ML102710628
| ML102710628 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 09/28/2010 |
| From: | Cotton K Division of Operating Reactor Licensing |
| To: | Thorpe A Office of Nuclear Reactor Regulation |
| Cotton K, NRR/DORL, 301-415-1438 | |
| References | |
| Download: ML102710628 (3) | |
Text
From:
Cotton, Karen Sent:
Tuesday, September 28, 2010 3:32 PM To:
Thorpe, April
Subject:
FW: RAI questions
- April, Please add to ADAMS.
- Thanks, Karen Karen Cotton NRR/DORL PM - Surry Units 1 and 2 Karen.Cotton@nrc.gov 301-415-1438 From: Cotton, Karen Sent: Friday, May 07, 2010 12:10 PM To: Gary D Miller
Subject:
RAI questions REQUEST FOR ADDITIONAL INFORMATION 2009 STEAM GENERATOR INSPECTIONS SURRY POWER STATION UNIT 1 DOCKET NUMBER 50-280 By letter dated November 4, 2009 (Agencywide Documents Access and management System (ADAMS) Accession Number ML093200207), Virginia Electric and Power Company (the licensee) submitted steam generator (SG) tube inspection results from the 2009 inspections at Surry Power Station (SPS) Unit 1. By letter dated September 16, 2009 (ADAMS Accession Number ML091950409), the U.S. Nuclear Regulatory Commission (NRC) documented conference calls between NRC staff and SPS Unit 1 representatives on April 29 and May 1, 2009. In order to complete its review of the documents listed above, the staff needs the following additional information:
- 1.
In the discussion of secondary side inspections performed in SG A, you note that two foreign objects (a wire and a small disc shaped object) could not be retrieved. Please discuss whether any wear was associated with these loose parts. Please clarify whether an analysis was performed to confirm that tube integrity near these foreign objects would be maintained until the next scheduled inspection. Please discuss whether the tubes adjacent to these parts were plugged and stabilized.
- 2.
In your discussion of inspections performed in the secondary side of SG A, you refer to the Post Deposit Minimization Treatment (DMT). Please provide a brief description of this process (e.g. purpose and description of chemicals used).
- 3.
Please confirm whether the tube in row 10 column 26 (R10C26) of SG C was plugged.
- 4.
Please discuss any insights you have as to why the indication in R3C66, as shown in Table 6, was not identified during the 1997, 2001, and 2006 inspections.
- 5.
The following abbreviations/acronyms are not defined; please provide definitions:
- a.
A-Codes
- b.
LPS
- c.
LPM
- 6.
In Table 3, please confirm that no Tier 1 tubes had indications of wear at the anti-vibration bars. Please confirm that there are only 33 Tier 2 tubes in SG A and 24 Tier 2 tubes in SG C.
- 7.
Please clarify the number of tubes with PTEs and the definition of a PTE.
- 8.
For all but one flaw plotted in Figures 1 and 2, the as-measured flaw size was used. For the other flaw, the structurally significant flaw size was plotted. Please discuss how the curves in Figures 1 and 2 were determined (i.e., using the NDE uncertainty associated with the as-measured flaw dimensions or the structurally significant flaw dimensions).
Please discuss why it is appropriate to use these curves to apply to both the
as-measured flaw size and the structurally significant flaw size.
- 9.
Please discuss the results of your secondary side inspections, including whether any degradation was detected.