ML102950591
| ML102950591 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 04/06/2010 |
| From: | David Lew NRC Region 1 |
| To: | Balian H, Arthur Burritt, Leonard Cline, Daniel Schroeder NRC Region 1 |
| References | |
| FOIA/PA-2010-0334 | |
| Download: ML102950591 (1) | |
Text
Patel, Amar From:
Lew, David Sent:
Tuesday, April 06, 2010 5:14 PM To:
Burritt, Arthur; Cline, Leonard; Schroeder, Daniel; Balian, Harry Cc:
Welling, Blake; Patel, Amar; Clifford, James
Subject:
FW: Quick notes on the Salem 1 AFW piping situation reported by Michael Modes FYI From: Roberts, Darrell.....
Sent: Tuesday, April 06, 2010 4:28 PM To: Wilson, Peter Cc: Roberts, Darrell; Lew, David; Clifford, James; Conte, Richard
Subject:
Quick notes on the Salem 1 AFW piping situation reported by Michael Modes Pete, et. al.,
Salem Unit 1: AFW "buried" piping (Class 2 Carbon Steel coated piping, 10" diameter) preliminary guided
,,wave inspection results indicate that buried piping is degraded below min wall. The affected 10" pipe comes out of an Auxiliary Storage Tank and ultimately splits into headers that feed SGs 12 and 14. Licensee is assembling teams, making plans for excavation to conduct UT (the official test method accepted by NRC). Tim O'hara (onsite for ISI inspections) informed the region. These are very preliminary results, so we should not react strongly until we understand better what the licensee's official UT results indicate. Conte is onsite as well monitoring the situation. (Need to confirm the following: Salem Unit 1 head detensioning was expected to start Monday, 4/5, so the plant should be in Refueling Mode (with S/Gs out of service). What is operating status of AFW, or TS requirement for it in this mode? Depending on UT results, this would be a restart issue for Salem.
Note: Per discussion with Michael Modes, guided wave is fine for long straight runs without valves and flanges and bends (e.g., natural gas pipelines). UT is still the methodology of record to meet Code-inspection requirements. Industry (EPRI) is in the process of building future mockup test facility in NC to qualify the guided wave technique, but for now guided wave technique is not a reliable indicator for some pipes in nuclear applications.
However, if this is an indication of significant degradation of safety-related buried piping (i.e., below minimum wall thickness requirements for Class 2 AFW system), then it could have implications on the agency's buried piping regulatory footprint going forward, especially given that most - if not all - earlier issues have dealt with non-safety related leaks of buried/underground piping that have less to do with function than they do with radiological impact.
Jim/Dave, you may receive more information through separate channels via the resident inspectors/BC. DRS should have the technical lead for this given our onsite presence already.
DJR 1/