ML20086G353

Environ RO 75-26:on 751116,two Towers Simultaneously Inoperable.Caused by Failure of Lubricating Water Pump Motor Bearings.Lubricating Water Pump Motor Bearings Replaced

ML20086G353
Person / Time
Site:	Peach Bottom
Issue date:	11/26/1975
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Boyd R Office of Nuclear Reactor Regulation
References
RO-75-26, NUDOCS 8401110248
Download: ML20086G353 (2)

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November 26, 1975 9 i ligc',,d137S

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• h5N"" h Mr. Roger S. Boyd ( * $$ i Acting Director g , g, Division of Reactor Licensing m Office of Nuclear Regulatory Coninission United States Nuclear Regulatory Conmission Washington, DC 20555

Subject:

Environmental Deviation The following deviation was reported to Mr. Walt Baunack, Region 1, Office of Inspection and Enforcement, United States Nuclear Regulatory Commission on November 17, 1975

Reference:

License Number DPR-M/56 Environmental Technical Specifications: 2.1 Report No.: 50-277/278-75-26 Report Date: November 26, 1975 Deviation Date: November 16, 1975 Facility: Peach Bottom Atomic Power Station Units 2 and 3 R. D. 1, Delta, Pennsylvania 17314 Identification of Deviation: ,

Two cooling towers simultaneously inoperable.

Conditions Prior to Deviation:

Unit 2 shutdown. Unit 3 operating at approximately 55% power.

The ' A' cooling tower out of service due to a previous lif t pump, bearing failure. The 'B' cooling tower was fully operable during the outage.

River flows varied between 56,000 and 38,000 cfs.

Description of Deviation:

On November 16, 1975, the 'C' cooling tower lift pump tripped due to the failure of its associated lubricating water pump. During the outage, an inspection of the cooling tower identified the need for additional corrective maintenance on the tower structure and f an bearing supports. This maintenanco significantly increased the cooling tower outage. f 05 .

50-277/278-75-26

.Mr. Rocer S. Bo Page 2 Novcmber 26, 1975 Desinnation of Apparent Cause of Deviation:

Failure of the lubricating wate- pump mocor bearings.

Analysis of Deviation:

Di f ferential temperatur es between the Pennsylvania-Maryland State Line and Holtwood Dam remained within Pennsylvania State limit s.

High river flows and the low plant power production during this period minimized the thermal impact of this occurrence.

. -Corr ec tive Ac tion :

The 'C' lif t pump was returned to service on November 26, 1975 af ter replacing the lubricating water pump motor bearings.

the shaft The inspection made during the outage revealed that fan had been di slodged from its mounting and had bearina box of the 'D' The bearing box had severcly damaged the been thrown by the fan shaft.'D' f an blades and had brchen some of the tower lower edge of two of tb:

int ernal s tructural support e.s An inspection of the shaf t bearing boxes on the rouainino fans was made to ensure that all supports were tight.

Addi tional bact -up lock nuts were also installed. High vibration on the 'C' and 'K' fans was correc ted by re-ali gnment.

failure Data:

None similar.

Very truly your s, M. ' Cooney Superi nt endent

- Generation Division - Nuclear cc: Mr. J. P. O'Reilly Director, Region 1 Office of Inspection and Enforcement Uni ted States Nuc1 car Regulatory Comni ssion 631 Park Avenue King of Prussia, PA 19f4 06 l

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