05000245/LER-1979-030, Forwards LER 79-030/03L-0

Forwards LER 79-030/03L-0

ML19210C425
Person / Time
Site:	Millstone
Issue date:	11/08/1979
From:	Opeka J NORTHEAST UTILITIES
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19210C426	List: 05000245/LER-1979-030, Forwards LER 79-030/03L-0
References
MP-1-1339, NUDOCS 7911140236
Download: ML19210C425 (2)

LER-1979-030, Forwards LER 79-030/03L-0

Event date:
Report date:
2451979030R00 - NRC Website

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L November 8, 1979 f4P-1-1339 Mr. Boyce H. Grier Director, Region I Office of Inspection and Enforcement U. S. flucicar Regulatory Commission 631 Park Avenue King of Prussia, Pennsy'Ivania 19406

Reference:

Provirional License DPR-21 Docket flo. 50-245 Reportable Occurrence R0-79-30/3L

Dear !!r. Grier:

This letter forwards the Licensee Event Report for Reportable Occurrence R0-79-30/3L required to be submitted within 30 days pursuant to the requirements of the liillstone Unit 1 Technical Specifications, Section 6.9.1.9b.

An additional three copies of the report are enclosed.

Yours truly, CL

. F.yOpeka Station Superintendent liillstone fluclear Power Station JF0/RHY:lla

Attachment:

(LERR0-79-30/3L)

Director, Office of Inspection and Enforcement, Washington, D.C.

cc:

(30)

Director, Office of lianagement Info cation and Program Control, Washington, D.C. (3)

' '9 266 7911140 h 3 b S

.ATTACHMErlT TO LER 79-30/3L NORTHEAST NUCLEAR ENERGY C0f!PANY MILLST0tlE flVCLEAR POWER ST.ATI0fl - UNIT 1 PROVISIONAL LICENSE ?! UMBER - DPR-21 DOCKET NUtiBER 50-245 IDENTIFICATI0fl 0F OCCURREtlCE Operation of the unit in a degraded mode permitted by a limiting condition for operation occurred when the emergency diesel generator was adminis-tratively declared inoperable due to missing seismic restraints on cooling water piping.

CONDITIONS PRIOR TO OCCURRENCE Prior to the occurrence the unit was operating at 100 percent steady state with piping restraint inspections in progress.

DESCRIPTI0fl 0F OCCURRENCE On October 9,1979, at 1545 hours0.0179 days <br />0.429 hours <br />0.00255 weeks <br />5.878725e-4 months <br />, the emergency diesel generator was adainistratively removed froa service. Uhile conducting piping seismic restraint inspections in accordance with NRC Bulletin 79-14, it was discovered that two diesel service water piping restraints had not been installed during original construction. Although these restraint locations were identified on the original stress isometric drawings, restraints were not shown, at these locations, on the construction drawings.

DESIGNATION OF APPARENT CAUSE The diesel generator was adninistratively declared inoperable for approxi-mately 52 hours6.018519e-4 days <br />0.0144 hours <br />8.597884e-5 weeks <br />1.9786e-5 months <br /> while tenporary piping restraints were fabricated, installed, and certified.

ANALYSIS OF OCCURRENCE Technical Specifications require that adequate power will be available to operate emergency safeguards equipment.

Normally both the gas turbine generator and diesel generator are required to be operable to assure adequate emergency power with no offsite power sources.

However, due to redundancy and reliability of offsite power, one of the two emergency on site power sources may be out of service for limited periods of time, providing two -offsite power sources are available during these periods.

Euring the 52 hour6.018519e-4 days <br />0.0144 hours <br />8.597884e-5 weeks <br />1.9786e-5 months <br /> period when the diesel generator was administratively out of service, two offsite power sources were availab4 wd did satisfy the power availability requirement.

Additionally, the uiesei generator could have been used in any non-seismically degraded power demand situation.

CORRECTIVC ACTION The ten.porary restraints were installed and the diesel was administratively declared operable.

Further information regarding the piping restraints is contained in the unit response to flRC Bulletin 79-14.

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