ML20003F959

Requests Util Perform Review to Determine What Design Changes or Operator Actions Would Be Necessary to Assure That High Energy Line Breaks Are Not Cause of Control Sys Failures.Supporting Info Encl

ML20003F959
Person / Time
Site:	Midland
Issue date:	04/16/1981
From:	Tedesco R Office of Nuclear Reactor Regulation
To:	Jackie Cook CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
References
IEIN-79-22, NUDOCS 8104270163
Download: ML20003F959 (4)

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APR 1 6 O Docket Nos.: 50-329/330 Mr. J. W. Cook Vice President Consumers Power Company 1945 West Parnall Road Jackson, Michigan 49201

SUBJECT:

HIGH ENERGY LINE BREAKS N;D CONSEQUENTIAL CONTROL SYSTEM FAILURES -

MIDLAND PLANT, UNITS 1 AND 2 Operating reactor licensees were informed by IE Infomation Notice 79-22, issued September 19, 1979, that certain non-safety grade or control equipment, if subjected to the adverse environment of a high energy ifne break, could impact the safety analyses and the adequacy of the protection functions perfonned by the safety grade equipment.

Enclosed is a copy of IE Infomation Notice 79-22, and reprinted ccpies of an August 30, 1979 Westinghouse letter and a September 10, 1979 Public Service Electric and Gas Company letter which address this matter. Operating Reactor if censees conducted reviews to determine whether such problems could exist at operating facilities.

The NRC is concerned that a similar potential may exist at light water facilities now under construction. You are, therefore, requested to perfom a review to determine what, if any, design changes or operator actions would be necessary to assure that high energy ifne breaks will not cause control system failures to complicate the event beyond the FSAR analysis. Provide the results of your review including all identified problems and the manner in which you have resolved them to NRR.

The specific " scenarios" discussed in the above ntferenced Westinghouse letter are to be considered as examples of the kinds of interactions which might occur.

Your review should include those scenarios, where appif cable, but should not necessarily be limited to them. Should you have any questions, contact our Licensing Project Manager, Darl S. Hood.

Sincerely, Oh Robert L. Tedesco, Assistant Director for Licensing Division of Licensing

Enclosure:

f/$k%/b As stated cc: See next page.

3 Mr. J. W. Cook Vice President Consumers Power Company 1945 West Parnall Road Jackson, Michigan 49201 I

cc: Michael I. Miller, Esq.

Mr. Don van Farowe, Chief.

Ronald G. Zamarin, Esq.

Division of Radiological Health Alan S. Farnell, Esq.

Department of Public Health

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Isham, Lincoln & Beale P.O. Box 31035 Suite 4200 Lansing, Mich196.7 48909 1 First National Plaza Chicago, Illinois 60603 James E. Brunner, Esq.

William J. Scanlon, Esq.

Consumers Power Company 2034 Pauline Boulevard 212 West Michigan Avenue Ann Arbor, Michigan 48103 Jackson, Michigan 49201 U. S. Nuclear Regulatory Commission 1

Myron M. Cherry, Esq.

Resident Inspectors Office 1 IBM Plaza Route 7 Chicago, Illinois 60611 Midland, Michigan 48640 s

Ms. Mary Sinclair Ms. Barbara Stamiris 5711 Summerset Drive 5795 N. River Midland, Michigan 48640 Freeland, Michigan 48623 l

l Frank J. Kelley, Esq.

c Attorney General l

State of Michigan Environmental Protection Division 720 Law Building Lansing, Michigan 48913 Mr. Wendell Marshall Route 10 Midland, Michigan 48640 Mr. Steve Gadler 2120 Carter Avenue i

St. Paul, Minnesota 55108.

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ENCLOSURE 1 UF' ED STATES NUCLEAR kEGULATORY Conil5510N OFFICE OF INSPECTIDH AND ENFORCEMENT l

t WASHINGTON, D.C.

20555 September 14, 1979 IE Information Notice No. 73-22 QUALIFICATION OF CONTROL SYSTEMS Pub 11'c Service E1ectric and Gas company notified the NRC of a potential unreview d t safety question at their Salem Unit 1 facility.

Th'is notification was based on a continuing review by Westinghouse of the environmental qualifications of equipment Based on the present status that they supply for nuclear steam supply systems.

of this effort, Westinghouse has informed their custocers that the performance of non-safety grade equipment subjected to an adverse environment could icpact These non-safetf the protective functions performed by saf ety grade equipment.

grade systems include:

Steam generator power operated relief valve control system Pressurizer power operated relief valve control, syste::

Main feedsater control system Automatic rod control system These systems cou1d potentially malfunction due to a high energy line break inside or outsids: of containment.

NRC is also concerned that the adverse environment could also give erroneous information to the plant operators.

Vestinghouse states that ths consequences of such an event could possibly be ante limiting than results presented in Safety Analysis Reports, however, Westinghouse also states that the severity of the results can be limited by operator actions together with operating characterisitics of the safety Fur,ther, Vestinghouse has recommended to their customers that zney systens.

ans exist.

review their systems to determine whether any unreviewed safety que

I mation Notice is provided as an early notification of a pmibly This Infor It is expected that recipients will. review the f.nformatiert significtat matter.

No specific action or response for possible applicability to their facilities.If NRO evaluations so indicate, further l is requested at this time.

a:tions may be requested or' required.

If you have quest; ions regarding this matter,

please contact the Director of the appropriate NRC Regional Office.

No written response to this Information Notice is required.

' uhe 79e8 L74 i

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l REPRINT Westinghouse Electric Corporation Water Reactor Division Nuclear Service Division Box 2728 Pittsburgh, Pennsylvania 15230 August 30, 1979

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PSE-79-21 Mr. F. P. L ibrizzi, General Manager Electric Production Public Service Electric and Gas Company 80 Park Place Newark, New Jersey 07101

Dear Mr. Librizzi:

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Public Service Electric and Gas Co.

Salem Unit No.1 OUALIFICATION OF CONTROL SYSTEMS As part of a continuing review of the environmental qualifications of l

> Westinghouse supplied NSSS equipment, Westinghouse has also found it l

necessary to consider the interaction with non-safety grade systems.

This ir.vestigation has been conducted to detemine if the perfomance l

of non safety grade systems which may not'be protected from an' adverse environment could impact the protective functions performed by NSSS The hSSS control and protection systems were f

safety grade equipment.

included in this review to assess the adequacy of the present environ-i mental qualification requirements.

As a result of this review, several systems were identified which, 'if subiected to an adverse environment, could potentially lead to control system operation which may impact protective functions. These systems are:

Steam generator power operated relief valve control system

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Pressurizer power operated relief valve control system, -

Main feedwater control system Automatic rod control system i

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