ML19209B550
| ML19209B550 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 10/07/1979 |
| From: | Cavanaugh W ARKANSAS POWER & LIGHT CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19209B551 | List: |
| References | |
| 1-109-7, NUDOCS 7910100103 | |
| Download: ML19209B550 (3) | |
Text
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ARKANSAS POWER & LIGHT COMPANY POST OFFICE BOX 551 LIT LE ROCK. ARKANSAS 72203 [501137*-4422 October 7, 1979 WILLIAM CAVANAUGH lli Vice Pmsidet Generation & Construction 1-109-7 Director of Nuclear Reactor Regulation ATTN: Mr. H. R. Denton, Director Division of Site Safety & Environmental Analysis ll.S. Nuclear Regulatory Commission Washington, D.C.
20555
Subject:
Arkansas Nuclear One-Unit 1 Docket No. 50-313 License No. DPR-51 Potential Unreviewed Safety Question on Interaction Between Non-safety Grade Systems and Safety Grade Systems (File:
i S10)
Gentlemen:
This letter and the attached report responds to your September 17, 1979 letter on the above subject.
In conjunction with Babcock and Wilcox, we have reviewed the specific non-safety grade systems listed in IE Information Notice 79-22, as well as others, for potential interactions that could constitute a substantial safety hazard. We have not been able to identify such an interaction.
While, in some cases, we have identified variations from the FSAR li-censing bases, the basic conclusion of the FSAR, that these events do not constitute an undue risk to the health and safety of the public, remains unchanged.
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,c Our investigation, within the limited time frame required by your September 17 letter, has convinced us that continued operation is warranted.
Justification for continued operation is provided in the attached report.
In addition, Nuclear Safety Analysis Center has determined that the probability of severe consequences resulting from one of these high energy pipe breaks is very low for a typical nuclear power plant. The Probabilistic Analysis of IE Information Notice 79-22 Scenarios was prepared by NSAC as a result of AIF's promotion of an industry wide generic response to this concern.
We have participated with AIF to the extent possible and the above referenced probability ar,alysis will be submitted to you by NSAC later this week.
Further AIF's generic analysis promotes that such breaks are more likely to be small cracks rather than catastrophic failures so that the resulting adverse environment builds up over a period of time providing a high potential for detection prior to component failure. Additionally, our review recognized the difference MEMBER MIDDLE SUUTH UTILITIES SYSTEM 79}Q} QQ /O}
Mr. H. R. Denton October 7,1979 between a demonstrated deficiency (e.g. determination that a control com-ponent would operate in a fashion not within the limits presented in the safety analysis) and a potential unreviewed question. As previously stated, we have not identified any events that would change the conclusion:;
of the FSAR, that is, that these events do not constitute an undue risk to the health and safety c' the public.
As a result of the Thrr Mile Island evenc, there are a significant number of industry, governmental and regulatory investigations under way examin-ing the licensing bases and the operating procedures of nuclear generating facilities. These investigations are already identifying areas where studies may result in the consideration of new or revised events as part of the bases for assuring the continued safety of nuclear power plants.
NUREG-0578 out-lines several such events and suggests remedies.
NUREG-0578 requirements for analyses of potential safety problems envision the kinds of scenerios identified by Westinghouse and made the subject of IE Information Notice 79-22. Section 3.2 of NUREG-0578, page 17 states in part,
...The f1RC raquirements for non-safety systems are generally limited to assuring that they do not adversely affect the operation of safety systems..."
Further, on page A-45 of NUREG-0578,
" Consequential failures shall also be considered..."
We, therefore, believe that the scope of the action required by IE Information Notice 79-22 is fully consistent with the requirements of NUREG-0578 and, therefore, will be integrated with the planread response sequence for com-pliance with NUREG-0578.
Very truly yours, 1T n
mp n
William Cas naugh, III WC: ERG:nak Attachment ll)4 db
STATE OF ARKANSAS
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SS COUNTY OF PULASKI
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William Cavanaugh III, being duly sworn, states that he is Vice President, Generation & Construction, for Arkansas Power & Light Company; that he is authorized on the part of said Company to sign and file with the Nuclear Regulatory Commission this Supplementary Infomation; that he has reviewed or caused to have reviewed all of the statements contained in such information, and that all such statements made and matters set forth therein are true and correct to the best of his knowledge, infoma-tion and belief.
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m William Cav,arjadgh III
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SUBSCRIBED AND ? WORN T0 before me, a Notary Public in and for the
[#ayof b _1979.
d County and State above named, this laun.:
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Notary Fu My Comission Expires:
My Ccmmis:!03 Erpires 9/1/g3 1134
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