ML20133K249

Submits Schedule for Completing Required ATWS Mods,Per 10CFR50.62.Mods Will Be Implemented by End of Third Refueling Outage After ATWS Rule Effective Date

ML20133K249
Person / Time
Site:	Hatch
Issue date:	10/14/1985
From:	Gucwa L GEORGIA POWER CO.
To:	Stolz J Office of Nuclear Reactor Regulation
References
2176N, NED-85-725, TAC-59931, NUDOCS 8510210142
Download: ML20133K249 (3)

Text

r-Gsorg.a Power Corroany 333 Pedmont Avenue

. AManta. Georg a 30308 Telephone 404 526-6526 Mahng Ad&ess:

Post Oft ce Ekw 4545 A:tanta. Geor;;'a 30302 L Georgia Power L T. cucu  % merc an~"

Mriager Nuclear Enane*rq and cruef Nuciear Eng neer NED-85-725 2176N October 14, 1985 Director of Nuclear Reactor Regulation Attention: Mr. John F. Stolz, Chief Operating Reactors Branch No. 4 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D. C. 20555 NRC DOCKET 50-366 OPERATING LICENSE NPF-5 EDWIN I. HATCH NUCLEAR PLANT UNIT 2 ANTICIPATED TRANSIENTS WITHOUT SCRAM IMPLEMENTATION SCHEDULE Gentlemen:

Section (d) of 10 CFR 50.62, the final Anticipated Transients Without Scram (ATWS) rule, requires the submittal of a schedule for completing the required plant ATWS modifications within 180 days of the issuance of QA guidance for non-safety related equipment. Justification is required for a schedule extending beyond the second refueling outage following the effective date of the ATWS rule (July 26, 1984). Pursuant to those requirements, Georgia Power Company (GPC) hereby proposes to implement the required modifications in Hatch Unit 2 by the end of its third refueling outage after the ATWS rule effective date. The proposed schedule is necessary because the required engineering and procurement are not likely to be completed in time to support implementation during an earlier outage.

Since the issuance of the final ATWS rule, GPC has undertaken a major effort to implement its requirements as early as possible. This effort has included participation in BWR Owners Group activity generically evaluating ATWS implementation alternatives, and performance of a detailed plant specific evaluation. Engineering and procurement activities for ATWS modifications are in progress. It appears, however, that the lead time requirements for the Alternate Rod Insertion (ARI) installation and Standby Liquid Control (SLC) modifications under consideration will not allow full implementation during the second Hatch 2 refueling outage following the ATWS rule. That outage, originally projected to begin in early September, 1986, could begin in June 1986, or even earlier, if the high availability achieved thus far in the operating cycle continues.

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Georgia Powerkh Director of Nuclear Reactor Regulation Attention: Mr. John F. Stolz, Chief Operating Reactors Branch No. 4 October 14, 1985 Page two Valves for the ARI system, which will vent the scram pilot air header under conditions indicative of an ATWS, have an estimated delivery date of mid-June 1986, which is questionable for the second outage.

Two SLC alternatives are being considered to satisfy the requirement for 86 gpm equivalency: two-pump operation and use of enriched boron. If the two-pump option is selected, it will be necessary to perform a test to determine if the existing SLC piping could accomodate the increased flow rate. The test could only be performed during a refueling outage, and any piping modifications found necessary would need to be implemented during the following refueling outage. Since one refueling outage has taken place for Hatch Unit 2 since the ATWS rule took effect, the two-pump SLC option could be implemented no earlier than the third outage. If the enriched boron option is chosen, the purchase of enriched boric acid would be necessary.

GPC is aware of only two suppliers, whose production capacities are rather limited. The delivery schedule for this material could vary greatly, depending on the number of plants which choose the enriched boron approach.

The most optimistic delivery schedule would support the second outage; however, prudent when the high degree of uncertainty is considered, it appears to allow the additional operating cycle for enriched boron implementation.

GPC considers the proposed schedule justified because a responsible effort has been made to implement the requirements of the ATWS rule in an expeditious manner, and because factors beyond GPC's control prevent earlier completion. The proposed schedule provides the minimum time required for orderly implementstion of the required modifications. Furthermore, the proposed schedule would not present undue risk to the health and safety of the public.

Numerous submittals made in behalf of the BWR utilities have documented the low probability of an ATWS event and the effectiveness of the installed Recirculation Pump Trip in mitigating its consequences. Recent generic studies of Reactor Protection System reliability performed to support Technical Specification improvements confirm the high reliability of that system. In light of the remote possibility of severe consequences from an ATWS event, GPC believes that no undue risk to the public would result from operation of Hatch Unit 2 for the additional period prior to implementing ATWS modifications.

Based on the above, GPC considers the proposed schedule to be reasonable and justified and requests NRC approval.

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i GeorgiaPower A j i

Director of Nuclear Reactor Regulation 1 Attention: Mr. John F. Stolz, Chief Operating Reactors Branch No. 4 October 14, 1985 Page three i

This submittal completes the reporting requirements of 10 CFR 50.62 Section (d). A detailed description and justification of the planned ATWS modifications, as required by 10 CFR 50.62 Section (c)(6), will be provided at a later date. A SWR Owners Group submittal will address the generic aspects of BWR ATWS modifications. GPC will supplement the Owners Group l report with the necessary Hatch-specific details.

If you have any questions, please bring them to our ininediate attention. If a meeting is desired to discuss this matter, we request that the NRC Licensing Project Manager contact us to make the necessary arrangements.

Very truly yours, WY %

', L. T. Gucwa l JH/mb xt: Mr. J. T. Beckham, Jr.

Mr. H. C. Nix, Jr.

Dr. J. N. Grace (NRC-Region II)

Senior Resident Inspector i

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I 700775