IR 05000259/2013012

IR 05000260-13-012, on 06-11-2013, Browns Ferry, Preliminary White Finding Letter

ML13162A780
Person / Time
Site:	Browns Ferry
Issue date:	06/11/2013
From:	Croteau R P Division Reactor Projects II
To:	Shea J W Tennessee Valley Authority
References
EA-13-0118 IR-13-012
Download: ML13162A780 (6)

Text

June 11, 2013

EA-13-0118 Mr. Joseph Vice President, Nuclear Licensing Tennessee Valley Authority 1101 Market Street, LP 3D-C Chattanooga, TN 37402-2801

SUBJECT: NRC REPORT 05000260/2013012; PRELIMINARY WHITE FINDING BROWNS FERRY NUCLEAR PLANT

Dear Mr. Shea:

This letter discusses a finding that has preliminarily been determined to be White, a finding with low to moderate safety significance that may require additional NRC inspections. This finding involved the failure to properly implement procedure 2-OI-99, Reactor Protection System, and was a performance deficiency. Specifically, during restoration of 2B Reactor Protection System (RPS) 480 volt power, the RPS motor generator set tie to battery BD 2 Breaker on the 2A RPS bus motor generator set was opened inappropriately, causing a Unit 2 reactor scram and closure of the main steam isolation valves (MSIV).

This finding was assessed based on the best available information using the applicable Significance Determination Process (SDP) and was calculated to have a preliminary increase in conditional core damage probability (CCDP) of 4.1E-6. This CCDP and additional risk insights were determined by evaluation of the increase in risk caused by the additional scram that resulted from the performance deficiency. Based on the risk evaluation, the preliminary significance determination is White or low to moderate safety significance. The final resolution of this finding will be conveyed in separate correspondence. This finding was determined to be more than minor because it was associated with the Initiating Events cornerstone attribute of the human performance area and adversely affected the cornerstone objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during at-power operations. Specifically, the failure to properly implement procedure 2-OI-99, Reactor Protection System, caused a Unit 2 reactor scram and MSIV closure. The NRC determined that this finding does not represent an immediate safety concern, because the licensee has taken actions to prevent recurrence of the associated human performance error that caused the event.

The finding is also an apparent violation (AV) of Technical Specification 5.4.1, Procedures, and was documented as AV 05000260/2013002-02, Failure to Follow Operating Procedure Guidance Resulted in Unit 2 Reactor Scram, in NRC Inspection Report (IR) 05000259, 260, 296/2013002, dated May 14 2013 (ADAMS Accession No. ML13134A237). This AV is being considered for escalated enforcement action in accordance with the Enforcement Policy, which can be found on the NRC's Web site at http://www.nrc.gov/about-nrc/regulatory/enforcement/enforce-pol.html. In accordance with NRC Inspection Manual Chapter (IMC) 0609, we intend to complete our evaluation using the best available information and issue our final determination of safety significance within 90 days of the date of the referenced report. The significance determination process encourages an open dialogue between the NRC staff and the licensee; however, the dialogue should not impact the timeliness of the staff's final determination. Before we make a final decision on this matter, we are providing you with an opportunity: (1) to attend a Regulatory Conference where you can present to the NRC your perspective on the facts and assumptions the NRC used to arrive at the finding and assess its significance, or (2)

submit your position on the finding to the NRC in writing. If you request a Regulatory Conference, it should be held within 30 days of the receipt of this letter and we encourage you to submit supporting documentation at least one week prior to the conference in an effort to make the conference more efficient and effective. If a Regulatory Conference is held, it will be open for public observation. If you decide to submit only a written response, such submittal should be sent to the NRC within 30 days of your receipt of this letter. If you decline to request a Regulatory Conference or submit a written response, you relinquish your right to appeal the final SDP determination, in that by not doing either, you fail to meet the appeal requirements stated in the Prerequisite and Limitation sections of Attachment 2 of IMC 0609.

Please contact Craig Kontz at 404-997-4715 or in writing within 10 days from the issue date of this letter to notify the NRC of your intentions. If we have not heard from you within 10 days, we will continue with our significance determination and enforcement decision. The final resolution of this matter will be conveyed in separate correspondence.

Because the NRC has not made a final determination in this matter, no Notice of Violation is being issued for these inspection findings at this time. In addition, please be advised that the number and characterization of the apparent violation described in the referenced inspection report may change as a result of further NRC review. In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter and its enclosure will be made available electronically for public inspection in the NRC Public Document Room or from the NRC's document system (ADAMS), accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html

Sincerely,/RA/

Richard P. Croteau, Director Division of Reactor Projects Docket No.: 05000260 License No.: DPR-52

Enclosure:

Phase 3 Risk Significance Determination cc w/encl: (See page 3)