ML110460617
| ML110460617 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 03/04/2011 |
| From: | Ellen Brown Plant Licensing Branch III |
| To: | Pacilio M Exelon Nuclear |
| Brown Eva, NRR/DORL, 415-2315 | |
| References | |
| TAC ME2376, TAC ME2377 | |
| Download: ML110460617 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555'()001 March 4, 2011 Mr. Michael J. Pacilio President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville,IL 60555
SUBJECT:
LASALLE COUNTY STATION, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO THE USE OF NEUTRON ABSORBING INSERTS (TAC NOS. ME2376 AND ME2377)
Dear Mr. Pacilio:
By letter to the Nuclear Regulatory Commission (NRC) dated October 5, 2009 (Agencywide Documents Access and Management Systems (ADAMS) Accession No. ML092810278), as supplemented by letters dated June 10, November 23, December 14, and December 22,2010, January 11 and January 24, 2011, (ADAMS Accession Nos. ML101650229, ML103270566, ML103490098, ML103570025, ML110130074 and ML110250141, respectively), Exelon Generation Company, LLC submitted a request to revise Technical Specification (TS)
Section 4.3.1, "Criticality," to address a non-conservative TS, for the LaSalle County Station, Units 1 and 2. The proposed change addresses the Boraflex degradation issue in the Unit 2 spent fuel storage racks by revising TS Section 4.3.1 to allow the use of NETCO-SNAP-IN rack inserts in Unit 2 spent fuel storage rack cells as a replacement for the neutron absorbing properties of the existing Boraflex panels.
Subsequently, on January 28, 2011 (ADAMS Accession No. ML110250051), the NRC issued a partial approval of the October 5, 2009, submittal, as supplemented. As concerns regarding the long-term crediting of BORAFLEX in the Unit 2 spent fuel pools (SFPs) have yet to be resolved, the amendments approved the use of the NETCO-SNAP-IN inserts, but provided limitations on the use of the nuclear criticality analysis provided and added license conditions related to a three-tiered SFP BORAFLEX crediting configuration. The resolution of these concerns are significant due to the amount of time it will take the licensee to complete installation of the approved NETCO SNAP-INrack inserts.
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 Mr. Ken Nicely of your staff on February 15, 2011, it was agreed that a response would be provided within 45 days from the date of this letter.
M. Pacilio
- 2 Please note that if you do not respond to this letter within the prescribed response time or provide an acceptable alternate date in writing, we may reject your application for amendment under the provisions of Title 10 of the Code of Federal Regulations, Section 2.108. Should you need to contact me, I can be reached at (301) 415-2315.
Sincerely, IRA!
Eva A. Brown, Senior Project Manager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-373 and 50-374
Enclosure:
Request for Additional Information cc w/encl: Distribution via Listserv
REQUEST FOR ADDITIONAL INFORMATION RELATED TO SPENT FUEL NEUTRON ABSORBERS EXELON GENERATION COMPANY, LLC LASALLE COUNTY STATION, UNITS 1 AND 2 DOCKET NOS. 50-373 AND 50-374 Exelon Generation Company (Exelon, the licensee) proposed the following actions to compensate for the BORAFLEX degradation in a letter dated November 23, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML103270566).
Following the LaSalle County Station (LSCS) Unit 2, Spring 2011, refueling outage 13, and until all of the NETCO-SNAP-IN can be installed, the licensee proposed to place storage cells in the rack models without inserts into one of three categories: Unrestricted, Restricted and Unusable.
- Unrestricted will be cells whose peak panel degradation is less than or equal to 29.97 percent, Unrestricted cells may contain fuel assemblies up to the maximum reactivity identified in Technical Specification 4.3.1.1.d.
Restricted will be cells whose peak panel degradation is greater than 29.97 percent, but less than 52.27 percent, Restricted cells will only contain LSCS Unit 1 and Unit 2 Cycle 1 General Electric (GE) and GE14 fuel assemblies.
- Unusable will be cells whose peak panel degradation is greater than 52.27 percent, unusable cells will be administratively controlled to remain empty of any fuel assembly.
In order to determine whether these actions will continue to meet the regulatory requirement for kelt to not exceed 0.95, at a 95 percent probability, 95 percent confidence level, if flooded with unborated water until all NETCO-SNAP-IN inserts are installed the following information is requested:
- 1.
On page 5 of Attachment 1 to a letter dated November 23, 2010, the licensee indicated that the 'current criticality analysis' had a discussion justifying why deviating from the analyses of record is acceptable. Provide the referenced analysis.
- 2.
On page 5 of Attachment 1 to the November 23, 2010 letter, the licensee stated that the analyses, performed to estimate the penalty to in-rack kelt. are based on a certain amount of panel thinning. Provide the referenced analyses.
- 3.
Provide all of the reports of BADGER measurement campaigns that have been completed for LaSalle Unit 2.
ENCLOSURE
M. Pacilio
- 2 Please note that if you do not respond to this letter within the prescribed response time or provide an acceptable alternate date in writing, we may reject your application for amendment under the provisions of Title 10 of the Code of Federal Regulations, Section 2.108. Should you need to contact me, I can be reached at (301) 415-2315.
Sincerely, IRA!
Eva A. Brown, Senior Project Manager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-373 and 50-374
Enclosure:
Request for Additional Information cc w/encl: Distribution via Listserv DISTRIBUTION:
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