ML19210D037

Responds to NRC Re Containment Purging & Venting. Vent & Purge Valves at Three Units Qualify W/Nrc Guidelines to Extent Guidelines Apply

ML19210D037
Person / Time
Site:	Haddam Neck, Millstone  File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	11/13/1979
From:	Counsil W NORTHEAST UTILITIES
To:	Ziemann D Office of Nuclear Reactor Regulation
References
TASK-06-04, TASK-6-4, TASK-RR TAC-42588, NUDOCS 7911200453
Download: ML19210D037 (2)

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November 13, 1979 Docket Nos. 50-213 50-245 50-336 Director of Nuclear Reactor Regulation Attn:

Mr. D. L. Ziemann, Chief Operating Reactors Branch #2 Mr. R. Reid, Chief Operating Reactors Branch #4 U. S. Nuclear Regulatory Commission Washington, D. C.

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References:

(1)

D. G. Eisenhut letter to All Light Water Reactors dated October 17, 1979.

(2)

W. G. Counsil letter to D. L. Ziemann dated January 3,1979.

(3)

W. G. Counsil letter to D. L. Ziemann dated January 2, 1979.

(4)

W. G. Counsil letter to D. L. Ziemann dated April 27, 1979, on Millstone Unit No. 1.

(5)

W. G. Counsil letter to R. W. Reid dated April 27, 1979, on Millstone Unit No. 2.

Gentlemen:

Haddam Neck Plant Millstone Nuclear Power Station, Unit Nos. 1 and 2 Containment Purging and Venting Reference (1) provided operability and demonstration guidelines that addressed generic concerns about containment purging and ventilation valves. This letter responds to those guidelines, to the extent that they pertain to the Haddam Neck Plant, Millstone Unit No.1, and Millstone Unit No. 2.

Haddam Neck Plant Our Reference (2) letter stated that Technical Specifications prohibit purging with the 42-inch purge valves unless the plant is in cold shutdown or refueling.

Some containment venting, however, can be performed through the much smaller one-inch valve on the air particulate monitoring line during plant opertion.

Our evaluations of the large purge valves had already considered the new opera-bility guidelines in Reference (1), however, since the larger valves remain closed, the operability guidelines for valve closure are non-applicable. The smaller valve is a containment isolation valve that receives automatic closure signals during an accident.

For both valves, scaling integrity has been periodically demonstrated as part of the 10CFR50, Appendix J, testing requirements. Thus, the vent and purge valves at the Haddam Neck Plant are qualified to meet the guide-lines in Reference (1), to the extent those guidelines apply.

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. Millstone Unit No. 1 Unlimited containment purging was justified in References (3) and (4).

Our evaluations of the purge and vent valves had already considered the new guidelines in Reference (1). The sealing integrity has been periodically demon-strated as part of the 10CFR50, Appendix J, testing requirements. Thus, the valves are qualified to meet the guidelines in Reference (1), to the extent those guidelines apply.

Millstone Unit No. 2 Our Reference (5) letter proposed Technical Specification changes that would maintain the purge valves in a locked closed position in Modes 1 through 4.

Our evaluations of the purge valves had already considered the new operability guidelines in Reference (1), however, the operability guidelines are not applica-ble to locked-closed valves. The sealing integrity has been periodically demonstrated as part of the 10CFR50, Appendix J, testing requirements.

Reference (5) also committed to maintain the purge valves locked closed during the interim prior to Technical Specification change approval. Thus, the purge valves at Millstone Unit No. 2 are qualified to meet the guidelines in Reference (1), to the extent those guidelines apply.

Should you have any questions, please contact us.

Very truly yours, CONNECTICUT YANKEE ATOMIC POWER COMPANY NORTHEAST NUCLEAR ENERGY COMPANY d

/Z W. G. Counsil Vice President h

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