ML15170A318
| ML15170A318 | |
| Person / Time | |
|---|---|
| Site: | Braidwood  |
| Issue date: | 06/29/2015 |
| From: | Joel Wiebe Plant Licensing Branch III |
| To: | Bryan Hanson Exelon Generation Co, Exelon Nuclear |
| Joel Wiebe, NRR/DORL 301- 415-6606 | |
| References | |
| TAC MF5222 | |
| Download: ML15170A318 (3) | |
Text
Mr. Bryan C. Hanson Senior Vice President UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 June 29, 2015 Exelon Generation Company, LLC President and Chief Nuclear Officer (CNO)
Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
BRAIDWOOD STATION, UNIT 2 - REVIEW OF THE SPRING 2014 STEAM GENERATOR TUBE INSERVICE INSPECTIONS DURING REFUELING OUTAGE 17 (TAC NO. MF5222)
Dear Mr. Hanson:
By letter dated November 14, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14318A211) as supplemented by letter dated April 27, 2015 (ADAMS Accession No. ML15117A126), Exelon Generation Company, LLC (the licensee) submitted information summarizing the results of the spring 2014 steam generator tube inspections performed at Braidwood Station, Unit 2. These inspections were performed during refueling outage 17.
The U.S. Nuclear Regulatory Commission staff has completed its review of the reports and concludes that the licensee provided the information required by their technical specifications and that no additional follow up is required at this time. The staff's review of the reports is enclosed. If you have questions regarding this review, please contact me at (301) 415-6606 or Joel.Wiebe@nrc.gov.
Docket No. STN 50-457
Enclosure:
NRC Staff Review cc w/encl: Distribution via Listserv Sincerely, 1
~oel S. Wiebe, Senior Project Manager Plant Licensing II 1-2 and Planning and Analysis Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
REVIEW OF THE SPRING 2014 STEAM GENERA TOR TUBE INSERVICE INSPECTION REPORT BRAIDWOOD STATION, UNIT 2 DOCKET NUMBER 50-457 By letter dated November 14, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14318A211), as supplemented by letter dated April 27, 2015 (ADAMS Accession No. ML15117A126), Exelon Generation Company, LLC (the licensee) submitted information summarizing the results of the spring 2014 steam generator (SG) tube inspections performed at Braidwood Station, Unit 2. These inspections were performed during refueling outage 17 (RFO 17).
Braidwood Station, Unit 2, has four Westinghouse Model D5 SGs. There are 4570 thermally treated Alloy 600 tubes in each SG, with an outside diameter of 0.750 inches and a nominal wall thickness of 0.043 inches. The tubes are hydraulically expanded for the full depth of the tubesheet at each end and are welded to the tubesheet at the bottom of each expansion.
The tubes are supported by a number of Type 405 stainless steel tube support plates with quatrefoil shaped holes.
The licensee provided the scope, extent, methods, and results of their SG tube inspections in the documents referenced above. In addition, the licensee described corrective actions (i.e., tube plugging) taken in response to the inspection findings.
After reviewing the information provided by the licensee, the U.S. Nuclear Regulatory Commission staff has the following comments/observations:
No crack-like indications were detected during RFO 17.
The red substance, which was observed during RFO 16, was not observed in the visual examination performed in the preheater of SG C during RFO 17. The licensee believes that the red substance was likely organic material because it was no longer present and is assumed to have decomposed during operating cycle 17.
Based on a review of the information provided by the licensee, the NRC staff concludes that the licensee provided the information required by their technical specifications. The SG tube inspections at Braidwood Station, Unit 2, appear to be consistent with the objective of detecting potential tube degradation and the inspection results appear to be consistent with industry operating experience at similarly designed and operated units.
Enclosure
ML15117A126), Exelon Generation Company, LLC (the licensee) submitted information summarizing the results of the spring 2014 steam generator tube inspections performed at Braidwood Station, Unit 2. These inspections were performed during refueling outage 17.
The U.S. Nuclear Regulatory Commission staff has completed its review of the reports and concludes that the licensee provided the information required by their technical specifications and that no additional follow up is required at this time. The staff's review of the reports is enclosed. If you have questions regarding this review, please contact me at (301) 415-6606 or Joel.Wiebe@nrc.gov.
Docket No. STN 50-457
Enclosure:
NRC Staff Review cc w/encl: Distribution via Listserv DISTRIBUTION:
PUBLIC RidsNrrPMBraidwood Resource RidsAcrsAcnw_MailCTR Resource RidsRgn3MailCenter Resource ADAMS Accession No. ML15170A318 OFFICE LPL3-2/PM LPL3-2/LA NAME JWiebe SRohrer DATE 6/22/15 6/23/15 Sincerely, IRA/
Joel S. Wiebe, Senior Project Manager Plant Licensing 111-2 and Planning and Analysis Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation LPL3-2 R/F LPL3-2/BC BBeasley (A) 6/29/15 RidsNrrDorllpl3-2 Resource RidsNrrLASRohrer Resource RidsNrrDorlDpr Resource LPL3-2/PM JWiebe 6/29/15