ML110320434
| ML110320434 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 02/08/2011 |
| From: | Michael Mahoney Plant Licensing Branch III |
| To: | Allen B FirstEnergy Nuclear Operating Co |
| mahoney, m NRR/DORL/LPLIII-2 415-3867 | |
| References | |
| TAC ME4867 | |
| Download: ML110320434 (5) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 February 8, 2011 Mr. Barry S. Allen Site Vice President FirstEnergy Nuclear Operating Company Davis-Besse Nuclear Power Station Mail Stop A-DB-3080 5501 North State Route 2 Oak Harbor, OH 43449-9760
SUBJECT:
DAVIS-BESSE NUCLEAR POWER STATION, UNIT NO.1 - REQUEST FOR ADDITIONAL INFORMATION REGARDING SAFETY-RELATED BATTERIES SEPARATION DESIGN AND LICENSING BASES (TAC NO. ME4867)
Dear Mr. Allen:
On November 30, 2007, the Nuclear Regulatory Commission (NRC) completed a biennial component design basis baseline inspection at Davis-Besse Nuclear Power Station, Unit 1.
This inspection examined activities conducted under your license as they relate to safety and to compliance with the Commission's rules and regulations, and with the conditions of your license.
Results of the inspection were documented in an inspection report 05000346-2007007 dated January 14, 2008 (Agencywide Documents Access and Management System Accession No. ML080140333).
Section 1.3.b.5, "Concem Regarding Safety-Related Battery Electrical Isolation," identified an unresolved issue (05000346/2007007-05) related to the safety-related battery design basis. During a review of the 125/250 Volts Direct Current (DC) safety-related distribution system, the NRC inspectors determined that the safety-related buses supplied power to non-safety-related loads.
The inspectors expressed a concern that, under such environments, the non-safety-related loads could become grounded and impose added loads on the DC buses from which they were powered. This concern was also expressed by FirstEnergy Nuclear Operating Company in Condition Report 05-01849.
So the NRC can fully assess the regulatory and safety implication of this issue, information is needed. The specific information requested is addressed in the enclosure to this letter. During a discussion with your staff on February 1, 2011, it was agreed that you would provide a response within 45 days from the date of this letter.
B.Allen
-2 The NRC staff considers that timely responses to requests for additional information help ensure sufficient time is available for staff review and contribute toward the NRC's goal of efficient and effective use of staff resources. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-3867.
IJ11JJ j; Michael Mahoney, Project M Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-346
Enclosure:
Request for Additional Information cc w/encl: Distribution via Listserv
REQUEST FOR ADDITIONAL INFORMATION DAVIS-BESSE NUCLEAR POWER STATION, UNIT NO.1 FIRSTENERGY NUCLEAR OPERATING COMPANY DOCKET NO. 50-346 On November 30, 2007, the Nuclear Regulatory Commission (NRC) completed a biennial component design basis baseline inspection at Davis-Besse Nuclear Power Station, Unit 1.
This inspection examined activities conducted under your license as they relate to safety and to compliance with the Commission's rules and regulations and with the conditions of your license.
Results of the inspection were documented in an inspection report 05000346-2007007 dated January 14,2008 (Agencywide Documents Access and Management System Accession No. ML080140333).
The NRC staff has determined that the following information is needed to fully assess the regulatory and safety implication of this issue:
- 1. Provide the ampere rating of the following fuses:
- a. Fuses installed between the 250 Volt direct current non safety-related bus and the safety-related bus powered from the safety-related station batteries and Motor Control Centers E 110 and F11 0 shown on drawing OS-060, Sheet 1.
- b. Fuses for the protection of non safety-related Reactor Coolant Pump Back up Oil Lift pump motors shown on drawing OS-060, Sheet 1.
- c. Fuses shown in Typical Detail "1" for each of the load shown in Table 1 of the drawing OS-060, Sheet 1.
- 2. Provide the postulated environmental conditions the following non safety-related equipment will experience during their installed life and the locations of these equipment:
- a. Reactor Coolant Pump Backup Oil Lift pumps powered from the safety-related batteries.
- b. Emergency Lighting Panel L49E1.
- c. Station Overhead Annunciator (Switch YSW1).
- d. Non-Nuclear Instrumentation (NNI) Channel X (Switch YSW2).
- e. NNI Channel Y (Switch YSW3).
ENCLOSURE
- f.
Integrated Control System (Switch YSW4)
- g. Plant Computer (Switch YSW5)
- 3. Davis-Besse Updated Final Safety Analysis Report (UFSAR) Section 3.11.1.2 states:
Non-safety related electric equipment, whose failure under postulated environmental conditions could prevent satisfactory accomplishment of the specified safety-related electrical equipment required safety functions or mislead an operator, is qualified as required.
Explain in detail for the equipment listed in Item 2 above and installed in the postulated environmental conditions, how these non safety-related equipment are qualified per UFSAR Section 3.11.1.2.
ENCLOSURE
B.Allen
-2 The NRC staff considers that timely responses to requests for additional information help ensure sufficient time is available for staff review and contribute toward the NRC's goal of efficient and effective use of staff resources. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-3867.
Sincerely, IRA!
Michael Mahoney, Project Manager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation RidsNrrDorlLpl3-2 Resource RidsNrrLA THarris Resource RidsOgcRp Resource RidsNrrDorlDpr Resource CBrown, Rill RidsNRRDeEEEB Resource
- via email
- By Memo Dated NRR-088 OFFICE LPL3-21PM LPL3-21LA DE/EEEB DPRlPLPB LPL3-2/BC LPL3-21PM NAME MMahoney THarris*
RMathew BMilier (Via Email)
RCarlson MMahoney DATE 211/11 211/11 12113/10*
212111 214/11 218111 OFFICIAL RECORD COPY Docket No. 50-346
Enclosure:
Request for Additional Information cc w/encl: Distribution via Listserv DISTRIBUTION:
PUBLIC LPL3-2 RlF RidsNrrPMDavis-Besse Resource RidsAcrsAcnw_MailCTR Resource RidsRgn3MailCenler Resource BMiller, NRR RMalhew, NRR PSahay, NRR ADAMS Accession No. ML110320434