ML20011E138

Forwards SER Concluding That Diverse Scram Sys,Diverse Auxiliary Feedwater Actuation Sys & Diverse Initiation of Turbine Trip Designs,Per ATWS Rule (10CFR50.62),acceptable

ML20011E138
Person / Time
Site:	Maine Yankee
Issue date:	01/31/1990
From:	Leeds E Office of Nuclear Reactor Regulation
To:	Frizzle C Maine Yankee
Shared Package
ML20011E139	List: ML20011E138 ML20011E140
References
TAC-59110, NUDOCS 9002080131
Download: ML20011E138 (3)

Text

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UNITED STATES

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January 31, 1990 j

Docket No. 50-309

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Mr. C. D. Frizzle, President Maine Yankee' Atomic Power Company L

83 Edison Drive Augusta, Maine 04336 1

SUBJECT:

SAFETY EVALVATION REPORT FOR MAINE YANKEE COMPLIANCE WITH ATWS RULE, 10CFR50.62 (TAC NO. 59110)

The ATWS Rule (10CFR50.62, " Requirements for Reduction of Risk from AnticipatedTransientsWithoutScram(ATWS)EventsforLight-Water-Cooled l

Nuclear Power Plants") reouires improvements in the design and operation of commercial nuclear power facilities to reduce the likelihood of failure to shutdown the reactor following anticipated transients, and to mitigate the consequences of an ATWS event. The requirements for Combustion Engineering plants such as Maine Yankee are to provide a diverse scram system (DSS),

diverse auxiliary feedwater actuation system (DAFAS), and diverse initiation of turbine trip (DTT).

Paragraph (c)(6) of the rule requires that information sufficient to demonstrate compliance with the requirements be submitted to NRR.

I You provided information concerning implementation of the ATWS Rule' requirements

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at Maine Yankee by letters dated July 31, 1985, March 24, 1986 and May 18, 1989.

Based on our review of this information, we have concluded that the DSS, DAFAS, and DTT designs are acceptable. The details of our review are discussed in the enclosed safety evaluation report (SER).

It should be noted that the staff is currently evaluating the need for technical specification operability and surveillance requirements for ATWS equipment. The results of the staff evaluation will be made available upon completion.

On August 3,1989, we requested that you perform an analysis to evaluate the potential for a Common Mode Failure (CMF) affecting both the DTT and the DAFAS as described in SER Sect 4ns 4.2.0 and 4.3.C, respectively. The staff will

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confirm the acceptance of this CMF analysis during a site inspection of the ATWS rule.

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C. D. Frizzle 2-January 31, 1990 i

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Now that you have received staff approval of your proposed design, installation and operation of ATWS equipment should no longer be delayed.

It is our under.

standing, through discussions with Maine Yankee personnel, that installation and operation of ATWS equipment is scheduled for the late 1991/early 1992 L

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j Sincerely, t

I-i Original signed by Eric J. Leeds, Project Manager Project Directorate 1 3 Division of Reactor Projects 1/11 Office of Nuclear Reactor Regulation

Enclosure:

Safety Evaluation Report cc w/ enclosure: See next page DISTRIBUTION: Docket File, NRC& Local PDRS, ELeeds, RWessman, MRushbrook, ACR5(10), EJordan, JJohnson,Rgn.I SVarga, BBoger 'HLi, DLynch, ANolan(INEL),

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i 4: /90 DATE:)4(/90 OFFICIAL RECORD COPY Document Name: MAN. YANK.T59110 LTR j

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Mr. C. D. Frizzle 3

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CC:

j tir. Charles B. Brinkman tir. G. D. Whittier, Manager Manager - Washington Nuclear Nuclear Engineering and Licensing Operations Maine Yankee Atomic Power Company Combustion Engineering. Inc.

83 Edison Drive 12300 Twinbrook Parkway, Suite 330 Augusta, Maine 04336 Rockville, Maryland 20852 Mr. Robert W. Blackmore, John A. Ritsher, Esquire Plant Manager Ropes & Gray Maine Yankee Atomic Power Company 225 Franklin Street P.O. Box 408 Boston, Massachusetts 02110 Wiscasset, Maine 04578 State Planning Officer Executive Department 189 State Street Augusta, Maine 04330 Dr. E. T. Boulette, Vice President Operations Maine Yankee Atomic Power Company P. O. Box 408 Wiscasset, Maine 04578 Mr. J. H. Garrity, Vice President Licensing and Engineering Maine Yankee Atomic Power Company 83 Edison Drive Angusta, Maine 04336 Regional Administrator, Region i U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, Dennsylvania 19406 First Selectman of Wiscasset Municipal Building U.S. Route 1 Wiscasset, Maine 04578 tir. Cornelius F. Holden Resident Inspector Maine Yankee Atomic Power Station U.S. Nuclear Regulatory Commission P. O. Box E Wiscasset, Maine 04578 Mr. P. L. Anderson, Project Manager Yankee Atomic Electric Company 580 Main Street Bolton, Massachusetts 01740-1398

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