ML072270247

RAI, to Extend the Completion Times, Bypass Test Times, & Surveillance Test Intervals for Reactor Protection Systems & Engineered Safety Features Actuation System Instrumentation

ML072270247
Person / Time
Site:	Byron, Braidwood
Issue date:	08/17/2007
From:	Robert Kuntz NRC/NRR/ADRO/DORL/LPLIII-2
To:	Crane C Exelon Generation Co
Kuntz, Robert , NRR/DLPM, 415-3733
References
TAC MD4009, TAC MD4010, TAC MD4011, TAC MD4012
Download: ML072270247 (5)

Text

August 17, 2007 Mr. Christopher M. Crane President and Chief Nuclear Officer Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

BYRON STATION, UNIT NOS. 1 AND 2, AND BRAIDWOOD STATION, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO LICENSE AMENDMENT REQUEST TO REVISE TECHNICAL SPECIFICATION REQUIREMENTS FOR SELECT REACTOR TRIP SYSTEM, ENGINEERED SAFETY FEATURE ACTUATION SYSTEM, AND CONTAINMENT VENTILATION ISOLATION, INSTRUMENTATION (TAC NOS.

MD4009, MD4010, MD4011, AND MD4012)

Dear Mr. Crane:

By letter to the Nuclear Regulatory Commission (NRC) dated January 8, 2007, Exelon Generation Company, LLC submitted a request to extend the completion times, bypass test times, and surveillance test intervals for reactor protection system (RPS) and engineered safety features actuation system instrumentation, for the Byron Station, Unit Nos. 1 and 2, and Braidwood Station, Units 1 and 2.

The NRC staff is reviewing your submittal and has determined that additional information is required to complete the review. The specific information requested is addressed in the enclosure to this letter. During a discussion with your staff on August 9, 2007, it was agreed that you would provide a response within 30 days from the date of this letter.

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 NRCs 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) 415-3733.

Sincerely,

/RA/

Robert F. Kuntz, Project Manager Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. STN 50-454, STN 50-455, STN 50-456 and STN 50-457

Enclosure:

Request for Additional Information cc w/encl: See next page

August 17, 2007 Mr. Christopher M. Crane President and Chief Nuclear Officer Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

BYRON STATION, UNIT NOS. 1 AND 2, AND BRAIDWOOD STATION, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO LICENSE AMENDMENT REQUEST TO REVISE TECHNICAL SPECIFICATION REQUIREMENTS FOR SELECT REACTOR TRIP SYSTEM, ENGINEERED SAFETY FEATURE ACTUATION SYSTEM, AND CONTAINMENT VENTILATION ISOLATION, INSTRUMENTATION (TAC NOS.

MD4009, MD4010, MD4011, AND MD4012)

Dear Mr. Crane:

By letter to the Nuclear Regulatory Commission (NRC) dated January 8, 2007, Exelon Generation Company, LLC submitted a request to extend the completion times, bypass test times, and surveillance test intervals for reactor protection system (RPS) and engineered safety features actuation system instrumentation, for the Byron Station, Unit Nos. 1 and 2, and Braidwood Station, Units 1 and 2.

The NRC staff is reviewing your submittal and has determined that additional information is required to complete the review. The specific information requested is addressed in the enclosure to this letter. During a discussion with your staff on August 9, 2007, it was agreed that you would provide a response within 30 days from the date of this letter.

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 NRCs 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) 415-3733.

Sincerely, Robert F. Kuntz, Project Manager Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. STN 50-454, STN 50-455, STN 50-456 and STN 50-457

Enclosure:

Request for Additional Information cc w/encl: See next page DISTRIBUTION:

PUBLIC LPL3-2 R/F RidsNrrDorlLpl3-2 RidsNrrPMRKuntz RidsNrrLAEWhitt RidsAcrsAcnwMailCenter RidsOgcRp RidsRgn3MailCenter RidsNrrDorlDpr RidsNrrDraApla CDoutt, NRR ADAMS Accession Number: ML072270247 OFFICE LPL3-2/PM LPL3-2/LA LPL3-2/BC NAME RKuntz EWhitt RGibbs DATE 8/16/07 8/16/07 8/17/07 OFFICIAL RECORD COPY

Byron Station, Unit Nos. 1 and 2 Senior Vice President - Operations Support via e-mail cc:

