ML050670298

Request for Additional Information Regarding Bulletin 2003-01, Potential Impact of Debris Blockage on Emergency Sump Recirculation at Pressurized-Water Reactors

ML050670298
Person / Time
Site:	Millstone
Issue date:	04/08/2005
From:	George Wunder NRC/NRR/DLPM/LPD1
To:	Christian D Dominion Nuclear Connecticut
Wunder G, NRR/DLPM, 415-1494
References
BL-03-001, TAC MB9588, TAC MB9589
Download: ML050670298 (7)

Text

April 8, 2005 Mr. David A. Christian Senior Vice President and Chief Nuclear Officer Dominion Nuclear Connecticut, Inc.

Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION, MILLSTONE POWER STATION, UNIT NOS. 2 AND 3, REGARDING BULLETIN 2003-01, POTENTIAL IMPACT OF DEBRIS BLOCKAGE ON EMERGENCY SUMP RECIRCULATION AT PRESSURIZED-WATER REACTORS (TAC NOS. MB9588 AND MB9589)

Dear Mr. Christian:

By letter dated August 8, 2003, Dominion Nuclear Connecticut, Inc. (DNC) provided the 60-day response to Bulletin 2003-01 for Millstone Power Station, Unit Nos. 2 and 3. By letter dated September 14, 2004, the Nuclear Regulatory Commission (NRC) sent you a request for additional information (RAI) regarding your response to the Bulletin. You provided your response to our RAI by letter dated November 10, 2004.

We have determined that additional information is needed (see enclosure) to complete our review. To support our closeout goal, the NRC is requesting that DNC respond within 60 days from the date of this letter. If you have any questions, please contact me at (301) 415-1484.

Sincerely,

/RA/

George F. Wunder, Project Manager, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos.: 50-336 50-423

Enclosure:

RAI cc w/encl: See next page

ML050670298 OFFICE PDI-2/PM PDI-2/PM PDI-2/LA PDI-2/SC VNerses NAME GWunder CRaynor DRoberts DATE 3/24/05 3/21/05 4/7/05 Millstone Power Station, Unit No. 3 cc:

Lillilan M. Cuoco, Esquire Senior Resident Inspector Senior Counsel Millstone Power Station Dominion Resources Services, Inc. c/o U.S. Nuclear Regulatory Commission Rope Ferry Road P. O. Box 513 Waterford, CT 06385 Niantic, CT 06357 Edward L. Wilds, Jr., Ph.D. Ms. Nancy Burton Director, Division of Radiation 147 Cross Highway Department of Environmental Protection Redding Ridge, CT 00870 79 Elm Street Hartford, CT 06106-5127 Mr. William D. Meinert Nuclear Engineer Regional Administrator, Region I Massachusetts Municipal Wholesale U.S. Nuclear Regulatory Commission Electric Company 475 Allendale Road Moody Street King of Prussia, PA 19406 P.O. Box 426 Ludlow, MA 01056 First Selectmen Town of Waterford Mr. J. Alan Price 15 Rope Ferry Road Site Vice President Waterford, CT 06385 Dominion Nuclear Connecticut, Inc.

Rope Ferry Road Mr. P. J. Parulis Waterford, CT 06385 Manager - Nuclear Oversight Dominion Nuclear Connecticut, Inc. Mr. Chris Funderburk Rope Ferry Road Director, Nuclear Licensing and Waterford, CT 06385 Operations Support Dominion Resources Services, Inc.

Mr. W. R. Matthews 5000 Dominion Boulevard Senior Vice President - Nuclear Operations Glen Allen, VA 23060-6711 Dominion Nuclear Connecticut, Inc.

Rope Ferry Road Mr. David W. Dodson Waterford, CT 06385 Licensing Supervisor Dominion Nuclear Connecticut, Inc.

Mr. John Markowicz Rope Ferry Road Co-Chair Waterford, CT 06385 Nuclear Energy Advisory Council 9 Susan Terrace Waterford, CT 06385 Mr. Evan W. Woollacott Co-Chair Nuclear Energy Advisory Council 128 Terry's Plain Road Simsbury, CT 06070

Millstone Power Station, Unit No. 3 cc:

Mr. S. E. Scace Assistant to the Site Vice President Dominion Nuclear Connecticut, Inc.

Rope Ferry Road Waterford, CT 06385 Mr. M. J. Wilson Manager - Nuclear Training Dominion Nuclear Connecticut, Inc.

Rope Ferry Road Waterford, CT 06385 Mr. A. J. Jordan, Jr.

Director - Nuclear Engineering Dominion Nuclear Connecticut, Inc.

Rope Ferry Road Waterford, CT 06385 Mr. S. P. Sarver Director - Nuclear Station Operations and Maintenance Dominion Nuclear Connecticut, Inc.

Rope Ferry Road Waterford, CT 06385

REQUEST FOR ADDITIONAL INFORMATION RELATED TO DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION, UNIT NOS. 2 AND 3 DOCKET NOS. 50-336 AND 50-423 Millstone, Unit No. 2 (MP2)

In a September 14, 2004, request for additional information (RAI) regarding Nuclear Regulatory Commission (NRC)Bulletin 2003-01, the NRC staff requested the following: Include a discussion of the WOG [Westinghouse owners group]-recommended compensatory measures that have been or will be implemented at your plant, and the evaluations or analyses performed to determine which of the WOG-recommended changes are acceptable at your plant. Provide a technical justification for those WOG-recommended compensatory measures not being implemented by your plant.

