ML19256A145

Forwards Proposed Mod to High Pressure Injection Sys.Mod Meets Staff Position Expressed in NRC 780916 Ltr Because No Oper Action Will Req & It Is Consistent W/All Assumptions of 781017 ECCs Small Breaks Analysis

ML19256A145
Person / Time
Site:	Arkansas Nuclear
Issue date:	10/27/1978
From:	David Williams ARKANSAS POWER & LIGHT CO.
To:	Reid R Office of Nuclear Reactor Regulation
References
1-108-14, NUDOCS 7811030159
Download: ML19256A145 (3)

Text

<i a, p 9 ARKANSAS POWER & LIGHT COMPANY POST OFRCE BOX 551 UTTLE ROCK. ARKANSAS 72203 (501) 37bSOOO october 27, 1978 1-108-14 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:

Art.anses Nuclear One - Unit 1 Docket No. 50-313 License No. DPR-51 ECCS Small Break Long-Term Modification (File: 1510, 0520)

Gentlemen:

Our letter of July 20, 1978, on the above subject, proposed our long-term ECCS modification and requested your approval of the modification. Although your response of September 26, 1978, did not specifically address our pro-posal, it provided staff positions that we could utilize in determining the acceptability of our proposal.

Following evaluation of the staff positions, we determined that, with possible small modification, our proposed modification would meet those positions. Ilowever, as we began to develop our detailed engineering design, we determined that another modification, that meets your positions, could be made at an improved cost / benefit to AP&L. The staff was informed of this decision by a telecon on October 10, 1978, in accordance with your letter of September 26, 1978. The conceptual design of the new modifi-cation is as follows.

Attached is a diagram of the ANO-1 High Pressure Injection (HPI) system with the proposed modifications shown in bubbles. The modification con-sists of adding a 3" cross tie between llPI lines to P32A - P32D and P32B - P32C. Downstream of each of the cross ties are flow restriction orifices. These orifices will be sized such that equal flow balance in all four HPI lines is achieved and RPI pump run out is precluded.

This proposed modification meets the staff positions of your September 16, 1978, letter as no operator action will be required and is consistent with and meets all the assumptions of our ECCS Small Breaks Analysis submitted to you by our letter of October 17, 1978.

Our intent is to implement this modification during our next refueling outage (currently scheduled for March, 1979) however, to support our implementation schedule, it is imperative that we receive staff concurrence of this proposal by December 1, 1978. Failure of the staff to approve m m, MEMBER MICOLE SOUTH UTILITIES SYSTEM

_ ~~

Mr. R. W. Reid October 27, 1978 this modification by this date will seriously impact our ability to implement this modification during the outage and could preclude it completely.

Your letter of May 10, 1978, asked us to inform you if we utilized any throttle valves to obtain required flow distribution in the llPI systems. In response, the above modification will preclude throttling the llP1 flow with valves as flow distribution will be achieved by the flow restricting orifices.

Very truly yours,

~

W /

Daniel 11. Williams Manager, Licensing DlIW:JTE:vb Attachment

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