ML042790205

RAI, Application of Alternative Source Term

ML042790205
Person / Time
Site:	Limerick
Issue date:	10/08/2004
From:	Travis Tate NRC/NRR/DLPM/LPD1
To:	Crane C Exelon Generation Co, Exelon Nuclear
Tate T, NRR/DLPM, 415-8474
References
TAC MC2295, TAC MC2296
Download: ML042790205 (6)

Text

October 8, 2004 Mr. Christopher M. Crane President and Chief Nuclear Officer Exelon Nuclear Exelon Generation Company, LLC 200 Exelon Way, KSA 3-E Kennett Square, PA 19348

SUBJECT:

LIMERICK GENERATING STATION, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION RE: APPLICATION OF ALTERNATIVE SOURCE TERM (TAC NOS. MC2295 AND MC2296)

Dear Mr. Crane:

By application dated February 27, 2004, Exelon Generation Company, LLC (Exelon), requested license amendments related to application of the alternative source term methodology, with the exception of Technical Information Document (TID) 14844, Calculation of Distance Factors for Power and Test Reactor Sites, which will continue to be used as the radiation dose basis of equipment qualification. The request involves changes to various requirements in the Technical Specifications for the Limerick Generating Station, Units 1 and 2.

The Nuclear Regulatory Commission (NRC) staff is reviewing the request and has determined that additional information is needed to complete the review. The specific information requested is addressed in the questions enclosed with this letter. These questions were previously transmitted by e-mail to Mr. Doug Walker of your staff on August 23, 2004, and were discussed with Mr. Dave Helker of your staff on September 23, 2004.

On October 5, 2004, Mr. Helker agreed to provide the requested information by October 15, 2004. If circumstances result in the need to revise the response date, please contact me at (301) 415-8474.

Sincerely,

/RA/

Travis L. Tate, Project Manager, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-352 and 50-353

Enclosure:

Request for Additional Information

cc w/encl: See next page Mr. Christopher M. Crane President and Chief Nuclear Officer Exelon Nuclear Exelon Generation Company, LLC 200 Exelon Way, KSA 3-E Kennett Square, PA 19348

SUBJECT:

LIMERICK GENERATING STATION, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION RE: APPLICATION OF ALTERNATIVE SOURCE TERM (TAC NOS. MC2295 AND MC2296)

Dear Mr. Crane:

By application dated February 27, 2004, Exelon Generation Company, LLC (Exelon), requested license amendments related to application of the alternative source term methodology, with the exception of Technical Information Document (TID) 14844, Calculation of Distance Factors for Power and Test Reactor Sites, which will continue to be used as the radiation dose basis of equipment qualification. The request involves changes to various requirements in the Technical Specifications for the Limerick Generating Station, Units 1 and 2.

The Nuclear Regulatory Commission (NRC) staff is reviewing the request and has determined that additional information is needed to complete the review. The specific information requested is addressed in the questions enclosed with this letter. These questions were previously transmitted by e-mail to Mr. Doug Walker of your staff on August 23, 2004, and were discussed with Mr. Dave Helker of your staff on September 23, 2004.

On October 5, 2004, Mr. Helker agreed to provide the requested information by October 15, 2004. If circumstances result in the need to revise the response date, please contact me at (301) 415-8474.

Sincerely,

/RA/

Travis L. Tate, Project Manager, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-352 and 50-353

Enclosure:

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

PUBLIC PDI-2 R/F CHolden DCollins TTate DNguyen GMatakas, RI OGC ACRS MOBrien MYoder GThomas DLPM DPR Accession Number: ML04279025 OFFICE PDI-2/PM PDI-2/LA PDI-2/SC(A)

NAME TTate MOBrien DCollins DATE 10/5/04 10/05/04 10/8/04 Official Record Copy

Limerick Generating Station, Unit Nos. 1 and 2 cc:

