ML20009C113

Forwards LER 81-089/03L-0.Detailed Event Analysis Encl

ML20009C113
Person / Time
Site:	McGuire
Issue date:	06/18/1981
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20009C114	List: ML20009C113 ML20009C118
References
NUDOCS 8107200296
Download: ML20009C113 (2)

Text

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• • ' O Piq DUKE POWER COMPANY P Powsu Buttutxo 422 SocTu CutHcu STREET, CIMHLoTTE, N. O. 28242 g-W WI L LI AM O. PAR K ER J R.

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Mr. James P. O'Reilly, Director U. S. Nuclear Regulatory Commission U

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Region II L{3-, lw 101 Marietta Street, Suite 3100 ' { i ).) N3 Atlanta, Georgia 30303 ~ g y 7 ;ggy, % ~

5, " "w P 4 Re: McGuire Nuclear Station I' nit 1 4 Docket No. 50-369  %-i%, - ,8

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Dear Mr. O'Reilly:

Please find attached Reportable Occurrence Report R0-369/81-89. This report concerns the noble gas activity monitor, EMF-33 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, William O. Parker, Jr. / -

A RWO:pw Attachment cc: Director Mr. Bill Lavallee Office of Management & Program Analysis Nuclear Safety Analysis Center U.S. Nuclear Regulatory Commission P. O. Box 10412 Washington, D. C. 20555 Palo Alto, CA 94303 Ms. M. J. Graham Resident Inspector - NRC McGuire Nuclear Station 8107200296 810618 PDR ADOCK 05000369 S PDR h/ :

McGUIRE NUCLEAR STATION INCIDENT REPORT Report Number: 81-89 Report Date: June 18, 1981 Occurrence Date: May 22, 1981 Facility: McGuire Unit 1, Cornelius, N. C.

Identification of Occurrence: The noble gas activity monitor (EMF-33) on

.he Condenser Steam Air Ejector (ZJ) System was declared inoperable.

Condition Prior to Occurrence: Mode 5, Cold Shutdown. Prior to initial criticality.

Description of Occurrence: A loss of sample flow alarm sounded in the Control Room on the morning of May 22. An examination of the monitor revealed no evidence of water in the sample line but the system would not function in the

' Auto' mode. The Shift Supervisor declared EMF-33 inoperable. This was a re-portable incident pursuant to Technical Specification 3.3.3.9 and required implementation of Action Statement No. 37 of Table 3.3-13.

Apparent Cause: Due to the recurrent problem of water being aspirated from the loop seal into the vacuum pump and causing damage to the system, the vacuum switch was adjusted from 8" W.C. to 2" W.C. This reduced the amount of water entering into EMF but possibly made the system more sensitive to minor fluct-uations in the vacuum present in the ZJ System.

It is believed that a spurious fluctuation in the system's vacuum caused the low flow alarm to occur.

Analysis of Occurrence: On May 22 at'0840 hours0.00972 days <br />0.233 hours <br />0.00139 weeks <br />3.1962e-4 months <br /> a loss of sample flow alarm was received in the Control Room. Health Physics was notified and requested to investigate. At 02*0 hours H.P. reported to Control Room personnel that the monitor would function in the ' Manual' mode; not in the ' Auto' mode. The Shift Supervisor declared the System inoperable at 0930 hours0.0108 days <br />0.258 hours <br />0.00154 weeks <br />3.53865e-4 months <br /> and instructed the H.P. technician to write a work request to have the system checked out and repaired as necessary.

The EMF was examined and the EMF vacuum pump was turned on again and functioned.

correctly. The system was declared operable at 1135 hours0.0131 days <br />0.315 hours <br />0.00188 weeks <br />4.318675e-4 months <br /> on May 22, 1981.

Safety Analysis: Only new, non-irradiated fuel existed in the core at the time of this incident. Sample analysis of the Reactor Coolant (NC) and the ZJ Systems confirmed that no radiation levels above background were present. Thus, the safe operation of the plant and the health and safet) of the public were not affected by this incident.

Corrective Action: Grab samples were taken and analyzed every eight hours as required by Action Statement No. 37 of Table 3.3-13. Health Physics initiated a work request to have the system repaired. A technician checked out the sys-tem vacuum switch and restarted the vacuum pump.

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