ML073170665

Request for Additional Information on Instrumentation and Controls and Fire Protection Regarding Stretch Power Uprate Amendment Request

ML073170665
Person / Time
Site:	Millstone
Issue date:	11/26/2007
From:	John Lamb NRC/NRR/ADRO/DORL/LPLI-2
To:	Christian D Virginia Electric & Power Co (VEPCO)
Lamb J, 415-1727
References
TAC MD6070
Download: ML073170665 (5)

Text

November 26, 2007 Mr. David A. Christian President and Chief Nuclear Officer Virginia Electric and Power Company Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711

SUBJECT:

MILLSTONE POWER STATION, UNIT NO. 3 - REQUEST FOR ADDITIONAL INFORMATION ON FIRE PROTECTION REGARDING STRETCH POWER UPRATE AMENDMENT REQUEST (TAC NO. MD6070)

Dear Mr. Christian:

By letter dated July 13, 2007, as supplemented on September 12, and November 19, 2007, Dominion Nuclear Connecticut, Inc. submitted a stretch power uprate license amendment request for Millstone Power Station, Unit No. 3. The proposed license amendment would allow an increase in the maximum authorized core power level from 3411 megawatts thermal (MWt) to 3650 MWt, and would make changes to the Technical Specifications, as necessary, to support operation at the stretch power level.

In order to complete its review of the reports, the U.S. Nuclear Regulatory Commission staff requires a response to each of the enclosed questions. The questions were sent by e-mail on October 19 and 23, 2007, and were discussed via teleconference on October 30, November 6 and 13, 2007, with your staff to ensure that the questions were understandable, the regulatory basis was clear and to determine if the information was previously docketed. Mr. Ron Thomas of your staff agreed to respond within 30 days of the date of this letter.

Please note that if you do not respond to this letter within the prescribed response times or provide an acceptable alternate date in writing, we may reject your application for amendment under the provisions of Title 10 of the Code of Federal Regulations, Section 2.108. If you have any questions, I can be reached at (301) 415-3100.

Sincerely,

/ra/

John G. Lamb, Senior Project Manager Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-423

Enclosure:

As stated cc w/encl: See next page

ML073170665

• Concurrence provided by Memo OFFICE LPL1-2/PM LPL1-2/LA AFPB/DRA/BC LPL1-2BC NAME JLamb ABaxter AKlein

• HChernoff DATE 11 / 19 /07 11 / 19 /07 10/18/07 11/26/07

Enclosure REQUEST FOR ADDITIONAL INFORMATION MILLSTONE POWER STATION, UNIT NO. 3 STRETCH POWER UPRATE LICENSE AMENDMENT REQUEST TAC NO. MD6070 DOCKET NO. 50-423 By letter dated July 13, 2007, as supplemented on September 12, 2007, Dominion Nuclear Connecticut, Inc. (DNC or licensee) submitted a stretch power uprate (SPU) license amendment request for Millstone Power Station, Unit No. 3 (MPS3). The proposed license amendment would allow an increase in the maximum authorized core power level from 3411 megawatts thermal (MWt) to 3650 MWt, and would make changes to the Technical Specifications (TS), as necessary, to support operation at the stretch power level.

The U.S. Nuclear Regulatory Commission (NRC) staff has been reviewing the submittal and has determined that additional information is needed to complete its review.

Fire Protection Branch AFPB-07-0006 RS-001, Revision 0, Review Standard for Extended Power Uprates, Attachment 2 to Matrix 5, Supplemental Fire Protection Review Criteria, states that power uprates typically result in increases in decay heat generation following plant trips. These increases in decay heat usually do not affect the elements of a fire protection program related to (1) administrative controls, (2) fire suppression and detection systems, (3) fire barriers, (4) fire protection responsibilities of plant personnel, and (5) procedures and resources necessary for the repair of systems required to achieve and maintain cold shutdown. In addition, an increase in decay heat will usually not result in an increase in the potential for a radiological release resulting from a fire. However, the licensees LAR should confirm that these elements are not impacted by the extended power uprate.

The NRC staff notes that LAR Attachment 5, Section 2.5.1.4.2.2, Description of Analyses and Evaluations, specifically addresses only item (1) above. Provide statements to address items (2), (3), (4), and (5), and a statement confirming no increase in the potential for a radiological release resulting from a fire.

AFPB-07-0007 LAR Attachment 5, Section 2.5.1.4.2.3.4, Safe Shutdown Evaluations, states that the safe-shutdown analysis identifies fire-induced failures that affect the plant and the operator actions that can be used to compensate for these failures...

