2CAN098904, Forwards Comments on Safety Evaluation Re Proposed Designs for Diverse Scram Sys & Diverse Turbine Trip for Plant & Installation of Diverse Emergency Feedwater Actuation Sys

Forwards Comments on Safety Evaluation Re Proposed Designs for Diverse Scram Sys & Diverse Turbine Trip for Plant & Installation of Diverse Emergency Feedwater Actuation Sys

ML20248B034
Person / Time
Site:	Arkansas Nuclear
Issue date:	09/25/1989
From:	James Fisicaro ARKANSAS POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
2CAN098904, 2CAN98904, TAC-59069, NUDOCS 8910030077
Download: ML20248B034 (4)

Text

ps Arkansas Powsr & Ught Comp 1ny

~AP8L =P Litue Rock AR 72203 Tel 501377 40C0 September 25, 1989 2CAN098904 U. S. Nuclear Regulatory Commission Document Control Desk Mail Station PI-137' Washington, DC 20555

SUBJECT:

Arkansas Nuclear One - Unit 2 Docket No. 50-368 License No. NPF-6 Safety Evaluation for Arkansas Nuclear One, Unit 2 (AN0-2)

Compliance with 10CFR50.62 (Anticipated Transient Without Scram (ATWS)) and Schedule Extension Request for DEFAS Installation Gentlemen:

The Arkansas Power and Light Company (AP&L) is in receipt of your correspondence of June 21, 1989 (2CNA068902) which transmitted the, NRC staff's acceptance of the proposed designs for the Diverse Scram System (DSS) and the Diverse Turbine Trip (DTT) for Arkansas Nuclear One, Unit 2 (AN0-2) as required by 10CFR50.62.

AP&L agrees with the staff position put forth in the aforementioned correspondence, regarding the AN0-2 DSS and DTT designs and as committed to in our correspondence of February 2,1989 (2CAN028904) we are proceeding with the installation of those designs during our refueling outage (2R7) currently in progress. However, after reviewing the Safety Evaluation, several points were identified which we believe should be further clarified.

These points are addressed in the attachment to this correspondence and were discussed with Messrs. Chester Poslusny, Hubert Li and Arthur Nolan of your staff in a meeting on July 12, 1989.

With regard to implementation schedules, your Safety Evaluation stated,

" Implementation of the ATWS Rule should be independent of the Staff's review of the DAFW system." In li 'l March 29, 1989 (2CAN038910)ght of this not only statement,our reiterated our2R7 correspondence s,chedule forof' 'l installing DSS and DTT on AN0-2, but also discussed the fact that the installation of the Diverse Emergency Feedwater Actuation System (DEFAS) to-satisfy the requirement of 10CFR50.62(c)(1) could not be accomplished during 2R7. The reason for this is two-fold. Fi rst , the the Combustion i Engineering Owners Group (CE0G) and the NRC Staff have not resolved the design issues surrounding DEFAS compliance with the ATWS Rule for ANO-2, 8910030077 890923 PDR P ADOCK 05000368 0 -

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U. S. NRC Page 2 September 25, 1989 l San Onofre Nuclear Generating Station, Units 2 and 3 (SONGS 2 and 3) and Waterford, Unit 3 (W-3). Secondly, a Design Change could nc now be implemented in the current refueling outage (2R7) even if acceptance of the ANO-2 specific DEFAS design was already reached due to shortage of time to do engineering, procure parts and arrange necessary installation. If NRC concurrence with the currently proposed DEFAS design for ANO-2 can be resolved and a safety evaluation issued prior to the end of the first quarter of 1990, then AP&L will be able to install this DEFAS design during our eighth refueling outage on ANO-2 (2R8) currently scheduled to begin in the spring of 1991. Consequently, AP&L is requesting a schedule extension for completion of this particular aspect of the the ATWS requirement contained in 10CFR50.62(c)(1) until the completion of 2R8 outage activities.

An extensive effort has been made by AP&L, as part of the CE0G, to address the DEFAS issues in order to close ATWS on ANO-2. Participating with the other affected CE0G members, AP&L has evaluated numerous alternate design approaches for DEFAS, met with the staff to discuss findings and resolve concerns as well as submit to the staff a proposal for an alternate generic design option for DEFAS (CEN-384 " Design for a Diverse Emergency Feedwater Actuation System") which is currently under review by the Staff.

It is our understanding that revised pages to the DSS and DTT SER, incorporating the appropriate changes will be forwarded in attachment to the DEFAS SER following our unit-specific DEFAS submittal. This has been discussed with Mr. Poslusny.

AP&L will continue to ma'Ke every effort to bring to a closure, those outstanding issues relating to 10CFR50.62 compliance on ANO-2.

If you should have any questions on this submittal, please don't hesitate to contact me.

Very truly yours, w &~

ames J. Fisicaro Manager, Licensing JJF:MT:lg Attachment

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. l V. S. NRC -l Page 3 i September 25, 1989

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cc: Mr. Robert Martin U. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 1000 1 I

Arlington, TX 76011 Mr. Chet Poslusny NRR Project Managel - ANO-2 U. S. NRC NRR Mail Stop 13-D-18 1 White Flint North 11555 Rockville Pike P.ockville, MD 20852 NRC Senior Resident Inspector Arkansas Nuclear One Number 1, Nuclear Plant Road Russellville, AR 72801 l

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t COMMENTS CONCERNING SAFETY EVALUATION FOR ARKANSAS NUCLEAR ONE, UNIT 2 (ANO-2)

COMPLIANCE WITH THE ATWS RULE, 10CFR50.62 TAC N0. 59069 The following comments resulted from a review of the above referenced Safety Evaluation Report (SER) (2CNA068902) regarding the design for the Diverse Scram System (DSS) and Diverse Turbine Trip (DTT) modifications for ANO-2, as required by 10CFR50.62.

Comment No. 1 SER, Page 4, 2nd Paragraph: Refers to "ATWS equipment is part of the broader class of structures, systems and components important to safety...".

Arkansas Nuclear One (AN0) does not maintain an equipment classification to designate equipment or components as "important to safety." Equipment is )

either classified as Safety-Related ("Q") or Non-Safety Related. Since ATWS equipment is not safety-related, it will not carry a "Q" Classification and will be classified as non-safety related. .

l Comment No. 2 SER, Page 7, 3rd Paragraph: States that, "The AN0-2 DSS design consists of four safety-related instrument channels...". This is incorrect. The design consists of four "non-safety related" instrument channels. .I Comment No. 3 SER, Page 8, 4th Paragraph: States, "The logic power is supplied by four Foxboro power supplies." Following subsequent design reviews with Foxboro, bus limitations within the Foxboro equipment necessitated providing DSS controller power from two power supplies operating in parallel for all four channels.

Comment No. 4 SER, Page 11. Item 5: Discusses the minimum Control Room annunciation. The ANO-2 DSS alarms have been designed and approved by the Control Room Design Review / Human Engineering Discrepancies Program as listed in Item 5 of the SER. However, Control Room annunciation will only consist of two l annunciator windows as follows:

" DSS TRIP"

" DSS SYSTEM TROUBLE" The " DSS System Trouble" is an alarm repeat (transfer) of all the alarms at the remote DSS cabinet.

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