ML110590833

Request for Additional Information Regarding License Amendment Request Related to the Emergency Core Cooling System Initiative

ML110590833
Person / Time
Site:	Mcguire, McGuire
Issue date:	02/28/2011
From:	Jacqueline Thompson Plant Licensing Branch II
To:	Ashe K Duke Energy Carolinas
Thompson Jon, NRR/DORL/LPL 2-1, 415-1119
References
TAC ME4051, TAC ME4052
Download: ML110590833 (3)

Text

From: Thompson, Jon Sent: Monday, February 28, 2011 1:42 PM To: Ashe, Ken Cc: Basavaraju, Chakrapani

Subject:

Request for Additional Information Re: License Amendment Request dated May 28, 2010

SUBJECT:

MCGUIRE NUCLEAR STATION, UNITS 1 AND 2 (MCGUIRE 1 AND 2),

REQUEST FOR ADDITIONAL INFORMATION (RAI) REGARDING LICENSE AMENDMENT REQUEST RELATED TO THE EMERGENCY CORE COOLING SYSTEM (ECCS) INITIATIVE (TAC NOS. ME4051 AND ME4052)

By letter dated May 28, 2010, as supplemented by letter dated November 15, 2010, Duke Energy Carolinas, LLC (the licensee), submitted a proposed license amendment to change the McGuire 1 and 2 Technical Specifications (TSs). The proposed change would revise the TSs to allow manual operation of the containment spray system and to change the setpoints for the refueling water storage tank at McGuire 1 and 2.

As part of its review, the U.S. Nuclear Regulatory Commission (NRC) staff sent a request for additional information (RAI) by email dated January 31, 2011 in order to complete our review.

This RAI was discussed on a telephone conference dated February 14, 2011. During this telephone conference, the NRC staff clarified its request with regard to questions numbered two and three. The enclosed document reissues these questions in order to clarify the information that the NRC staff needs to complete its review. These reissued questions numbered two and three supersede these same numbered questions described in the email dated January 31, 2011. The other RAI questions described in the email January 31, 2011, remain unaffected.

A written response is expected by the NRC staff for all of the RAI questions, with the exception of question 2(b) by March 3, 2011, in order to support our timely review of this application.

Please inform me as soon as possible if you are unable to support this response timeframe.

If you have any questions, please call me at 301-415-1345.

Sincerely, Jon Thompson, Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-369, 50-370

Enclosure:

As stated REQUEST FOR ADDITIONAL INFORMATION (RAI)

BY THE OFFICE OF NUCLEAR REACTOR REGULATION REGARDING LICENSE AMENDMENT REQUEST (LAR) RELATED TO IMPLEMENTATION OF THE EMERGENCY CORE COOLING SYSTEM (ECCS) WATER MANAGEMENT INITIATIVE MCGUIRE NUCLEAR STATION, UNITS 1 AND 2 (MCGUIRE 1 and 2)

By letter dated May 28, 2010 (ADAMS Accession No. ML101600256), as supplemented by letter dated November 15, 2010 (ADAMS Accession No. ML103270051), Duke Energy Carolinas, LLC (Duke Energy or the licensee), submitted a license amendment request (LAR) for the McGuire Nuclear Station, Units 1 and 2. The proposed amendment would allow the manual operation of the containment spray system (CSS) in lieu of automatic operation, and revise the minimum volume and low level set point on the refueling water storage tank (RWST).

One of the objectives of this LAR is to maximize the amount of water available for emergency core cooling from the RWST.

Based on our review of the license amendment request, the US Nuclear Regulatory Commission (NRC) staff identified RAI questions which were transmitted by email on January 31, 2011. RAI questions 2 and 3 are being resubmitted with clarification as described below and supersede these same numbered questions in the email dated January 31, 2011. All other RAI questions transmitted by email dated January 31, 2011, remained unaffected.

2. In Section 3.2.3 of Attachment 1 of the LAR, the licensee describes that as a result of the revised loadings from the evaluation of the CSS pipe stress analysis, 13 pipe support restraints in the auxiliary building were re-qualified and 224 pipe supports in the reactor building will be requalified.

(a) The licensee is requested to clarify if the increased loadings on such a significant number of pipe supports are caused by the small increase in the sump temperature only, or if any other effects contributed to the re-qualification of the supports.

(b) The licensee is also requested to complete the re-qualification of the affected pipe support restraints and provide a summary of the results of this analysis by a letter dated no later than April 15, 2011. The letter should also inform the NRC staff whether the requalification of these support restraints is complete. This information is needed for the NRC staff to complete its review.

3. In Section 3.2.3 of Attachment 1 of the LAR, the licensee describes that the re-qualification of the reactor building pipe supports (approximately three pipe support restraints in the Unit 2 reactor building annulus, and one pipe support restraint in the Unit 1 reactor building annulus) potentially require modification and will be performed in accordance with the requirements of 10 CFR 50.59. The NRC staff needs to determine whether the licensee has established the scope of the modifications for the pipe support restraints.

(a) While the installation of the modified supports can be done under 10 CFR 50.59, the licensee is requested to provide a summary of the pipe support restraints requiring modification.

(b) The licensee is requested to complete the pipe support restraint re-qualification for those support restraints used in support of this LAR and provide a summary of the results of this analysis by a letter dated no later than April 15, 2011. The letter should also inform the NRC staff whether the requalification of these support restraints is complete. This information is needed for the NRC staff to complete its review.

(c) The licensee is also requested to provide a summary table of the support restraints requiring modification, including a brief description of the support restraint direction and type, and the required modification.