ML052380520
| ML052380520 | |
| Person / Time | |
|---|---|
| Site: | Millstone, Surry, North Anna  |
| Issue date: | 08/26/2005 |
| From: | Hartz L Dominion Nuclear Connecticut, Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 05-237A, BL-03-001 | |
| Download: ML052380520 (11) | |
Text
1 Dominion August 26, 2005 U. S. Nuclear Regulatory Commission Serial No.
05-237A Attention: Document Control Desk NLOS/PRW R1 1 1555 Rockville Pike Docket Nos. 50-336/423 Rockville, MD 20852 50-338/339 50-280/28 1 License Nos. DPR-65/NPF-49 N PF-4/7 D PR-32/37 SUPPLEMENT TO RESPONSE TO NRC BULLETIN 2003-01 RECIRCULATION AT PRESSURIZED-WATER REACTORS POTENTIAL IMPACT OF DEBRIS BLOCKAGE ON EMERGENCY SUMP In a letter dated August 7, 2003, Dominion Nuclear Connecticut, Inc. (DNC) and Virginia Electric and Power Company (Dominion) provided the 60-day response to Bulletin 2003-01 for Millstone Power Station Units 2 and 3 (MPS2&3), North Anna Power Station Units 1 and 2 (NAPS1&2) and Surry Power Station Units 1 and 2 (SPS1&2). The bulletin requested Dominion to either (1) state that the emergency core cooling system (ECCS) and containment spray system (CSS) recirculation functions have been analyzed with respect to the potentially adverse post-accident debris blockage effects identified in the bulletin and are in compliance with all existing applicable regulatory requirements, or (2) describe any interim compensatory measures that have been implemented or that will be implemented to reduce the interim risk associated with potentially degraded or nonconforming ECCS and CSS recirculation functions until an evaluation to determine compliance is complete.
In a conference call with DNC and Dominion on July 13, 2005, the NRC requested that supplemental information be provided regarding the Westinghouse Owners Group/Combustion Engineering Owners Group Candidate Operator Action 05 (COA 05) for refill of the refueling water storage tank during certain accident conditions. Attachment 1 of this letter provides supplemental information for MPS2&3. Attachment 2 of this letter provides supplemental information for NAPS1 &2 and SPS1&2.
There are no commitments contained within this letter
Serial No. 05-237A Supplement to BL 2003-01 Response Page 2 of 5 Should you have any further questions regarding this matter, please contact Mr.
Paul R. Willoughby at (804) 273-3572.
Very
_- truly yours, Lesfie N. Hartz Vice President - Nuclear Engineering Virginia Electric and Power Company and Dominion Nuclear Connecticut, Inc.
Attachments (2)
Serial No. 05-237A Supplement to BL 2003-01 Response Page 3 of 5 cc:
U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, Pennsylvania 19406-1 41 5 U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW Suite 23 T85 Atlanta, Georgia 30303-8931 Mr. S. M. Schneider NRC Senior Resident Inspector Millstone Power Station Mr. J. T. Reece NRC Senior Resident Inspector North Anna Power Station Mr. N. P. Garrett NRC Senior Resident Inspector Surry Power Station Mr. V. Nerses NRC Senior Project Manager Millstone Power Station Unit 2 Mr. G. F. Wunder NRC Project Manager Millstone Power Station Unit 3 Mr. R. E. Martin NRC Senior Project Manager North Anna Power Station, Surry Power Station Mr. J. Honcharik NRC Project Manager North Anna Power Station Mr. S. R. Monarque NRC Project Manager Surry Power Station
Serial No. 05-237A Supplement to BL 2003-01 Response Page 4 of 5 Mr. J. E. Reasor, Jr.
Old Dominion Electric Cooperative lnnsbrook Corporate Center, Suite 300 4201 Dominion Blvd.
Glen Allen, Virginia 23060
Serial No. 05-237A Supplement to BL 2003-01 Response Page 5 of 5 COMMONWEALTH OF VIRGINIA
)
)
COUNTY OF HENRICO 1
The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by Leslie N. Hartz, who is Vice President -
Nuclear Engineering of Dominion Nuclear Connecticut, Inc. and Virginia Electric and Power Company. She has affirmed before me that she is duly authorized to execute and file the foregoing document in behalf of that company, and that the statements in the document are true to the best of her knowledge and belief.
Acknowledged before me this c?LT4day o f, / h & k d
, 2005.
J My Commission Expires:
- 34. Jam.
