ML20248C540

Forwards Request for Addl Info in Support of Util 890518 Response to ATWS Rule 10CFR50.62, Requirements for Reduction of Risk from ATWS Events for Light-Water-Cooled Nuclear Power Plants, Per 890628 Telcon

ML20248C540
Person / Time
Site:	Maine Yankee
Issue date:	08/03/1989
From:	Sears P Office of Nuclear Reactor Regulation
To:	Frizzle C Maine Yankee
References
TAC-59110, NUDOCS 8908100076
Download: ML20248C540 (6)

Text

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2-9 ~. w H -. August 3, 1989 DockeiNo.50-309.

- Mr. C. D, Frizzle, President '

Maina Yankee Atomic Power Company 83 Edison Drive Augusta, Ma ke 04336-

SUBJECT:

10 CFR 50.62 (ATWS RULE) REQUEST FOR ADDITIONAL-

'INFORMATION(TACN0.59110)

TM .\TWS ruN 90 CFR 50.62), " Requirements for Reduccion of Risk from Anticipated Transiets Without Scrac [ATWS] Events for Light-Water-Cooled Nec, ear Power Plants' requires improvements in the design and operation of commercial nuclear p) war facilities to reduce the likelihood of failure to -

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' shutdown the reactor following anticipated transients and to mitigate the consequences of an ATWS event. Paragraph (c)(6) of t% rule requires that information sufficient to demonstrate compliance with the requirements be submittedtotheOfficeofNuclearReactorRegulation(NRR).

You provided information concerning implementation of the ATWS rule requirements at Maine Yankeo by letter NN-89-63 dated May 18, 1989. The information contained in the submittal was discussed with Maine Yankee personnel by telecon on June 28, 1989. As a result of the telecon additional information u required to determine compliance with the Commission's regulatiorb Therefore, in order to continue our review, it is requested that you provice us the additional information delineated in the enclosure.

Sincerely,

/s/

Patrick M. Sears, Project Manager "T Project Directorate 1-3 8908100076 890a03 9 Division of Reactor Projects DR ADOCK 0500

Enclosure:

Request for Addtional Information pFt>I cc w/ enclosure: l See next page Ii JCTRIBUTION v.,% . , ,

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V. Thomas E. Leeds g JWiggins RI NRC PDR Local PDR PDI- P 3/D MRusi okpPSearsPD1 '3/PM RWessman 1/6:L/89 8/g/89 8/J/89

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UNITED STATES

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o NUCLEAR REGULATORY COMMISSION

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• August 3, 1989 Docket No.'50-309 Mr. C. D. Frizzle, President Maine Yankee Atomic Power Company 83 Edison Drive Augusta, Maine 04336

SUBJECT:

10 CFR 50.62'(ATWS RULE) REQUEST F0P ADDITIO!!AL INFORMATION(TACNO.59110)

The'ATWS rule (10 CFR 50.62), " Requirements for Reduction of Risk from Anticipated Transients Without Scram [ATWS] Events for Light-Water-Cooled Nuclear Power Plants"' requires 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. Paragrcph (c)(6) of the rule requires that information sufficient to demonstrate compliance with the requirements be submitted to the Office of Nuclear Reactor Regulation (NRR).

You provided information concerning implementation of the ATWS rule requirements at Maine Yankee by letter NN-89-63 dated Hay 18, 1989. The information contained in the submittal was discussed with Maine. Yankee personnel by telecon on June 28, 19~89. As a rest!1+ of the teleton additional information is' required to determine ~ compliance with the Commission's regulations. Therefo*e, in order to cai.inue our review, it is requested that .yo : provide us the additional informatioti delineated in the enclosure.

