ML20085F377

AO AO-75-7:on 750406,plant Discharge Effluent Heat Rate & Discharge Temp Increase Found Greater than Tech Spec Limits. Apparently Caused by Plant Procedure Problems & Beginning Operation of Newly Installed Closed Cycle Cooling Sys

ML20085F377
Person / Time
Site:	Palisades
Issue date:	04/16/1975
From:	Sewell R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	Office of Nuclear Reactor Regulation
Shared Package
ML20085F367	List: ML20085F358 ML20085F377 ML20085F388
References
AO-75-7, NUDOCS 8308220071
Download: ML20085F377 (2)

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$ ) Consumers Power company NsC/j s General Offices: 212 West Machigan Avenue, Jackenn Michigan 49201

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April 16, 1975

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'I Division of Reactor Licensing Re: Docket 50-255 US Nuclear Regulatory Commission License DPR-20 Washington, DC 20555 Palisades Plant A0-75-7 Gentlemen:

Attached is Itbnormal Occurrence Report A0-75-7 which covers the release of heated water at a rate and temperature which exceeded the Tech-nical Specifications limits. There were no safety implications associated (dp) with this occurrence.

Yours very truly, Ralph B. Sewell (Signed)

DAB /ce Ralph B. Sewell Nuclear Licensing Administrator CC: JGKeppler, USNRC l

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ABNORMAL OCCURRENCE REPORT

] Palisades Plant i

i 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 standby / operating 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.

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7 . Apparent Cause of Occurrence: The cause of this occurrence appears to be as-

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 unlikely to have occurred.

9. Corrective Action:

a. The discharge heat rate was reduced below the Technical Specifications l

limit when the "A" cooling tower was placed in service.

j 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/A.

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l This occurrence is similar to A0-75-6.

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