05000369/LER-1981-139, Forwards LER 81-139/03L-0.Detailed Event Analysis Encl

Forwards LER 81-139/03L-0.Detailed Event Analysis Encl

ML20010G719
Person / Time
Site:	McGuire
Issue date:	09/09/1981
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20010G720	List: 05000369/LER-1981-139, Forwards LER 81-139/03L-0.Detailed Event Analysis Encl 05000369/LER-1981-139-03, /03L-0:on 810812,loss of Water from Reactor Coolant Inventory Exceeded Tech Spec Limit for 4-h Period W/O Operations Knowledge.Caused by Failure to Isolate Reciprocating Charging Pump 1 Relief Valve Prior to Maint
References
NUDOCS 8109220453
Download: ML20010G719 (3)

LER-1981-139, Forwards LER 81-139/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
3691981139R00 - NRC Website

text

.f DUKE POWER COMPANY PowEn Ucu.utwo 422 Sourn Cnuncu STHEET, CHAHwTTE, N. C. aam

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September 9, 19P,1 4

(A Mr. James P. O'Reilly, Director

!;, S. Nuclear Regulatory Commission Region II 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 Re: McGuire Nuclear Station Unit 1 Docket No. 50-369

Dear Mr. O'Reilly:

Please find attached Reportable Occurrence Report R0-369/81-139. This report concerns T.S. 3.4.7.2, " Reactor coolant system leakage shall be limited to:...b. 1 GPM unidentified leakage...."

This incident was con-sidered to be of no significance wit' respect to the health and s

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the public.

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'1 x Very tritly yours, i

SEP2 21981- %

ngarmi u.s.

William O. Parker, Jr.

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M MI'.sb' PBN/php Attachment cc: Director Mr. Bill Lavallee Office of Manageraent and Program Analysis Nuclear Safety Analysis Center U. S. Nuclear Regulatory Commission P. O. Box 10412 Washington, D. C. 20555 Palo Alto, California 94303 Ms. M. J. Graham Resident Inspector-N"C McGuire Nuclear Station [hY s

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McGUIRE NUCLEAR STATION REPORTABLE OCCURRENCE l

REPORT NUMBER:

81-139 REPORT DATE:

September 9, 1981 t'

OCCURREhCE DATE: August 12, 1981 g

l-FACILITY: McGuire Unit 1; Cornelius, N. C.

IDENTIFICATION OF OCCURRENCE: A loss of water from the reactor coolant 1

.(NC) inventory, in excess of one gpm, occurred without Operations' knowledge t

for about four hours.

CONDITIONS PRIOR TO OCCURRENCE: Mode 2, Start-up DESCRIPTION OF OCCURRENCE: 'On August 12, 1981 maintenance personnel' broke the flange on the outlet of the Reciprocating Charging Pump #1 Discharge

- Line Safety-Relief Valve to begin work on the valve. They expected to drain water from the line for an extended period of time and had assembled a funnel, hose, plastic sheet and clamps to direct the drainage to a floor drain in the Reciprocating Charging'(PD) Pump Room. The outlet of this valve is I

connected directly to-the Volume Control Tank (VCT) without any isolation-f valves in between. Maintenance personnel were unauare of the source of the

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drainage and thought they were draining an isolated volume. Operations

. personnel were unaware that water was being drained.from the VCT, and the water was being replaced by the automatic makeup system. -The drainage began between 0930 and 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br />. Maintenance left the area about 1230 for lunch.

I About 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br />, control room.~ operators"not' iced the abnormally high makeup-l flow'to the VCT, and began looking for leaks. Health Physics personnel, touring the auxiliary building, noticed.the drain setup and called the control room to'ask about it.

Immediately after'the call, the Shift Super-visor ansked Maintenance if they were working;on the vals. When they.

replied that they were, they were instructed to reconnect the outlet flange on the valve and stop the drainage. The flange was reconnected and the leak stopped at about 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br />.

APPARENT CAUSE OF OCCURRENCE: Operations failed to adequately isolate the valve before giving maintenance ch irance to begin work.

t ANALYSIS OF OCCURRENCE: In order to investigate, loud noises associated with operation of the PD Pump, a work request was-written to examine the Recip-

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rocating Charging Pump-Accumulator. Operations isolated and drained a section.

l of the Chemical Volume and Control (NV) System around the pump to prepare l

- for this work. The safety-relief valve.was used as one.lof the isolation valves. Later, a second work request was written to disassemble and check-the valve in case the improper cycling of this valve was contributing to the noise problem. When the second work request was brought to the attenthn of-the duty engineer, he was distracted by other problems and only gave it a cursory glance.

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l Report Number 81-139 Page 2 He told the operators that the PD Pump was already isolated and tagged and no further action was necessary. The duty engineer failed to realize that the outlet of the valve was connected directly to the VCT and could only be isolated by a freeze seal.

SAFETY ANALYSIS

The drainage of water from the VCT never resulted in an unacceptable level of water in the tank and did not seriously challenge the capacity of automatic makeup system. :At no time was the inventory of water in the NC System reduced or threatened. The water was sampled for radio-l activity when the draining began and was completely contained by the hose setup and directed to the Nuclear Waste System. The flow rate was also j

controlled by the opening in the flange and the capacity of the hose.

l Operators were enable to determine actual leakage from the NC System during this time because VCT level and makeup are part of the NC System leakage calculations. Since no NC System water was lost the safe operation of the plant and the health and safety of the public were not affected by this incident.

l CORRECTIVE ACTION _: Operations personnel were cautioned to thoroughly review work requests for proper isolation and drainage action, and were reminded that outlet of relief valves cannot be isolated from their respective dis-charge tanks by isolation valves. Maintenance personnel were directed to stay at the locatica of any drainage work until it is complete. They were also told to contact Operations if a system continues to drain past a reasonable time, consiaer.'ng-thu volume involved l

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