ML072960179

Millstone Power Station, Unit 3 - Request for Additional Information, Stretch Power Uprate Amendment Request (TAC MD6070)

ML072960179
Person / Time
Site:	Millstone
Issue date:	10/29/2007
From:	Lamb J G NRC/NRR/ADRO/DORL/LPLI-2
To:	Christian D A Dominion Nuclear Connecticut, Virginia Electric & Power Co (VEPCO)
Lamb John G./NRR/DORL, 415-3100
References
TAC MD6070
Download: ML072960179 (5)

Text

October 29, 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 REGARDING STRETCH POWER UPRATE AMENDMENT REQUEST (TAC NO. MD6070)

Dear Mr. Christian:

By letter dated July 13, 2007, as supplemented on September 12, 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 responses to the enclosed questions. The questions were sent by e-mail on October 15 and 19, 2007, and were discussed via teleconference on October 23, 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. Mohamed Elmaghrabi of your staff agreed to respond within 21 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

ML072960179

• Concurrence provided by memo OFFICE LPL1-2/PM LPL1-2/LA DCI/CVIB/BC LPL1-2BC NAME JLamb ABaxter MMitchell HChernoff DATE 10 / 25 /07 10 / 25 /07 08/27/07

• 10 / 25 /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, 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.

Vessels & Internals Integrity Branch

CVIB-07-001

Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix G, provides fracture toughness requirements for ferritic materials (low alloy steel or carbon steel) materials in the reactor coolant pressure boundary (RCPB) components. 10 CFR Part 50, Appendix G also identifies that RCPB materials must satisfy the criteria in Appendix G of Section XI of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) to ensure the structural integrity of the ferritic components of the RCPB during any condition of normal operation, including anticipated operational occurrences and hydrostatic tests.

Consistent with the requirements specified in 10 CFR Part 50, Appendix G, the licensee performed fracture toughness analyses of the ferritic reactor vessel (RV) materials.

The staff requests that the licensee confirm that these analyses bound the fracture toughness requirements of the ferritic RCPB components other than the RV components at MPS3.

CVIB-07-002 Section 2.1.2.2-1 delineates the difference between 1/4T neutron fluence (E > 1 MeV) estimated in the license extension application and the value proposed in the current application for SPU, i.e., 1.97x10 19 n/cm 2 and 1.63x10 19 n/cm 2, respectively. Similarly, Section 2.1.3.2.3 indicates a similar difference between the peak inside surface vessel fluence to 54 effective full power years (EFPYs) of operation. Apparently, both calculations were carried out using methodologies adhering to the guidance in Regulatory Guide 1.190, "Calculational and Dosimetry Methods for Determining Pressure Vessel Neutron Fluence."

Please describe the physical reasons that justify the lower fluence value for the 54 EFPYs under SPU conditions.

CVIB-07-003

In 2001, one Babcock and Wilcox licensee experienced failures of two control rod drive mechanism 17-4 precipitation hardened (PH) lead screw male couplings. The failures were attributed to thermal embrittlement of the 17-4 PH martensitic stainless steel materials.

The staff issued NRC Information Notice (IN) 2007-02, AFailure of Control Rod Drive Mechanism Lead Screw Male Coupling at a Babcock and Wilcox Designed Facility.

@ In IN 2007-02, the staff reiterated the importance of implementing frequent visual and surface examinations for identifying thermal embrittlement in 17-4 PH martensitic stainless steel reactor vessel internals (RVI) components.

The staff requests that the licensee provide the following information with respect to monitoring the aging degradation of the 17-4 PH martensitic stainless steel materials used in RVI components at MPS3: 1. Identify 17-4 PH martensitic stainless steel RVI components at MPS3, if any.

2. Identify the method of inspection that was performed thus far on these components and provide information regarding any aging degradation that was identified thus far in these components.

Balance of Plant Branch

SBPB-07-004

In Attachment 5, on page 2.5-114, under the section ATurbine Driven Feedwater Pump Turbine Control Valves,@ the licensee stated in the application that A[the] engineering evaluation to confirm whether or not more steam flow is required for turbine driven feedwater pump turbines for SPU conditions is in progress.

@ The NRC staff cannot initiate a review of this section until the results of the evaluation and a description of any impacts or modifications are submitted.

Please provide the results of the evaluation and a description of any impacts or modifications.

SBPB-07-005

In Attachment 5, on page 2.5-22, under the section, ATurbine Results,@ DNC performed high-pressure turbine rotor phased array testing of the tangential-entry dovetail regions of the wheel rim, which revealed indications on the turbine first stage wheel. DNC is currently evaluating either installing a new high-pressure rotor, or disassembling first stage buckets, conducting inspections, removing indications and possible repairs. DNC needs to identify their proposed resolution and affects on the proposed SPU before the NRC staff can complete its review.

Millstone Power Stat ion, Unit No. 3

cc:

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

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