NRC-96-0113, Withdraws Plans for Implementation of Mod During Fifth Refueling Outage to Moisture Separator Reheaters to Improve Moisture Removal

Withdraws Plans for Implementation of Mod During Fifth Refueling Outage to Moisture Separator Reheaters to Improve Moisture Removal

ML20128H626
Person / Time
Site:	Fermi
Issue date:	10/04/1996
From:	Gipson D DETROIT EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CON-NRC-96-0113, CON-NRC-96-113 NUDOCS 9610100010
Download: ML20128H626 (2)

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Douglas R Gipson Senior Vce Pres # dent Nuclear Gt neration DOITOli rer e 6400 North Dme Highway Newport. Mrchigan 48166 (313) 586-5249 I

l October 4,1996 NRC-96-0113 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555

References:

1) Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43

2) Detroit Edison Letter, NRC-95-0100, dated October 20,1995

3) Detroit Edison Letter, NRC-94-0075, dated August 24,1994

4) NRC Letter, Martin to Gipson, dated December 28,1993

5) Detroit Edison Letter, NRC-94-0093, dated October 13,1994

6) NRC Letter, Colburn to Gipson, dated December 1,1994

Subject:

Change to Commitment on Moisture Separator Reheaters In Reference 2, Detroit Edison committed to implement a modification during the fifth refueling outage (RFOS) to the Moisture Separator Reheaters (MSR) to improve '

moisture removal. The purpose of this letter is to formally withdraw plans for this modification.

The commitment to modify the MSRs during RF05 replaced an earlier commitment in Reference 3 to perform moisture carry over/ moisture removal testing following the fourth refueling outage. The original commitment was made in response to the NRC nnnnn, I

9610100010 961004 PDR ADOCK 05000341 p PDR

USNRC

, October 4,1996 l l NRC-96-0113 Page 2 l

Confirmatory Action Letter (CAL) on the December 25,1993 turbine event

. (Reference 4). The NRC issued a Safety Evaluation on the restart issues of the main

} steam turbine in Reference 6. The commitment was documented in Reference 6, but i not explicitly credited in the NRC findings or conclusions.

l The most important turbine modification scheduled for RF05 is replacement of the  !

Iow pressure turbine steam path. Replacement of the low pressure steam path during l l RF05 as committed in Reference 3, is the principle long term corrective action for the i December 25,1993 turbine event. The new low pressure turbine rotors have been i designed to operate with the existing MSRs. Additionally, recently installed

instrumentation indicates that the MSR performance is closer to design performance i and therefore better than previously indicated. For these reasons operation with the i existing MSRs will not have an adverse impact on the new low pressure turbines.

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. Withdrawal of the MSR modification will eliminate congestion on the turbine deck j and potential interference with the more important low pressure turbine steam path j replacement. This will allow a more cencentrated focus on the turbine replacement j project. Potential udustrial safety challenges due to the number of activities in the congested area would also be prevented.

l j The revised commitment is:

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Detroit Edison will reassess performance of the MSRs following RF05 and determine

an appropriate course of action.

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j The effects of this change will be improvement of the implementation of the low

{ pressure steam flow path replacement, and postponement ofimproved thermal

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i efficiency and corresponding economic benefit to Detroit Edison. l

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If there are any questions, please contact Peter W. Smith at (313) 586-4097, s

Sincerely, .

cc: A. B. Beach M. J. Jordan A. J. Kugler A. Vegel

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