Chairman Illinois Emergency Management Agency Will County Board of Supervisors Division of Disaster Assistance & Will County Board Courthouse Preparedness Joliet, IL 60434 1035 Outer Park Dr Springfield, IL 62704 Director - Licensing and Regulatory Affairs via e-mail Document Control Desk - Licensing via e-mail Manager Regulatory Assurance - Byron via e-mail Mr. Dwain W. Alexander, Project Manager via e-mail Associate General Counsel via e-mail Howard A. Learner Environmental Law and Policy Vice President - Regulatory Affairs Center of the Midwest via e-mail 35 East Wacker Drive Suite 1300 Manager Licensing - Braidwood/Byron Chicago, IL 60601-2110 via e-mail U.S. Nuclear Regulatory Commission Senior Vice President - Midwest Operations Byron Resident Inspectors Office via e-mail via e-mail Vice President - Regulatory Affairs Ms. Lorraine Creek via e-mail RR 1, Box 182 Manteno, IL 60950 Manager Licensing - Braidwood, Byron and LaSalle Chairman, Ogle County Board via e-mail P.O. Box 357 Oregon, IL 61061 Senior Vice President - Midwest Operations via e-mail Mrs. Phillip B. Johnson 1907 Stratford Lane Mr. Barry Quigley Rockford, IL 61107 3512 Louisiana Rockford, IL 61108 Attorney General 500 S. Second Street Springfield, IL 62701 Plant Manager - Byron Station via e-mail Site Vice President - Byron Station via e-mail

REQUEST FOR ADDITIONAL INFORMATION BYRON STATION, UNIT NOS. 1 AND 2, AND BRAIDWOOD STATION, UNITS 1 AND 2 DOCKET NOS. STN 50-454, STN 50-455, STN 50-456 AND STN 50-457 In reviewing the Exelon Generation Companys (Exelons) submittal dated January 8, 2007, related to extending the completion times (CT), bypass test times, and surveillance test intervals (STIs) for reactor protection system and engineered safety features actuation system (ESFAS) instrumentation, for the Byron Station, Unit Nos. 1 and 2 (Byron) and Braidwood Station, Units 1 and 2 (Braidwood), the NRC staff has determined that the following information is needed in order to complete its review:

1. The analysis for WCAP-14333/WCAP-15376 assumed that maintenance on master and slave relays, logic cabinets, and analog channels while at power occurs only after a component failure, and that preventive maintenance does not occur. The topical report does not preclude the practice of at-power preventive maintenance but limits the total time a component is unavailable due to corrective or preventive maintenance to the values used in the analysis. If preventive maintenance is to be performed at Byron/Braidwood, confirm that the unavailability for components evaluated in WCAP-14333 are consistent with the plant specific estimates at Byron/Braidwood and do not exceed those assumed in the analysis.

See the submittal, Attachment 6, Page 1, Implementation Guidelines, Table 1, Analog Channel Calibration as an example.

2. Provide an assessment of external events risk impact including, seismic, fire, and external floods/high wind with respect to the proposed CT and STI extensions, per Regulatory Guide (RG) 1.174 Section 2.2.4, Acceptance Guidelines and RG 1.177 Section 2.3.2, Scope of the Probabilistic Risk Assessment (PRA) for technical specification (TS) Applications. Include any seismic vulnerabilities associated with instrumentation/logic systems or components and risk impacts on fire screening criteria and quantification of fire sequences in unscreened areas. In addition, confirm that the combined total Core Damage Frequency (CDF) from external and internal events remains less than the RG 1.174 base CDF of 1E-4 per year.

3. Provide a discussion on the following aspects of PRA quality for Byron/Braidwood.

• Provide the date of Byron/Braidwoods PRA industry peer review and the date of certification. Provide the results of the Peer review including disposition of A and B facts and observations.

Enclosure

• The plant-specific PRA reflects the as-built, as-operated plant.

• Applicable PRA updates conducted since completion of individual plant examination (IPE) and individual plant examination of external events (IPEEE) and the status of any improvements identified by the IPE and IPEEE.

• Reference PRA quality assurance programs/procedures, including expected PRA revision schedules.

• PRA adequacy and completeness with respect to evaluating the proposed CT, bypass test time under Tier 3 configuration risk management.

• Plant design or operational modifications not reflected in the WCAP-14333/WCAP15376 PRA used in this application that are related to or could impact this application. Justify the acceptability of not including these modifications in the PRA, as part of this application.

4. Consistent with RG 1.174, the cumulative risk of the present TS change in light of past applications (or additional applications planned or under review) should be understood.

Cumulative risks were addressed for Byron/Braidwood with respect to the implementation of WCAP-10271, WCAP-14333, and WCAP-15376 only. Provide an evaluation of cumulative risk impact of previous and additional TS applications under development or review per RG 1.174, Section 3.3.2, as applicable to the implementation of WCAP-14333 and WCAP-15376.

5. Does the configuration risk management program at Byron/Braidwood provide modeling of the reactor trip and ESFAS systems and components addressed by WCAP-15376 and WCAP-14333 when performing Tier 3 evaluations? Discuss how signals or components not specifically modeled will be addressed.

6. Discuss the omission of reactor coolant system pressure relief systems from the regulatory commitments listed in Attachment 5, Page 1 of the submittal, see WCAP-15376 (Tier 2).