ML20055D405

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Special Rept:On 900607,inoperable Fire Suppression Water Sys Not Restored within 7-day Time Frame Per Tech Spec 3.14.B.2. Caused by Worn Bearing/Impeller Assembly.Efforts Underway to Procure Spare Bearing Housings for All Fire Pumps
ML20055D405
Person / Time
Site: Prairie Island  Xcel Energy icon.png
Issue date: 06/28/1990
From: Parker T
NORTHERN STATES POWER CO.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation
References
NUDOCS 9007060271
Download: ML20055D405 (2)


Text

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Nortem testes Power Comparty 414 Nicohet Mall Minneapolis, Minnesota 654011927 Telephone (611) 330 5500 June 28, 1990 Tech. Spec. 3.14.B.2 Director of Nuclear Reactor Regulation U S Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 PRAIRIE ISIAND NUCLEAR GENERATING PLANT Docket Nos. 50-282 License Nos. DPR 42

$0 306 DPR 60-Loss of Fire Sunoression Water System Redundancy Technical Specification 3 14.B.1 requires that che Fire Suppression Water System be operable at all times with the diesel and motor driven fire pumps and_the screen wash pump operable. Technical Specif! cation 3.14.B.2 requires that, "With one or two of the pumps required by Specific:. tion 3.14.B.1.a inoperable, restore the inoperable equipment to operable status within 7 days

.or provide a special report to the Commission within 30 days outlining the plans and procedures to be used to provide for the loss of redundancy in the Fire Suppression Water System". This special report is being submitted in accordance with Prairie Island Technical Specification 3.14.B.2.

No. 121 screen wash pump was removed from service on May 29, 1990 to investigate abnormal vibration and axial movement of the pump shaft. The pump was disassembled to determine the cause of the problem. It was determined that the bearing / impeller assembly was woru and needed to be repicced. Upon further disassembly, it was discovered that one of the bearing housings was worn and also had to be replaced. Bearing housings are not maintained as spare parts for the screen wash pump and had to be procured frota the manufacturer. The procurement of the replacement bearing housing took 2 days which resulted in a delay in the repair of the screen wash pump. Pump repair was not cotopleted until June 7,1990. This was two days beyond the seven day period allowed by Technical Specification 3.14.B.2.

During the time when No. 121 Screen Wash Pump was out of service, No. 121 motor driven fire pump and No. 121 diesel driven fire pump were available for service. In addition, the cooling water to the fire header crossover valves were available t., maintain the fire header pressure from the cooling water

. system if required.

9007060271 900628 $

PDR *ADOCK 05000282 S FDC j. [/\{0 \

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' :: , , . .n Dir:ct:r cf NRR l p,- J.une 28, 1990

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Northem States Power Company In response to this event, efforts are underway to procure spare bearing housings for all the fire pumps.

Please contact us if you require additional information.

b Thomas M Parker Manager Nuclear Support Services I

c: Regional Administrator Region III, NRC Senior Resident Inspector, NRC NRR Project Manager, NRC C Charnoff~

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