ML20212F030

Application for Amend to License DPR-6,changing Tech Specs to Include Second Scram Dump Tank Vent & Drain Valve

ML20212F030
Person / Time
Site:	Big Rock Point File:Consumers Energy icon.png
Issue date:	12/30/1986
From:	Buckman F CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
Shared Package
ML20212F028	List: ML20212F024 ML20212F030 ML20212F036
References
NUDOCS 8701050562
Download: ML20212F030 (2)

Text

CONSUMERS POWER COMPANY Docket 50-155 Request for Change to the Technical Specificatione License DPR-6 For the reasons herinafter set forth, it is requested that the Technical Specifications contained in the Facility Operating License DPR-6, Docket 50-155, issued to Consumers Power Company on May 1, 1964, for the Big Rock Point Plant be changed as described in Section I below:

I. Changes Section 5.2.2(b)

Revise the first sentence of Section 5.2.2(h) to read as follows:

"The scram dump tank air operated vent and drain valves shall be (1) verified open at least once per 31 days, and (2) cycled through at least one complete cycle of full travel once per quarter."

II. Discussion As identified in the Big Rock Point IPSAR (NUREG-0828) and Integrated Plan Issue #84, the Big Rock Point Plant staff evaluated the potential for LOCA due to single failure in the scram dump tank vent and drain isolation system. It was found that the probability for such an occurrence was significant enough to justify adding a redundant vent and drain valve to the scram dump tank isoir. tion system. These two new valves are air operated similar to those currently utilized and will operate in unison with the existing two valves and their control scheme. This modification is planned to be installed during the 1987 refueling outage.

This proposed change involves elimination of the reference to identification numbers (ie, CV/NC11 and CV/NC12) in the Technical Specification. This would then require that all air operated vent and drain valves (four total following completion of the modification) be tented per the requirements of this Technical Specification.

III. Analysis of No Significant Hazards Consideration Incorporation of the proposed change expands the scope of current Technical Specification to include all valves in the vent and drain line as opposed to the current specification which uniquely specifies two valves. The addition of the second vent and drain valve significantly reduces the probability of a LOCA through the scram dump tank and therefore decreases the probability of a previously evaluated accident.

8701050562 861230 PDR P

ADOOK 05000155 PDR AT1286-0205-NLO2

Big Rock Point Plant 2 The proposed change does not alter the operational or testing requirements for the scram dump tank vent and drain valves. Since the additional valves operate in unison with existing valves from the same control air source, test methods are not changed. This does not create the possibility of a new or different type of accident than was previously identified.

The underlying purpose of this portion of technical specification is to insure that scram dump tank discharge volume failures do not significantly increase the probability of an Anticipated Transient Without Scram (ATWS). By adding the proposed vent and drain valve it has been found through probability analysis that the modification has virtually no impact on the probability of an ATWS that could be caused by an inadvertent closure of the drain and vent valves. Thus the margin of safety associated with this proposed change is not decreased.

Consequently, this proposed change does not involve a significant hazards consideration.

IV. Conclusion The Big Rock Point Plant Review Committee has reviewed this Technical Specification Change Request and has determined that this change does not involve an unreviewed safety question and therefore involves no significant hazards consideration. This change has also been reviewed under the cognizance of the Nuclear Safety Board. A copy of this Technical Specification Change Request has been sent to the State of Michigan official designated to receive such Amendments to the Operating License.

CONSUMERS POWER COMPANY By , w(

F/W Buckman, Vice Pres 1tlegt Nuclear Operations Sworn and subscribed to before me this 30th day of December 1986.

d4 As Y mm, Barbara P Townsend, Notary Public Jackson County, Michigan My commission expires August 23, 1988 i

AT1286-0205-NLO2

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