ML20134D039

Updates 850626 Response to Question 4 in NRC Re LOCA Analysis.Evaluation of Control Rod Restrictions for Coastdown Completed.Method for Restricting Movement of Control Rods During Coastdown Listed

ML20134D039
Person / Time
Site:	Yankee Rowe
Issue date:	08/12/1985
From:	Papanic G YANKEE ATOMIC ELECTRIC CO.
To:	Zwolinski J Office of Nuclear Reactor Regulation
References
FYR-85-85, NUDOCS 8508190028
Download: ML20134D039 (2)

Text

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Te'epho"' (e ") 8 ' -* 'oo YANKEE ATOMIC ELECTRIC COMPANY TWX 710-380-7619

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August 12, 1985 United States Nuclear Regulatory Commission Washington, D. C. 20555 Attention: Mr. John A. Zwolinski, Chief Operating Reactors Branch No. 5 Division of Licensing

References:

(a) License No. DPR-3 (Docket No. 50-29)

(b) USNRC Letter to YAEC, dated May 22, 1985 (c) YAEC Letter to USNRC, dated June 26, 1985

Subject:

LOCA Analysis

Dear Sir:

This letter provides an update to Yankee's response in Reference (c) to the USNRC's Question No. 4 in Reference (b).

In Reference (c), Yankee stated that:

(1) It took action to limit movement of Control Rod Group C between 80-84 inches to maintain the plant within the bounds of the current analyses through 11,000 mwd /Mtu.

(2) It modified the limit on the novement of Control Group C to 80-83 inches through 12,500 mwd /Mtu, or essentially the end of full power life.

Reference (c) states that the control rod restrictions for coastdown were under evaluation. The evaluation has been completed, and we intend to restrict the movement of control rods during the coastdown as follows:

(1) Control Rod Group C will be restricted to 80-83 inches during full coastdown power operations until the plant reaches 80% of rated full power.

(2) At or below 80% of rated full power, Control Rod Group C will be withdrawn to its full-out position (90 inches) at a not-to-exceed rate of 2 inches per day. The power level during the rod withdrawal will be maintained below 85% and the maximum linear heat generation rate will not exceed 8.9 kW/ft.

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United States Nuclear Regulatory Conaission August 12, 1985 Attention: Mr. John A. Zwolinski Page 2 (3) The plant will be maintained in the all rods out condition for the remainder of full coastdown power operation until shutdown for refueling.

.All of the above specified actions taken by Yankee insure that the plant's operation complies with 10CFR50.46 requirements.

Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY lbs George yu apanic, Jr.

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Senior Project Engineer Licensing GP/glw i