ML19275A248

Forwards LER 79-026/03L-0

ML19275A248
Person / Time
Site:	Millstone
Issue date:	09/21/1979
From:	Opeka J NORTHEAST UTILITIES
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19275A249	List: ML19275A248 ML19275A250
References
MP-2-4143, NUDOCS 7910030388
Download: ML19275A248 (2)

Text

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September 21, 1979 MP 4143 Nr. Boyce H. Grier Director, Region I Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406

Reference:

Facility Operating License flo. DPR-65 Docket No. 50-336 Reportable .0ccurrence R0-50-336/79-26/3L-0

Dear lir. Grier:

This letter fonvards Licensee Event Report 79-26/3L-0 required to be submitted within thirty days pursuant to itillstone Unit 2 Appendix A Technical Specifications, Section 6.9.1.9.b, conditions leading to operation in a degraded mode pemitted by a limiting condition for operation. An additional three copies of the report are enclosed.

Yours truly, 4

aJi-

.F Opeka Station Superintendent Millstone Nuclear Power Station JF0/ RAS /llm

Attachment:

LER 79-26/3L-0 '

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

(30)

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

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Y ATTACllMENT LER 79-26/3L-0 Millstone Unit 2 Docket Number 50/336 EVENT DESCRIPTION During steady state power operation, a fluctuation in the indicated level for number 3 safety injection tank was noted with no concurrent plant evolution or change in tank pressure. This resulted in an indicated level reading of 58.4 percent, which exceeds the limit of 58 percent called for by section 3.5.1.b of the Technical Specifications. The indicated level reading was verified to correspond to the level transmitter output. The tank level was then lowered to 57.8 percent. A containment entry was then made, and the. transmitter calibration was checked. As a result of this calibration, the zero adjustment on the transmitter had to be altered. This resulted in a tank level indication of 58.4 percent necessitating a further lowering of tank level to 56.8 percent. The clapsed time between the init'ial level fluctuation and the final adjustment to the tank level was approximately 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br />.

CAUSE DESCRIPTION The cause of the erratic transnitter operation was not detennined. A calibration of the instrument determined that a small correction was needed to the transmitter zero adjustment. On the following day 9/7/79, the transmitter was replaced. This resulted in the tank being declared inoperable for approximately three hours. No significant difference was noted between the level indication before and after the replacement of the transmitter. The transmitter is a General Electric tbdel 555.

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