05000245/LER-1981-042, Forwards LER 81-042/03L-0.Detailed Event Analysis Encl

Forwards LER 81-042/03L-0.Detailed Event Analysis Encl

ML20040B864
Person / Time
Site:	Millstone
Issue date:	01/15/1982
From:	Mroczka E NORTHEAST NUCLEAR ENERGY CO.
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20040B865	List: 05000245/LER-1981-042, Forwards LER 81-042/03L-0.Detailed Event Analysis Encl 05000245/LER-1981-042-03, /03L-0:on 811215,valve 1-SD-1 Torque Switch Was Stuck in Open Position During Cycling to Seat Valve to Prevent Further Leakage.Possibly Caused by Mechanical Binding.Valve Will Be Inspected & Reworked
References
MP-1-1981, NUDOCS 8201260493
Download: ML20040B864 (2)

LER-1981-042, Forwards LER 81-042/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2451981042R00 - NRC Website

text

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IMHtTHI!AST ITI'II.ITII!S b

4ARTFORD CONNECTICUT 06101 (203) 666-6911 k

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Jant.ary M,1981 MP-1-1931 f1r. Ronald C. Haynes Regional Administrator, Region 1 Of fice of Inspection and Enforcement y

U.S. Nuclear Regulatory Commission

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f 631 Park Avenue f'.f '

King of Prussia, Pennsylvania 19406

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Referee:ce:

Provisional License DPR-21

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Docket No. 50-245 Reportable Occurrence R0-81-42/3L

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Dear f1r. Haynes:

x This ietter forwards the Licensee Event Report for Reportable Occurrence R0-P1-42/3L required to be submitted within 30 days pursuant to the requirements of the Millstone Unit 1 Technical Specifications, Section S.9.1.9.b.

An additional three copies of the report are enclosed.

Yours truly, NORTHEAST NUCLEAR ENERGY COMPANY Y

/. Mroczka ]

Stati6n Superintendent Millstone Nuclear Power Station EJM/TST:mo

Attachment:

LER R0-81-42/3L cc:

Director, Office of Inspection and Enforcement, Washington, D.C. (30)

Director, Office of Management Information and Program Control, Washington, D.C. (3)

U.S. Nuclear Regulatory Commission, c/o Document Management Branch, Washington, D.C.

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{DRADOCK 05000245 PDR (f,b*')

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ATTACHMENT TO LER 81-42/3L i

NDRTHEAST NUCLEAR ENERGY COMPANY MILLSTONE NUCLEAR POWER STATION - UNIT 1 PROVISIONAL LICENSE NUMBER DPR-21 D0CET NUMBER 50-245 l

l Identification of Occurrence Conditions leading to operation in a degraded mode permitted by a limiting condition for operation occurred when a Group III isolation valve was declared inoperable.

Conditions Prior to Occurrence l

Prior to occurrence the unit was operating at, a steady state power level of 100 percent.

Description of Occurrence On December 15, 1981, at 1055 hours0.0122 days <br />0.293 hours <br />0.00174 weeks <br />4.014275e-4 months <br />, valve 1-SD-1 was cycled in an attempt to seat the valve to pevent further leakage past the valve.

While cycling 1-SD-1 in the open direction for approximately 10 seconds, the valve torque switch stopped the motor.

Operations personnel attempted to shut the valve but found 1-SD-1 to be inoperable.

Downstream isolation valves 1-SD-2A and 1-SD-2B were verified shut and breakers opened as per Technical Specification 3.7.D.2 requirements.

Technical Specification Table 3.7.1 requires isolation valve 1-SD-1 to be operable during reactor power operating conditions.

On December 21, 1981 a successful attempt was made to shut 1-SD-1 electrically from the control room.

Apparent Cause of Occurrence Presently the cause cannot be determined due to plant Conditions which will not allow an inspection to be made.

With the successful attempt to close 1-SD-1 on December 21, 1981, the valve is sespected to have stuck because of mechanical binding.

Analysis of Occurrence Double isolation valves are provided on lines penetrating the primary containment.

Closure of one of the valves in each line would be sufficient to maintain the integrity of the pressure suppression system. Automatic initiation is required to minimize the potential leakage paths from the containment in the event of a loss of coolant accident.

Failure of the valve in question did not impair the system's ability to meet the Technical Specification containment isolation valve requirements.

1-SD-2A and 1-SD-2B, the redundant isolation valves for 1-SD-1 were found to be operable. Additionally their breakers were placed in the open position, ensuring the valve positions to remain closed while 1-50-1 was inoperable.

Corrective Action

At the next scheduled cold shutdown that permits drywell entry, 1-SD-1 will be inspected and reworked.

Until that time operations personnel will continue to closely observe 1-SD-1.

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