Site Vice President Associate General Counsel Limerick Generating Station Exelon Generation Company, LLC Exelon Generation Company, LLC 4300 Winfield Road P.O. Box 2300 Warrenville, IL 60555 Sanatoga, PA 19464 Correspondence Control Desk Plant Manager Exelon Generation Company, LLC Limerick Generating Station P.O. Box 160 Exelon Generation Company, LLC Kennett Square, PA 19348 P.O. Box 2300 Sanatoga, PA 19464 Regional Administrator, Region I U.S. Nuclear Regulatory Commission Regulatory Assurance Manager - Limerick 475 Allendale Road Exelon Generation Company, LLC King of Prussia, PA 19406 P.O. Box 2300 Sanatoga, PA 19464 Senior Resident Inspector U.S. Nuclear Regulatory Commission Senior Vice President - Nuclear Services Limerick Generating Station Exelon Generation Company, LLC P.O. Box 596 4300 Winfield Road Pottstown, PA 19464 Warrenville, IL 60555 Library Vice President - Operations, Mid-Atlantic U.S. Nuclear Regulatory Commission Exelon Generation Company, LLC Region I 200 Exelon Way, KSA 3-N 475 Allendale Road Kennett Square, PA 19348 King of Prussia, PA 19406 Vice President Chief-Division of Nuclear Safety Licensing and Regulatory Affairs PA Dept. of Environmental Resources Exelon Generation Company, LLC P.O. Box 8469 4300 Winfield Road Harrisburg, PA 17105-8469 Warrenville, IL 60555 Chairman Director Board of Supervisors of Limerick Township Licensing and Regulatory Affairs 646 West Ridge Pike Exelon Generation Company, LLC Linfield, PA 19468 200 Exelon Way, KSA 3-E Kennett Square, PA 19348 Dr. Judith Johnsrud National Energy Committee Manager Licensing Sierra Club Limerick Generating Station 433 Orlando Avenue Exelon Generation Company, LLC State College, PA 16803 200 Exelon Way, KSA 3-E Kennett Square, PA 19348

REQUEST FOR ADDITIONAL INFORMATION LIMERICK GENERATING STATION, UNITS 1 AND 2 REQUEST FOR LICENSE AMENDMENTS RELATED TO APPLICATION OF ALTERNATIVE SOURCE TERM

1. Limerick Generating Station (LGS), Units 1 and 2, Technical Specifications (TSs) 3.8.1.2, 3.8.2.2, and 3.8.3.2 (which are currently applicable in Modes 4, 5, and during handling of irradiated fuel assemblies in the secondary containment) currently requires, in part, immediate suspension of handling irradiated fuel in the secondary containment when both offsite preferred sources, redundant safety related electric onsite power sources, or redundant safety related distribution systems are no longer operable. The proposed requirements relax the current TS requirements such that TSs 3.8.1.2, 3.8.2.2, and 3.8.3.2 would be applicable when in Modes 4, 5, and during handling of recently irradiated fuel. The proposed change would thus allow, without TS restrictions, the handling of irradiated fuel assemblies that has decayed at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> without any offsite power, onsite power, or A.C. and D.C. electrical power sources through the electric distribution system to safety related loads.

The Technical Specifications Task Force (TSTF)-51 guidelines for systems removed from service during movement of irradiated fuel that has decayed for two days or more and during core alternations state that:

During fuel handling/core alterations, ventilation system and radiation monitor availability (as defined in NUMARC 91-06) should be assessed, with respect to filtration and monitoring of releases from the fuel. Following shutdown, radioactivity in the fuel decays away fairly rapidly. The basis of the Technical Specification operability amendment is the reduction in doses due to such decay.

The goal of maintaining ventilation system and radiation monitor availability is to reduce doses even further below that provided by the natural decay. A single normal or contingency method to promptly close primary or secondary containment penetration should also be developed. Such prompt methods need not completely block the penetrations or be capable of resisting pressure. The purpose of the prompt methods mentioned above is to enable ventilation systems to draw the release from a postulated fuel handling accident in the proper direction such that it can be treated and monitored.

Please provide the justification for handling irradiated fuel assemblies that have decayed at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> without the availability of power source to any safety systems such as those needed to maintain plant shutdown, to monitor and maintain the plant status, or to mitigate a postulated fuel handling accident.

2. In the February 27, 2004, submittal, an evaluation of the sump pH control was performed to support the determination that the pH is maintained above 7. The sump pH is maintained above 7 in order to minimize the release of radioactive iodine and to minimize stress corrosion cracking susceptibility in stainless steel following a loss-of-Enclosure

coolant accident (LOCA). In order to complete its evaluation, the NRC staff needs to review the assumptions and calculations used to support a conclusion that the containment sump pH will be maintained above 7 throughout the duration of the accident. Please provide a description of the methodology used to calculate the pH at different time intervals during the 30 day period after a LOCA. Please include sufficient detail to enable the NRC staff to perform independent calculations, including sample calculations, computer code descriptions, and inputs.

3. In the February 27, 2004, submittal, the licensee proposed a change to TS 3/4.4.7, for the Main Steam Isolation Valve (MSIV) closing time. The proposed change would increase the closing time from 5 seconds to 10 seconds. Please identify all transient and accident analyses where the MSIV closure time of 5 seconds is currently assumed.

Please provide the results of the recalculated analyses using the proposed closure time of 10 seconds. Include a comparison of the revised results using the 10 second closure time to the applicable acceptance criteria, and a discussion of deviations, if any, from the previous calculation methodology used.