Discuss the response time, including any assumptions, especially those of a potentially non-conservative nature, which may have been made in determining that the operator manual actions can confidently be accomplished within the available time.

AFPB-07-0008 LAR Attachment 5, Section 2.5.1.4.2.3.7, Operator Actions Required Following a Fire states that [an] analysis was performed to determine the steam generator dryout time at the support stretch power uprate (SPU) power level; the results showed a dryout time of approximately 37 minutes. Therefore, there continues to be adequate time for the operator to manually initiate auxiliary feedwater to the steam generators (SGs) at SPU conditions...

Discuss the response time, including any assumptions that may have been made in determining that the operator manual actions can confidently be accomplished before SG dryout.

AFPB-07-0009 LAR Attachment 5, Table 2.5.1.4-1, Fire Shutdown and Long-Term SG Inventory Makeup Required to Support the Decay Heat Removal Design Function BTP 9.5-1 Deviation Request -

Section c.5.c.3 and c.5.c.5, states that, the current fire shutdown design is based upon a combined DWST [demineralized water storage tank] and CST [condensate storage tank] usable inventory that allows for 38 hours4.398148e-4 days <br />0.0106 hours <br />6.283069e-5 weeks <br />1.4459e-5 months <br /> of hot standby operation, followed by a 5-hour cooldown to RHR [residual heat removal] entry conditions (38 + 5 = 43-hours)

Dominion Nuclear Connecticut proposed an alternative fire shutdown design approach for long-term decay heat removal to SPU after reactor trip. This is based on the DWSTs 334,000-gallons of water corresponding to 13-hours of SG inventory makeup under natural circulation conditions with decay heat load after SPU, and the CST with 210,000-gallons additional SG makeup. This combined DWST and CST inventory provides 33 hours3.819444e-4 days <br />0.00917 hours <br />5.456349e-5 weeks <br />1.25565e-5 months <br /> of makeup water with decay heat load after SPU.

It is not clear whether the reported 43-hours represent the current (i.e., pre-SPU) requirement for long-term hot standby operation plus cooldown or the capacity available for this combination. If the latter, then the staff notes a significant reduction in the amount of time (10-hours) in the proposed fire shutdown long-term decay heat removal approach to support SPU condition after reactor trip. If this is the case, then the staff requests the licensee to discuss the impact of this reduction in time on the post-fire safe-shutdown capability in accordance with 10 CFR Part 50, Appendix R.

On the other hand (i.e., if the former), then it follows that a shorter time (i.e., less than 33-hours) is currently needed to accomplish long-term hot standby and cooldown (i.e., pre-SPU).

Therefore, an increase from this current time requirement to the 33-hours value is proposed, decreasing the margin of reserve (i.e., relative to the cited 43-hour combined capacity of the DWST and CST) under SPU. The reason for this decrease in margin, as well as the impact, would need to be discussed. The staff requests that the licensee discuss if, indeed, this is the implication of the alternative approach.

Millstone Power Station, Unit No. 3 cc:

Lillilan M. Cuoco, Esquire Senior Counsel Dominion Resources Services, Inc.

Building 475, 5th Floor Rope Ferry Road Waterford, CT 06385 Edward L. Wilds, Jr., Ph.D.

Director, Division of Radiation Department of Environmental Protection 79 Elm Street Hartford, CT 06106-5127 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 First Selectmen Town of Waterford 15 Rope Ferry Road Waterford, CT 06385 Mr. J. W. "Bill" Sheehan Co-Chair NEAC 19 Laurel Crest Drive Waterford, CT 06385 Mr. Evan W. Woollacott Co-Chair Nuclear Energy Advisory Council 128 Terry's Plain Road Simsbury, CT 06070 Senior Resident Inspector Millstone Power Station c/o U.S. Nuclear Regulatory Commission P. O. Box 513 Niantic, CT 06357 Ms. Nancy Burton 147 Cross Highway Redding Ridge, CT 00870 Mr. Joseph Roy, Director of Operations Massachusetts Municipal Wholesale Electric Company Moody Street P.O. Box 426 Ludlow, MA 01056 Mr. J. Alan Price Site Vice President Dominion Nuclear Connecticut, Inc.

Building 475, 5th Floor Rope Ferry Road Waterford, CT 06385 Mr. Chris Funderburk Director, Nuclear Licensing and Operations Support Dominion Resources Services, Inc.

5000 Dominion Boulevard Glen Allen, VA 23060-6711 Mr. David W. Dodson Licensing Supervisor Dominion Nuclear Connecticut, Inc.

Building 475, 5th Floor Rope Ferry Road Waterford, CT 06385