ML20069P385: Difference between revisions

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Discussion of Changes introduction Virginia Electric and Power Company requested changes to the North Anna Unit 1 and Unit 2 Technical Specifications by letter dated March 1,1994. The proposed changes modify the testing and surveillance requirements for the emergency diesel generators (EDG) as per NRC Generic Letter 93-05 "Line-Item Technical Specifications improvements to Reduce Surveillance Requirements for Testing During Power Operation", dated September 27,1993. A notice that the NRC had made a proposed finding that no significant hazard exists was published on March 30,1994 in the Federal Register (59FR14899).
Discussion of Changes introduction Virginia Electric and Power Company requested changes to the North Anna Unit 1 and Unit 2 Technical Specifications by {{letter dated|date=March 1, 1994|text=letter dated March 1,1994}}. The proposed changes modify the testing and surveillance requirements for the emergency diesel generators (EDG) as per NRC Generic Letter 93-05 "Line-Item Technical Specifications improvements to Reduce Surveillance Requirements for Testing During Power Operation", dated September 27,1993. A notice that the NRC had made a proposed finding that no significant hazard exists was published on March 30,1994 in the Federal Register (59FR14899).
On May 17,1994, a conference call was held with the NRC staff concerning the allowed time frame to determine the operability of one EDG when the opposite train EDG has been declared inoperable. Generic Letter 93-05, item 10.1, specified that this determination must be made within 8 hours. The currently approved Technical Specifications for North Anna Units 1 and 2 (Specification 3.8.1.1, Action b) and NUREG-1431, " Standard Technical Specifications - Westinghouse Plants," dated September,1992, Specification 3.8.1, Action B.3 allow 24 hours to make this determination. Based on our discussion with the NRC staff on May 17,1994, that portion of our previously submitted Technical Specification (TS) change request is being changed to remain consistent with NUREG-1431. The change described in this supplemental change request for Technical Specification 3.8.1.1, Action b replaces the corresponding change in our March 1,1994 submittal.
On May 17,1994, a conference call was held with the NRC staff concerning the allowed time frame to determine the operability of one EDG when the opposite train EDG has been declared inoperable. Generic Letter 93-05, item 10.1, specified that this determination must be made within 8 hours. The currently approved Technical Specifications for North Anna Units 1 and 2 (Specification 3.8.1.1, Action b) and NUREG-1431, " Standard Technical Specifications - Westinghouse Plants," dated September,1992, Specification 3.8.1, Action B.3 allow 24 hours to make this determination. Based on our discussion with the NRC staff on May 17,1994, that portion of our previously submitted Technical Specification (TS) change request is being changed to remain consistent with NUREG-1431. The change described in this supplemental change request for Technical Specification 3.8.1.1, Action b replaces the corresponding change in our March 1,1994 submittal.
Backaround Operability testing of an EDG is required by North Anna Technical Specification 3/4.8.1.1 whenever the alternate safety buses' EDG is declared inoperable due to any cause other than preplanned preventative maintenance or testing. Since there are many potential failures of EDG subsystems that would not be classified as a common mode failure yet would cause an EDG to be declared inoperable, this Technical Specification requirement can cause unnecessary testing of the operable EDG when the alternate safety buses' EDG is declared inoperable due to inoperable support equipment or an independently testable component. NUREG-1366 stated that "The NRC staff recommends that the requirements to test the remaining diesel generator (s) when one diesel generator is inoperable due to any cause other than preplanned preventative maintenance or testing be limited to those situations where the cause for inoperability hcs not been conclusively demonstrated to preclude the potential for a common mode failure.        However, when such testing is required, it should be performed within 8 hours of having determined that the diesel generator is inoperable." However, NUREG-1431 allows 24 hours to determine the cause of the inoperable EDG's failure before requiring testing of the remaining operable EDG. This  ;
Backaround Operability testing of an EDG is required by North Anna Technical Specification 3/4.8.1.1 whenever the alternate safety buses' EDG is declared inoperable due to any cause other than preplanned preventative maintenance or testing. Since there are many potential failures of EDG subsystems that would not be classified as a common mode failure yet would cause an EDG to be declared inoperable, this Technical Specification requirement can cause unnecessary testing of the operable EDG when the alternate safety buses' EDG is declared inoperable due to inoperable support equipment or an independently testable component. NUREG-1366 stated that "The NRC staff recommends that the requirements to test the remaining diesel generator (s) when one diesel generator is inoperable due to any cause other than preplanned preventative maintenance or testing be limited to those situations where the cause for inoperability hcs not been conclusively demonstrated to preclude the potential for a common mode failure.        However, when such testing is required, it should be performed within 8 hours of having determined that the diesel generator is inoperable." However, NUREG-1431 allows 24 hours to determine the cause of the inoperable EDG's failure before requiring testing of the remaining operable EDG. This  ;