(SEAL)
Serial No. 05-237A Docket Nos.: 50-336/423 ATTACHMENT 1 BULLETIN 2003-01. POTENTIAL IMPACT OF DEBRIS BLOCKAGE ON EMERGENCY SUMP RECIRCULATION AT PRESSURIZED-WATER REACTORS SUPPLEMENT TO RESPONSE DOMINION NUCLEAR CONNECTICUT, INC.
MILLSTONE POWER STATION UNITS 2 AND 3
Serial No. 05-237A Docket Nos. : 50-336/423 Supplement to BL 2003-01 Response Page 1 of 2 BULLETIN 2003-01. POTENTIAL IMPACT OF DEBRIS BLOCKAGE ON EMERGENCY SUMP RECIRCULATION AT PRESSURIZED-WATER REACTORS SUPPLEMENT TO RESPONSE MILLSTONE POWER STATION UNITS 2 AND 3 In a conference call with Dominion Nuclear Connecticut, Inc. (DNC) and Virginia Electric and Power Company (Dominion) on July 13, 2005, the NRC requested that supplemental information be provided for DNCs and Dominions response to NRC Bulletin 2003-01. Specifically, DNC and Dominion were requested to forward information regarding the Westinghouse Owners Group (WOG)/Combustion Engineering Owners Group (CEOG) Candidate Operator Action 05 (COA 05) for refill of the refueling water storage tank during certain accident conditions. The requested supplemental information for Millstone Power Station Units 2 and 3 (MPS2&3) is provided below.
NRC Reauested Information DNC did not commit to immediately commence refill of the refueling water storage tank (RWST) per COA 05 of the WCAP-16204, Rev. 1, Evaluation of Potential ERG and EPG Changes to Address NRC Bulletin 2003-01 Recommendations (PA-SE-0085), Volume 1 - Engineering Evaluations and Analyses Report, March 2004, for Millstone Power Station Units 2 and 3. Please advise the NRC why this action was not incorporated per the COA.
DNC ResDonse DNC had committed to refill of the RWST in previous letters. Therefore, DNC will make the following commitments to modify its emergency procedures to incorporate the guidance of Revision 1 of WCAP 16204:
For MPS2:
DNC has reviewed the revised guidance given in Revision 1 of WCAP-16204 Evaluation of Potential ERG and EPG Changes to Address NRC Bulletin 2003-01 Recommendations (PA-SEE-0085) and concurs with the revised guidance that there is benefit in initiating actions to refill the RWST once injection from the RWST has stopped and the RWST has been isolated. Thus, consistent with the guidance provided in Revision 5 of CEN-152, described in Volume 3 of Revision 1 of WCAP-16204, the MPS2 Emergency Operating Procedures are being modified to initiate actions to refill the RWST once injection from the RWST has stopped and the RWST has been isolated. Implementation of this change is scheduled for completion by September 1, 2005.
Serial No. 05-237A Docket Nos.: 50-336/423 Supplement to BL 2003-01 Response Page 2 of 2 For MPS3:
DNC has reviewed the revised guidance given in Revision 1 of WCAP-16204 Evaluation of Potential ERG and EPG Changes to Address NRC Bulletin 2003-01 Recommendations (PA-SEE-0085) and concurs with the revised guidance that there is benefit in initiating actions to refill the RWST once injection from the RWST has stopped and the RWST has been isolated. Thus, consistent with the guidance provided in DW-03-018, described in Volume 2 of Revision 1 of WCAP-16204, the MPS3 Emergency Operating Procedures are being modified to initiate actions to refill the RWST once injection from the RWST has stopped and the RWST has been isolated.
Implementation of this change is scheduled for completion by September 1, 2005.
Serial No. 05-237A Docket Nos.: 50-280/281, 50-338/339 ATTACHMENT 2 BULLETIN 2003-01. POTENTIAL IMPACT OF DEBRIS BLOCKAGE ON EMERGENCY SUMP RECIRCULATION AT PRESSURIZED-WATER REACTORS SUPPLEMENT TO RESPONSE VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNITS 1 AND 2 SURRY POWER STATION UNITS 1 AND 2
Serial No. 05-237A Docket Nos.: 50-280/281, 50-338/339 Supplement to BL 2003-01 Response Page 1 of 2 BULLETIN 2003-01. POTENTIAL IMPACT OF DEBRIS BLOCKAGE ON EMERGENCY SUMP RECIRCULATION AT PRESSURIZED-WATER REACTORS SUPPLEMENT TO RESPONSE NORTH ANNA POWER STATION UNITS 1 AND 2 SURRY POWER STATION UNITS 1 AND 2 In a conference call with Dominion Nuclear Connecticut, Inc. (DNC) and Virginia Electric and Power Company (Dominion) on July 13, 2005, the NRC requested that supplemental information be provided for DNCs and Dominions NRC Bulletin 2003-01 response. Specifically, DNC and Dominion was requested to forward information regarding the Westinghouse Owners Group (WOG)/Combustion Engineering Owners Group (CEOG) Candidate Operator Action 05 (COA 05) for refill of the refueling water storage tank during certain accident conditions. The requested supplemental information for NAPS 1 &2 and SPS 1 &2 is provided below.
