ML082910831
| ML082910831 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 10/21/2008 |
| From: | Sanders C Plant Licensing Branch 1 |
| To: | Christian D Dominion Nuclear Connecticut |
| Sanders, Carleen, NRR/DORL 415-1603 | |
| References | |
| TAC MD9954 | |
| Download: ML082910831 (5) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 October 21, 2008 Mr. David A. Christian President and Chief Nuclear Officer Dominion Nuclear Connecticut, Inc.
Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711
SUBJECT:
MILLSTONE POWER STATION, UNIT NO.3 - UPCOMING STEAM GENERATOR TUBE INSERVICE INSPECTION (TAC NO. MD9954)
Dear Mr. Christian:
Inservice inspections of steam generator (SG) tubes playa vital role in assuring that adequate structural integrity of the tubes is maintained. The reporting requirements of Millstone Power Station, Unit No 3 (MPS3) Technical Specifications require submission of a report within 180 days following completion of the inspection. The content of the report 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, and
- The effective plugging percentage for all plugging in each SG.
Based on discussions on October 17, 2008, with Mr. William D. Bartron of your staff, Dominion Nuclear Connecticut, Inc. (DNC) has agreed to participate in a conference call with the U.S.
Nuclear Regulatory Commission (NRC) staff to discuss the ongoing results of the SG tuoe inspection during the ongoing outage at MPS3. A conference call will be arranged with members of your staff 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 phone conference.
D. Christian
- 2 The NRC staff plans to document a brief summary of the conference call, including any material that you may have provide to the NRC staff in support of the call. Please contact me at 301-415-1603 if you have any questions.
Si"l;,eIY, C{NI/
/
Carleen J. San er, Project Manager Plant Licensin Br* nch 1-2 Division of Op at" g Reactor Licensing Office of Nuclea eactor Regulation Docket No. 50-423
Enclosure:
SG Tube Inspection Discussion Points cc w/encls: Distribution via ListServ
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 DOMINION NUCLEAR CONNECTICUT, INC., ET AL.
MILLSTONE POWER STATION, UNIT NO.3 DOCKET NO. 50-423 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 tube inspections to be conducted during the ongoing Millstone Power Station, Unit NO.3 refueling outage. This conference call is scheduled to occur towards the end of the planned steam generator tube inspections, but before the unit completes the inspections and repairs.
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 steam generator, 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% 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 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 primary water stress corrosion cracking at the expansion transition for the first time at this unit).
- 6.
Describe repair/plugging plans.
- 2
- 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 steam generator (including the source or nature of the loose part, if known) if the loose parts were removed from the steam generator 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, feedring inspections, sludge lancing, assessing deposit loading, etc).
- 10. Discuss any unexpected or unusual results.
- 11. Provide the schedule for steam generator-related activities during the remainder of the current outage.
D. Christian
- 2 The NRC staff plans to document a brief summary of the conference call, including any material that you may have provide to the NRC staff in support of the call. Please contact me at 301 415-1603 if you have any questions.
Sincerely,
/raJ Carleen J. Sanders, Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-423
Enclosure:
SG Tube Inspection Discussion Points cc w/encls: Distribution via ListServ DISTRIBUTION:
PUBLIC LPLI-2 RlF RidsAcrsAcnw_MailCTR Resource RidsNrrDirsCsgb Resource RidsNrrDorlDpr Resource RidsNrrDorlLpl1-2 Resource RidsNrrPMCSanders Resource RidsNrrLAABaxter Resource RidsOgcRp Resource RidsRgn1 MailCenter Resource Accession Number: ML082910831 OFFICE NRR/LPLI-2/PM NRR/LPLI-2/LA NRR/DCI/CSGB NRR/LPLI-2/BC NAME CSanders ABaxter AHiser HChernoff DATE 10/20/2008 10/20/08 10/20/2008 10/21/08 Official Record Copy