ML14114A697

Relaxation of the Schedule Requirements for Order EA-12-049 Issuance of Order to Modify Licenses with Regard to Requirements for Mitigation Strategies for Beyond Design Basis External Events

ML14114A697
Person / Time
Site:	Arkansas Nuclear
Issue date:	05/20/2014
From:	Leeds E Office of Nuclear Reactor Regulation
To:	Entergy Operations
Hughey J, NRR/DPR, 415-3204
References
TAC MF0942
Download: ML14114A697 (4)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 May 20, 2014 Vice President, Operations Arkansas Nuclear One Entergy Operations, Inc.

1448 S.R. 333 Russellville, AR 72802

SUBJECT:

ARKANSAS NUCLEAR ONE, UNIT 1 -RELAXATION OF THE SCHEDULE REQUIREMENTS FOR ORDER EA-12-049 "ISSUANCE OF ORDER TO MODIFY LICENSES WITH REGARD TO REQUIREMENTS FOR MITIGATION STRATEGIES FOR BEYOND DESIGN BASIS EXTERNAL EVENTS" (TAC NO. MF0942)

Dear Sir or Madam:

By letter dated March 12, 2012 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML12054A735), the U.S. Nuclear Regulatory Commission (NRC) ordered Entergy Operations, Inc. (Entergy, the licensee) to take certain actions at Arkansas Nuclear One, Units 1 (AN0-1) and 2 (AN0-2), assoc1ated with the Fukushima Near-Term Task Force Recommendations. Order EA-12-049 directed that act1ons be taken by licensees to develop and implement strategies to maintain or restore core cooling, reactor coolant system inventory, containment cooling, and spent fuel pool cooling capabilities during beyond design basis external events (BDBEE).

Section IV of the order states that licensees proposing to deviate from requirements contained in NRC Order EA-12-049 may request that the Director, Office of Nuclear Reactor Regulation, relax or rescind certain conditions. By letter dated April 7, 2014 (ADAMS Accession No. ML14098A114), the licensee informed the NRC of its request for a schedule relaxation of the full implementation schedule requirements for AN0-1 as prescribed in Sectron IV.A.2 of NRC Order EA-12-049 Entergy has requested an extension for full impler: 1entation to coincide with the startup of AN0-2 from refueling outage 2R24 currently scheduled for October 2015. The requested relaxation would move the AN0-*1 implementation ciate from February 2015 to October 2015.

Entergy's letter dated April 7, 2014, provided a basis and justification for the request for schedule relief. Entergy's letter notes that train-specific modifications during AN0-2 refueling outages are required to implement AN0-1 Diverse and Flexible Coping Strategies (FLEX) to utilize the AN0-2 charging pumps, powered by a portable diesel generator (PDG). Specifically, modifications are required to two AN0-2 electrical load centers that provide power separately to independent, safety-related charging pump trains. The modifications are associated with providing a direct connection to a PDG for each of the two diverse, safety-related AN0-2 load centers. Work on both load centers in a single refueling outage would require that both trains of diverse, safety-related switchgear at AN0-2 be taken out of ser11ice in the same outage. The licensee states that this is typically not done, in order to reduce risk. Therefore. the licensee

requested that the AN0-1 compliance date be relaxed to allow the modifications to be implemented in separate AN0-2 refueling outages that are pre-.scheduled for alternating safety-related switchgear train maintenance.

The licensee's April 7, 2014, letter also identifies that additional risk would be introduced from the extensive schedule changes that would be required to implement the modifications to both trains of safety-related switchgear in a single AN0-2 refueling outage. Introduction into the scheduling process of the additional safety-related train modifications would require the rescheduling of tests associated with the additional train, including numerous motor operated valve tests. The licensee states that this amount of rescheduling flux introduces the risk of improperly mitigating the comprehensive risk of multiple equipment schedule interactions.

In light of the facts presented in the Entergy's April 7, 2014, letter, the NRC staff has determined that the licensee has presented good cause for a relaxation of the order implementation date for AN0-1. The extension would provide additional time to implement modifications to AN0-2 safety-related switchgear in accordance with prudent outage risk reduction practices and achieve AN0-1 compliance with Order EA-12-049. Implementation of these modifications is a significant action intended to enhance the licensee's capability to cope with a BDBEE.

Furthermore, the requested extension will support compliance for AN0-1 before December 2016 and coincident with AN0-2. The NRC staff also considered that, following the accident at Fukushima Dai-ichi, the NRC concluded that a sequence of events such as the Fukushima Dai-ichi accident is unlikely to occur in the United States, based on the current regulatory requirements and existing plant capabilities. Therefore, the extension time of one additional AN0-2 refueling outage for AN0-1 to achieve full implementation of the requirements of the mitigation strategies order is justified and completion before December 2016 is consistent with the intent of the order. These circumstances lead the NRC staff to approve the relaxation of the order implementation date.

Accordingly, based upon the authority granted to the Director, Office of Nuclear Reactor Regulation, the requirement for full order implementation is relaxed for AN0-1 until October 2015.

If you have any questions, please contact John Hughey, Mitigating Strategies Project Manager, at 301-415-3204, or atjohn.hughey@nrc.gov.

Sincerely,

~~

Eric J. eeds, Director Office of Nuclear Reactor Regulation Docket No. 50-313 cc: Listserv

ML14114A697 OFFICE NRR/MSD/PM NRR/MSD/LA NRR/MSD/MSPB/BC OE NAME JHughey Slent JBowen RFretz DATE 04/25/14 04/24/14 04/28/14 05/01/14 OFFICE OGC MSD/D NRR/D NAME CHair JDavis Eleeds DATE 05/07/14 05/14/14 05/20/14