ML101690172

RAI, Regarding 16th Steam Generator Tube Inservice Inspection Performed During Refueling Outage 17

ML101690172
Person / Time
Site:	Wolf Creek
Issue date:	06/21/2010
From:	Balwant Singal Plant Licensing Branch IV
To:	Matthew Sunseri Wolf Creek
Singal, Balwant, 415-3016, NRR/DORL/LPL4
References
TAC ME3774
Download: ML101690172 (3)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 June 21, 2010 Mr. Matthew W. Sunseri President and Chief Executive Officer Wolf Creek Nuclear Operating Corporation Post Office Box 411 Burlington, KS 66839 SUB..IECT: WOLF CREEK GENERATING STATION - REQUEST FOR ADDITIONAL INFORMATION REGARDING 16TH STEAM GENERATOR TUBE INSERVICE INSPECTION (TAC NO. ME3774)

Dear Mr. Muench:

By letter dated April 8, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML101100676), Wolf Creek Nuclear Operating Corporation (WCNOC, the licensee) submitted the results of the 16th steam generator tube inservice inspection for Wolf Creek Generating Station.

The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the information provided by the licensee and determined that additional information identified in the enclosure to this letter is needed in order for the NRC staff to complete its review. The draft copy of the request for additional information was provided to Ms. Diane Hooper of your staff via e-mail on June 9, 2010. WCNOC did not request further discussion to clarify the request for additional information and agreed to provide the response within 30 days of the date of the letter.

Sincerely, C~i~~itOject 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: Distribution via Listserv

REQUEST FOR ADDITIONAL INFORMATION REGARDING 16TH STEAM GENERATOR TUBE INSERVICE INSPECTION WOLF CREEK GENERATING STATION DOCKET NO. 50-482 By letter dated April 8, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML101100676), Wolf Creek Nuclear Operating Corporation (the licensee) submitted the results of the 16th steam generator (SG) tube inservice inspection for Wolf Creek Generating Station.

The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the information provided by the licensee and determined that the additional information is needed in order for the NRC staff to complete its review as follows:

1. In its letter dated April 8, 2010, the licensee indicated that no precursor signals were found in tubes identified as potentially having an elevated residual stress condition.

Please provide the number of tubes with this condition for each of the four SGs. Also, please discuss whether locations in these tubes that may elevate the residual stresses (e.g., dents, dings, expansion transitions) were examined preferentially with a rotating probe.

2. Please clarify whether all new dents and dings were examined with a rotating probe or whether just 50 percent of these locations were examined.

3. For the wear indications at the tube supports and flow distribution baffle, please discuss whether the depths of these indications have changed since the last inspection (i.e.,

changed beyond what would be expected as a result of normal measurement variability).

4. Please clarify whether any degradation was observed during the secondary side inspections.

5. In its letter dated April 8, 2010, the licensee indicated that analysis of the data collected for scale profiling was on-going. Please discuss whether this analysis has been completed, and, if so, briefly describe the results. In particular, please discuss the extent to which the tUbe support openings (e.g., quatrefoil shaped holes) are blocked.

Enclosure

June21,2010 Mr. Matthew W. Sunseri President and Chief Executive Officer Wolf Creek Nuclear Operating Corporation Post Office Box 411 Burlington, KS 66839 SUB"IECT: WOLF CREEK GENERATING STATION - REQUEST FOR ADDITIONAL INFORMATION REGARDING 16TH STEAM GENERATOR TUBE INSERVICE INSPECTION (TAC NO. ME3774)

Dear Mr. Muench:

By letter dated April 8, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML101100676), Wolf Creek Nuclear Operating Corporation (the licensee) submitted the results of the 16th steam generator tube inservice inspection for Wolf Creek Generating Station.

The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the information provided by the licensee and determined that additional information identified in the enclosure to this letter is needed in order for the NRC staff to complete its review. The draft copy of the request for additional information was provided to Ms. Diane Hooper of your staff via e-mail on June 9, 2010. WCNOC did not request further discussion to clarify the request for additional information and agreed to provide the response within 30 days of the date of the letter.

Sincerely, IRA by James R. Hall fori 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: Distribution via Listserv DISTRIBUTION:

PUBLIC RidsNrrPMWolfCreek Resource AObodoako, NRR/DCI//CSGB LPLIV r/f RidsNrrLAIBurkhardt Resource RidsNrrDciCsgb Resource RidsAcrsAcnw_MailCTR Resource RidsOgcRp Resource RidsNrrDorlLpl4 Resource RidsRgn4MailCenter Resource ADAMS Accession No" "" ML101690172

• Memo dated 6/8/10 OFFICE NRR/LPL4/PM NRR/LPL4/LA DCI/CSGB/BC OGC NRRlLPL4/BC NRRlLPL4/PM BSingal JRHall NAME BSingal ,IBurkhardt RTaylor* Not Required MMarkley for DATE 6/18/10 6/18/10 6/8/10 - 6/21/10 6/21/10 OFFICIAL RECORD COpy