ML14034A049

Davis-Besse, Response to Request for Additional Information Regarding Response to Bulletin 2012-01, Design Vulnerability in Electric Power System.

ML14034A049
Person / Time
Site:	Davis Besse
Issue date:	02/03/2014
From:	Lieb R A FirstEnergy Nuclear Operating Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
BL-12-001, L-14-03, TAC ME9326
Download: ML14034A049 (3)

Text

FENOC-\FirstEneryy Nuclear Opanting Cam pany5501 North Staic noub 2Oak Harbor, Ahio 43449Raymond A. UebVice Prasident, NuclearFebruary 3,2014L-14-039ATTN: Document Control DeskU.S. Nuclear Regulatory CommissionWashington, DG 20555-0001419-321-7676Fas<: 41*321-758210 cFR 50.54(0

SUBJECT: Davis-Besse Nuclear Power StationDocket No. 50-346, License No. NPF-3Response to. Req uest for Ad d itional I nfo rmation Rega rd ing.. Resppnse toBulletin 2Q1?-01. "Des_ign Vulnerabilily irtElectric Power:,$ystgr,n" (TAC.No. ME9326)FirstEnergy Nuclear Operating Company responded to Nuclear RegulatoryCommission (NRC)Bulletin 2012-01, "Design Vulnerability in Electric Power System,"in a letter dated October 24,2A12 (Agencyruide Documents Access and ManagementSystem (ADAMS) Accession No. MI12299A468). The NRC staff requested additionalinformation in a letter dated December 20, 2013 (ADAMS Accession No.ML13351A314). The requested information is provided for the Davis-BesseNuclear Power Station in an attachment to this letter.There are no regulatory commitments contained in this submittal. lf there are anyquestions or if additional information is required, please contact Mr. Thomas A, Lentz,Manager - Fleet Licensing, at 330-315-6810.I declare under penalty of perjury that the foregoing is true and correct. Executed onFebruary 3 , 2014.

Sincerely,

Attachment:

Response to Request for Additional Information on Bulletin 2012-01 forthe Davis-Besse Nuclear Power Stationcc: NRC Region lll AdministratorNRC Resident InspectorNRC Project ManagerUtility Radiological Safety BoardRaymond A. Lieb AttachmentL-14-039Response to Request for Additional Information on Bulletin 2012-01for the Davis-Besse Nuclear Power StationPage 1 of 2For the Davis-Besse Nuclear Power Station, FirstEnergy Nuclear Operating Company(FENOC) responded to Nuclear Regulatory Commission (NRC)Bulletin 2012-01,"Design Vulnerability in Electric Power System," in a letter dated October 24,2A12(Agencywide Documents Access and Management System (ADAMS) Accession No.ML12299A468). The NRC staff requested additional information in a letter datedDecember 20, 2013 (ADAMS Accession No. ML13351A314). The requested informationis identified using bold text, followed by the FENOC response.1. Provide a summary of all interim corrective actions that have been taken sincethe January 30, 2012, event at Byron Station, Unit 2,to ensure that plantoperators can promptly diagnose and respond to open phase conditions onthe offsite power circuits for ClasE-i E vital buses until permanent correctiveactions are completed,Response:Lessons learned from the events at the Byron station were reviewed and various interimcorrective actions evaluated for safety and efficiency at the Davis-Besse Nuclear PowerStation (DBNPS). Based on the plant's offsite power configuration, electrical designdetails, and the lessons learned, the following actions were taken to ensure plantoperators can diagnose and respond to an open phase condition:Operator walkdowns (three times per week at a minimum) of the switchyard areperformed to identify open phase condition vulnerabilities.Bus transfer procedures were revised to ensure three phase voltages arechecked prior to planned transfers to an offsite power circuit.Periodic surveillances (seven day Technical Specification Frequency) includesteps to identify an open phase condition in the offsite power supply circuits.2. Provide a status and schedule for completion of plant design changes andmodifications to resolve issues with an open phase of electric power.:Response:IndustrylDBNPS Status:Holders of operating licenses and combined licenses for nuclear power reactorsare investigating options being researched by several vendors to detect openphase conditions, There is cui"rently no generic, off-the-shelf technology thathas been proven to detect all the required open phase fault conditions for allplant and transformer designs.Holders of operating licenses and combined licenses for nuclear power reactorsare engaged in devElopment of a Nuclear Energy Institute (NEl) Open PhaseCondition Industry Guidance Document, as well as development of AttachmentL-14-039Page 2 of 2enhancements to software tools being used to analyze open phase conditions.A December 2013 version of the Open Phase Gondition Industry GuidanceDocument (NEl 13-12) was provided to the NRC in December.. With the goal of ensuring accurate detection without compromising nuclearsafetyor increasing plant risk, new open phase condition technology will bethoroughly evaluated, tested, and analyzed before installation.. Vulnerability studies of open phase fault conditions have been started for theDavis-Besse Nuclear Power Station.DBNPS Schedule:. FENOC intends to meet the remaining milestones identified in the industryOpen Phase Condition Initiative (October 2013; ADAMS Accession No,ML13333A1 47)for the Davis-Besse Nuclear Power Station; however, deviationsmay be required to accommodate outage schedules, software and hardwareavailability, manufacturer's delivery capabilities, or other unexpected delays.. Any deviation from the industry Open Phase Condition Initiative schedule will bedocumented through an appropriate deviation process. Revision 2 of the OpenPhase Condition lndustry Guidance Document, which is scheduled to be issuedin June 2014, is expected to provide a deviation process forthe industry.