Latest revision as of 09:37, 31 May 2023

Application for Amends to Licenses NPF-4 & NPF-7,revising TS Re Removal of Unnecessary EDG Surveillance Requirements,Per GL 93-05
ML20069P385
Person / Time
Site: North Anna  Dominion icon.png
Issue date: 06/16/1994
From: Ohanlon J
VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20069P387 List:
References
94-120A, GL-93-05, GL-93-5, NUDOCS 9406240176
Download: ML20069P385 (8)


Text

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VinoixA Es.crinic Axt> Pownu Conswxy ItictiMoxn,Vinoixir unsu61 June 16, 1994 U.S. Nuclear Regulatory Commission Serial No. 94-120A Attention: Document Control Desk NL&P/EJW Washington, DC. 20555 Docket Nos. 50-338 50-339 License Nos. NPF-4 NPF-7 Gentlemen:

YlRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNITS 1 AND 2 SUPPLCMENTAL REVISION TO PROPOSED TECHNICAL SPECIFICATIONS CHANGES REMOVAL OF UNNECESSARY EMERGENCY DIESEL GENERATOR SURVEILLANCE REQUIREMENTS On March 1,1994, the Virginia Electric and Power Company requested amendments, in the form of changes to the Technical Specifications, to Facility Operating License Nos. NPF-4 and NPF-7 for North Anna Power Station Units 1 and 2, respectively. The changes were proposed to eliminate certain surveillance requirements for the emergency diesel generators which have been deemed unnecessary in accordance with NRC Generic Letter 93-05,"Line-Item Technical Specifications improvements For Testing During Power Operation," and NUREG-1366, " Improvements To Technical Specifications Surveillance Requirements." A revision to the March 1,1994 Technical Specification change request is hereby submitted and is detailed below.

On May 17,1994, a conference call was held with the NRC staff concerning the allowed time frame to determine the operability of one EDG when the opposite train EDG has been declared inoperable. Generic Letter 93-05, item 10.1, specified that this determination must be made within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. The currently approved Technical Specifications for North Anna Units 1 and 2 (Specification 3.8.1.1, Action b) and NUREG-1431, " Standard Technical Specifications - Westinghouse Plants," dated September,1992, Specification 3.8.1, Action B.3 allow 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to make this determination. Based on our discussion with the NRC staff on May 17,1994, that portion of our previously submitted Technical Specification (TS) change request is being changed to remain consistent with NUREG-1431.

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l A discussion of the proposed Technical Specifications changes is provided in  :

Attachment 1. The proposed Technical Specifications changes are provided in Attachment 2. It has been determined that the proposed Technical Specifications changes do not involve an unreviewed safety question as defined in 10 CFR 50.59 or ,

a significant hazards consideration as defined in 10 CFR 50.92. The basis for our '

determination that these changes do not involve a significant hazards consideration is provided in Attachment 3. The proposed Technical Specifications changes have been reviewed and approved by the Station Nuclear Safety and Operating Committee and j' the Management Safety Review Committee.

Should you have any questions or require additional information, please contact us.

Very truly yours,

(. / hw J. P. O'Hanlon '

Senior Vice President - Nuclear Attachments cc: U.S. Nuclear Regulatory Commission Region 11 101 Marietta Street, N.W.

Suite 2900 Atlanta, Georgia 30323 1

Mr. R. D. McWhorter NRC Senior Resident inspector North Anna Power Station Commissioner Department of Health Room 400 109 Governor Street Richmond, Virginia 23219 f

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COMMONWEALTH OF VIRGINIA )

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COUNTY OF HENRICO ) j The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by J. P. O'Hanlon, who is Senior Vice President -

Nuclear, of Virginia Electric and Power Company. He is duly authorized to execute I and file the foregoing document in behalf of that Company, and the statements in the document are true to the best of his knowledge and belief.

Acknowledged before me this [d day of b//Av ,19 9/. I My Commission Expires: b/2 3/ 8.19.ff. ,

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l Attachment 1 Discussion of Changes I

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Discussion of Changes introduction Virginia Electric and Power Company requested changes to the North Anna Unit 1 and Unit 2 Technical Specifications by letter dated March 1,1994. The proposed changes modify the testing and surveillance requirements for the emergency diesel generators (EDG) as per NRC Generic Letter 93-05 "Line-Item Technical Specifications improvements to Reduce Surveillance Requirements for Testing During Power Operation", dated September 27,1993. A notice that the NRC had made a proposed finding that no significant hazard exists was published on March 30,1994 in the Federal Register (59FR14899).

