ML111250264
| ML111250264 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 05/13/2011 |
| From: | John Hughey Plant Licensing Branch 1 |
| To: | Heacock D Dominion Nuclear Connecticut |
| Hughey J, NRR/DORL, 301-415-3204 | |
| References | |
| TAC ME5193 | |
| Download: ML111250264 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 May 13, 2011 Mr. David A. Heacock 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 - REQUEST FOR ADDITIONAL INFORMATION REGARDING STEAM GENERATOR TUBE INSERVICE INSPECTION REPORT FOR END OF CYCLE 13 (TAC NO. ME5193)
Dear Mr. Heacock:
By letter dated October 28, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML103130038), Dominion Nuclear Connecticut, Inc., submitted information summarizing the results of the 2010 steam generator tube inspections at Millstone Power Station, Unit NO.3. To complete its review of the submitted information, the Nuclear Regulatory Commission staff requests responses to the enclosed questions.
The draft questions were sent to Ms. Wanda Craft, of your staff, to ensure that the questions were understandable, the regulatory basis for the questions was clear, and to determine if the information was previously docketed. On April 20, 2011, Ms. Craft agreed that you would provide a response by June 6, 2011.
If you have any questions regarding this matter, please contact me at 301-415-3204.
Sincerely.
dD"'..-J?~
J~g£~~; ~ager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-423
Enclosure:
As stated cc w/encl: Distribution via Listserv
OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR ADDITIONAL INFORMATION STEAM GENERATOR TUBE INSERVICE INSPECTION REPORT FOR END OF CYCLE 13 MILLSTONE POWER STATION, UNIT NO.3 DOCKET NUMBER: 50-423 By letter dated October 28,2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML103130038), Dominion Nuclear Connecticut, Inc. (DNC or the licensee), submitted information summarizing the results of the 2010 steam generator (SG) tube inspections at Millstone Power Station, Unit NO.3 (MPS3). The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the information provided by the licensee and has determined that the following additional information is needed in order to complete the review.
The information provided in response to Technical Specification (TS) 6.9.1.7.j does not appear to follow the methodology outlined in your supporting technical documents for the H* alternate repair criteria.
In item U), you indicated that the administrative limit for operational leakage should be: leakage through faulted SG (500 gallons per day (GPD) - 2.49 x 0.22 =499.5 GPD). Later in the report, you indicated that the administrative limit for operational leakage is 499.5 GPD/2.49 =200.6 GPD.
In order to calculate the administrative limit for operational leakage (for the next operating cycle), consistent with the H* approved methodology, the accident-induced leakage rate (for the next operating cycle) from all other sources, other than the tube end indications, must be determined. This value must then be subtracted from your accident-induced leakage limit, (presumably 500 GPD based on your submittal), and the resultant value is then divided by 2.49.
If there is no prOjected accident-induced leakage for the next operating interval from any other sources (e.g., plugs, flaws in the free-span), then the limit on operational leakage to account for the accident-induced leakage from the tube ends during the next operating interval would be 500 GPD/2.49, or 200.8 GPD. Since this number exceeds your current technical specification limit on operating leakage, the limit in your technical specifications would be governing.
RAI -01: Please confirm that the latter approach is being used to calculate your administrative limit for operational leakage and that you have determined the accident-induced leakage from sources other than the tube ends for the next operating interval.
TS 6.9.1. 7.a requires that a report of the scope of the inspection performed on each SG be generated. Table 2 in the submittal implies that visual inspections of the plugs were performed and that a visual inspection of secondary side internals (other than for Foreign Object Search and Retrieval (FOSAR>> may have been performed.
Enclosure
- 2 RAI-02: Please discuss the scope and results of any tube plug inspections and/or secondary side inspections (other than FOSAR).
A list of newly reported tube support plate (TSP) wear indications is provided in Table 7 of the submittal. Results for previously-reported volumetric degradation (non-support related) wear is summarized in Table 9. Tube R30 C52 in SG B appears in both tables with the same wear indication.
RAI-03: Please clarify whether the wear indication for tube R30 C52 in SG B is new or previously reported. Additionally, clarify whether it is a TSP wear indication or a non support related indication since Table 9 lists the results for the previously-reported, non-support related, volumetric degradation and the only entry in the table has a suspected cause of TSP wear.
The report stated that three tubes in SG B had shallow probable foreign object wear in locations that were not accessible by FOSAR. The report further stated that the three inaccessible tubes were removed from service since the probability of continued wear growth could not be confirmed visually. Table 8, which summarizes the results for the neWly-reported, non-support related volumetric degradation, shows the three tubes that were plugged in SG B, but also indicates that the suspected cause was due to a foreign object that is no longer present.
RAI-04: Please clarify whether the foreign object has been confirmed to be no longer present at the tubes in question.
RAI-05: Please clarify the nature of the indication in tube R44 C98 in SG B listed in Table 8 of the submittal.
May 13, 2011 Mr. David A. Heacock 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.2 REQUEST FOR ADDITIONAL INFORMATION REGARDING RELI REQUEST FOR ALTERNATIVE PRESSURE TESTING CRITERIA (TAC NO. ME4473)
Dear Mr. Heacock:
By letter dated October 28, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML103130038), Dominion Nuclear Connecticut, Inc., submitted information summarizing the results of the 2010 steam generator tube inspections at Millstone Power Station, Unit NO.3. To complete its review of the submitted information, the Nuclear Regulatory Commission staff requests responses to the enclosed questions.
The draft questions were sent to Ms. Wanda Craft, of your staff, to ensure that the questions were understandable, the regulatory basis for the questions was clear, and to determine if the information was previously docketed. On April 20, 2011, Ms. Craft agreed that you would provide a response by June 6, 2011.
If you have any questions regarding this matter, please contact me at 301-415-3204.
Sincerely, IRAI John D. Hughey, Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-423
Enclosure:
As stated cc w/encl: Distribution via Listserv Distribution:
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