2CAN119002, Provides Further Clarification Re Safety Evaluation for Compliance W/Atws Rule

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Provides Further Clarification Re Safety Evaluation for Compliance W/Atws Rule
ML20058H944
Person / Time
Site: Arkansas Nuclear Entergy icon.png
Issue date: 11/16/1990
From: James Fisicaro
ENTERGY OPERATIONS, INC.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
2CAN119002, NUDOCS 9011260179
Download: ML20058H944 (3)


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November 16, 1990 2CAN119002 U. S. Nuclear Regulatory Commission Document Control Desk Mail Station P1-137 Washington, DC 20555

$UBJECT: Arkansas Nuclear One - Unit 2 Docket No. 50-368 License No. NPF-6 Further Clarification Regarding the Safety Evaluation for Arkansas Nuclear One, Unit 2 Compliance with the ATWS Rule Gentlemen:

By. letter dated June 21,1989(2CNA068902), the NRC forwarded the Safety Evaluation (SE) regarding Arkansas Nuclear One, Unit 2 (ANO-2) designs for the Diverse Scram System (DSS) and the Diverse Turbine Trip (OTT) stating that the proposed OSS and DTT conformed to the requirements of 10CFR50.62 (ATWS rule).

  • Subsequent to the issuance of the SE, Entergy Operations in letter dated September 25, 1989 (2CAN098904), identified several items included in the SE which needed clarification. By NRC letter, dated August 16, 1990 (2CNA089001), revised pages to the June 21, 1989, SE incorporated the identified clarifications.

After reviewing these revised pages Entergy Operations has identified 21, 1989, SE, which should be three additional items, from the JuneThese items are addressed in the attachment to th further clarified.

correspondence. We believe these clarifications do not invalidate the conclusions of the June 21, 1989, NRC Safety Evaluation.

If you should have any questions on this submittal, please do not hesitate to contact me.

Very truly yours, r, w & & & -v James . Fisicato Manager, Licensing JJF:RWC:fc Attachment s . . J l

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l cc: Mr. Robert Martin V. S. Nuclear Regulatory Commission Region IV ,

611 Ryan Plaza Drive, Suite 1000 l Arlington, TX 70011 NRC Senior Resident Inspector Arkansas Nuclear One - ANO-1 & 2 Number 1, Nuclear Plant Road Russellville, AR 72801 i

Ms. Sheri Peterson NRR Project Manager, Region IV/ANO-2 U. S. Nuclear Regulatory Commission NRR Mail Stop 11-B-19 One White Flint North 11555 Rockville Pike Rockville, Maryland 20852 Thomas W. Alexion l'RR Project Manager, Region IV/ANO-1 U. S. Nuclear Regulatory Commission NRP Mail Stoo 11-B-19 '

One White F at North 11555 Rockville ?ike Rockville,i, 'and 20852 l

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COMMENTS CONCERNING THE REVISED PAGES TO THE SAFETY EVALUATION FOR ARKANSAS NUCLEAR ONE, UNIT 2 (ANO-2)

COMPLIANCE WITH THE ATVS RULE, 10CFR50.62 ,

The following comments resulted from a review of the above referenced revised pages to the Safety Evaluation (2CNA089001) regarding the design for the Diverse Scram System (DSS) and the Diverse Turbine Trip (DTT) modifications for ANO-2, as required by 10CFR50.62.

Comment 1: Page 7, Section B, second paragraph, first sentence reads "The XNO-2 D3S design consists of four non-safety-related instrument channels, each of which provides an input to two, separate, two-out-of-four, energize-to-actuate logic matrices."

It should read "The ANO-2 DSS design consists of four non-safety-related instrument channelt., each of which provides an input to four, separate, two-out-of-four, energize-to-actuate logic matrices."

Comment 2: Page 7 Section B, second paragraph, second and third sentences read "The output of each logic is used to open one of the two RPS motorgenerator(MG)setoutputcontractors. Both contractors must open to remove power from the control element assemblies (CEA), causing a reactor scram."

Contractors is a typographical error, it should be contactors.

Comment 3: Page 8, Section C, second paragraph discussing the DSS power supply /W S is in error. This discussion is based on conceptual design.

This paragraph should be revised to be consistent with the final design.

It-should read "The DSS at ANO-2 receives power from two, separate, non-Class 1E instrument AC power sources, each of which feeds one Foxboro multi-nest power supply which is operated in parallel with the other multi-nest power supply. Each power supply contains the capacity to supply all DSS cabinet loads. These power supplies are provided with 24 VDC battery back-up inputs from an UPS. The UPS for each power supply consists of a Power Conversion Products battery charger and a Johnson Controls .

battery set."

It should be noted that the DSS design does not contain a multiplexer as referenced.

The final design for DSS was reviewed during the inspection conducted by Messrs P. C. Wagner and C. J. Paulk during the period of October 16-20 and October 30 through November 3,1989, and the inof fice review conducted during the period October 23-27, 1989 (Inspection Report 50-313-368/89-37, November 30,1989).

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