SBK-L-09122, Response to Request for Additional Information Regarding a Request for Relief from Inservice Inspection Requirements
| ML091520033 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 05/27/2009 |
| From: | St.Pierre G NextEra Energy Seabrook |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| SBK-L-09122 | |
| Download: ML091520033 (4) | |
Text
9 NEXTera EN ERGY SEABROOK May 27, 2009 SBK-L-09122 Docket No. 50-443 U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852 Seabrook Station Response to Request for Additional Information Regarding a Request for Relief from Inservice Inspection Requirements In a letter dated February 24, 2009, FPL Energy Seabrook, LLC, now NextEra Energy Seabrook, LLC (NextEra), submitted a supplement to its request for approval for relief from inservice inspection requirements for the Seabrook Station pressurizer welded attachments (4 lugs) and their associated supports pursuant to 10 CFR 50.55a(a)(3)(ii).
In an e-mail April 23, 2009, the NRC provided a request for additional information regarding NextEra's submittal.
The attachment to this letter provides NextEra's response to the request for additional information.
If you have any questions regarding this response, please contact Mr. Michael O'Keefe, Licensing Manager, at (603) 773-7745.
Sincerely, NextEra Energy Seabrook, LLC Gene St. Pierre Vice President - North cc:
S. J. Collins, NRC Region I Administrator D. L. Egan, NRC Project Manager 4c o W. J. Raymond, NRC Resident Inspector
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NextEra Energy Seabrook, LLC, P.O. Box 300, Lafayette Road, Seabrook, NH 03874
Attachment to SBK-L-09122
ATTACHMENT Response to Request for Additional Information Re~ardini! a Request for Relief from Inservice Inspection Requirements By letter dated February 24, 2009, NextEra Energy Seabrook, LLC, (the licensee) submitted its revision to Request for Relief No. 21R-12, Revision 1 for the Seabrook Station. The licensee's submittal proposed to use an alternative examination methodology in lieu of certain ASME Code,Section XI requirements. The staff has reviewed the information the licensee provided that supports the proposed Relief Request 21R-12, Revision 1 and would like to discuss the following issues to clarify the submittal:
NRC Question 1.
In its letter dated February 24, 2009 the licensee noted that the pressurizer support for integral attachments is a passive support for use only during a seismic event. For other ASME Code, Category F-A supports such as seismic pipe supports have you had any experience of failure of these supports other than say a water hammer event? Or have you had any failures of any other passive supports in the plant? (Not necessarily under the same conditions and design of the pressurizer support?)
NextEra Response NextEra Energy Seabrook, LLC (NextEra) has not experienced functional failures of ASME Code Category F-A pipe supports other than a water hammer event. A water hammer event in the Steam Blowdown system did cause minor damage to a component support in that system.
On passive supports, VT-3 examinations have not discovered functional failures due to operational, environmental, or transient conditions.
NRC Question 2.
Is the only possible failure mechanism that would occur to subject passive support would be corrosion?
NextEra Response Credible failure mechanisms on the subject passive supports include corrosion mechanisms only.
VT-3 examinations on accessible components within the pressurizer cubical have shown no evidence of corrosion.
NRC Question 3.
Is the pressurizer cubicle area heated and dry and not a conducive environment to perpetuate corrosion during operation?
NextEra Response During normal power operation, the pressurizer is at primary system temperature and pressure. The cubical enclosure limits ventilation and heat transfer. Barring a significant leak, the environment is not conducive to corrosion.
NRC Question 4.
Although the licensee can't directly observe the subject support from the bottom of the pressurizer cubicle, because of duct work blocking its view can you access the area below the pressurizer bottom and observe the area for any signs of leakage, or damage, or corrosion of the area below the duct work?
NextEra Response During conduct of the Class 1 leak test prior to plant operation at the end of a refueling outage, as required by ASME Section XI, Category B-P, a VT-2 examination is performed. VT-2 examiners physically enter the elevation just below the pressurizer ventilation ductwork (0'),
and observe the area for evidence of leakage, corrosion and boric acid.
NRC Question 5.
Does the licensee have any plans to perform the ASME Code examinations on the subject components, if for some reason the subject lugs and support becomes accessible?
NextEra Response NextEra has no plans to make substantial physical changes to the pressurizer cubicle. Should some transient or unforeseen condition require access to the subject lugs and supports, NextEra intends to meet ASME Code examination requirements on these components. Action Request
- 00007007-02 tracks incorporation of this note in the ISI Program (SIIR Manual).