NL-12-1598, Backfit for Degraded Grid Voltage Protection - Implementation of Plant Modifications

Backfit for Degraded Grid Voltage Protection - Implementation of Plant Modifications

ML12223A032
Person / Time
Site:	Hatch
Issue date:	08/09/2012
From:	Ajluni M Southern Nuclear Operating Co, Southern Co
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
NL-12-1598
Download: ML12223A032 (3)

Text

Mark J. Ajluni, P.E. Southern Nuclear Nuclear Licensing Director Operating Company, Inc.

40 Inverness Center Pa rkway Post Office Box 1295 Birmingham, Alabama 35201 Tel 205992.7673 Fax 205.992.7885 August 9, 2012 SOUIHERN ' \

COMPANY Docket Nos.: 50-321 NL-12-1598 50-366 U. S. Nuclear Regulatory Commission ATTN : Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant - Units 1 and 2 Backfit for Degraded Grid Voltage Protection -Implementation of Plant Modifications Ladies and Gentlemen:

On May 25, 2011, the Nuclear Regulatory Commission (NRC) staff issued a letter to Southern Nuclear Operating Company (SNC) stating that the measures in effect at Edwin I. Hatch Nuclear Plant (HNP) to demonstrate compliance with the applicable provisions of 10 CFR 50.55a(h)(2) and 10 CFR Part 50, Appendix A, General Design Criterion 17 (GDC-17) are not acceptable.

This conclusion constituted a change from the position taken by the NRC staff in the February 23,1995 Safety Evaluation Report (SER) regarding the reliance on administrative controls and manual actions at HNP for maintaining adequate voltage to protect Class 1E (safety-related) electrical equipment in the event of degraded grid voltage conditions.

The NRC staff position is that the 1995 SER was issued in error and that a compliance backfit is necessary, as provided for by 10 CFR 50.1 09(a)(4)(i). SNC appealed this decision in a letter dated June 17, 2011 (NL-11-1065), which was denied by NRC in a letter dated September 29, 2011. A further SNC appeal, in a letter dated October 28, 2011 (NL-11-2032), was denied by the NRC Executive Director of Operations (EDO) in a letter dated June 19, 2012, based on a chartered review by a Backfit Appeal Panel.

As requested in the June 19, 2012 NRC letter, SNC hereby provides the following information regarding the plans and schedule to resolve this issue (that is, to eliminate manual actions as part of the HNP degraded grid voltage protection system for dealing with a sustained degraded voltage condition).

SNC is developing a project plan which will involve replacement of major plant equipment (the Startup Auxiliary Transformers (SATs)) and include other design changes. Due to the integral role of the SA Ts and their connected electrical buses in the operation of each unit, project implementation must be performed during scheduled refueling outages, with two outages per unit required .

U.S. Nuclear Regulatory Commission NL-12-1598 2

Schedule milestones include:

2012 May begin Project Plan development (in progress) 2013 June approval of Project Plan and Design Package 2014 June issuance of purchase orders for new 2015 December completion of design 2015 December submittal of Technical Specification amendment request 2016 January of new 6 September issuance of Technical Specification amendments 2017 February begin 2R24 outage work - SAT(s), cabling, switchgear 2018 February begin 1 outage work - SAT(s), cabling, switchgear 2019 February begin 2R25 outage work SAT(s), cabling, switchgear 2020 February begin 1R29 outage work - SAT(s), cabling, switchgear 2020 March completion of project implementation Non-critical path work activities performed at power are not included in the above schedule. with similar major foregoing are dependent upon the absence of unanticipated events and conditions.

While this schedule for implementation extends over several years, SNC intends to it, if possible. Many in fully implementing the project result from nature and complexity of the design change, which includes such as protective scheme between the plant and switchyard, Bulletin 2012-01, "Design Vulnerability in Electric Power System" considerations, submittal and approval of Technical Specification amendments and an anticipated long lead time for large electrical equipment. These and other factors dictate the implementation schedule, which will require two outage periods of unit's 24-month operating cycle to complete.

This letter contains no NRC commitments. If you any contact Doug McKinney at (205) 992-5982.

Respectfully submitted, M. J. Ajluni Nuclear Licensing Director MJNDWD/lac

u.s. Nuclear Regulatory Commission NL-12-1598 Page 3 cc: Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman , President & CEO Mr. D. G. Bost, Executive Vice President & Chief Nuclear Officer Mr. D. R. Madison, Vice President - Hatch Mr. B. L. Ivey, Vice President - Regulatory Affairs Mr. B. J. Adams, Vice President - Fleet Operations Mr. C . E. Boone, Fleet Emergency Preparedness Manager RTYPE: CHA02.004 U. S . Nuclear Regulatory Commission Mr. V . M. McCree, Regional Administrator Mr. R. L. Martin, NRR Senior Project Manager - Hatch Mr. E. D. Morris, Senior Resident Inspector - Hatch Mr. J. T. Munday, Director of New Construction Projects Mr. L. D. Wert, Deputy Regional Administrator Mr. T. Reis, Director Division of Reactor Safey Mr. H. O. Christensen, Deputy Director Division of Reactor Safety