ML113530034
| ML113530034 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 12/21/2011 |
| From: | Peter Bamford Plant Licensing Branch 1 |
| To: | Pacilio M Exelon Nuclear |
| Bamford, Peter J., NRR/DORL 415-2833 | |
| References | |
| TAC ME7333 | |
| Download: ML113530034 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555"()001 December 21, 2011 Mr. Michael J. Pacilio President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville,lL 60555
SUBJECT:
LIMERICK GENERATING STATION, UNIT 1 - REQUEST FOR ADDITIONAL INFORMATION REGARDING PROPOSED TECHNICAL SPECIFICATION SAFETY LIMIT MINIMUM CRITICAL POWER RATIO CHANGES (TAC NO.
ME7333)
Dear Mr. Pacilio:
By letter dated October 12, 2011 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML112870080), Exelon Generation Company, LLC submitted a license amendment request proposing to modify the safety limit minimum critical power ratios contained in Section 2.1 of the Technical Specifications at Limerick Generating Station (LGS), Unit 1. The basis for the proposed revision was a cycle-specific analysis performed to support operation of LGS Unit 1, in the upcoming Cycle 15.
The Nuclear Regulatory Commission staff has been reviewing the request and has determined that additional information is needed to complete its review. The specific questions are found in the enclosed request for additional information (RAI). The questions were sent via electronic transmission on December 16, 2011, to Mr. Thomas Loomis, of your staff. The draft questions were sent to ensure that the questions were understandable, the regulatory basis for the questions was clear, and to determine if the information was previously docketed. The draft questions were discussed in a teleconference with your staff on December 21, 2011. It was agreed that a response to this RAI would be submitted by January 17, 2012.
Please contact me at 301-415-2833, if you have any questions.
Sincerely, Peter Bamford, Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor licensing Office of Nuclear Reactor Regulation Docket No. 50-352
Enclosure:
As stated cc w/encl: Distribution via Listserv
REQUEST FOR ADDITIONAL INFORMATION LIMERICK GENERATING STATION, UNIT 1 LICENSE AMENDMENT REQUEST REGARDING PROPOSED SAFETY LIMIT MINIMUM CRITICAL POWER RATIO CHANGE DOCKET NO. 50-352 By letter dated October 12, 2011 (Agencywide Documents Access and Management System Accession No. ML112870080), Exelon Generation Company, LLC (Exelon, the licensee) submitted a license amendment request (LAR) proposing to modify Technical Specification (TS) 2.1, "Safety Limits," for Limerick Generating Station (LGS), Unit 1. The requested change involves revised Safety Limit Minimum Critical Power Ratios (SLMCPRs) calculated as a result of the cycle-specific analysis performed by Global Nuclear Fuel (GNF) to support operation in the upcoming LGS, Unit 1, Cycle 15. The Nuclear Regulatory Commission (NRC) staff has been reviewing the submittal and has determined that additional information is needed to complete its review.
- 1. In the LAR, Attachment 5, Tables RAI-06-1 and RAI-06-2, provide core maps to show those bundles experiencing 0.1 % boiling transition criterion for limiting cases of single loop operation (SLO) and two-loop operation (TLO). Please identify the bundle group and number of bundles in Figure 1 corresponding to their burnup status (once-burned, twice-burned, or fresh fuel) for Cycle 15.
- 2. Core design is an iterative process designed to develop an optimal configuration that meets operational requirements. In the LAR, Attachment 6, for the slides titled "Preliminary Energy Utilization Plan for Limerick 1 Cycle 15" and "Pre-Estimation -
Linear Reactivity," please provide the most current updated parameters applicable to LGS, Unit 1, Cycle 15.
- 3. GNF2 fuel deviates from traditional 1 Ox1 0 design through the introduction of a new part length rod configuration, the use of higher linear power, and the use of mixing vanes.
The staff considers this a new fuel design with regards to the four restrictions identified in the Safety Evaluation of General Electric (GE) Licensing Topical Reports NEDC 32601 P, NEDC-32694 and Amendment 25 to NEDE-24011-P-A. Given that LGS, Unit 1 Cycle 15 uses a core loading pattern which includes GNF2 fuel, please provide the following: (1) an evaluation of the four restrictions in NEDC-32601 P, NEDC-32694 and Amendment 25 to NEDE-24011-P-A, (2) a description that explains under what conditions the methodologies listed in Section 1.0 of Attachment 4 are applied to the LGS, Unit 1, Cycle 15 application, (3) the reason why GNF2 has much higher critical power uncertainty than that of GE14, as shown in Table 6 of Attachment 4, and (4) a clarification for the statement "no new GNF fuel designs are being introduced in Limerick 1 Cycle 15" in Section 2.5 of Attachment 4.
Enclosure
- 2
- 4. In the LAR, Attachment 5, "GNF Response to RAI Applied to LGS Unit 1," it states that LGS Unit 1 Cycle 15 is the first full reload of GNF2. Figure 1 of Attachment 4, indicates that Cycle 15 will contain both GE14 and GNF2 fuel. Please clarify the "full reload" statement against Figure 1.
- 5. Please identify the breakdown of the 1 Ox1 0 data shown in Attachment 4, Figure 5, by fuel type (Le. GE14, GNF2), because Figure 5 only shows combined data points for the two fuel types.
- 6. Please clarify that there is no adverse impact relating to the GNF2 bent spacer wing operating experience to LGS, Unit 1, Cycle 15, operation. If there is an adverse impact, please provide an assessment of the impacts of such operation on fuel thermal performance.
- 7. Please provide an updated version of power/flow map for Cycle 15 operation, including stability Option III features of the scram region and controlled entry region, based on the Boiling Water Reactor Owners Group position, as specified in NEDO-31960, for SLO and TLO.
December 21,2011 Mr. Michael J. Pacilio President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
LIMERICK GENERATING STATION, UNIT 1 - REQUEST FOR ADDITIONAL INFORMATION REGARDING PROPOSED TECHNICAL SPECIFICATION SAFETY LIMIT MINIMUM CRITICAL POWER RATIO CHANGES (TAC NO.
ME7333)
Dear Mr. Pacilio:
By letter dated October 12, 2011 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML112870080), Exelon Generation Company, LLC submitted a license amendment request proposing to modify the safety limit minimum critical power ratios contained in Section 2.1 of the Technical Specifications at Limerick Generating Station (LGS), Unit 1. The basis for the proposed revision was a cycle-specific analysis performed to support operation of LGS Unit 1, in the upcoming Cycle 15.
The Nuclear Regulatory Commission staff has been reviewing the request and has determined that additional information is needed to complete its review. The specific questions are found in the enclosed request for additional information (RAI). The questions were sent via electronic transmission on December 16, 2011, to Mr. Thomas Loomis, of your staff. The draft questions were sent to ensure that the questions were understandable, the regulatory basis for the questions was clear, and to determine if the information was previously docketed. The draft questions were discussed in a teleconference with your staff on December 21,2011. It was agreed that a response to this RAI would be submitted by January 17, 2012.
Please contact me at 301-415-2833, if you have any questions.
Sincerely,
/raJ Peter Bamford, Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-352
Enclosure:
As stated cc w/encl: Distribution via Listserv DISTRIBUTION:
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NAME PBamford ABaxter AUlses*
HChernoff, CSanders for DATE 12/21/2011 12/21/2011 12/13/2011 1212112011 OFFICIAL RECORD COpy