ML20148G348

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Proposed Tech Specs,Changing Frequency of Testing RHR Cross Tie valve,RHR-MOV-MO20,position Indication from Once Per Month to Once Per Operating Cycle
ML20148G348
Person / Time
Site: Cooper Entergy icon.png
Issue date: 05/30/1997
From:
NEBRASKA PUBLIC POWER DISTRICT
To:
Shared Package
ML20148G303 List:
References
NUDOCS 9706050288
Download: ML20148G348 (4)


Text

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  • Attacl$ ment to NLS970115 Page1of3 COOPER NUCLEAR STATION TECHNICAL SPECIFICATIONS RHR CROSS TIE VALVE TESTING Revised Pages 55 71 1.0 Description of Requested Change Change Technical Specification Table 4.2.B (Page 2) Item No.14 identification number to read as "RHR-MO-20 LMS (NFC contact)" vice "RHR-LMS-8".

Change Technical Specifications Table 4.2.B (Page 2) liem No.14 Functi .2al Test Freq. to read "Once/Oper. Cycle" vice "Once / Month (1)".

Change Technical Specification Table 3.2.B (Page 3) Instrument identification i number to read as "RHR-MO-20 LMS (NFC contact)" vice "RHR-LMS-8".

1 2.0 Justification of Change:

The RHR Crosstie Valve functional test is currently required to be performed by j full stroking RHR-MOV-20 to verify the operability of the Not-Fully-Closed l (NFC) limit switch contact and associated position indicating lights and )

annunciator. Full stroking the valve also tests the full-open contact and verifies pickup of the associated relay (10A-K103). Relay 10A-K103 contacts provide information to the RHR Minimum Flow Valve when the RHR Crosstie Valve is full open.

Opening RHR-MO-20 places both LPCI subsystems in a configuration which is susceptible to common cause failure. This requires an LCO entry during conditions that require LPCI to be operable. Revising the surveillance frequency would reduce the potential for common cause failure by not placing LPCI in the configuration described above when LPCI is required to be operable.

The current Item identification number for the NFC limit switch contact (RHR-LMS-8) is incorrect. The correct limit switch contact number is LS-16. This editorial change has no impact on the specifications.

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  • Attachment to NLS970115 Page 2 of 3 3.0 Significant Hazard Determination 10 CFR 50.91 (a) (1) requires that licensee requests for operating license amendments be accompanied by an evaluation of significant hazard posed by the issuance of an amendment. This evaluation is performed with respect to the criteria given in 10 CFR 50.92 (c).

3.1 The proposed amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated because none of the accident initiators (pipe breaks, control rod malfunctions, fuel handling equipment etc.) are affected by not opening RHR-MO20 during power operation. No new equipment is being installed which could impact accident initiation frequency. The only operational change introduced is the removal of a plant condition which would make both the LPCI subsystems vulnerable to a common mode failure while the plant is at power. No other operational changes are being introduced.

3.2 The proposed change will not significantly increase the consequences of an accident previously evaluated in the USAR because not opening MO20 during power operation will ensure that the LPCI system can fulfill its safety function in the event of an accident. The only design basis function for MO20 is to remain closed to maintain separation of the two LPCI loops in the event of an accident.

Credit is taken for the opening of MO20 in a "Beyond Design Basis Event" involving flooding of the Primary Containment. Testing MO20 once per cycle will still ensure that the valve will be capable of fulfilling this function. The intent of the testing of the MO20 limit switch is to ensure that any inadvertent opening of the MO20 valve is annunciated in the control room. This objective is maintained by 1) testing the limit switch during each refueling outage,2) monthly checks to ensure that MO20 is closed, and 3) requiring a keylock switch to open MO20.

Thus, this change will assist in assuring operability of the LPCI subsystems and therefore will not increase the consequences of an accident previously evaluated.

3.3 The proposed change will not create the possibility of a new or different kind of accident than evaluated in the USAR. The proposed change does not result in any physical change to CNS Structures, Systems, or Component, nor does it change the fit, form, or function of any equipment / component taken credit for in the accident analyses described in the USAR.

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  • Attachment

' to NLS970115 Page 3 of 3 4.0 Conclusion The District has evaluated the proposed changes described above against the criteria of 10 CFR 50.92 in accordance with the requirements of 10 CFR 50.91 (a) (1). This evaluation has determined that the proposed change to Technical Specifications will not (1) involve a significant increase in the probability or consequences of an accident previously evaluated, (2) create the-possibility for a new or different kind of accident from any accident previously evaluated, or (3) create a significant reduction in the margin of safety. Therefore, the District requests NRC approval of this proposed change.

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.* I l ATTACHMENT 3 LIST OF NRC COMMITMENTS l 1

l "6crre'spondence No: NLS970115 The following table identifies those actions committed to by the District in this document. Any other actions discussed in the submittal represent intended or l

planned actions by the District. They are described to the NRC for the NRC's l information and are not regulatory commitments. Please notify the Licensing Manager i at Cooper Nuclear Station of any questions regarding this document or any associated regulatory commitments.

COMMITTED DATE COMMITMENT OR OUTAGE )

l Develop a procedure to check that RHR-MO20 is in the Within 30 days of closed position monthly. receipt of NRC '

Amendment I

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l PROCEDURE NUMBER 0.42 l REVISION NUMBER 4 l PAGE 8 OF 9 l