Sincerely,

< C

'N g,h h 0,4 Patrick M. Sears, Fioject nanager Project Directorate 1-3 Division of Reactor Projects

Enclosure:

Request for Additional Information cc w/ enclosure:

See next page

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Mr. C. Di Frizzle _

cc'w/ enclosure:-

Mr. Charles .B. Brinkman -Mr. G. D. Whittier, Manager Manager - Washington Nuclear Nuclear Engineering and Licensing Operations- Maine Yankee Atoric Power f.ompany Combustion Engineering, Inc. _

83 Edison Drive 12300 Twinbrook Parkway, Suite 330_ Augusta, Maine 04336 Rockville, Maryland 20852 -i John A; Ritsher, Esquire

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1 Ropes & Gray  !

225 Franklin Street Boston, Massachusetts 02110 State Planning Officer Executive Department 189 State Street Augusta, Maine 04330

'Dr. E. T. Boulette, Vice President Operations and Plant Manager Maine Yankee Atomic Power Company P. O. Box 400 Wiscastet, Maine 04578 Mr. J. H. Garrity, Vice President Licensing and Engineering Maine Yankee Atomic Power Company 83 Edison Drive Augusta, Maine 04336 Regional Administrator, Region I U.S. Nuclear Regulatory Commiss'on 475 Allendale Road King of Prussia, Pennsylvania i9406 1

.First Selectman of Wiscasset ,

Municipal Building  ;

U.S. Route .

Wiscasset, Maine 04578  !

I Mr. 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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ENCLOSURE MAINE YANKEE 10 CFR 50.62 (ATWS RULE)

REQUEST FOR ADDITIONAL INFORMATION TAC NO. 59110 A telephone conference call (telecon) was held on June 28, 1989 with Maine Yankee Atomic Power Company (NYAPCo), licensee for the Maine Yankee Atomic Power Station, for the purpose of discussing their submittal dated May 18, i 1989(Ref.1). This submittal was in response to a staff request for additional information (RAI) forwarded to the licensee by letter dated August 11,1988(Ref.2).

During the teleton, the response to the RAI was discussed as well as the eleven items of guidance contained in the " Statement of Consideration" as published in the Federal Register dated June 26, 1984 (Ref. 3). Also

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discussed were three other items which the staff considers important to the ATWS system design. The licensee clarified some of the information centained in the submittal and provided some new info:re. tion as well.

Durin.; the telecon four items were identified that the staff feels require i attention on behalf of the licensee and these items are:

1. Quality Assurance The licensee should provide a commitment to incorporate the provisions of The NRC generic letter (GL) 85-06 into his QA program for the non-safety related ATMS equipment.

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'E. Safety Related Power Supply The licensee should provide a common raode failure (CMF) analysts on any ATWS circuit and design that share power supplies with the reactor protection system (RPS). The analysis should demonstrate that power supply faults (e.g., overvoltage and undervoltage conditions, degraded _ frequencies, ano overcurrent) will not compromise the reactor trip system (RTS) and the diverse emergency feedwater actuation system (DEFAS) equipment. This analysis should include consideration of alarms for early detection of degraced voltage and f requency conditions to allow time for the operators to take corrective action while the affected circuits / components are still-capable of performing their intended functions. The diversity of the lower level power supplies (logic power supplies) between the RPS and the ATWS circuits should be shown. ';

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3. Testability The diverse scram system (DSS) and the DEFAS should have an overlapping end-to-end test capability that encompasses the input sensor through.to the final actuated oevice. Information shculd be provided to demonstrate this test capability along with the procedures that are in place to perform these test during refueling outages.

4. Information Readout Infonaation should be providec to demonstrate that the status information received by the operator with rcspect to the ATWS mitigation systern is generated directly by the ATWS circuits.

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3-REFERENCES

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1. Letter, G. D. Whittier (MYAPCo) to Director of Nuclear Reactor }'

Regulaticn, U.S. NRC, " Imp 1 mentation of Maine Yankee ATWS Prevention and Hiti9ation Systems," May 18, 1989.

2. Letter, R. H. Wesstaan (NRC) to J. Randazza, (MYAPCo), "10 CFR 50.62 (ATWS Rule) Review Request for Information," August 11, 1988.

3. Stateraent of Considerations, Federa'l Register, Vol. 49, No.124, June 26, 1984.

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