ML18353B234

Abnormal Occurrence Report AO-75-7 Re Release of Heated Water at Rate & Temperature Exceeded Tech Spec Limits

ML18353B234
Person / Time
Site:	Palisades
Issue date:	04/16/1975
From:	Sewell R Consumers Power Co
To:	Office of Nuclear Reactor Regulation
References
LER 1975-007-00
Download: ML18353B234 (2)

Text

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• File Cy. Gentlemen:

Re: consumers*

Power company Docket 50-255 License DPR-20 Palisades Plant A0-75-7 Attached is Abnormal Occurrence Report A0-75-7 which covers the release of heated water at a rate and temperature which exceeded the nical Specifications limits. There were no safety implications associated with this occurrence.

D.AB/ce CC: JGKeppler, USNRC Yours very truly, Ralph B. Sewell Nuclear Licensing Administrator I; *2-? j,J "1*

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• ABNORMAL OCCURRENCE REPORT Palisades Plant 1. Report No: A0-75-7, Docket 50-255 2a. Report Date: April 16, 1975 2b. Occurrence Date: April 6, 1975 3. Facility:

Palisades Plant, Covert, Michigan

• 4. Identfication of Occurrence:

Plant discharge effluent heat rate and discharge temperature increase greater than 0.5 billion Btu/hour and 5°F, respectively.

5. Condition Prior to Occurrence:

Plant was in the hot condition.

6. Description of Occurrence:

From 0130 to approximately 0500 on April 6, 1975, the plant was discharging heat at a rate of 1.42 billtion Btu/hour and at a temperature 38°F above the lake inlet temperature.

This occurrence was the result of action taken to reduce the hot well temperature in order to avoid thermal shocking of the condenser tubes. Water from the cooling tower basin and/or dilution pumps was slowly introduced to the condenser and allowed to drain to the lake through the mixing basin

• 7. Apparent Cause of Occurrence:

The cause of this occurrence appears to be sociated with plant procedure problems and the beginning operation of our newly installed closed cycle cooling system. 8. Analysis of Occurrence:

There were no safety implications associated with this occurrence.

An analysis of the mixing zone was made using ANL/ES-5 (April 1971) which showed that the mixing zone area was within the limits specified by the Michigan Water Resources Commission NPDES Permit for the plant. In addition, there were no observed adverse effects upon fish and other biological damage is considered lllllikely to have occurred.

9. Corrective Action: a. The discharge heat rate was reduced below the Technical Specifications limit when the "A" cooling tower was placed in service. b. A study of the closed cycle cooling system has been initiated.

This study will include this and other operational problems which have been observed.

The results_of the study will be available at the plant for review by members of the NRC staff. 10. Failure Data: N/Ao This occurrence is similar to A0-75-6 *