ML14353A460

NRR E-mail Capture - Prairie Island Nuclear Generating Plant, Units 1 and 2 - Requests for Additional Information Related to 10 CFR 50.55a Requests Associated with Reactor Vessel Head Leak-off Line (MF4833 and MF4834)

ML14353A460
Person / Time
Site:	Prairie Island
Issue date:	12/18/2014
From:	Scott Wall Plant Licensing Branch III
To:	James Anderson Northern States Power Co
References
TAC MF4833, TAC MF4834
Download: ML14353A460 (4)

Text

NRR-PMDAPEm Resource From: Wall, Scott Sent: Thursday, December 18, 2014 3:44 PM To: Anderson, Jon S.; Vincent, Dale M.

Cc: Alley, David; Rezai, Ali; Pelton, David; Beltz, Terry; Willard, Bryan J.; Hammargren, Benjamin J.

Subject:

Prairie Island Nuclear Generating Plant, Units 1 and 2 - Requests for Additional Information Related to 10 CFR 50.55a Requests Associated with Reactor Vessel Head Leak-off Line (MF4833 and MF4834)

Attachments: Prairie Island- RAIs for 10 CFR 50 55a Requests Associated with Reactor Vessel Head Leak-off Line (MF4833 and MF4834).pdf Mr. Anderson By letter dated September 15, 2014 (Agencywide Documents Access and Management System (ADAMS)

Accession No. ML14258A073), Northern States Power Company (NSPM), a Minnesota Corporation, submitted relief requests for Prairie Island Nuclear Generating Plant (PINGP), Units 1 and 2. The 10 CFR 50.55a requests numbered 1-RR-5-1 and 2-RR-5-1 are in support of the fifth ten-year interval for the PINGP, Units 1 and 2, lnservice Inspection Program.

The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the information provided by NSPM and has determined that additional information is needed to complete the review. On December 16, 2014, the NRC staff forwarded, via an electronic mail, a draft of the requests for additional information (RAIs) to the NSPM staff. The attachment to this electronic mail contains the finalized RAIs. On December 18, 2014, your staff agreed to response to the finalized RAIs no later than February 9, 2015.

Please note that review efforts on this task are being continued and further RAIs may develop.

Finally, please dont hesitate to contact me if you have any additional questions or concerns.

Sincerely, Scott P. Wall, PMP, LSS BB, BSP Senior Project Manager Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation 301.415.2855 Scott.Wall@nrc.gov 1

Hearing Identifier: NRR_PMDA Email Number: 1785 Mail Envelope Properties (Scott.Wall@nrc.gov20141218154423)

Subject:

Prairie Island Nuclear Generating Plant, Units 1 and 2 - Requests for Additional Information Related to 10 CFR 50.55a Requests Associated with Reactor Vessel Head Leak-off Line (MF4833 and MF4834)

Sent Date: 12/18/2014 3:44:26 PM Received Date: 12/18/2014 3:44:23 PM From: Wall, Scott Created By: Scott.Wall@nrc.gov Recipients:

"Alley, David" <David.Alley@nrc.gov>

Tracking Status: None "Rezai, Ali" <Ali.Rezai@nrc.gov>

Tracking Status: None "Pelton, David" <David.Pelton@nrc.gov>

Tracking Status: None "Beltz, Terry" <Terry.Beltz@nrc.gov>

Tracking Status: None "Willard, Bryan J." <Bryan.Willard@xenuclear.com>

Tracking Status: None "Hammargren, Benjamin J." <Benjamin.Hammargren@xenuclear.com>

Tracking Status: None "Anderson, Jon S." <jon.anderson@xenuclear.com>

Tracking Status: None "Vincent, Dale M." <Dale.Vincent@xenuclear.com>

Tracking Status: None Post Office:

Files Size Date & Time MESSAGE 1427 12/18/2014 3:44:23 PM Prairie Island- RAIs for 10 CFR 50 55a Requests Associated with Reactor Vessel Head Leak-off Line (MF4833 and MF4834).pdf 156365 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received:

REQUEST FOR ADDITIONAL INFORMATION RELATED TO SYSTEM LEAKAGE TEST OF REACTOR VESSEL HEAD LEAK-OFF LINE RELIEF REQUEST 1-RR-5-1 AND 2-RR-5-1 PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNITS 1 AND 2 DOCKET NOS. 50-282 AND 50-306 By letter dated September 15, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14258A073), Northern States Power Company (NSPM, the licensee), doing business as Xcel Energy, submitted relief requests for Prairie Island Nuclear Generating Plant (PINGP), Units 1 and 2. The 10 CFR 50.55a requests numbered 1-RR-5-1 and 2-RR-5-1 are in support of the fifth ten-year interval for the PINGP, Units 1 and 2, lnservice Inspection Program. The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the information provided by NSPM and has determined that additional information is needed to complete the review, as described in the attached request for additional information (RAIs).

RAI-RR-(5-1)-1: Provide materials of construction of the RPV leak off lines piping.

RAI-RR-(5-1)-2: NRC Information Notice 2014-02 Failure to Properly Pressure Test Reactor Vessel Flange Leak-off Lines discusses the requirements for system leakage testing of reactor pressure vessel (RPV) flange leak off lines. According to the requirements for the American Society of Mechanical Engineers (ASME)

Boiler and Pressure Vessel Code (ASME Code),Section XI, IWB-2500, Table IWB-2500-1, Examination Category C-H, Item Numbers B15.10, the ASME Code Class 1 piping shall be subjected to system leakage testing each refueling outage.

(a) Has the licensee performed system leakage test of the RPV leak off lines piping in the fourth 10-year ISI interval in accordance with the above requirement? If no, provide justification.

(b) Does the licensee plan to perform system leakage test of the RPV leak off lines piping in the fifth 10-year ISI interval in accordance with the above requirement? If no, provide justification.

RAI-RR-(5-1)-3: The ASME Code,Section XI, IWB-5222(b), requires that the Class 1 pressure retaining boundary which is not pressurized when the system valves are in the position required for normal reactor startup shall be pressurized and examined at or near the end of the inspection interval. This boundary may be tested in its entirety or in portions and testing may be performed Enclosure

during the testing of the boundary of IWB-5222(a). The licensee requested relief from IWB-5222(b).

(a) Does the licensee consider the RPV flange seal as a pressure boundary? If yes, provide justification.

(b) Provide a detailed diagram of the RPV head flange seal leak-off lines piping and identify clearly in the diagram the boundary for which the IWB-5222(b) requirement apply and is covered by this relief request.

RAI-RR-(5-1)-4: The licensee mentioned excessive dose in Section 4 of Enclosure to 1-RR-5-1 and 2-RR-5-1. Provide a total estimate for person-roentgen equivalent man (rem) exposure with consideration of an as low as reasonably achievable.

RAI-RR-(5-1)-5: Discuss whether there has been any plant specific, fleet, and industry operating experience regarding degradation of the subject piping due to known degradation mechanisms that would lead to leakage.

RAI-RR-(5-1)-6: Discuss leakage detection capabilities at the plant. Discuss any measure(s) that would be taken to monitor and identify leakage in an unlikely event of a through wall leak in the RPV flange seal leak-off lines piping concurrent with leak or failure of the RPV flange O-ring seal during normal operation.

RAI-RR-(5-1)-7: Is any segment(s) of the RPV flange leak-off piping insulated and inaccessible for the ASME Code required VT-2 visual examination? If yes, discuss how the licensee will perform the VT-2 visual examination of the insulated and inaccessible segment(s) of the subject piping.