05000245/LER-1981-041, Forwards Revised LER 81-041/03L-1.Detailed Event Analysis Encl

Forwards Revised LER 81-041/03L-1.Detailed Event Analysis Encl

ML20040B195
Person / Time
Site:	Millstone
Issue date:	01/12/1982
From:	Mroczka E NORTHEAST NUCLEAR ENERGY CO.
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20040B196	List: 05000245/LER-1981-041, Forwards Revised LER 81-041/03L-1.Detailed Event Analysis Encl 05000245/LER-1981-041-03, While Performing Gas Turbine Black Start Test,Generator Carrying Load of 7.5 MW for 45 Minutes When Output Breaker Tripped Open.Caused by Governor Instability Due to Oil Contaminants
References
MP-1-1978, NUDOCS 8201250259
Download: ML20040B195 (2)

LER-1981-041, Forwards Revised LER 81-041/03L-1.Detailed Event Analysis Encl

Event date:
Report date:
2451981041R00 - NRC Website

text

.

I NHrl'HI!A!iT llTII.ITII!!i 1

f4fn"fdn!! covacncur mioi (203) f//r6911 k

k iJ January 12, 1982 MP-1 1978 LLElf f1r. Ronald C. flaynes S'

A Regional Administrator, Region 1 M

Office of Inspection and Enforcement sd/

i U.S. fluclear Regulatory Commission

,b

631 Park Avenue King of Prussia, Pennsylvania 19406 Re ference:

Provisional License DPR-21 x

Docket lio. 50-245 y

Reportable Occurrence R0-81-41/3L-1

Dear Mr. llaynes:

This letter forwards the revised Licensee Event Report for Reportable Occurrence R0-81-41/3L sulxnitted on January 8,1982 pursuant to the requirements of the Millstone Unit 1 Technical Specifications, Section 6.9.l.9.b.

An additional three copies of the report are enclosed.

Yours truly, fiORTilEAST flVCLEAR EfiERGY COMPAflY fU &B' E... Mroczka Sta tion "Superintenden t Millstone fluclear Power Station EJM/TST:mo

Attachment:

LER R0-lu-41/3L-1 Director, Office of Inspection and Enforcement, Washington, D.C. (30) cc:

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

U.S. fluclear Regulatory Commission, c/o Decument flanagement Branch, Washington, D.C.

20555 8201250259 820112 gDRADOCK 05000245 PDR

i O

ATTACH!1EilT LER 81-41/3L-1 fl0RTHEAST flVCLEAR EllERGY COMPAtlY MILLST0fiE fiUCLEAR POWER STATI0fl - UllIT 1 PROVISI0ftAL LICEf4SE flVMBER DPR-21 DOCKET fiUMBER 50-245 Identification of Occurrence

~0peration in a degraded mode permitted by a limiting condition for operation i

occurred when the Gas Turbine Generator output breaker tripped open while carrying a load.

Conditions Prior to Occurrence

[

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

Description of Occurrence On December 8,1981, at 0615 hours0.00712 days <br />0.171 hours <br />0.00102 weeks <br />2.340075e-4 months <br />, while performing Gas Turbine Black Start Test, the Gas Turbine generator was carrying a load of approximately 7.5 megawatts for 45 minutes when the output breaker tripped open.

Operations personnel attempted to take manual control of the speed / load control in an effort to re-synchronize and reclose the output breaker.

Since the start j

was initiated by a simulated emergency start condition the Gas Turbine was under automatic control and this could not be accomplished.

T nt. Gas Turbine was then shutdown and declared inoperable. Technical Speci ficatioc 3.F.1 requires both emergency power sources (the Diesel and Gas Turbine) :o be operable I

whenever irradiated fuel is in the reactor.

Apparent Cause of Occurrence The apparent cause of the Gas Turbine output breaker tripping was governor I

instability caused by oil contaminants.

It is suspected that a large power 1

increase which resulted from a sticking pilot valve in the EG-R actuator was overcompensated for causing the power output to decrease to the point where the reverse power relay tripped the output breaker open.

Analysis of Occurrence Failure of the Gas Turbine to carry a load because of an opened output breaker during a Black Start Test did not create a condition which had not been analyzed.

4 The Gas Turbine is one out of two emergency power sources that are utilized for engineered sa feguard systems.

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

Each power source is 1

independent of the other, thereby allowing the Gas Turbine or Diesel to solely provide emergency power if the other fails.

Corrective Action

The governor was inspected, tested and adjusted. Additionally the EG-R actuator was replaced and the oil system was repeatedly flushed with clean oil and run to remove any contaminants that might have been in the oil.

Inspection of the oil reservoir revealed two small particles of foreign material.

To prevent a future reoccurrence a fine mesh screen was installed on the inlet o f the EG-R actuator.