ML20009C214

Forwards LER 81-057/03L-0.Detailed Event Analysis Encl

ML20009C214
Person / Time
Site:	McGuire
Issue date:	05/15/1981
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20009C215	List: ML20009C214 ML20009C219
References
NUDOCS 8107200381
Download: ML20009C214 (2)

Text

_ _ _

. 's OFFICIAL > CW DUKE POWERT CUNMSY '

~

hb d ~'Oi Powra Utst.ntso

' 422 SocTu Cucacu STnEET, CnAH1DTTE, N. C. 28242

. ..,,- .,g . d 'd i w w A,4 o. pan =ca,sa.

1. c,p.c.,er , May 15, 1981 rca.-o~c:4.c. ,o.

sec.- p coveto~ 2,2-4ees I

Mr. J. P. O'Reilly, Director

'J. S. Nuclear Regulatory Commission Region II U '

101 Marietta Street, Suite 3100 /4 .

9, Atlanta, Georgia 30303 Re: McGuire Nuclear Station Unit 1 I L I II38l A =

Docket No. 50-369 k "'"Dgte Qf i

Dear Mr. O'Reilly:

Please find attached Reportable Occurrence Report R0-369/81-57. This rcport concerns the Upper Head Injection System being declared inoperable.

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

! Very truly yours, f.

William O. Parker Jr.

RWO/djs Attachment cc: Director Mr. Bill Lavalee Office of Management and Program Analysis Nuclear Safety Analysis Center U. S. Nuclear Regulatory Commission Post Office Box 10412 Washington, D. C. 20555 Palo Alto, California 94303 M. J. Graham NRC - Resident Inspector p McGuire Nuclear Sr.ation / f L

l 8107200381 810515 PDR ADOCK 05000369 S pop

McGUIRE NUCLEAR STATION INCIDENT REPORT REPORT NUMBER: 81-57 REPORT DATE: May 7, 1981 OCCURRENCE DATE: April 17, 1981 FACILITY: McGuire Unit 1, Cornelius, N.C.

IDENTIFICATION OF OCCURRENCE: Upper Head Injection (UHI) System declared inoperable.

CONDITIONS PRIOR TO OCCURRENCE: Mode 3, Hot Standby DESCRIPTION OF OCCURRENCE: Several times beginning on April 17, 1981, the UHI System was declared inoperable. The UHI surge tank low pr?ssure alarm was received in the Control Room. The pressure was approximately 1200 psig. This was reportable pursuant to Technical Specification 3.5.1.2.

APPARENT CAUSE OF OCCURRENCE: Various Safety Injection (NI) System valves have been found to be leaking which apparently allowed the UHI surge tank to drain down and thus reduce tank pressure.

ANALYSIS OF OCCURRENCE: At 1456 hours0.0169 days <br />0.404 hours <br />0.00241 weeks <br />5.54008e-4 months <br /> on April 17, 1981, a low UHI surge tank pressure alarm was received in the Control Room. Water was added to the surge tank and the alarm cleared. At 2146 hours0.0248 days <br />0.596 hours <br />0.00355 weeks <br />8.16553e-4 months <br />, the low pressure alarm was again received. Since the surge tank water was within normal limits, nitrogen was added and the alarm was cleared at 2220 hours0.0257 days <br />0.617 hours <br />0.00367 weeks <br />8.4471e-4 months <br />. On April 18, at 0610, 1028, and 1519 hcurs, the surge tank low pressure alarm was received in the Control Room. Water was added to the surge tank each time and the alarm was cleared at 0628, 1120, and 1559 hours0.018 days <br />0.433 hours <br />0.00258 weeks <br />5.931995e-4 months <br /> respectively. The UHI surge tank pressure was monitored and water was added as needed to insure the pressure stayed within normal operating limits. Several NI valves have been found to be leaking and work requests were written to repair them, t

I

' SAFETY ANALYSIS: The UHI system is passive and only used during a loss-of-coolant accident. Since there was only new fuel in the core, safe plant operation and the health and safety of the public were not affected. If the I reactor had been at power and a NC system break had occurred, the UHI System l

would have functioned as designed because the UHI surge tank level and l pressure were close to its normal operating limits.

CORRECTIVE ACTION: The UHI surge tank was filled with water after the low pressure alarm was received in order to increase level and pressure to within normal limits. Work Requests have been written to repair the i

leaking NI valves, i

. _ _ _ - _ _ _ _ _