ML062280655
| ML062280655 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 08/09/2006 |
| From: | Shawn Campbell NRC/NRR/ADRO/DORL/LPLIII-2 |
| To: | Dan Collins NRC/NRR/ADRO/DORL/LPLIII-2 |
| Campbell S, NRC/NRR/DORL, 415-1486 | |
| References | |
| TAC MD0528 | |
| Download: ML062280655 (4) | |
Text
August 9, 2006 MEMORANDUM TO: Daniel S. Collins, Chief Plant Licensing Branch III-2 Division of Operating Reactor Licensing/RA/
Office of Nuclear Reactor Regulation FROM:
Stephen J. Campbell, Project Manager Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
SUBJECT:
DAVIS-BESSE NUCLEAR POWER STATION, UNIT NO 1 - DRAFT REQUEST FOR ADDITIONAL INFORMATION (RAI), REGARDING THE 2005 (MID-CYCLE 14) STEAM GENERATOR TUBE INSPECTIONS (TAC MD0528)
The attached draft RAI was transmitted by facsimile on August 4, 2006, to Mr. Henry Hegrat of FirstEnergy Nuclear Operating Company in preparation for an upcoming conference call. Review of the RAI would allow the licensee to identify areas where clarification may be needed, as well as determine and agree upon a schedule for responding to the RAI. This memorandum and its attachment do not convey a formal request for information or represent a Nuclear Regulatory Commission position.
Docket No. 50-346
Attachment:
As stated CONTACT: S. Campbell, NRR 301-415-1486
August 9, 2006 MEMORANDUM TO: Daniel S. Collins, Chief Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM:
Stephen J. Campbell, Project Manager/RA/
Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
SUBJECT:
DAVIS-BESSE NUCLEAR POWER STATION, UNIT NO 1 - DRAFT REQUEST FOR ADDITIONAL INFORMATION (RAI), REGARDING THE 2005 (MID-CYCLE 14) STEAM GENERATOR TUBE INSPECTIONS (TAC MD0528)
The attached draft RAI was transmitted by facsimile on August 4, 2006, to Mr. Henry Hegrat of FirstEnergy Nuclear Operating Company in preparation for an upcoming conference call. Review of the RAI would allow the licensee to identify areas where clarification may be needed, as well as determine and agree upon a schedule for responding to the RAI. This memorandum and its attachment do not convey a formal request for information or represent a Nuclear Regulatory Commission position.
Docket No. 50-346
Attachment:
As stated CONTACT: S. Campbell, NRR 301-415-1486 Accession No: ML062280655 Office LPL3-2/PM LPL3-2/BC Name SCampbell DCollins Date 8/4/06 8/9/06 OFFICIAL RECORD COPY
DRAFT DRAFT REQUEST FOR ADDITIONAL INFORMATION DAVIS BESSE NUCLEAR POWER STATION, UNIT NO. 1 (DBNPS) 2005 STEAM GENERATOR TUBE INSPECTIONS DOCKET No. 50-346 DBNPS Technical Specification 4.4.5.5a requires FirstEnergy Nuclear Operating Company (FENOC), the licensee, to report to the Nuclear Regulatory Commission (NRC) the number of tubes plugged in each steam generator (SG) following each inservice inspection of SG tubes.
As a result of the Cycle 14 Mid-Cycle Outage SG tube inservice inspection findings and outage activities, 76 tubes were newly plugged in SG 1-B and 7 tubes were newly plugged in SG 2-A.
The licensee submitted the results in accordance with the requirements of the DBNPS, Operating License, Appendix A, Technical Specifications by letters dated February 17, 2005, (ML050530314), April 29, 2005, (ML051230212), and February 16, 2006 (ML060530594). In addition to these reports, the NRC staff summarized additional information concerning the 2005 SG tube inspections at Davis Besse in a letter dated September 1, 2005, (ML052310010).
In order for the NRC staff to complete its review of the licensees reports, the NRC staff requests that the licensee provide responses to the following questions.
1.
Discuss whether any indications were identified as dents or dings. If so, identify the tube and provide the size and orientation of the flaw along with the size of the dent/ding.
2.
Discuss the number and size of any flaws within the sleeved portions of tubes or within 6-inches of the bottom of the sleeves.
- 3.
Identify any tubes in which groove intergranular attack/stress corrosion cracking was observed during your 2005 inspections. Discuss the severity of the flaws detected.
- 4.
Discuss the cause of the volumetric indications (other than wear) detected during the outage. For example, the volumetric indications identified in SG 1B in tubes 10-47, 78-67 and 81-73, and in SG 2A in tube 146-50.
- 5.
Discuss the nature, cause, and severity of the obstruction identified in SG 2A in tube 61-109. Discuss the largest size probe to ever pass through this tube and the probe sizes used on this tube during your 2005 inspections.
- 6.
Following the identification in the shop rerolls in 2005, you indicated that you were planning to investigate construction records for other unusual design characteristics.
Discuss whether you have identified any other unique conditions which could affect a tubes susceptibility to degradation. In addition, discuss any other corrective actions taken as a result of the discovery of the shop rerolls (other than the performance of the tube inspections).
DRAFT DRAFT
- 7.
Confirm that no cracks were observed at wear scars.
- 8.
Confirm that no indications were identified during your rotating probe examinations in the sludge pile region that were not also identified with a bobbin probe.
- 9.
You identified an indication in SG 2A which was attributed to an alignment pin (dowel pin) associated with an internal auxiliary feedwater header. You also indicated that the indication increased in size when compared to the prior outage. Discuss the dates and results of your visual inspections of the secured internal auxiliary feedwater header, header to shroud attachment welds, and the external header thermal sleeves. Discuss whether the header will remain stable during all postulated accident conditions such that tube integrity will not be affected. Discuss the eddy current criteria you use to ensure the header is not moving (or approaching the tubes) for the time period between the visual inspections of the header. Summarize the basis for this criteria.
- 10.
Summarize the number of tubes with rerolls in each SG.
11.
Confirm that all tubes in which degradation was identified had adequate tube integrity at the time of the inspection.