ML080500017
| ML080500017 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 02/21/2008 |
| From: | Balwant Singal NRC/NRR/ADRO/DORL/LPLIV |
| To: | Muench R Wolf Creek |
| Singal, Balwant, 415-3016, NRR/DORL/LPL4 | |
| References | |
| TAC MD8099 | |
| Download: ML080500017 (6) | |
Text
February 21, 2008 Mr. Rick A. Muench President and Chief Executive Officer Wolf Creek Nuclear Operating Corporation Post Office Box 411 Burlington, KS 66839
SUBJECT:
WOLF CREEK GENERATING STATION - UPCOMING STEAM GENERATOR TUBE INSERVICE INSPECTION (TAC NO. MD8099)
Dear Mr. Muench:
Inservice inspections (ISI) of steam generator (SG) tubes play a vital role in assuring that adequate structural integrity of the tubes is maintained. The reporting requirements of the plant Technical Specifications range from submitting a special report within 15 days following completion of each ISI of SG tubes, which identifies the number of tubes plugged and/or repaired, to submitting a special report within 180 days following completion of the inspection, which provides the complete results of the SG tube ISI. The special report containing the complete results shall include the following:
The scope of inspections performed on each SG, Active degradation mechanisms found, Nondestructive examination techniques utilized for each degradation mechanism, Location, orientation (if linear), and measured sizes (if available) of service induced indications, Number of tubes plugged during the inspection outage for each active degradation mechanism, Total number and percentage of tubes plugged to date, and The results of condition monitoring, including the results of tube pulls and in-situ testing.
Based on discussions on February 15, 2008, with Mr. Steve Wideman, Wolf Creek Nuclear Operating Corporation has agreed to participate in a conference call with U.S. Nuclear Regulatory Commission (NRC) staff to discuss the results of the SG tube inspections during the upcoming Wolf Creek Generating Station refueling outage in spring 2008. A conference call will be arranged with members of your staff after the majority of the tubes have been inspected, but
R.A. Muench before the SG inspection activities have been completed. Enclosed is a list of discussion points to facilitate this phone conference.
The NRC staff plans to document a brief summary of the conference call as well as any material that you may have provided to the staff in support of the call.
Sincerely,
/RA/
Balwant K. Singal, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-482
Enclosure:
As stated cc w/encl: See next page
R.A. Muench before the SG inspection activities have been completed. Enclosed is a list of discussion points to facilitate this phone conference.
The NRC staff plans to document a brief summary of the conference call as well as any material that you may have provided to the staff in support of the call.
Sincerely,
/RA/
Balwant K. Singal, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-482
Enclosure:
As stated cc w/encl: See next page DISTRIBUTION:
PUBLIC LPLIV Reading RidsAcrsAcnwMailCenter RidsNrrDorlDpr RidsNrrDciCsgb RidsNrrDorlLpl4 RidsNrrPMBSingal RidsNrrLAJBurkhardt RidsOgcRp RidsRgn4MailCenter JBurke, NRR/DCI/CSGB ADAMS Accession No. ML080500017
(*) E-mail dated 2/15/08 OFFICE NRR/LPL4/PM NRR/LPL4/LA NRR/CSGB/BC NRR/LPL4/BC NAME BSingal JBurkhardt AHiser (*)
THiltz, JND for DATE 2/21/08 2/21/08 2/15/08 2/21/08 OFFICIAL AGENCY RECORD
Wolf Creek Generating Station (2/2006) cc:
Jay Silberg, Esq.
Pillsbury Winthrop Shaw Pittman LLP 2300 N Street, NW Washington, D.C. 20037 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011 Senior Resident Inspector U.S. Nuclear Regulatory Commission P.O. Box 311 Burlington, KS 66839 Chief Engineer, Utilities Division Kansas Corporation Commission 1500 SW Arrowhead Road Topeka, KS 66604-4027 Office of the Governor State of Kansas Topeka, KS 66612 Attorney General 120 S.W. 10th Avenue, 2nd Floor Topeka, KS 66612-1597 County Clerk Coffey County Courthouse 110 South 6th Street Burlington, KS 66839 Chief, Radiation and Asbestos Control Section Kansas Department of Health and Environment Bureau of Air and Radiation 1000 SW Jackson, Suite 310 Topeka, KS 66612-1366 Vice President Operations/Plant Manager Wolf Creek Nuclear Operating Corporation P.O. Box 411 Burlington, KS 66839 Supervisor Licensing Wolf Creek Nuclear Operating Corporation P.O. Box 411 Burlington, KS 66839 U.S. Nuclear Regulatory Commission Resident Inspectors Office/Callaway Plant 8201 NRC Road Steedman, MO 65077-1032
STEAM GENERATOR TUBE INSPECTION DISCUSSION POINTS WOLF CREEK GENERATING STATION DOCKET NO. 50-482 The following discussion points have been prepared to facilitate a phone conference to be arranged with the licensee to discuss the results of the steam generator (SG) tube inspections to be conducted during the upcoming spring 2008 Wolf Creek Generating Station refueling outage.
This phone call is scheduled to occur towards the end of the planned SG tube inspection interval, but before the unit completes the inspections and repairs.
The NRC staff plans to document a brief summary of the conference call as well as any material that is provided in support of the call.
- 1.
Discuss any trends in the amount of primary-to-secondary leakage observed during the recently completed cycle.
- 2.
Discuss whether any secondary-side pressure tests were performed during the outage and the associated results.
- 3.
Discuss any exceptions taken to the industry guidelines.
- 4.
For each SG, provide a description of the inspections performed including the areas examined and the probes used (e.g., dents/dings, sleeves, expansion-transition, U-bends with a rotating probe), the scope of the inspection (e.g.,
100 percent of dents/dings greater than 5 Volts and a 20 percent sample between 2 and 5 Volts), and the expansion criteria.
- 5.
For each area examined (e.g., tube supports, dent/dings, sleeves, etc.), provide a summary of the number of indications identified to-date of each degradation mode (e.g., number of circumferential primary water stress-corrosion cracking (PWSCC) indications at the expansion transition). For the most significant indications in each area, provide an estimate of the severity of the indication (e.g.,
provide the voltage, depth, and length of the indication). In particular, address whether tube integrity (structural and accident-induced leakage integrity) was maintained during the previous operating cycle. In addition, discuss whether any location exhibited a degradation mode that had not previously been observed at this location at this unit (e.g., observed circumferential PWSCC at the expansion transition for the first time at this unit).
- 6.
Describe repair/plugging plans.
- 7.
Describe in-situ pressure test and tube-pull plans and results (as applicable and if available).
- 8.
Provide the schedule for SG-related activities during the remainder of the current outage.
ENCLOSURE
- 9.
Discuss the following regarding loose parts:
what inspections are performed to detect loose parts a description of any loose parts detected and their location within the SG if the loose parts were removed from the SG indications of tube damage associated with the loose parts the source or nature of the loose parts, if known
- 10.
Discuss the results of any secondary-side inspections.
- 11.
Discuss any unexpected or unusual results.