ML19262A960

Interim Deficiency Rept Re Safe Shutdown Boration Capability.Bechtel Preparing Sys Design to Increase safety- Grade Boration Capability.Finalization of Sys Design Estimated by End of Mar 1980.Next Rept by 800411

ML19262A960
Person / Time
Site:	Midland
Issue date:	12/06/1979
From:	Howell S CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
References
HOWE-308-79, NUDOCS 7912110358
Download: ML19262A960 (2)

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Consumers Power

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Stephen H. Howell

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Senior Vice Pressdent Generet offices: 1945 West Pernell Road, Jackson, Michigan 49201 * (5171 788 4453 December 6, 1979 Hove-308-79 Mr J G Keppler, Regional Director Office of Inspection and Inforcement US Nuclear Regulatory Cec =ission Regica III 799 Roosevelt Ecad Glen Ellyn, IL 60137 MIDLAND NUCLE.G PLA'!"'

U'iIT :10 1, DCCKET !C 50-329 UNIT NO 2, EOCKE' : 0 50-230 SAFE SHUTDOM! ECEATIO: CAFABILITY

Reference:

Letter SHHovell to JGKeppler; Midland Nuclear Plant; Unit :!o 1, Dcchet No 50-329; Unit :To 2, Docket No 50-330; Safe Shutdevn 3craticn Capability; Serial Hove-283-79; dated October 31, 1979 This letter, as was the referenced letter, is an interin 50.55(e) report regarding safe shutdown capability assuming a cost restrictive core ecndition and the centrol red of highest worth stuck out of the core. The referenecd letter was not sufficiently specific vith regard to the statement that

"...present Midland design does not permit achieving and =aintaining a is 6 h/k....".

In fact, the present design can achieve the 15 A k/k shutdevn margin as required by General Design Criterion 26 en rods alene with the conditions stated. However, under these conditicns and also with the assumption that non-safety grade systems cannot be utilized, the 15 6 k/k shutdown margin cannot be maintained as the xenen decays with the safety grade beration capability that now exists.

On October 15, 1979, CPCo directed Bechtel, the Architect-Engineer, to prepare a systes design which increases the safety grade boration capability.

Eechtel's preliminary system design is presently undergoing review by CPCo and EW, the NSSS supplier. Finalization of the system design is antic.ipated by the end of March, 1980.

1528 242 gdIf 5E o 1-3ss S

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Hove-308-79 Another report, either interim or final, vill be sent on or before April 11, 1980.

E G CD' w &Q g

WRB/lr CC: Director of Office of Inspection & Enforcement Att: Mr Victor Stello, US:IEC (15)

Director of Cffice of Management Informatien & Program Centrol, US:IRC (1) 1528 2 0

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