ML19340C533

Describes Status of Environ Qualification Deficiency Re Namco EA-180 Limit Switch Installation Discovered During IE Bulletin 79-01B Investigations.Matl Necessary to Upgrade Switch Installation Has Been Ordered

ML19340C533
Person / Time
Site:	Prairie Island
Issue date:	11/13/1980
From:	Mayer L NORTHERN STATES POWER CO.
To:	Office of Nuclear Reactor Regulation
References
IEB-79-01B, IEB-79-1B, TAC-12428, TAC-12429, NUDOCS 8011170802
Download: ML19340C533 (2)

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"' M I N N E A PO L.l S. M e N N E S OTA 55401

) L'7/ !7 C 53 November 13, 1980 i'TES Director of Nuclear Reactor Regulation US Nuclear Regulatory Commission Washington, DC 20555 PRAIRIE ISLAND NUCLEAR GENERATING PLANT Docket No. 50-282 License No. DPR-42 50-306 DPR-60 Lessons Learned Item 2.1.3.a Position Indication-Felief and Safety Valves Ref:

1) NSP letter; L 0 Mayer to Director Nuclear Reactor Regulation, USNRC, December 14, 1979, " Lessons Learned Implementation"

2) NRC letter; H Denton to L 0 Mayer, NSP, October 30, 1979,

" Discussion of Lessons Learned Short Term Requirements" During review of our program of upgrading environmental qualification of safety related electrical equipment, a deficiency was noted with respect to the status of NAMCO limit switches by the Prairie Island NRC Resident Inspector.

The purpose of this letter is to describe the current status of these switches and our plans for resolving the deficiency that was found.

Our original plans for upgrading the NAMCO switches were described in the response to Item 2.1.3 a of the short term lessons learned requirements. As noted in Reference (1):

For the pressurizer power operated relief valves, qualified limit switches are installed on Unit I for the closed indicaton. According to clarifica-tion 5 of Reference (2), the position indication should be environmentally qualified.

Though this is a recommendation, not a requirement, we have ordered environmentally qualified limit switches to assure both open and closed indication will be satis factory.

The NUREG-0578 discussion for Item 2.1.3a points out that closed indication is of most concern. We expect to receive the limit switches in January and will install these prior to January 31, 1980 on Unit 2.

A special outage would be required for Unit 1 for modification of the open limit switches and is not planned.

New qualified EA-180 limit switches were installed on both units by February 26, 1980.

In late August, 1900, during investigations required by IE Bulletin 79-01B, we received the NAMCO test report on the qualification of EA-180 switches.

In reviewing this report we learned that additional installation requirements had to be met to assure environmental qualification applicability. As stated in our 8 013 3 q.9 50p.

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s NORTHZRN STATES POWER COMPANY Director of NRR November 13, 1980 Page response of October 31,1980 to 79-01B, we have ordered material necessary to upgrade the EA-180 installation and will perform this work during planned outages after receipt. We had no prior information of the need for special installation in any documentation from NAMCO.

Please contact us if you have any questions related to this deficiency or our schedule for resolving it.

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L 0 Mayer, P '

Manager of Nuclear Support Services LOM/DMM/jh 1

cc J G Keppler G Charnof f NRC Resident Inspector i

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