ML101110725
| ML101110725 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 04/22/2010 |
| From: | David M Plant Licensing Branch III |
| To: | Pardee C Exelon Nuclear |
| David Marshall NRR/DORL/LPL3-2 415-154 | |
| References | |
| TAC ME0971, TAC ME0972, TAC ME0973, TAC ME0974 | |
| Download: ML101110725 (5) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 April 22, 2010 Mr. Charles G. Pardee President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
BRAIDWOOD STATION, UNITS 1 AND 2, AND BYRON STATION, UNIT NOS. 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO UPPER CABLE SPREADING ROOM FIRE PROTECTION REQUIREMENTS (TAC NOS. ME0971, ME0972, ME0973, AND ME0974)
Dear Mr. Pardee:
By letter to the Nuclear Regulatory Commission (NRC) dated March 26, 2009. (Agencywide Documents Access and Management System (ADAMS) Accession No. ML090861015). as supplemented by letters dated September 10, 2009 (ADAMS Accession No. ML092540075).
and March 15,2010 (ADAMS Accession No. ML100740499). Exelon Generation Company, LLC (the licensee), submitted a license amendment request (LAR) to revise the fire protection program to eliminate the requirement for the backup manual carbon dioxide fire suppression system in the upper cable spreading rooms.
The NRC staff is reviewing your LAR, and has determined that additional information is required to complete its review. The specific information requested is addressed in the enclosed Request for Additional Information (RAI). A draft of the RAI was provided to your staff on April 15, 2010, and they determined that a call to discuss the draft was not necessary. The NRC staff requests that you provide a response to the enclosed RAI within 30 days after the date of this letter.
The NRC staff considers that timely responses to RAls 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) 415-1547.
~re;~M(!GJ Mar~ J. David, Senior Project Manager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. STN-456, STN-457, STN 50-454, and STN 50-455
Enclosure:
Request for Additional Information cc w/encls: Distribution via Listserv
REQUEST FOR ADDITIONAL INFORMATION BRAIDWOOD STATION, UNITS 1 AND 2 AND BYRON STATION, UNIT NOS. 1 AND 2 DOCKET NOS. STN 50-456. STN 50-457 STN 50-454. AND STN 50-455 The Nuclear Regulatory Commission (NRC) staff is reviewing Exelon Generation Company, LLC's (the licensee's) letter dated March 26, 2009, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML090861015), as supplemented by letters dated September 10, 2009 (ADAMS Accession No. ML092540075), and March 15, 2010 (ADAMS Accession No. ML100740499), which requested a license amendment concerning a change to the fire protection program requirements for Braidwood Station (Braidwood), Units 1 and 2, and Byron Station (Byron), Unit Nos. 1 and 2. The license amendment request (LAR) relates to the removal of the backup manually-actuated carbon dioxide fire suppression systems for the upper cable spreading rooms (UCSRs) at Braidwood and Byron. In addition to the LAR, the NRC staff has reviewed the applicable licensing and regulatory documents, i.e., Braidwood's and Byron's Fire Protection Report, related safety evaluation reports, and Updated Final Safety Analysis Report.
The NRC staff is continuing its review, and has determined that the following additional information is required to complete the review. The numbering, below, represents a continuation in the numbering in the NRC staff's previous request for additional information (January 27,2010, ADAMS Accession No. ML100251433).
9.0 The NRC staff is aware that recently at Byron Station, during UCSR fire hose surveillance testing, water leaked onto the UCSR floor and then through the floor fire seals into an Auxiliary Electric Equipment Room (AEER) cabinet located below in a separate fire area. The water leakage into an annunciator cabinet resulted in numerous spurious alarms being generated in the Main Control Room due to wet circuit cards or wiring. The NRC staff is also aware that there have been previous instances of water leaking through the UCSR floor fire seals into the Main Control Rooms at both Byron and Braidwood. The UCSR floor fire seal design configuration is similar at both Byron and Braidwood.
Title 10 of the Code of Federal Regulations (10 CFR) Section 50.48(a) requires nuclear power plants to have a fire protection plan that satisfies General Design Criterion 3 (GDC 3) of Appendix A to 10 CFR Part 50. It further requires that plants licensed to operate prior to January 1,1979, comply with Appendix R to 10 CFR Part 50, Sections III.G, J and O. The fire protection requirements were incorporated into NUREG-0800, Standard Review Plan (SRP), Section 9.5-1. Although, the Byron and Braidwood plants were licensed to operate after January 1, 1979, (post-79 plants), the requirements of 10 CFR Part 50, Appendix R, were incorporated into their approved fire protection program. The requirement to implement ENCLOSURE
- 2 the program was incorporated into the licensee's operating licenses as license conditions.
SRP Section 9.5-1 and Appendix R represent one means of demonstrating compliance with GDC3.
