ML20151A612

Special Rept:On 880304,valve Found Improperly Locked During NRC Insp Tour.Caused by Personnel Error.Valve Lineup Performed & Required to Be Locked,Checked & Confirmed to Be Locked

ML20151A612
Person / Time
Site:	Millstone
Issue date:	04/04/1988
From:	Scace S NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
MP-11689, NUDOCS 8804070116
Download: ML20151A612 (2)

Text

O NORTHEAST UTILITIES

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cener.i Orr,ces . seieen street. Bernn. connecticut 1 .u, =. ..ees u : -: a*. P.O BOX 270 wr .n. .w. c:+- H ARTFORD. CONNECTICUT 06141-0270 L L J 7.'.%d,%T,"'[l, (203) 665-5000 April 4, 1988 MP-11689 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D. C. 20555

Reference:

Facility Operating License No. NPF-49, Docket Nc. 50-423 Gentlemen:

FAILURE TO PROPERLY LOCK AN AUXILIARY FEEDWATER PUMP SUCTION VALVE This event is being submitted as a Special Report because no definitive reporting requirements per the guidelines of 10CFR50.73 could be identified. However, this information is considered of sufficient interest to submit this Special Report.

On March 4, 1988 at 1530 hours0.0177 days <br />0.425 hours <br />0.00253 weeks <br />5.82165e-4 months <br /> with the plant at 99% power in Mode 1 at 2250 psia and 587 degrees F, a normally locked open suction valve (3 WA*V2) to the "A" Motor Driven Auxiliary Feedwater (MDAFW) Pump was discovered to have its lock improperly installed. The valve was found improperly locked during an NRC inspection tour.

Immediate corrective action was to lock the valve in position. Since the valve was in its required position, there were no direct safety responses required by the operators, no adverse safety consequences resulted from the incident and the AW System was capable of performing its intended safety function.

An investigation revealed that 3WA*V2 was verified to be locked open by two operators (dual verification) on December 6, 1987. Since that time, no work has been done on the subject valve or any other AW equipment which required tagging or repositioning of the valve. Root cause of the incident was personnel error although firm evidence linking this incident to the lineup perforned on December 6, 1987 could not be established.

A valve lineup was performed on the AW Systems. In addition, all valves located outsi'a the Containment Structure which are in safety related systems and are required to be locked were checked and confitned to be locked. A description of this event and a caution to verify valves are locked by physically inspecting the locking mechanism has been distributed among all tii plant operating shifts.

There have been no previous events where valves that should have been locked were found to be improperly locked.

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Plant Technical Specifications (TS) 4.7.1.2.1.a.3 requires that each non-automatic valve in the AFW flowpath that is not locked, sealed, or otherwise secured in position be verified in its correct position once at least every 31 days. 3FWA*V2 is administrative 1y controlled under a locked valve progran as allowed by the Technical Specificatic..s. Under the locked valve program, it is verified locked in position in accordance with the established frequency requirements for that valve as indicated by the valve lineup performed on December 6, 1987. Firm evidence to believe that the valve was improperly locked dur'ng position verification of 3FWA*V2 could not be established.

Because firm evidence could not be established that the valve had been improperly locked since December 6, 1987, this incident !s not considered to be a violation of the Technical Specifications (reference TS 4.7.1.2.1.a.3). It is assumed that the incident occurred at the time of discovery. S!nce immediate corrective action was taken upon incident discovery, this incident is not reportable per the guidance provided in supplement I to NUREG 1022 and should be addressed as a breakdown in administrative controls. Were this incident considered to be a violation, it wo"Id be reportable pursuant to the reporting requirements of 10CFR50. 7 3 (a) (2) (i) .

The licensee contact for this Special Feport is Nelson Hulme who may be reached at (203) 444-1791, ext. 5398.

Yours truly, NORTHEAST NUCLEAR ENERGY COMPANY

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/ Step en E. Scace ML Station Superintendent Millstone Nuc1 car Power Station SES/NDH:mo cc: W. T. T ussell, Pegion I W. J. Raymond, Senior Resident Inspector i