05000369/LER-1981-018, Forwards LER 81-018/03L-0.Detailed Event Analysis Encl

Forwards LER 81-018/03L-0.Detailed Event Analysis Encl

ML20032B359
Person / Time
Site:	McGuire
Issue date:	03/19/1981
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20032B360	List: 05000369/LER-1981-018, Forwards LER 81-018/03L-0.Detailed Event Analysis Encl 05000369/LER-1981-018-03, /03L-0:on 810219,annunciator Alarm Indicated Loss of Sample Flow on Radiation Monitor 1-EMF-33.Monitor Vacuum Pump Internally Damaged Due to Water Inside Pump.Pump Vanes & Bearings Replaced & Water Removed
References
NUDOCS 8111050467
Download: ML20032B359 (2)

LER-1981-018, Forwards LER 81-018/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
3691981018R00 - NRC Website

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DUKE POWER COMPANT ;.'p,C REP ~

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\\VM WILLIAM O. PA R K E R, J R.

March 19, 1981 Vice Patsaccat Tc tc enow c:Aata704 S7 TAM Paoovction 373-4083 h/.-0$ 0- S N Mr. James P. O'Reilly, Director U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, Suite 3100

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ih NOVO 31981*f l

a Re: McGuire Nuclear Station Unit 1

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f.77 Docket No. 50-369 Sj

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Dear Mr. O'Reilly:

Please find attached Reportable Occurrence Report R0-369/81-18. This report concerns the operability of the noble gas activity monitor, 1-EMF-33, on the condenser evacuation system. This incident was considered to be of no signi-ficance with respec to the health and safety of the public.

Ver truly yours,<

d w.s 6 c+k -

b, William O. Parker, Jr.

RWO:ses Att;achment cc: Director Mr. Bill Lavallee Office of Fbnagement and Program Analysis Nuclear Safety Analysis Center U. S. Nuclear Regulatory Commission P. O. Box 10412 Washington, D. C.

20555 Palo Alto, California 94303 GI l a'

I DR 67 810319 S

K 05000369 PDR

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DUKE POWER COMPANY MCGUIRE NUCLEAR STATION INCIDENT REPORT Report Number: R0-369/81-18 Report Date: March 10, 1981 Occurrence Date: February 19, 1981, 1358 Hours Facilit_r: McGuire Unit No. 1, Cornelius, North Carolina Identification of Occurrence:

The Noble Gas Activity Monitor on the Condenser Steam Air Ejector (EMF-33) was Declared Inoperable Due to Low Sample Flow Condition Prior to Occurrence: Mode 6, Initial Fuel Loading On February 19, 1981 at 1358 hours0.0157 days <br />0.377 hours <br />0.00225 weeks <br />5.16719e-4 months <br />, Operations received an annunciator alarm indicating a loss of sample flow on 1-EFIF-33.

Technical Specification 3.3.3.9 requires EMF-33 to be operable at all times. Consequently, this failure resulted in a degraded mode of operation and necessitated implementation of action state-ment No. 37 of Table 3.3-13.

Apparent Cause of Occurrence:

The loss of flow was the result of the failure of the associated vacuum pump.

Its failure was apparently due to water in the sample lines. This water has been a recurrent problem caused by condensation in the sample line.

Analysis of Occurrence:

Upon receiving a loss of flow alarm on EHF-33, Operations initiated work request No. 101831 OPS, at 1350 hours0.0156 days <br />0.375 hours <br />0.00223 weeks <br />5.13675e-4 months <br />, to have 16E investigate the cause of the failure.

Action statement No. 37 requires grab samples be obtained every eight hours, and analyzed within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Health Physics obtained representative gas samples at eight (8) hour intervals, and the results of these confirmed that the health and safety of the public were not affected.

I&E personnel determined that the air pump was internally damaged due to wate-found inside the pump.

The pump vanes and bearing were replaced, the water ws removed, and the system was returned to normal operation.

It was declared operable at 1107 hours0.0128 days <br />0.308 hours <br />0.00183 weeks <br />4.212135e-4 months <br />, on February 10, 1981.

Corrective Action

The inoperability of EMF-33 has been a recurrent problem and each time, the failure has been attributed to excessive amounts of water in the sample lines.

The sample line will be redesigned to incorporate a seal loop to trap excessive moisture before it reaches the EMF. A Nuclear Station Modification has been submitted by I6E to incorporate an air filter to remove entrained water before it reaches the EMF.

A loop seal will provide the barrier between the air filter drain and the WL system.