ML093000253

RAI, Regarding Steam Generator Tube Inspection Report( TAC No. ME0942)

ML093000253
Person / Time
Site:	Millstone
Issue date:	11/02/2009
From:	Sanders C Plant Licensing Branch 1
To:	Heacock D Dominion Nuclear Connecticut
Sanders, C J, NRR/DORL/LPL1-2, 415-1603
References
TAC ME0942, FOIA/PA-2011-0115
Download: ML093000253 (4)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 November 2, 2009 Mr. David A. Heacock President and Chief Nuclear Officer Dominion Nuclear Connecticut, Inc.

lnnsbrook 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 INSPECTION REPORT (TAC NO. ME0942)

Dear Mr. Heacock:

By letter dated March 13, 2009 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML090850344), Dominion Nuclear Connecticut, Inc., submitted information summarizing the results of the 2008 steam generator (SG) tube inspections at Millstone Power Station, Unit NO.3. These inspections were performed during the 1i h refueling outage (3R12). Additional details of these inspections are documented in a conference call summary letter dated December 12, 2008 (ADAMS Accession No. ML083370136). To complete its review, the Nuclear Regulatory Commission staff requests the enclosed additional information.

The draft questions were sent to Mr. William Bartron, 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 October 30, 2009, Ms. Marylou Calderone, of your staff, agreed that you would provide a response by December 3, 2009.

If you have any questions regarding this matter, please contact me at 301-415-1603.

~.~9JereIY, tJ . Isid P~tM'---'

A C ar Ieen n ers, rojec anager Plant Li en ng Branch 1-2 Division perating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-423

Enclosure:

As stated cc w/encl: Distribution via Listserv

REQUEST FOR ADDITIONAL INFORMATION 2008 STEAM GENERATOR TUBE INSPECTIONS MILLSTONE POWER STATION UNIT 3 DOCKET NUMBER 50-423 By letter dated March 13, 2009 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML090850344), Dominion Nuclear Connecticut, Inc., submitted information summarizing the results of the 2008 steam generator (SG) tube inspections at Millstone Power Station, Unit NO.3. These inspections were performed during the 12th refueling outage (3R 12). Additional details of these inspections are documented in a conference call summary letter dated December 12, 2008 (ADAMS Accession No. ML083370136). In order to complete its review of the documents listed above, the Nuclear Regulatory Commission staff needs the following additional information:

1. Technical Specification (TS) 6.9.1.7.j states that the SG report shall include, "... the primary-to-secondary LEAKAGE rate observed in each steam generator (if it is not practical to assign leakage to an individual SG, the entire primary-to-secondary LEAKAGE should be conservatively assumed to be from one steam generator) during the cycle preceding the inspection which is the SUbject of the report ..." On page 26 of the March 13, 2009, submittal, it was stated that, "[t]he leakage rate at the EOC [end of cycle] 12 (prior to 3R12) was less than one gallon per day (GPD). The detection threshold is approximately 1 GPD - actual leakage was too small to measure accurately."

Please specify whether the primary-to-secondary leakage was assigned to one SG or distributed between all SGs.

2. TS 6.9.1.7.k states that the SG report shall include, "... the calculated accident leakage rate from the portion of the tube below 17 inches from the top of the tubesheet for the most limiting accident in the most limiting steam generator." To calculate this rate, the operational leakage from the most limiting SG is multiplied by a factor of 2.5.

The aforementioned information was not provided, please provide the required information.

3. The calculations provided in section j and k of Enclosure 1 to the March 13, 2009, submittal do not appear to have been required to be submitted.

a. The calculation appears to calculate the administrative limit for operational leakage following the formula in TS Amendment No. 245; if this is the case, Enclosure

-2 please explain why sources of leakage, other than the tube sheet, were not included in these calculations. In addition, please explain why 2.5 gallons per day (presumably attributed to leakage from indications below 17 inches from the top of the tubesheet) was subtracted from the accident induced leakage limit in determining the administrative limit for operational leakage.

b. If this is not the case, please explain what these calculations are for.

4. Table 2, of the March 13, 2009, submittal, indicates that visual examinations of the plugs were performed during 3R12. TS requirement 6.9.1.7.b requires a report of the degradation mechanisms found during the inspection. Please clarify whether any degradation was associated with the plugs.

5. Per TS requirement 6.9.1. 7.b, you indicated that tube end cracking was found. Please clarify whether this cracking initiated from the inside or outside diameter of the tube.

November 2, 2009 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 INSPECTION REPORT (TAC NO. ME0942)

Dear Mr. Heacock:

By letter dated March 13, 2009 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML090850344), Dominion Nuclear Connecticut, Inc., submitted information summarizing the results of the 2008 steam generator (SG) tube inspections at Millstone Power Station, Unit No.3. These inspections were performed during the 12'h refueling outage (3R12). Additional details of these inspections are documented in a conference call summary letter dated December 12, 2008 (ADAMS Accession No. ML083370136). To complete its review, the Nuclear Regulatory Commission staff requests the enclosed additional information.

The draft questions were sent to Mr. William Bartron, 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 October 30, 2009, Ms. Marylou Calderone, of your staff, agreed that you would provide a response by December 3, 2009.

If you have any questions regarding this matter, please contact me at 301-415-1603.

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:

As stated cc w/encl: Distribution via Listserv Distribution:

PUBLIC Branch Reading RidsAcrsAcnw_MailCTR Resource RidsNrrDorlDpr Resource RidsNrrDorlLpl1-2 Resource RidsNrrSRXB Resource RidsNrrLAABaxter Resource RidsNrrMilistone Resource RidsOgcRp Resource RidsRgn 1MailCenter Resource TMorgan, NRR KKarwoski, NRR Adams Accession N 0.: ML093000253 *Bsy Memo dated OFFICE LPL 1-2/PM LPL 1-2/LA DCI/CSGB/BC LPL 1-2/BC NAME CSanders ABaxter MGavrilas HChernoff DATE 10/30/09 10/29/2009 09/13/2009* 11/02/09 Official Record Copy