GDC 3 states that, "...Firefighting systems shall be designed to assure that their rupture or inadvertent operation does not significantly impair the safety capability of these structures, systems, and components... "
Furthermore, Generic Letter 86-10, "Implementation of Fire Protection Requirements,", Interpretation 3, "Fire Damage," states:
"Appendix R to 10 CFR Part 50 utilizes the term "free of fire damage." In promulgating Appendix R, the Commission has provided methods acceptable for assuring that necessary structures, systems and components are free of fire damage (see Section III.G.2a, b and c), that is, the structure, system or component under consideration is capable ofperforming its intended function during and after the postulated fire, as needed. Licensees seeking exemptions from Section III.G.2 must show that the alternative proposed provides reasonable assurance that this criterion is met. (Note also that Section III.G.2 applies only to equipment needed for hot shutdown. Therefore, an exemption from III.G.2 for cold shutdown equipment is not needed. The term "damage by fire" also includes damage to equipment from the normal or inadvertent operation of fire suppression systems."
It appears to the NRC staff that impairment or damage occurred at Byron and Braidwood due to water leakage into the Main Control Room and AEER.
Based on the generic guidance cited above, the licensee should have considered the effects of fire suppression systems and activities on the Main Control Room and other safety-related areas.
When Byron and Braidwood were originally licensed, the licensee installed automatic Halon 1301 and manually-actuated backup CO2 fire suppression systems in lieu of an automatic water sprinkler system in the UCSRs. Now the UCSRs' fire suppression configuration has changed, i.e., the Halon 1301 fire suppression system is no longer backed up by the manually-actuated CO2 system. Therefore, greater reliance in the event of failure of the Halon 1301 fire suppression system now resides with the various other suppression provisions (water based hose stations, portable extinguishers, etc.)
instead of the CO2 fire suppression system. However, the potentially greater impact from use of water suppression was not addressed in the March 26, 2009, LAR. Specifically, the licensee did not provide for NRC staff review an analysis of the change that considers the impact of firefighting water on the fire seal design configuration in the UCSRs. Additionally, it is the NRC staffs understanding that the UCSR floor fire seals are not rated for flood and that the floor seal configuration has not been modified commensurate with the potentially greater impact from the use of water suppression in the UCSR.
In light of the potential impact from the use of water suppression in the UCSR, provide the basis for not discussing, in the March 26, 2009, LAR, that the floor seals
- 3 in the UCSRs are not watertight and for not assessing in the LAR the water leakage events into the Main Control Rooms and AEER that have occurred over the life of the plants.
Provide an analysis of the impact of using firefighting water in the UCSR in light of the design of the UCSR floor fire seals, or justify why such an analysis is not necessary.
- The NRC staff notes that, prior to the early events when water entered the Main Control Room, the NRC issued a generic communication and summarized the lessons learned from the interaction between fire protection water systems and safety-related structures, systems, and components. The information was documented in NRC Information Notice (IN) 85-85, "Systems Interaction Event Resulting in Reactor System Safety Relief Opening Following a Fire-Protection Deluge System Malfunction," October 31, 1985 (ADAMS Accession No. ML031180210). In light of 11\\1 85-85 and to satisfy GDC 3, discuss what actions EGC considered, including any corrective actions taken, at Braidwood and Byron to avoid problems with operating experience as discussed in IN 85-85.
April 22, 2010 Mr. Charles G. Pardee President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
BRAIDWOOD STATION, UNITS 1 AND 2, AND BYRON STATION, UNIT NOS. 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO UPPER CABLE SPREADING ROOM FIRE PROTECTION REQUIREMENTS (TAC NOS. ME0971, ME0972, ME0973, AND ME0974)
Dear Mr. Pardee:
By letter to the Nuclear Regulatory Commission (NRC) dated March 26, 2009, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML090861015), as supplemented by letters dated September 10, 2009 (ADAMS Accession No. ML092540075),
and March 15,2010 (ADAMS Accession No. ML100740499), Exelon Generation Company, LLC (the licensee), submitted a license amendment request (LAR) to revise the fire protection program to eliminate the requirement for the backup manual carbon dioxide fire suppression system in the upper cable spreading rooms.
The NRC staff is reviewing your LAR, and has determined that additional information is required to complete its review. The specific information requested is addressed in the enclosed Request for Additional Information (RAI). A draft of the RAI was provided to your staff on April 15, 2010, and they determined that a call to discuss the draft was not necessary. The NRC staff requests that you provide a response to the enclosed RAI within 30 days after the date of this letter.
The NRC staff considers that timely responses to RAls 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) 415-1547.
Sincerely, IRA!
Marshall J. David, Senior Project Manager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. STN-456, STN-457, STN 50-454, and STI\\! 50-455
Enclosure:
Request for Additional Information cc w/encls: Distribution via Listserv DISTRIBUTION:
PUBLIC RidsNrrPMByron Resource RidsNrrDraAfpb Resource LPL3-2 R/F RidsNrrPMBraidwood Resource RidsOgcRp Resource RidsNrrDorlLpl3-2 Resource RidsAcrsAcnw_MailCTR Resource Nlqbal, NRR RidsNrrLATHarris Resource RidsRgn3MailCenler Resource PQuals, NRR RidsNrrDorlDpr Resource ADAMS Accession No.: ML101110725
- Dateof e-mail NRR-088 OFFICE LPL3-2/PM LPL3-2/LA DRAlAFPB/BC LPL3-2/BC NAME I'v1David THarris AKlein*
SCampbell DATE 4/22/10 4/22/10 4/15/10 4/22/10 OFFICIAL RECORD COpy