ML20140C701

Informs That Analyses Demonstrating Ability to Reach Cold Shutdown within 130 H,Using Solid Water Steam Generator Mode of Operation Complete.Fire Protection Alternate Shutdown Capability Acceptable

ML20140C701
Person / Time
Site:	Maine Yankee
Issue date:	06/15/1984
From:	Whittier G Maine Yankee
To:	John Miller Office of Nuclear Reactor Regulation
References
30611-SEN, GDW-84-141, MN-84-107, NUDOCS 8406190418
Download: ML20140C701 (2)

Text

P

1. 1Al# ##EE ATO##CPBWEBCB#lPA##. AUGUSTA A NE 33

p. f"En,M

(207) 623-3521 O

June 15, 1984 MN-84-107 GDW-84-141 Director of Nuclear Reactor Regulation United States Nuclear Regulatory Commission Washington, D. C. 20555 Attention: Mr. James R. Miller, Chief Operating Reactors Branch No. 3 Division of Licensing

References:

(a) License No. DPR-36 (Docket No. 50-309)

(b) MYAPCo Letter to USNRC (MN 82-251), dated December 22, 1982 (c) MYAPCo Letter to USNRC (MN 83-259), dated December 22, 1983 (d) USNRC Letter to MYAPCo dated February 3, 1983 (e) MYAPCo Letter to USNRC (MN 84-69), dated April 26, 1984

Subject:

Fire Protection - Safe Shutdown Capability

~

Gentlemen:

In Reference (d), the staff stated that Maine Yankee's alternate shutdown capability is acceptable pen 11ng completion of analyses which demonstrate the ability to .aach cold shutoown within 130 hours0.0015 days <br />0.0361 hours <br />2.149471e-4 weeks <br />4.9465e-5 months <br /> using a solid water steam generator twde of operation. The purpose of this letter is to inform the staff that tnose inalyses are complete.

In their Safety Evaluation Report, Reference (d), the staff questioned the capability of the steam piping supports to brace the additional load associated with the solid water mode of operation. The staff was also concerned with a potential release of radioactive water assuming steam generator tube leakage.

As committed in Reference (b), Maine Yankee reviewed the adequacy of the main steam pipe supoorts. Modifications were made to accommodate a solid water mode of operation. With respect to the radiological concerns, the cooldown analyses demonstrate that a solid water mode of operation occurs late in the cooldown and exists for a short period of time. The primary coolant pressure (hence leskage rate), therefore, is very low. It is expected that any release would be wall within present release limitations. However, should the release of water be evaluated at the time to pose a radiological concern, it can be held within the condenser and on-site tanks for treatment, as necessary.

The cooldown analyses have also demonstrated that cold shutdown conditions can be achieved using only the RWST for baration. Accordingly, the components associated with the boric acid storage and transfer system need no longer be listed as required shutdown equipment.

3061L-SEN B406190418 840615 b 00h PDR ADOCK 05000309

- F mm 8) 0

I' . , , ,

MAINE YANKEE ATOMIC POWER COMPANY United States Nuclear Regulatory Commission Page Two Attention Mr. James R. Miller, Chief MN-84-107 We trust this information is satisfactory and resolves the open items listed in the SER. If you have any questions, however, please contact us.

Very truly yours, MAINE YANKEE ATOMIC POWER CO WANY bhW G. D. Whittier Licensing Section Head GDW/bjp cc: Dr. Thomas E. Murley Mr. Cornelius F. Holden

.f*

s l

I I

'3061L-SEN L .