05000369/LER-1981-039, Forwards LER 81-039/03L-0.Detailed Event Analysis Encl

Forwards LER 81-039/03L-0.Detailed Event Analysis Encl

ML20005A081
Person / Time
Site:	McGuire
Issue date:	05/01/1981
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20005A082	List: 05000369/LER-1981-039, Forwards LER 81-039/03L-0.Detailed Event Analysis Encl 05000369/LER-1981-039-03, /03L-0:on 810403,pressure Operated Relief Valve Found Lifting While in Automatic W/Associated Block Valve Closed.Caused by Low RCS Pressure Setpoint.Pressure Reduced & Valve Returned to Svc
References
NUDOCS 8106290353
Download: ML20005A081 (2)

LER-1981-039, Forwards LER 81-039/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
3691981039R00 - NRC Website

text

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Mr. James P. O'Reilly, Director U.S Nuclear Regulatory. Commission Region II 101 Marietta Street, Suite 3100 Atlanta, Geor,gia 30303 Re: McGuire Nuclear Station Unit 1 Docket No. 50-369

Dear Mr. O'Reilly:

Please find attached Reportable Occurrence Report R0-369/81-39. This report concerns the power operated relief valve INC-34 being declared inoperable.

This incident was considered to be of no significance with respect to the health and safety of the public.

Ve truly yours, I

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William O. Parker, Jr RWO:pw Attachment ec: Director Mr. Bill Lavallee Office of Management and Program Analysis Naclear Safety Analysis Center U.S. Nuclear Regulatory Comnission Post Office Box 10412 Washington, D.C.

20555 Palo Alto, California 94303 4: I m.

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O McGUIRE NUCLEAR STATION INCIDENT REPORT

. Report Number: 81-39 Report Date: April 24, 1981 Occurrence Date: April 3, 1981 Facility:

McGuire Unit 1, Cornelius, N.C.

_ Identification of Occurrence:

was declared inoperable.

Power operated relief valve (PORV), INC34A

_ Condition Prior to Occurrence: Mode 5 Description of Occurrence:

lifting while in automatic. On April 3, 1981 at 2257 hours0.0261 days <br />0.627 hours <br />0.00373 weeks <br />8.587885e-4 months <br />, PORV INC34A was INC34A became inoperable.Its associated block valve (lo INC33A, was closed.

Thus, degraded mode of operation as stated in Techrical Sp This constituted a ecification 3.4.10.3.

Apparent Cause of OccurrenceL:

maintained at 355 psig.

Reactor Coolant System pressure was being However, because the setpoint range for the PORV is 0 3000The low pre difficult to. set it exactly.

psig, it is very the best accuracy reasonably achievableI&E personnel indicated that a 30 psi range is set on the low side.

The actual setpoint was apparently Analysis of Occurrence:

vides Reactor Coolant System protection during lov temper tThe POR This pro-water solid operation.

INC34A are equipped with the low pressure setpoint soOnly one PORV is a ure (<300 F),

protection.

Pressure was reduced from 355 psig to 340 psigWhen INC34A lifte ock valve.

an operable status and no. further problems were expThis returned the valve to erienced.

_ Corrective Action _:

Af ter PORY INC34A lif ted, its associated block INC33A was closed.

re-opened.

The PORV was declared operable again at 2348 hours0.0272 days <br />0.652 hours <br />0.00388 weeks <br />8.93414e-4 months <br />

Safety Analysis

available for operation.During the time INC34A was inoperable, INC323 was still safety of the public were not affected.It is a 100% redundant valve 'so the health and