ML11307A167
| ML11307A167 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 03/01/2011 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| References | |
| Download: ML11307A167 (3) | |
Text
1 SeabrookNPEm Resource From:
Plasse, Richard Sent:
Tuesday, March 01, 2011 11:39 AM To:
Cliche, Richard
Subject:
FW: Follow up RAI for Flux Thimbles Attachments:
Seabrook DRAFT RAI Roger - Jim M peer review_AFD comments.docx
Hearing Identifier:
Seabrook_License_Renewal_NonPublic Email Number:
2253 Mail Envelope Properties (Richard.Plasse@nrc.gov20110301113900)
Subject:
FW: Follow up RAI for Flux Thimbles Sent Date:
3/1/2011 11:39:10 AM Received Date:
3/1/2011 11:39:00 AM From:
Plasse, Richard Created By:
Richard.Plasse@nrc.gov Recipients:
"Cliche, Richard" <Richard.Cliche@fpl.com>
Tracking Status: None Post Office:
Files Size Date & Time MESSAGE 3
3/1/2011 11:39:00 AM Seabrook DRAFT RAI Roger - Jim M peer review_AFD comments.docx 20311 Options Priority:
Standard Return Notification:
No Reply Requested:
No Sensitivity:
Normal Expiration Date:
Recipients Received:
Draft RAI 3.1.1.60-01a Follow up to RAIs 3.1.1.60-01 & RAIs 3.1.1.60-02
=
Background===
By letter dated January 5, 2011, the staff issued two RAIs to the applicant. RAI 3.1.1-60-01 requested that the applicant justify not including an applicable aging management review (AMR) line item to manage loss of material due to wear in the nickel alloy flux thimble tubes and to justify why a Flux Thimble Tube Inspection Program is not credited to manage loss of material due to wear for these nickel alloy flux thimble tubes. RAI 3.1.1-60-02 requested that the applicant justify using the PWR Vessel Internals Program to manage cracking in the flux thimble tubes, considering that MRP-227 Rev. 0 does not contain recommendations for managing cracking in Westinghouse-design flux thimble tubes.
In its response dated February 3, 2011, the applicant stated that its design is unique and can accommodate both fixed and movable incore detectors. The applicant also stated that since its Operating Cycle 5, the moveable incore detectors have not been used and were placed in a lay-up condition during Refueling Outage 7 (Fall of 2000). The applicant also stated that since Refueling Outage 7, as part of a design change, the seal table tubing between the inner calibration tubing and the isolation valves has been removed and the inner calibration tube has been capped.
The applicant further stated that, based on the unique design features of the incore detectors, the aging effects managed by NUREG-1801 Rev. 1, XI.M37, do not apply to Seabrook Station.
The applicant also stated that the movable flux thimbles do not have a license renewal intended function and the line items referencing the flux thimble tubes will be deleted from LRA Tables 2.3.1-3 and 3.1.2-3.
Issue During its review of the applicants responses to RAIs 3.1.1-60-01 and 3.1.1-60-02, the staff noted that the flux thimbles for the moveable incore detectors, if left in a permanent lay-up condition, would not be subject to flow induced vibrations, and therefore would not be subject to wear. However the staff also noted that, under the plants CLB and design basis, the applicant has the option to place the movable incore detectors back in service and the flux thimbles will once again provide a pressure boundary function.
Request Since the applicant has the option to place the movable incore detectors back in service, justify the deletion of the AMR line items associated with cracking of the flux thimble tubes from LRA Table 3.1.2-3. Also, justify why an aging management program is not required to manage loss of material due to wear of the flux thimbles if the movable incore detectors were placed back into service.