ML19247B242

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Responds to Re Reactor Cavity Annulus Seal Ring. Requests Analysis of Seal Ring Effect on Other Containment Safety Components Should Ring Become Missile.Statement Promising Seal Ring Removal Before Next Refueling Outage
ML19247B242
Person / Time
Site: Yankee Rowe
Issue date: 07/26/1979
From: Ziemann D
Office of Nuclear Reactor Regulation
To: Groce R
YANKEE ATOMIC ELECTRIC CO.
References
TASK-03-04.C, TASK-3-4.C, TASK-RR TAC-11846, NUDOCS 7908080222
Download: ML19247B242 (2)


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% bQ /g July 26,1979 Jocket tio. 50-29 Mr. Robert fi. Groce Licensing Engineer Yankee Atomic Electric Company 20 Turnpike Road Westboro, Massachusetts 01581

Dear Mr. Groce:

We have reviewed your response to our letter dated February 2,1978, in regard to the potential for the reactor cavity annulus seal ring to become a destructive missile in the event of a loss-of-coolant accident pipe break inside the reactor cavity.

In your response, you indicated that in the event of a large coolant pipe rupture the subsequent ECCS analysis takes no credit for control rod insertion. Therefore, damage to the control rod drive mechanisms (CRDM) would not affect the safe shutdown of the reactor subsequent to a loss-of-coolant accident as previously analyzed.

However, the role of CRDM for the safe shutdown of the reactor for small break LOCA has not been addressed.

Moreover, you have not analyzed the effects of the seal ring, should it become a missile, on other safety related components located inside the containment. Therefore, pursuant to 10 CFR 50.54 (f) of the Conmission's regulations, you are requested to (a) demonstrate by appropriate analysis that the seal ring cannot become a destructive missile during continued long-tenn operation and that it poses no threat to the health and safety of the public; or (b) furnish a statement that the seal ring will be removed by no later than the next refueling outage.

Please respond within 60 days of your receipt of this letter.

irgcerely,

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n%d Dennis L. Ziemaa, Chief Operating Reactors Branch #2 Division of Operating Reactors cc:

See next page

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4 Mr. Robert H. Groce July 26,1979 cc Mr. Lawrence E. Minnick, President Yankee Atomic Electric Company 20 Turnpike Road

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Westboro, Massachusetts 01581 Greenfield Community College 1 College Drive Greenfield, Massachusetts 01301 4