ML19309A497

Responds to NRC Request for Info on Three Proposed Followup Actions Re Crystal River 800226 Event.Mods Necessary to Improve Coping W/Loss of Instrumentation & Control Sys Will Be Completed by 800621.Affidavit Encl

ML19309A497
Person / Time
Site:	Arkansas Nuclear
Issue date:	03/24/1980
From:	Steel C ARKANSAS POWER & LIGHT CO.
To:	Reid R Office of Nuclear Reactor Regulation
References
NUDOCS 8003310366
Download: ML19309A497 (3)

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ARKANSAS POWER & LIGHT COMPANY SU TE 2900/THE FIRST NATIONAL BUILDING /P.O. BOX 551/LITTLE ROCK. ARKANSAS 72203/IS011371-42B2 CHARLES L STEEL Vice President Assistant to President March 24, 1980 60-30?/303 1-030-12 Director of Nuclear Reactor Regulation ATTN: Mr. R. W. Reid, Chief Operating Reactor Branch #4 U. S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

Arkansas Nuclear One-Unit 1 Docket No. 50-313 License No. DPR-51 Followup Actions As A Result of Crystal River - Unit 3 Event on February 26, 1980 (File: 1510)

. Gentlemen:

In accordance with your verbal request to address three proposed actions to be taken within 90 days by each operating B&W reactor licensee, Arkansas Power & Light Company has evaluated the feasibility of each and herein provides the following.

Item 1 Commit to take actions which will allow the operator to cope with various combinations of loss of instrumentation and control functions. This includes changes in (A) equipment and control systems to give clear indications of functions which are lost or unreliable; (B) procedures and training to assure positive and safe manual response by the operator in the event that competent instruments are unavailable.

Response

Our evaluation of the reliability of the Non-Nuclear Instrumentation (NNI) power supplies has revealed the availability of instrumentation may be enhanced via the addition of a backup AC power supply to the NNI-X and NNI-Y cabinets fed through a transfer switch. Therefore, upon loss of the preferred power source, the transfer switch will pick up.the backup power supply to feed the NNI cabinets. This modification and any procedural modifications deemed necessary will be completed prior to power operation after June 21, 1980.

8003310 bb MEMBER MEDOLE SOUTH UTIUTI YSTEM

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'Also, as delineated in our March 17, 1980 letter, emergency procedures are being amplified to give the operator additional guidance during transients. These revisions will be completed by March 31, 1980.

Operator training on these revised procedures will be completed by April 15, 1980.

Item 2 Commit to a verification of the effects of various combinations of loss of instrumentation and control functions by design review analysis and by test.

Response

Design verification of the NNI has been part of our evaluation of the Crystal River event through drawing review and equipment testing. Prior to power operation after June 21, 1980, a design verification of the NNI will be completed. This verification will consist of a drawing review and analysis and a test.to show the effects of various single power supply failures.

Item 3 Commit to correction of electrical deficiencies which may allow the power operated relief valve and pressurizer spray valve to open on i non-nuclear instrumentation power failures, such as, the event which occurred at Crystal River 3 on February 26, 1980.

Response

Prior to power operation after June 21, 1980, a modification to the power operated relief valve and the pressurizer spray valve will be made to preclude an NNI power supply failure from causing them to open.

These responses are provided under 10 CFR 50.54 (f).

Very truly yours,

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C,harles L. Steel Los:vGM:nak l

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STATE OF ARKANSAS )

) ss COUNTY OF PULASKI )

Charles L. Steel, being duly sworn, states that he is Vice President /

Assistant to President for Arkansas Power and Light Company; that he is authorized on the part of said Company to sign and file with the Nuclear Regulatory Commission this Supplementary Information; that he has reviewed or caused to have reviewed all of the statements contained in such in-formation, and that all such statements made and matters set forth therein are true and correct to the best of his knowledge, information and belief.

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~d CL~ oL dEk Charles L. Steel SUBSCRIBED AND SWORN TO before me, a Notary Public in and for the County and State above named, thisc ,74Tl, day of om_/v , 1980.

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' // Notary Public My Commission Expires:

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