ML17052A035

NRR E-mail Capture - Verbal Authorization for Relief Request HNP-ISI-RR-05-01

ML17052A035
Person / Time
Site:	Hatch
Issue date:	02/17/2017
From:	Michael Orenak Plant Licensing Branch II
To:	Joyce R, Mcelroy G Southern Nuclear Operating Co
References
MF9271
Download: ML17052A035 (4)

Text

NRR-PMDAPEm Resource From: Orenak, Michael Sent: Friday, February 17, 2017 2:05 PM To: Joyce, Ryan M.; McElroy, G. Ken Cc: CRPIERCE (CRPIERCE@southernco.com); Markley, Michael; Rudland, David; Dijamco, David

Subject:

Verbal Authorization for Relief Request HNP-ISI-RR-05-01 Ryan and Ken, Below is the script for the verbal authorization of relief request HNP-ISI-RR-05-01 that was provided at approximately 1:10 pm EDT on 2/17/2017 by David Rudland and Michael Markley. As I stated during the call, a written relief request authorization will be issued within 150 days from today if the relief is needed.

Please let us know the results of the attempt to remove the stud by COB 1/20.

Mike VERBAL AUTHORIZATION BY THE OFFICE NUCLEAR REGULATION FOR RELIEF REQUEST HNP-ISI-RR-05-01 TEMPORARY RELIEF FROM REQUIREMENTS OF IWB-3515 OF SECTION XI OF THE ASME CODE EDWIN I. HATCH NUCLEAR PLANT, UNIT 2 SOUTHERN NUCLEAR OPERATING COMPANY, INC.

DOCKET NO. 50-366 FEBRUARY 17, 2017 Technical Evaluation read by David Rudland, Chief of the Vessels and Internals Integrity Branch, NRR By letter dated February 17, 2017, Southern Nuclear Operating Company, Inc. (the licensee) requested relief from the requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, IWB-3515.2(c), at Edwin I. Hatch Nuclear Plant, Unit 2, which specifies surface examination requirements for the reactor pressure vessel (RPV) studs. Specifically, the relief is pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(g)(5)(iii) on the basis that complying with the required surface examination of IWB-3515.2(c) is impractical.

On February 10, 2017, the licensee notified the U.S. Nuclear Regulatory Commission (NRC) that during the volumetric examination of the 56 RPV studs of the Hatch, Unit 2 RPV closure flange, it had detected an indication in stud location number 33. IWB-3515.2(c) of Section XI of the ASME Code requires surface examination of the stud if an indication is found through volumetric examination. The licensee has indicated that they may not be able to remove the stud during the current refueling outage (2R24), and therefore it is impractical to meet the requirements of IWB-3515.2(c) of Section XI of the ASME Code. For contingency planning, the licensee requested relief from the surface examination requirements in case the planned removal of the stud at location number 33 is not successful.

The licensee requested relief from the required surface examination to allow the stud to be untensioned during full power operations. As a basis, the licensee developed structural evaluations to determine the impact of the untensioned stud to the remaining 55 RPV studs and the ASME code stress and fatigue limits. The NRC staff reviewed the structural evaluations. The increased primary membrane stress on the remaining studs is below the design stress allowable value for the stud material. Additionally, the evaluations demonstrate that leaving 1

one untensioned stud in service does not cause exceedance of the ASME Code stress and fatigue limits in the remaining studs and RPV closure flange. Finally, the evaluations show that the increase in flange interface separation is less than the allowable separation.

The NRC staff finds that the licensee provided reasonable assurance of structural integrity of the remaining RPV 55 studs and RPV closure flange at Hatch, Unit 2 if stud at location number 33 is left untensioned in service until the beginning of the next refueling outage (2R25). Therefore, the NRC staff concludes that complying with the required surface examination is impractical and grants relief from IWB-3515.2(c) of Section XI of the ASME Code for RPV stud location number 33.

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Authorization read by Michael Markley, Chief of the Plant Licensing Branch II-1, NRR As Chief of the Plant Licensing Branch II-1, Office of Nuclear Reactor Regulation, I agree with the conclusions of the Vessels and Internals Integrity Branch.

The NRC staff finds that the licensee has provided reasonable assurance of structural integrity of the remaining studs and the RPV closure flange if the stud at location number 33 is left untensioned in service.

The NRC staff concludes that complying with IWB-3515.2(c) of Section XI of the ASME Code is impractical and that the licensee addressed all of the regulatory requirements set forth in 10 CFR 50.55a(g)(5)(iii).

Therefore, as of February 17, 2017, the NRC grants Relief Request HNP-ISI-RR-05-01 for the Edwin I. Hatch Nuclear Plant, Unit 2, until the beginning of the next refueling outage (2R25).

All other requirements in ASME Code,Section XI, for which relief was not specifically requested and approved in this relief request remain applicable, including third-party review by the Authorized Nuclear Inservice Inspector.

This verbal authorization does not preclude the NRC staff from asking additional clarifying questions regarding Relief Request HNP-ISI-RR-05-01 while preparing the subsequent written safety evaluation.

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Hearing Identifier: NRR_PMDA Email Number: 3352 Mail Envelope Properties (Michael.Orenak@nrc.gov20170217140400)

Subject:

Verbal Authorization for Relief Request HNP-ISI-RR-05-01 Sent Date: 2/17/2017 2:04:44 PM Received Date: 2/17/2017 2:04:00 PM From: Orenak, Michael Created By: Michael.Orenak@nrc.gov Recipients:

"CRPIERCE (CRPIERCE@southernco.com)" <CRPIERCE@southernco.com>

Tracking Status: None "Markley, Michael" <Michael.Markley@nrc.gov>

Tracking Status: None "Rudland, David" <David.Rudland@nrc.gov>

Tracking Status: None "Dijamco, David" <David.Dijamco@nrc.gov>

Tracking Status: None "Joyce, Ryan M." <RMJOYCE@southernco.com>

Tracking Status: None "McElroy, G. Ken" <GKMCELRO@southernco.com>

Tracking Status: None Post Office:

Files Size Date & Time MESSAGE 4840 2/17/2017 2:04:00 PM Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received: