ML20090B151

Amend to Application for Ol,Providing Info in Support of Licensee Request to Delete Boron Dilution Mitigation Sys Tech Specs,Per NRC 840627 Request

ML20090B151
Person / Time
Site:	Wolf Creek
Issue date:	07/09/1984
From:	Koester G KANSAS GAS & ELECTRIC CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
References
KMLNRC-84-109, NUDOCS 8407120322
Download: ML20090B151 (3)

Text

4 KANSAS GAS AND ELECTRIC COMPANY THE ELECTFhC COMPANY GLENN L MOESTER vitt pass 40*NT hvCLEA4 July 9, 1984 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555 KMLNRC 84-13 Re: Dock No. STN 50-482 Ref: NRC Letter dated 6/27/84 from BJYoungblood, NRC, to GLKoester, KG&E Subj: Boron Dilution Mitigation System Technical Specifications

Dear Mr. Denton:

The Referenced letter requested additional information re-garding the KG&E request to delete the Boron Dilution Mitigation System Technical Specifications.

Transmitted herewith is the response to the question in the Referenced letter. This information is hereby incorporated into the Wolf Creek Generating Station, Unit No.1, Operating License Application.

Yours very truly, f,,'g)

GLK:bb Attach xc: PO'Connor (2)

HBundy 8407120322 840709 \

PDR ADOCK 05000482 T A PDR

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l 201 N. Market - Wichita. Kansas - Mail Address: RO. Box 208 i Wichita, Kansas 67201 - Telephone: Area Code (316) 261-6451

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OATII OF AFFIRMATION STATE OF KANSAS )

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COUNTY OF SEDGWICK )

I, Glenn L. Koester, of lawful age, being duly sworn upon oath, do depose,  ;

state and affirm that I am Vice President - Nuclear of Kansas Gas and Electric Company, Wichita, Kansas, that I have signed the foregoing letter

" w of transmittal, know the contents thereof, and that all statements contained

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therein are true.

KANSAS GAS AND ELECTRIC COMPANY By , gg 4

, 'Glenn L. Koester Vice President - Nuclear l E.D. Prothro, Assistant Secretary I

t STATE OF KANSAS )

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COUNTY OF SEDGWICK )

BE IT REMEMBERED that on this 9th day of July, 1984 , before I me, Evelyn L. Fry, a Notary, personally appeared Glenn L. Koester, Vice President - Nuclear of Kansas Gas and Electric Company, Wichita, Kansas, who is personally known to me'and who executed the foregoing instrument, and he duly acknowledged the execution of the same for and on behalf of and as the act and deed of said corporation.

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,,,,,,,,,,,IN WITNESS WHEFEOF , I-have hereunto set my hand and affixed my seal the e and year above written.

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Ouestions/ Responses - Boron Dilution Mitigation System i

0. By letter dated March 16, 1984, Kansas Gas and Electric Cmpany (KG&E)  !

requested deletion of the Boron Dilution Mitigation System Technical Specification. Based upon our review of your subr.ittal, we have determined that we require additional information to emplete our review.

.t You conclude that autmatic termination of the boron dilution event is not necessary, and that manual action can be relied upon based upon a calculated low probability of resulting core damage. The staff has historically allowed reliance of manual action to mitigate boron dilution events. The acceptability of allowing reliance on manual action is based on: (a) assuring that the operator has sufficent time to be alerted to a boron dilution event so that appropriate manual actions can be taken before the subcritical margin is lost, and (b) assuring that appropriate alarms are available to alert the operator to a boron dilution event. The Standard Review Plan (SRP) section identifies acceptable times, frm the time the operator is alerted to a boron dilution event, for the operator to take the necessary corrective action for each mode of operation. In general, the alarm system should meet the single failure criterion.

Please demonstrate that manual action can be relied upon to mitigate boron dilution events by showing how your design conforms to the SRP criteria.

If you choose not to conform to the SRP criteria (e.g. , allow shorter times for operator actions, do not install positive alarms which meet the single failure criterion), please provide justification for the acceptibility of your design. We will specifically need the data base (operational history, similator data, etc.) which supports any significant reduction in the operator action times specified in the SRP.

R. In justifying the deletion of the Boron Dilution Mitigation System (BDMS)

Technical Specifications, KG&E dio not conform to the Standard Review Plan (SRP) criteria in Section 15.4.6 of NUREG-0800 (Chemical and Volume Control System Malfunction that results in a decrease in Boron Concentration in the Reactor Coolant (PWR). KG&E instead chose to propose an alternative method, as provided for the SRP, for justifying the deletion of the BDMS Technical Specifications. This method employed a probabilistic argument. Similar studies were generated by the NRC for St.

Lucie Unit I and NUREG-0933 (A Prioritization of Generic Safety Issues). i

'Ihe study that KG&E generated utilizes conventional PRA techniques in a conservative fashion. We utilized data frm Swain and Guttman (NUREG-1278) for human reliability in conjunction with our specific procedures and training to demonstrate the reliability of manual actions. We showed that no significant increase in reliability is achieved by using the automated system. This appears to confirm on a Wolf Creek specific basis the generic conclusions reached by NUREG-0933 in that boron dilution events do not constitute a significant risk to the public. We, in addition, conclude that the autmated system does not improve reliability beyond what can be achieved using manual action.

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