ML19261B620

Informs of Status of Class IE Equipment Per IE Bulletin 79-01, Environ Qualification of Class IE Equipment. Problem Switches Will Be Changed During Next Refueling Outage in Apr 1979

ML19261B620
Person / Time
Site:	Cooper
Issue date:	02/21/1979
From:	Pilant J NEBRASKA PUBLIC POWER DISTRICT
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 7902280291
Download: ML19261B620 (2)

Text

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e COOPER NUCLEAR STATION P.O. BOX 98 BRoWNVILLE. NEB R ASKA 68 321 Nebraska Publ.ic Power Distr.

ic t TcLe m o~c o m>82s.n u February 21, 1979 Director, Division of Operating Reactors Office of Nuclear Reactor Regulation Nuclear Regulatory Commission Washington, D.C. 20555

Reference:

IE Bulletin No. 79-01

Dear Sir:

The reference bulletin specified action to be taken by licensees con-cerning environmental qualification of Class lE equipment. Item 2 of the bulletin required a determination if certain listed types of stem counted limit switches are being used on safety-related valves located inside containment. Item 4 of the bulletin requires that items not meeting qualification requirements for service intended also be re-ported.

Although we do not have any switches inside containment of the models listed, we do have NAMCO Model SL3ML switches inside containment. We believe these switches may be those listed in error as Model S3CML.

Each Main Steam Isolation Valve (MSIV) uses three NAMCO !bdel SL3ML switches for position indication and/or Rer.ctor Protection System (RPS) input. The switches are tested weekly. We have not experienced any significant problems with these switchas during plant operation, however we have had some problems with the switches after plant outages. We attribute these problems to the fact that the switches are not exercised during an outage. We are planning to change out these switches during the next refueling outage in April 1979.

These taitches do not meet the LOCA environmental condi-49ns and they do not se rve a primary safety function during the event. The RPS input, a scram from the MSIV closure, is a backup to the high drywell pressure and low reactor water level scrams during a LOCA. It should also be noted that if in the highly unlikely event of all the subject switches in containment failing, the switches on the MSIV's outside containment would provide the MSIV isolation scram.

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790 2 28 0M I

Director, Divisior of Operating Reactors February 21, 1979 Page 2.

Based on the discussions above, we plan to operate the plant until such time as we can change them out during a routine plant outage.

Sincerely, M

. .. Pilant Director of Licensing and Quality Assurance JMP:LCL:cg cc: K. V. Seyfrit .