ML112790525
| ML112790525 | |
| Person / Time | |
|---|---|
| Site: | Three Mile Island  |
| Issue date: | 10/24/2011 |
| From: | Geoffrey Miller Plant Licensing Branch 1 |
| To: | Pacilio M Exelon Nuclear |
| Miller G, NRR/DORL/LPL1-2, 415-2481 | |
| References | |
| TAC ME7229 | |
| Download: ML112790525 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 October 24, 2011 Mr. Michael J. Pacilio President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
THREE MILE ISLAND NUCLEAR STATION, UNIT 1 - UPCOMING STEAM GENERATOR TUBE INSERVICE INSPECTION (TAC NO. ME7229)
Dear Mr. Pacilio:
Inservice inspections of steam generator (SG) tubes playa vital role in assuring SG tube integrity. Based on my discussion with Mr. David Helker on October 5,2011, a telephone conference call has been tentatively arranged for November 1, 2011, with members of your staff to discuss the ongoing results of the SG tube inspections to be conducted during the upcoming refueling outage for Three Mile Island, Unit 1. This call will occur after the majority of the tubes have been inspected, but before the SG inspection activities have been completed. Enclosed is a list of discussion points to facilitate this call.
The Nuclear Regulatory Commission (NRC) staff will document a summary of the conference call, including any material that you provide to the NRC staff in support of the call.
Should you have any questions, please contact me at (301) 415-2481.
Sintj;DIS ~lL~
G. Edward Miller, Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-289
Enclosure:
As stated cc w/encl: Distribution via Listserv
STEAM GENERATOR TUBE INSPECTION DISCUSSION POINTS The following discussion points have been prepared to facilitate the conference call arranged with the licensee to discuss the results of the steam generator (SG) tube inspections to be conducted during the upcoming fall 2011 refueling outage at Three Mile Island, Unit 1 (TMI-1).
This conference call is scheduled to occur towards the end of the planned SG tube inspections, but before the inspections and repairs are completed.
The NRC staff plans to document a 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% 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 for 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. 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 (including the source or nature of the loose part, if known);
Enclosure
-2
- if the loose parts were removed from the SG; and
- indications of tube damage associated with the loose parts.
- 9. Discuss the scope and results of any secondary side inspection and maintenance activities (e.g., in-bundle visual inspections, feed-ring inspections, sludge lancing, assessing deposit loading, etc.).
- 10. Discuss any unexpected or unusual results.
- 11. Provide the schedule for SG-related activities during the remainder of the current outage.
October 24, 2011 Mr. Michael J. Pacilio President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
THREE MILE ISLAND NUCLEAR STATION, UNIT 1 - UPCOMING STEAM GENERATOR TUBE INSERVICE INSPECTION (TAC NO. ME7229)
Dear Mr. Pacilio:
Inservice inspections of steam generator (SG) tubes playa vital role in assuring SG tube integrity. Based on my discussion with Mr. David Helker on October 5, 2011, a telephone conference call has been tentatively arranged for November 1, 2011, with members of your staff to discuss the ongoing results of the SG tube inspections to be conducted during the upcoming refueling outage for Three Mile Island, Unit 1. This call will occur after the majority of the tubes have been inspected, but before the SG inspection activities have been completed. Enclosed is a list of discussion points to facilitate this call.
The Nuclear Regulatory Commission (NRC) staff will document a summary of the conference call, including any material that you provide to the NRC staff in support of the call.
Should you have any questions, please contact me at (301) 415-2481.
Sincerely,
/ra/
G. Edward Miller, Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-289
Enclosure:
As stated cc w/encl: Distribution via Listserv DISTRIBUTION:
Public RidsOgcRp Resource KKarwoski, NRR LPL 1-2 R/F RidsRgn1 MailCenter Resource EMurphy, NRR RidsNrrDorlLpl1-2 Resource RidsAcrsAcnw_MailCTR Resource AJohnson, NRR RidsNrrLAABaxter Resource RidsNrrDciCsgb Resource AObodoako, NRR DWerkheiser, RI RidsNrrPMThreeMilelsland Resource Accession No' .. ML112790525 OFFICE LPL1-2/PM LPL 1-2/LA CSGB/BC NRR/LPL 1-2/BC NAME GEMiller ABaxter RTaylor HChernoff (REnnis (VCusumano for) for)
DATE I 'v'' 10/17/11 10/17/11 10/24/11 OFFICIAL RECORD COPy