On May 17,1994, a conference call was held with the NRC staff concerning the allowed time frame to determine the operability of one EDG when the opposite train EDG has been declared inoperable. Generic Letter 93-05, item 10.1, specified that this determination must be made within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. The currently approved Technical Specifications for North Anna Units 1 and 2 (Specification 3.8.1.1, Action b) and NUREG-1431, " Standard Technical Specifications - Westinghouse Plants," dated September,1992, Specification 3.8.1, Action B.3 allow 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to make this determination. Based on our discussion with the NRC staff on May 17,1994, that portion of our previously submitted Technical Specification (TS) change request is being changed to remain consistent with NUREG-1431. The change described in this supplemental change request for Technical Specification 3.8.1.1, Action b replaces the corresponding change in our March 1,1994 submittal.

Backaround Operability testing of an EDG is required by North Anna Technical Specification 3/4.8.1.1 whenever the alternate safety buses' EDG is declared inoperable due to any cause other than preplanned preventative maintenance or testing. Since there are many potential failures of EDG subsystems that would not be classified as a common mode failure yet would cause an EDG to be declared inoperable, this Technical Specification requirement can cause unnecessary testing of the operable EDG when the alternate safety buses' EDG is declared inoperable due to inoperable support equipment or an independently testable component. NUREG-1366 stated that "The NRC staff recommends that the requirements to test the remaining diesel generator (s) when one diesel generator is inoperable due to any cause other than preplanned preventative maintenance or testing be limited to those situations where the cause for inoperability hcs not been conclusively demonstrated to preclude the potential for a common mode failure. However, when such testing is required, it should be performed within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of having determined that the diesel generator is inoperable." However, NUREG-1431 allows 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to determine the cause of the inoperable EDG's failure before requiring testing of the remaining operable EDG. This  ;

was discussed with the NRC cn May 17,1994, and they stated that 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> was an appropriate time frame for comolying with the intent of Generic Letter 93-05.

Therefore, in accordance with NRC Generic Letter 93-05 and NUREG-1431, we are l

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l requesting that North Anna Technical Specifications be amended to require i operability testing of an EDG only when the alternate safety buses' EDG is declared l inoperable for any cause other than an inoperable support system, an independently  !

testable component, or preplanned preventative maintenance or testing. This testing shall be completed within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, unless the absence of any potential common mode failure for the remaining diesel generator is conclusively demonstrated.

Descriotion Of Specific Chances This Technical Specification change applies to both Unit 1 and Unit 2.

TS 3.8.1.1 Action "b" is being changed as follows:

Action "b": End the first sentence at "thereafter" by deleting the semi-colon (;)

and adding a period (.). Delete the remainder of Action "b" and replace with "If the EDG became inoperable due to any cause other than an inoperable support system, an independently testable component, or preplanned preventative maintenance or testing, demonstrate the OPERABILITY of the remaining OPERABLE EDG by performing Surveillance Requirement 4.8.1.1.2.a.4 within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> *, unless the absence of any potential common mode failure for the remaining diesel generator is demonstrated. Restore the diesel generator to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />."

Changes to TS 3.8.1.1, Action "a" have been addressed in the March 1,1994, Technical Specification change request submittal.

Safety Significance The proposed change to the operability testing requirements for the Emergency Diesel Generators (EDGs) are consistent with the intent of Generic Letter 93-05, "Line-Item Technical Specifications improvement to Reduce Surveillance Requirements for Testing During Power Operation," dated September 27,1993, and NUREG-1431

" Standard Technical Specifications - Westinghouse Plants," dated September,1992.

The proposed change will modify the requirement for operability testing of an EDG when the alternate safety buses' EDG is inoperable.

Changing the operability testing requirements of the EDGs does not affect the probability of occurrence or the consequences of the accidents identified in the UFSAR. No new accident precursors are being generated by the proposed surveillance requirement. Furthermore, the EDGs will continue to be tested in accordance with Revision 2 of Regulatory Guide 1.9 (December 1979) which provides assurance that the system is capable of performing its intended safety function.

Therefore, the consequences of a postulated accident are not increased by this change in operability testing requirements for the EDGs.

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The reduced operability testing requirements of the EDGs will not significantly increase the probability of a malfunction of an EDG to perform its intended safety function. This reduction in operability testing requirements of the EDGs at power has been examined and accepted by the NRC staff in Generic Letter 93-05 and NUREG-1431, " Standard Technical Specifications - Westinghouse Plants." The staff found that while the majority of the testing at power is important, safety can be improved, equipment degradation decreased, and an unnecessary burden on personnel resources eliminated by reducing the amount of testing at power that is required by Technical Specifications.

This change in the operability testing requirements does not affect plant or EDG operations. Therefore, no new accident precursors are being generated by this proposed change for the EDGs.

Operability testing of the EDGs will continue to be performed in accordance with Revision 2 of Regulatory Guide 1.9 (December 1979). This change reduces unnecessary starting and loading of the EDGs thereby reducing the wear and tear on those machines. Therefore, this change in operability testing requirements for the EDGs do not reduce the margin of safety as described in the Technical Specifications.

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Attachment 2 Technical Specifications Changes i

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