ML20126B551

Confirmatory Action Ltr Re 850609 Reactor Trip.Corrective Actions Listed,Including Reviews of MSIV Actuation & Auxiliary Feed Sys Actuation

ML20126B551
Person / Time
Site:	Davis Besse
Issue date:	06/10/1985
From:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:	Crouse R TOLEDO EDISON CO.
References
CAL, CAL-RIII-85-06, CAL-RIII-85-6, TAC-57932, NUDOCS 8506140134
Download: ML20126B551 (3)

Text

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CONFIRMATORY ACTION LETTER b rn 6 F

" June 10, 1985 Docket No. 50-346 Toledo Edison company ATTN: Mr. Richard P. Crouse c Vice Asesident Nuclear Edison Plaza

-300 Madison Avenue Toledo, OH. 43652 Gentlemen:

This letter confirms the conversations on June 10, 1985, between you and Charles E. Norelius of my staff related to the reactor trip at the Davis-Besse Nuclear Plant on June 9, 1985. While operating initially at 90% power, a reactor trip and other subsequent problems with the main and auxiliary feedwater systems resulted in a situation where no feedwater-flow was available for 10-12 minutes causing low level in the steam generators.

With regard to the matters discussed, we understand you have taken or will take the following actions:

1. Hold in abeyance any work in progress (electrical or mechanical) and/or any work planned on equipment that malfunctioned during the incident, such as dismantling or disturbing existing evidence, until the NRC Investigative Team has had a opportunity to evaluate this event and concur on your proposed corrective action (s).

2. Review main steam isolation valve actuation. ,

a. Establish the cause(s) of the unexplained closure of both MSIVs.

b. Determine and implement the corrective action (s) ~

necessary to prevent recurrence.

c. Perform additional testing to ensure the MSIVs operate as required.

'3. Review the auxiliary feed system actuation.

a. Establish the cause(s) of the inadvertent trip of both auxiliary feedwater pumps (AFP).

b. Determine and implement the corrective action (s) necessary to prevent recurrence.

CONFIRMATORY ACTION LETTER h

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CONFIRMATORY ACTION LETTER D

Toledo Edison Company 2 June 10, 1985

4. Review the main feed system operation.

a. Establish the cause(s) of the inadvertent trip of the No. I main feed pump (MFP).

b. , Determine and implement corrective action (s) to prevent recurrence for both main-feed pumps.

5 . -- Complete and submit to NRC Region III the results of your investigation of this event including your safety evaluation, an evaluation of thermal shock considerations for both Steam Generators (SG), the maximum S/G shell differential temperature, and possible general mechanical damage to any affected system (s). Also report your basis for event classification and the adequacy of information as originally reported to the NRC on June 9, 1985.

6. Complete the actions required by items 1-5 and obtain verbal concurrence from the NRC Region III Regional Administrator or his designee prior to authorizing restart (Mode 2) of the reactor.

7. Main and Auxiliary Feed System Testing.

a. Perform testing which can be performed below 5% power, of the MFP's to demonstrate all pumps operate as required.

b. Perform testing of the AFP's to assure all pumps operate as required.

- c. Appropriate test results, your conclusions, and a summary of corrective actions taken will be provided to the NRC resident office upon completion.

8. After all actions required above are completed obtain verbal concurrence from the NRC Region III Regional Administrator or his designee prior to exceeding 5% reactor power.

CONFIRMATORY ACTION LETTER

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CONFIRMATORY ACTION LETTER RIII-CAL-85-06 a.

Toledo Edison Company 3 June 10, 1985 Please let us know immediately if your. understanding differs from that set

'forth above.

' Sincerely, Original signed by Jar:03 G. Keppler James G. Keppler Regional Administrator cc w/ enclosure:

S. Quennoz, Station Superintendent DMB/ Document Control Desk (RIDS)

Resident Inspector, RIII-Harold W. Kohn, Ohio EPA James W. Harris, State of Ohio Robert H.-Quillin,-Ohio

. Department of Health CONFIRMATORY ACTION LETTER RII RIII RII RI I RIII ktfr 5 Fo ney/kr buress Green b, H rrison we g g s 06/10/85

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