ML20212Q058

Responds to 870123 Request for Inquiry Into 870101 Automatic Shutdown of Plant,Plant History & Public Safety Factors.Shutdown Caused by Obstruction in Lubrication Oil Line & Damage to Turbine Bearing & Main Shaft

ML20212Q058
Person / Time
Site:	Davis Besse
Issue date:	03/17/1987
From:	Zech L NRC COMMISSION (OCM)
To:	Kaptur M HOUSE OF REP.
Shared Package
ML20209A941	List: ML20209A936 ML20209A978 ML20209B036 ML20209B099 ML20209B104 ML20209B147 ML20209B256 ML20209B399 ML20209B453 ML20209B680 ML20209B739 ML20209B817 ML20209B839 ML20209B958 ML20209C058 ML20209C138 ML20209C191 ML20209C309 ML20209C372 ML20209C397 ML20212Q058 ML20212Q062 ML20212Q066 ML20212Q110
References
NUDOCS 8703230067
Download: ML20212Q058 (6)

Text

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NUCLEAR REGULATORY COMMISSION

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C W ASHINGTON. O. C. 20555

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• • ...* March 17, 1987 CHAIRMAN The Honorable Marcy Kaptur United States House of Representatives Washington, DC 20515

Dear Congresswoman Kaptur:

I am responding to your January 23, 1987 letter in which you request an inquiry into the January 1, 1987 automatic shutdown of the Davis-Besse Nuclear Power Station. In your letter, you also refer to the troubled history of the facility and the public safety factors involved.

The failure of the main feedpump, and subsequent plant shutdown, is not related to any of the corrective actions taken since the June 9, 1985 loss-of-feedwater event. Our Region III inspection staff has reviewed the event and followup analysis by Toledo Edison Company and is satisfied that the failure could not have been predicted through normal maintenance and operational activity. The Commission does not believe that any further inquiry beyond the followup by the NRC staff is warranted at this time.

The Davis-Besse facility resumed operations on December 22, 1986, following an 18-month shutdown which began with the June 9, 1985 loss-of-feedwater event. Immediately following the event, the NRC-sent a fact-finding team to the site to investigate the event to determine what happened and why.

In response to the investiaation team's findings and other initiatives by the NRC staff, Toledo Edison Company took action to correct the deficiencies and restored the condition of the plant to the level necessary for safe and reliable operation. These efforts were reviewed by the NRC prior to its approval of the restart of the Davis-Besse plant.

An important part of these efforts was a detailed system review and test program to verify proper system design, configuration, and operation. The first automatic shutdown of Davis-Besse since  ;

l operation was resumed occurred on December 23, 1986 at 15% power while a special test was being conducted on the integrated control system. Subsequent investigation showed the shutdown was caused i

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by an error in the test procedure itself. All safety systems operated as they were designed to bring the plant to a safe shutdown. The procedure error was corrected and the test was then successfully completed.

The January 1, 1987, shutdown was caused by an obstruction in a lubrication oil line on one main feedpump turbine resulting in overheating and damage to the turbine bearing and main shaft.

Because the second main feedpump was out-of-service for maintenance, the plant was automatically shut down. Again, all safety systems functioned properly. The obstruction was found to be a drain plug. Plant records show it would have been present from maintenance work done during or prior to the 1984 refueling outage since there has been no access to that portion of the turbine since that time.

The NRC has been monitoring licensee performance in all areas since before startup and will continue to do so. We will provide our overall evaluation of the effectiveness of the licensee's programs and performance at the end of a six-month period starting with restart of the facility. The NRC staff is generally encouraged by day-to-day observations of the performance of the licensee to date, and believe that the corrective actions taken will be effective.

Sincerely, W. .

L a n d o 11. Z e , Jr l

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