ML20085F655

AO AO-74-15:on 740715,containment Air Cooler Temp Control Valve Body Failed.Apparently Caused by Erosion of Valve Body on Downstream Side of Valve Plug Where Water Exits Through Valve Seat

ML20085F655
Person / Time
Site:	Palisades
Issue date:	07/29/1974
From:	Sewell R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20085F653	List: ML20085F651 ML20085F655 ML20085F657 ML20085F659 ML20085F665 ML20085F671
References
AO-74-15, NUDOCS 8308230117
Download: ML20085F655 (3)

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- conc, i o.,,ce. 2i2 west u.cn.gan Avenue Jackson, M.chigan 49201. Area Code 517 788-0550 July 29, 1974 Directorate of Licensing Re: Docket 50-255 US Atomic Energy Commission License DPR-20 Washington, DC 20545 Palisades Plant Gentlemen:

Attached hereto are copies of two (2) abnormal occurrence reports that occurred recently at the Palisades Plant.

Yours very truly, Ralph B. Sewell (Signed)

RBS/mel Ralph B. Sewell Nuclear Licensing Administrator CC: JGKeppler, USAEC r308230117 760412 PDRADOCKOS000g S

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ABNORMAL OCCURRENCE REPORT Palisades Plant

1. Report Number: A0-Th-15, Docket 50-255

2. a. Report Date: July 29, 197h

b. Occurrence Date: July 17, 197h.

3 Facility: Palisades Plant.

h. Identification of Occurrence: Containment air cooler temperature control valve body, failure of.

5 Conditions Prior to Occurrence: Cold shutdown during steam generator repairs.

6. Description of Occurrence: Plant personnel discovered water dripping on the floor of the containment. Subsequent investigation revealed that service water was dripping on the floor from the valve body of one of four containment air cooler temperature control valves. The service water was shut off, the valve removed from the system, repaired and reinstalled.

7 Designation of Apparent Cause of Occurrence: The apparent cause was erosion of the valve body on the downstream side of the valve plug where the water exits through the valve seat. Defects in the casting in this area may have contributed to the erosion.

! 8. Analysis of Occurrence: Under the plant condition that this valve failed the water was leaking into the containment. However, if an accident had occurred and the valve body had failed as in this case, j air or water from the containment could have entered the service water system and thus the lake. This would only happn 11 the containment j pressure exceeded the service water pressure at this point in the system.

9 Corrective Action:

a. The valve body was removed and repaired.

b. A new valve body conforming to the original specifications was ordered and will be installed at the first convenient outage after its receipt.

c. The othar three (3) identical valves will be inspected,

d. An inspection schedule vill be set up on these four valves to coincide with the refueling outages.

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e. A spare valve that complies with ASME Section III is being procured. It vill be stocked as a replacement valve if the inspection program indicates further degradation.

10. Failure Data: No previous similar failures.