI turbine exhaust drain isolation valve (AO-4248) indicated closed.

Investigation revealed that the solenoid valve in the air supply line had failed, thus closing the valve.

8109010525 810821 PDR ADOCK 05000277 PDR

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After the redundant isolation valve (AO-4247) was stroked from the control room to prove operability, the failed isolation valve was manually opened.

The redundant isolation valve was left in the normal open position.

This provided a drain path for the HPCI, turbine exhaust line and maintained the operability of HPCI.

It was judged that maintaining the operability of HPCI under given plant conditions (Reactor near full power with only two of three reactor feed pumps operating) provided for greater safety than closing the redundant isolation valve.

This judgment was made with consideration of the following factors: 1) the redundant valve had been proven to be operable, 2) the redundant valve fails closed on loss of electrical signal or air supply, 3) i the redundant valve could be closed manually and, 4) the replacement of the failed solenoid valve would take a relatively short time.

The failed solenoid coil was replaced and the HPCI system returned to normal operation within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> which satisfies the requirements of Te:hnical specification 3.7.D.3.

I, Probable Consequences of the Occurrence consequences are considered to be minimal because the redundant isolr. tion valve (AO 4247) was demonstraced to be operable and the failed valve (AO 4248) was manually opened to assure draining of the exhaust line.

1 As previously discussed, it was felt to be safer to maintain HPCI operability then to close one of the isolation valves.

The failure to initiate a shutdown was an oversight and not significant due to the amount of time involved to replace the i

defective solenoid or the relatively short period of time required to reach cold shutdown.

Cause,of the Occurrence The cause of the occurrence was an open coil on the ASCO solenoid valve (Cat # 83215A).

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.T.mmediate Corrective Action t

The redundant isolation valve was proven to be operable and the failed coil and solenoid valve were replaced.

The valve was tested successfully and returned to service within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

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Actions Taken to Prevent Recurrence i

In addition to thote actions discussed above, the operations personnel involved were counseled regarding the initiation of shutdowns as recuired by Technical specifications.

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I very truly yours, i

p/l J.l [/M(A I

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M J.

Cooney perintenden deneration Division / Nuclear i

Attachment i

cc:

Director, NRC - Office of Inspection and Enforcement i

Mr. Norman M.

IIaller, NRC - Office of Management &

Program Analysis I

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