ML16096A352

Review of the Fall 2015 Steam Generator Tube Inservice Inspections During Refueling Outage 20

ML16096A352
Person / Time
Site:	Byron
Issue date:	04/11/2016
From:	Joel Wiebe Plant Licensing Branch III
To:	Bryan Hanson Exelon Generation Co
Wiebe J
References
CAC MF7348
Download: ML16096A352 (3)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 April 11, 2016 Mr. Bryan C. Hanson Senior Vice President Exelon Generation Company, LLC President and Chief Nuclear Officer (CNO)

Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

BYRON STATION, UNIT NO. 1 - REVIEW OF THE FALL 2015 STEAM GENERATOR TUBE INSERVICE INSPECTIONS DURING REFUELING OUTAGE 20 (CAC NO. MF7348)

Dear Mr. Hanson:

By letter dated February 5, 2016 (Agencywide Documents Access Management System (ADAMS) Accession No. ML16036A061), Exelon Generation Company, LLC (the licensee) submitted information summarizing the results of its 2015 steam generator tube inspections performed during refueling outage 20 at Byron Nuclear Power Station, Unit No. 1 (Byron 1).

The U.S. Nuclear Regulatory Commission staff has completed its review of the report and concludes that the licensee provided the information required by the Byron 1 technical specifications. No additional follow up is required at this time. The staff's review is enclosed.

If you have questions regarding this review please contact me at (301) 415-6606 or Joel.Wiebe@nrc.gov.

Sincerely, el S. Wiebe, Senior Project Manager lant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. STN 50-454

Enclosure:

Review of Steam Generator Tube Inspections cc w/encl: Distribution via Listserv

SUMMARY

OF THE NRC STAFF REVIEW OF THE STEAM GENERATOR TUBE INSERVICE INSPECTIONS FOR REFUELING OUTAGE 20 FOR BYRON NUCLEAR POWER STATION, UNIT NO. 1 DOCKET NO. 50-454 By letter dated February 5, 2016 (Agencywide Documents Access Management System (ADAMS) Accession No. ML16036A061), Exelon Generation Company, LLC (the licensee) submitted information summarizing the results of their 2015 steam generator (SG) tube inspections performed during refueling outage 20 at Byron Nuclear Power Station, Unit No. 1 (Byron 1).

Byron 1 has four Babcock & Wilcox SGs. Each contains 6,633 thermally treated Alloy 690 tubes. Each tube has a nominal wall thickness of 0.040 inches. The tubes were hydraulically expanded at both ends for the full length of the tubesheet and are supported by a number of stainless steel lattice grid structures and fan bars.

The licensee provided the scope, extent, methods, and results of its SG tube inspections in the document referenced above. In addition, the licensee described corrective actions taken in response to the inspection findings. The tubes in all four SGs were inspected this outage.

The following observation is noted regarding the 2015 inspections:

• The licensee noted that during the visual inspections of SG 1A, some deposit accumulation was identified at the lattice-grids and on the tube surfaces at the uppermost (9 1h) support location on the hot-leg side.

Based on a review of the information provided, the U.S. Nuclear Regulatory Commission staff concludes that the licensee provided the information required by the Byron 1 technical specifications. In addition, the staff concludes that there are no technical issues that warrant follow-up action at this time since the inspections 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

ML16096A352 *via Memorandum OFFICE NRR/DORL/LPL3-PM NRR/DORL/LPL3-2/LA NRR/DE/ESGB/BC*

NAME JWiebe SRohrer GKulesa DATE 4/7/16 4/6/16 3/24/16 OFFICE NRR/DORL/LPL3-2/PM NRR/DORL/LPL3-2/PM NAME JPoole JWiebe DATE 4/8/16 4/11/16