05000245/LER-1982-011, Forwards LER 82-011/03L-0.Detailed Event Analysis Encl

Forwards LER 82-011/03L-0.Detailed Event Analysis Encl

ML20054G816
Person / Time
Site:	Millstone
Issue date:	06/07/1982
From:	Mroczka E NORTHEAST NUCLEAR ENERGY CO.
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20054G817	List: 05000245/LER-1982-011, Forwards LER 82-011/03L-0.Detailed Event Analysis Encl 05000245/LER-1982-011-03, /03L-0:on 820508,gas Turbine Trouble Annunciator Alarmed on Panel 908 in Control Room.Caused by Shorted Undervoltage Relay for Ac Lube Oil Pump.Undervoltage Relay Replaced.One Amp Fuse Will Be Added
References
MP-1-2093, NUDOCS 8206220325
Download: ML20054G816 (2)

LER-1982-011, Forwards LER 82-011/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2451982011R00 - NRC Website

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""T" June 7, 1982 MP-1-2093 Mr. Ronald C. Haynes Regional Administrator, Region 1 Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406

Reference:

Provisional License DPR-21 Docket No. 50-245 Reportable Occurrence R0-82-ll/3L

Dear Mr. Haynes:

This letter forwards the Licensee Event Report for Reportable Occurrence R0-82-ll/3L required to be submitted within 30 days pursuant to the requirements of the Millstone Unit 1 Technical Specifications, Section 6.9.1.9.a.

An additional three copies of the report are enclosed.

Yours truly, NORTHEAST NUCLEAR ENERGY COMPANY b

E. J. Mroczka Station Superintendent Millstone Nuclear Power Station EJM/TST:mo

Attachment:

LER R0-82-ll/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 Conmission, c/o Document Management Branch, Washington, D. C. 20555 6'h 8206220325 820607 3

- PDR ADOCK 05000245 S

PDR f

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ATTACINENT TO LER 82-ll/3L NORTHEAST NUCLEAR ENERGY COMPANY MILLSTONE NUCLEAR POWER STATION - UNIT 1 PROVISIONAL LICENSE NUMBER DPR-21 DOCKET NUMBER 245 Identification of Occurrence Operation in a degraded mode permitted by a limiting condition for operation o

occurred when the Gas Turbine Generator A.C. oil pump breaker failed.

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

Description of Occurrence On May 8, 1982, at 1740. hours, a " Gas Turbine Trouble" annunciator alarmed on i

Panel 908. An investigation into the cause of the alarm revealed the A.C. oil l

pump breaker had tripped. Operations personnel attempted to reset the breaker and failed.

The D.C. lube oil pump was secured to conserve the battery and the Gas Turbine -

Generator declared inoperable.

Technical Specifications 3.9.a requires the 1

Diesel Generator and the Gas Turbine Generator (both emergency power sources) to be operable at all times.

Apparent Cause of Occurrence The undervoltage relay for the A.C. lube oil pump shorted and blew the control fuse.

Analysis,of Occurrence Inoperability of the Gas Turbine did not result in a condition which had not t

been analyzed. The Gas Turbine is one out of two emergency power sources that are utilized for engineered safeguard systems.

In an actual emergency condition where emergency core cooling systems are required and a loss of'off-site power accompany it, the Gas Turbine and the Diesel provide emergency power.

Each power source is independent of the other, thereby allowing the Gas Turbine or Diesel to solely provide emergency power to redundant systems if the other fails.

Corrective Action

The undervoltage relay was replaced. Additionally a one amp fuse will be added in series with the undervoltage relay.

This will prevent the main six amp control fuse from blowing if a short develops in the undervoltage relay.