05000369/LER-1981-047, Forwards LER 81-047/03L-0.Detailed Event Analysis Encl

Forwards LER 81-047/03L-0.Detailed Event Analysis Encl

ML20009C105
Person / Time
Site:	McGuire
Issue date:	05/07/1981
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20009C106	List: 05000369/LER-1981-047, Forwards LER 81-047/03L-0.Detailed Event Analysis Encl 05000369/LER-1981-047-03, /81-03L-0:on 810408,while in Mode 4,containment Particulate Radiation Activity Monitor EMF-38 Was Declared Inoperable Due to False High Radiation Alarm.Caused by Low Level Setting of Alarm Setpoints.Setpoints Adjusted
References
NUDOCS 8107200289
Download: ML20009C105 (2)

LER-1981-047, Forwards LER 81-047/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
3691981047R00 - NRC Website

text

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U. S. Nuclear Regulatory Commission

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Region II

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101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 7

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Re: McGuire Nuclear Station Unit 1 M

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Dear Mr. O'Reilly:

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Please find attached Reportable Occurrence Report R0-369/8 -

This report concerns the operability of the containment particulate radiation activity monitor EMF-38.

This incident was considered to be of r.o significance web.

respect to the health and safety of the public.

Very truly yours,

/

William O. Parker, Jr.

RWO:pw Attachment cc: Director Mr. Bill Lavallee Office of Management & Program Analysis Nuclear Safety Analysis Centcr U. S. Nuclear Regulatery Commission P. O. Box 10412 Washington, D. C.

20555 Palo Alto, CA 94303 M. J. Graham Resident Inspector McGuire Nuclear Station

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8107200289 910507 PDRADOCK05000g S

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1 McGUIRE NUCLEAR STATION INCIDENT REPORT Report Number:

81-47 Report Date: April 23, 1981 Occurrence Date: April 8, 1981; 2110 hours0.0244 days <br />0.586 hours <br />0.00349 weeks <br />8.02855e-4 months <br /> Facility:

McGuire Nuclear Station, Unit 1, Cornelius, N. C.

Identification of Occurrence:

The containment particulate radiation activity monitor, EMF-38, was declared inoperable due to a false, con-tinuous high radiation alarm.

Conditions Prior to Occurrence: Mode 4, Hot Shutdown Description of Occurrence:

Personnel in the Control Room received a high radiation annunicator alarm on EMF-38 which could not be cleared. A survey indicated no activity greater than normal background levels.

The EMF was, therefore, declared inoperable by the Shift Supervisor.

This constituted a degraded mode of operation as stipulated by Technical Specification 3.3.3.1 and required going into action statement #25 of Table 3.6.

Apparent Cause:

The high radiation alarm setpoints were set to a very low value. Consequently, the high radiation alarm sounded when radiation levels inc: eased slightly above naturally occurring background levels.

Analysis of Occurrence: Prior to being declared inoperable, Operations had received several high radiation and low flow alarms on EMF-38. Health Physics technicians were dispatched several times to investigate.

Each time, however, the surveys indicated that no radioactivity greater than normal background was present in their grab samples.

These alarms would cease, following the advancement of the paper filter on the EMF.

Technicians tested the EMF and found everything to be in good working order.

The alarm setpoints were modified to prohibit the recurrence of this problem.

This item was cleared at 1430 hours0.0166 days <br />0.397 hours <br />0.00236 weeks <br />5.44115e-4 months <br /> on April 21, 1981.

Corrective Action

Health Physics collected and analyzed air samples from EMF-38/39/40 every eight (8) hours as stipulated by the appropriate Action Statement.

Technicians checked out EMF-38 and modified the alarm setpoints.

The alarm setpoints of this and all affected EMF's are currently being re-set to avoid any future problems.

Safety Evaluation:

The health and safety of the public were not affected by this incident.

No irradiated fuel or airborne radioactivity was pre-sent in the plant at the time of this occurrence.