ML12345A188

Request for Additional Information E-mail - Relief Request C-2 for the Reactor Pressure Vessel Leak-Off Flange, Third 10-Year Inservice Inspection Interval

ML12345A188
Person / Time
Site:	Comanche Peak
Issue date:	12/10/2012
From:	Balwant Singal Plant Licensing Branch IV
To:	Hope T Luminant Generation Co
Singal B
References
TAC ME9409
Download: ML12345A188 (2)

Text

Lent. Susan From: Singal, Salwant Sent: Monday, December 10,201210:03 AM To: 'Hope, Timothy' Cc: 'Jack.Hicks@luminant.com'

Subject:

Comanche Peak Nuclear Power Plant (CPNPP), Unit 1, Relief Request C-2 Request for Additional Information (TAC ME9409)

Attachments: ME9409-RAl.docx

Tim, By letter dated August 23, 2012, luminant Generation Company, llC (luminant), submitted "Relief Request No. C-2 for the CPNPP, Unit 1 Reactor Pressure Vessel leak-Off Flange for U.S. Nuclear Regulatory Commission (NRC) review and authorization. In order to complete our review, the NRC staff requests for additional information identified in the attached document.

Draft request for additional information (RAI) was transmitted via e-mail on November 30,2012. A clarification conference call was held on December 10,2012 and Mr. Jack Hicks of luminant agreed to provide the RAI response within 30 days from the date of this e-mail.

Please consider this e-mail as formal transmittal of RAI.

Thanks.

Balwant K. Singal Senior Project Manager (Comanche Peak and STP)

Nuclear Regulatory Commission Division of Operating Reactor licensing Balwant.Singal@nrc.gov Tel: (301) 415-3016 Fax: (301) 415-1222 1

REQUEST FOR ADDITIONAL INFORMATION ALTERNATIVE PRESSURE TESTING REQUIREMENTS FOR THE REACTOR PRESSURE VESSEL (RPV) FLANGE LEAK-OFF PIPING LUMINANT GENERATION COMPANY LLC COMANCHE PEAK NUCLEAR POWER PLANT (CPNPP), UNIT 1 DOCKET NUMBER 50-445 By letter dated August 23, 2012 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML12250A670), Luminant Generation Company, LLC, (the licensee) submitted "Relief Request No. C-2 for the CPNPP, Unit 1 Reactor Pressure Vessel Leak-Off Flange for U.S. Nuclear Regulatory Commission (NRC) review and authorization. The licensee has proposed an alternative to the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, IWC-2500, Table IWC-2500-1, Examination Category C-H, required system leakage test of the RPV flange leak-off line. Specifically, the licensee proposes to pressurize the leak-off line using the static pressure head of the refueling water prior to a visual VT-2 examination. In order to complete our review, the staff requests the following additional information.

1. Please state what is the CPNPP, Unit 1 third 1O-year inservice inspection interval scheduled end date?

2. Please provide a piping and instrumentation diagram (P&ID) and a piping isometric drawing showing the subject flange leak-off line.

3. Please state the material of construction of the leak-off line.

4. Please describe the CPNPP, Units 1 and 2 experience with degradation (corrosion, stress corrosion cracking, fatigue, etc.) of these lines.

5. The proposed alternative would utilize the fluid head of the refueling water to pressurize the leak-off line prior to a VT-2 examination.

a. Please state the fluid head pressure that exists in the line when the refueling cavity has been filled to its normal refueling water level?

b. In order for a leak to be observed, sufficient time must have elapsed between the time that the line was pressurized and the time that the examination is performed. Please specify the minimum time between the time that the refueling cavity has been filled to its normal refueling water level and the VT-2 examination is performed.

6. Please discuss whether th line could be pressurized and inspected at the beginning of an outage before removing the head.