NRC Reauested Information Dominion did not commit to immediately commence refill of the refueling water storage tank (RWST) per COA 05 of WCAP-16204, Rev. 1, Evaluation of Potential ERG and EPG Changes to Address NRC Bulletin 2003-01 Recommendations (PA-SE-0085), Volume 1 - Engineering Evaluations and Analyses Report, March 2004. Please advise the NRC why this action was not incorporated per the COA.
Dominion ResDonse For NAPS 1&2 In a letter dated August 7, 2003, Virginia Electric and Power Company (Dominion) stated the North Anna Power Station (NAPS) Units 1 and 2 design includes the capability to cross connect to the non-faulted units charging system.
This feature provides an additional RWST volume immediately available for injection in the event of sump blockage. This sump blockage recovery strategy has been incorporated into the NAPS 1 & 2 Emergency Operating Procedures (EOPs).
In addition, upon indication of sump blockage the EOPs provide guidance for refilling the faulted units RWST while injecting from the RWST of the non-faulted unit. This strategy is an improvement to the guidance provided in Revision 1 of WCAP-16204 Evaluation of Potential ERG and EPG Changes to Address NRC Bulletin 2003-01 Recommendations (PA-SEE-0085).
The guidance in Revision 1 of WCAP-16204 recommends that actions be considered for refilling the RWST once injection from the RWST has stopped and the RWST has been isolated. The intent is to provide another RWST volume
Serial No. 05-237A Docket Nos.: 50-280/281, 50-3381339 Supplement to BL 2003-01 Response Page 2 of 2 available for injection in the event that it is needed to mitigate sump blockage. In the strategy implemented at NAPS 1 & 2, the non-faulted units RWST volume is available without the time delay associated with filling the tank. This additional water volume will be available for the full range of possible times for sump blockage, from the time of switchover to 30 days and beyond. Once sump blockage is experienced and the non-faulted units RWST is being used for injection, current procedures direct operators to initiate refill of the faulted units RWST to provide a third RWST volume available for mitigating sump blockage.
The strategy implemented at NAPS 1 & 2 not only meets the intent of the guidance in Revision 1 of WCAP-16204, but is superior in that adequate core cooling will be available to mitigate sump blockage without the time delays associated with refilling the RWST. Thus, it is concluded that the guidance for COA 05 in Revision 1 of WCAP-16204 has been fully addressed by the site specific design feature that provides for the immediate functional capability intended by the COA.
For SPS 1&2 In a letter dated August 7, 2003, Dominion stated the Surry Power Station (SPS)
Units 1 & 2 design includes the capability to cross-connect to the non-faulted units RWST through the charging system. This feature provides an additional RWST volume immediately available for injection in the event of sump blockage.
This sump blockage recovery strategy has been incorporated into the SPS 1 & 2 EOPs. In addition, upon indication of sump blockage the EOPs provide guidance for refilling the faulted units RWST while injecting from the RWST of the non-faulted unit. This strategy is an improvement over the guidance provided in Revision 1 of WCAP-16204.
The guidance in Revision 1 of WCAP-16204 recommends that actions be considered for refilling the RWST once injection from the RWST has stopped and the RWST has been isolated. The intent is to provide another RWST volume available for injection in the event that it is needed to mitigate sump blockage. In the strategy implemented at SPS 1 & 2, the non-faulted units RWST volume is available without the time delay associated with filling the tank. This additional water volume will be available for the full range of possible times for sump blockage, from the time of switchover to 30 days and beyond. Once sump blockage is experienced and the non-faulted units RWST is being used for injection, current procedures direct operators to initiate refill of the faulted units RWST to provide a third RWST volume available for mitigating sump blockage.
The strategy implemented at SPS 1 & 2 not only meets the intent of the guidance in Revision 1 of WCAP-16204, but is superior in that adequate core cooling will be available to mitigate sump blockage without the time delays associated with refilling the RWST. Thus, it is concluded that the guidance for COA 05 in Revision 1 of WCAP-16204 has been fully addressed by the site specific design feature that provides for the immediate functional capability intended by the COA.