In an November 10, 2004, RAI response, Dominion Nuclear Connecticut, Inc. (Dominion) stated that the WOG recommendation was, to implement some changes to CEN-152, Combustion Engineering Emergency Procedure Guidelines.

The RAI response also stated that the changes had been compared to the changes already made to the MP2 emergency operating procedures (EOPs), and that the strategy changes for CEN-152 were addressed in the MP2 changes with one exception: early termination of one containment spray train. You stated that the MP2 radiological analysis credits containment spray operation for two hours for iodine removal from the containment atmosphere, and that early termination of one train of containment spray would make the plant vulnerable to a subsequent single failure of the operating containment spray train (an unanalyzed condition).

Although not implemented as an interim compensatory measure for Bulletin 2003-01, you stated that this action is being assessed for long-term consideration.

1. Dominion has not provided a schedule for completing this assessment. The WOG published WCAP-16204, Evaluation of Potential ERG [emergency response guideline] and EPG [emergency procedure guideline] Changes to Address NRC Bulletin 2003-01 Recommendations (PA-SEE-0085), in March 2004, and licensees have already had a full year in which to evaluate these proposed candidate operator actions (COAs).

Compensatory measures such as those described in Bulletin 2003-01 were intended to be implemented on a timely basis in order to reduce the risks associated with potential sump blockage while evaluations to confirm compliance with the regulations could be completed.

An evaluation schedule consistent with Generic Letter 2004-02 resolution does not meet the intent of Bulletin 2003-01. Please provide a schedule for evaluating these COAs (which is consistent with the intent of Bulletin 2003-01), as the staff expects a valid technical basis for any decisions not to implement these COAs.

2. The Dominion approach implies that the entirety of Volume I and Appendix A of Volume I of WCAP-16204, Revision 1, was not considered for its usefulness in further reducing risk from a sump clogging event. Please verify that the 11 COAs evaluated in Volume I of

WCAP-16204, Revision 1 are included in the CEN-152 actual MP2 changes. Also, please discuss the plant-specific evaluations and verifications performed to justify the applicability and usability of the generic CEN-152 changes for MP2. Provide technical justification for any plant-specific deviations which do not implement any of the 11 COAs.

3. You stated that a plant-specific calculation has been performed to quantify the benefits of implementing the EOP changes, and that the core damage frequency is reduced by a factor of 12 when the analysis considered the effect of recovery by operator actions. The NRC staff has stated that licensees may use quantitative data to justify not taking an interim compensatory measure. Based on Dominions RAI response, it appears that the licensee may be relying on this quantitative risk analyses to justify not implementing certain COAs.

However, due to the level of detail in the RAI response, it is not clear that this is the case.

Therefore, if Dominion is relying on a quantitative risk analyses to justify not implementing certain COAs, please provide the staff with a listing the COAs not being implemented and a detailed discussion of the quantitative analysis and results which formulate the technical basis for this decision.

Millstone, Unit No. 3 (MP3)

In a September 14, 2004, RAI regarding NRC Bulletin 2003-01, the NRC staff requested the following: Include a discussion of the WOG-recommended compensatory measures that have been or will be implemented at your plant, and the evaluations or analyses performed to determine which of the WOG-recommended changes are acceptable at your plant. Provide a technical justification for those WOG-recommended compensatory measures not being implemented by your plant.

In a November 10, 2004, RAI response, Dominion stated that the WOG recommendation was, to implement the Sump Blockage Control Room Guideline (SBCRG) documented in Volume 2 to WCAP-16204, Revision 1 as an interim compensatory action to reduce the risk associated with sump blockage.

The RAI response also stated that, Dominion has compared the SBCRG to the Millstone Unit 3 plant-specific EOP Changes that were implemented in March 2004 and has concluded that the Millstone Unit 3 EOP changes encompass the strategies provided in the SBCRG.

The Dominion approach implies that the entirety of Volume I and Appendix A of Volume I of WCAP-16204, Revision 1, was not considered for its usefulness in further reducing risk from a sump clogging event. Although the 11 COAs of Volume I may or may not be included in the SBCRG, may or may not be applicable for the MP3 design, and may or may not be risk beneficial for MP3, it is incumbent upon the licensee to provide technical justifications for not implementing them.

1. Please provide information to verify that the 11 COAs evaluated in Volume I of WCAP-16204, Revision 1 are included in the SBCRG. Also, please discuss the plant-specific evaluations and verifications performed to justify the applicability and usability of the generic SBCRG for MP3. Provide technical justification for any plant-specific deviations which do not implement any of the 11 COAs.

2. You stated that a plant-specific calculation has been performed to quantify the benefits of implementing the EOP changes, and that the core damage frequency is reduced by a factor of 29 when the analysis considered the effect of recovery by operator actions. The staff has stated that licensees may use quantitative data to justify not taking an interim compensatory measure. Based on Dominions RAI response, it appears that the you may be relying on this quantitative risk analyses to justify not implementing certain COAs. However, due to the level of detail in the RAI response, it is not clear that this is the case. Therefore, if Dominion is relying on a quantitative risk analyses to justify not implementing certain COAs, please provide the staff with a listing of the COAs not being implemented and a detailed discussion of the quantitative analysis and results which formulate the technical basis for this decision.