ML20245C054

Forwards Detailed Responses to Addl Questions Re Facility Following Hearing Before Subcommitte on Energy & Power,Per

ML20245C054
Person / Time
Site:	San Onofre
Issue date:	06/16/1989
From:	Zech L NRC COMMISSION (OCM)
To:	Bates J HOUSE OF REP.
Shared Package
ML13323A481	List: ML20245C054 ML20245C077 ML20245C091
References
NUDOCS 8906260042
Download: ML20245C054 (3)

Text

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             -{                  qi '           WASHINGTON, D. C. 20555
              \,4,,. /                             -June 16, 1989                                         j CHA4tRMAN The Honorable Jim Bates                                                                 0 United. States House of Representatives                                                 l Washington, D. C. 20515
                                                                                                         ]

Dear Congressman Bates:

i 1 In response to your letter of May 11, 1989, I am enclosing our detailed responses to the additional questions you' raised regarding Southern California Edison's San Onofre Unit I facility following last month's hearing before the Subcommittee on Energy and Power. Since that hearing, the Nuclear Regulatory Commission (NRC) staff, on May 16, 1989, authorized the restart of San Onofre Unit 1, and the licensee began to implement its power ascension program on May 21, 1989.

I hope that the information we are providing will resolve your concerns.about the safe operation of this facility. I can assure you that the NRC will carefully monitor-the performance of San Onofre Unit " as.it resumes full power. operation to ensure that the public health.and safety are adequately protected.

Sincerely, Lando W. 7.ec , Jr.

Enclosure:

As stated Df* l I' I l 7_. ..% i OY )g a M /G_ __

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QUESTION 1 Why was the Connecticut Yankee (Northeast Utilities) reactor (Haddam Neck, CN) required by the NRC to make repairs to its thermal heat shield in late 1987 (which had similar broken bolts 1 and cracked supports), but.now the NRC is close to allowino So. Calif. Edison to restart San Onofre.1 without requiring the > l repairs to be made? ANSWER The NRC did not require the repairs made to the Haddam Neck thermal shield in 1987. The repairs were made by the utility on its own initiative, although NRC did review the existing condition of the shield and the licensee's repair plan.. Northeast Utilities' decision to repair the thermal shield was based on the difficulty experienced in removing the lower reactor core support structure, indications'of motion (significant vibration) of the shield, evidence of wear at some of the support blocks (indicating that most of the bolts were broken),. and severe wear of the limiter keys. Since the reactor internals were on the inspection stand for the regular 10-year inservice inspection, it was a logical time to accomplish the necessary repairs. By contrast, none of these conditions existed at San Onofre Unit 1. Video tapes recorded during the visual examination at the time of the last outage showed no sign of motion of the thermal shield and no wear at the support blocks. More detailed information on the condition of the San Onofre Unit I thermal shield is contained in the May 15, 1989 Safety Evaluation Report included in the attachments to Question 3. * . 4 _ _ _ _ _ - _ _ _ - - . __ _-_ ._ -_ _ __ . _ _ _ __. _ _ -_. __. -.__ 2

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               - QUESTION 2'     - NRC ' staff has raised a' number of'other issues and problems related.to San Onofre l'that they want settled before allowing Edison to restart the reactor. Specifically, what are those .

concerns; and will.NRC make the list available? ANSWER Additional issues related to San Onofre Unit-I that needed to be resolved before startup are documented in an NRC letter to Southern California Edison (SCE). dated February 8,1989, a copy of which is attached for your information. l 1}}