ML110330429
| ML110330429 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 02/03/2011 |
| From: | Peter Bamford Plant Licensing Branch 1 |
| To: | Chernoff H Plant Licensing Branch 1 |
| Bamford, Peter J., NRR/DORL 415-2833 | |
| References | |
| TAC ME5182 | |
| Download: ML110330429 (4) | |
Text
February 3, 2011 MEMORANDUM TO: Harold K. Chernoff, Chief Plant Licensing Branch I-2 Division of Operating Reactor Licensing /ra/
Office of Nuclear Reactor Regulation FROM:
Peter Bamford, Project Manager Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
SUBJECT:
LIMERICK GENERATING STATION, UNIT 2 - ELECTRONIC TRANSMISSION, DRAFT REQUEST FOR ADDITIONAL INFORMATION REGARDING PROPOSED TECHNICAL SPECIFICATION SAFETY LIMIT MINIMUM CRITICAL POWER RATIO CHANGES (TAC NO.
ME5182)
The attached draft request for additional information (RAI) was transmitted by electronic transmission on February 2, 2011, to Mr. Thomas Loomis, at Exelon Generation Company, LLC (Exelon). This draft RAI was transmitted to facilitate the technical review being conducted by the Nuclear Regulatory Commission (NRC) staff and to support a conference call (if needed) with Exelon in order to clarify the licensees submittal. The draft RAI is related to Exelons submittal dated December 15, 2010, regarding Limerick Generating Station, Unit 2, proposing to incorporate revised safety limit minimum critical power ratios into Technical Specification 2.1.
The draft questions were sent to ensure that they were understandable, the regulatory basis was clear, and to determine if the information was previously docketed. Additionally, review of the draft RAI would allow Exelon to evaluate and agree upon a schedule to respond to the RAI.
This memorandum and the attachment do not represent an NRC staff position.
Docket No. 50-353
Enclosure:
As stated
February 3, 2011 MEMORANDUM TO: Harold K. Chernoff, Chief Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM:
Peter Bamford, Project Manager /ra/
Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
SUBJECT:
LIMERICK GENERATING STATION, UNIT 2 - ELECTRONIC TRANSMISSION, DRAFT REQUEST FOR ADDITIONAL INFORMATION REGARDING PROPOSED TECHNICAL SPECIFICATION SAFETY LIMIT MINIMUM CRITICAL POWER RATIO CHANGES (TAC NO.
ME5182)
The attached draft request for additional information (RAI) was transmitted by electronic transmission on February 2, 2011, to Mr. Thomas Loomis, at Exelon Generation Company, LLC (Exelon). This draft RAI was transmitted to facilitate the technical review being conducted by the Nuclear Regulatory Commission (NRC) staff and to support a conference call (if needed) with Exelon in order to clarify the licensees submittal. The draft RAI is related to Exelons submittal dated December 15, 2010, regarding Limerick Generating Station, Unit 2, proposing to incorporate revised safety limit minimum critical power ratios into Technical Specification 2.1.
The draft questions were sent to ensure that they were understandable, the regulatory basis was clear, and to determine if the information was previously docketed. Additionally, review of the draft RAI would allow Exelon to evaluate and agree upon a schedule to respond to the RAI.
This memorandum and the attachment do not represent an NRC staff position.
Docket No. 50-353
Enclosure:
As stated DISTRIBUTION:
Public RidsNrrPMLimerick LPL1-2 R/F Accession No.: ML110330429 OFFICE LPL1-2/PM DSS/SRXB NAME PBamford AUlses*
DATE 2/3/11 01/28/2011 OFFICIAL RECORD COPY
DRAFT Enclosure REQUEST FOR ADDITIONAL INFORMATION LIMERICK GENERATING STATION, UNIT 2 LICENSE AMENDMENT REQUEST REGARDING SAFETY LIMIT MINIMUM CRITICAL POWER RATIO CHANGE DOCKET NO. 50-353 By letter dated December 15, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML103500180), 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 2. The requested change involves revised Safety Limit Minimum Critical Power Ratios (SLMCPRs) calculated as a result of the cycle-specific analysis performed Global Nuclear Fuel (GNF) to support operation in the upcoming LGS, Unit 2, Cycle 12. The Nuclear Regulatory Commission (NRC) staff has been reviewing the submittal and has determined that additional information is needed to complete its review.
- 1. Please provide: (1) the number of fuel assemblies for each fuel type in Figures 1 and 2 for Cycle 12 and Cycle 11, including Cycle 11 (thrice-burn) through Cycle 12 (fresh fuel), and; (2) a core map to show those bundles experiencing the 0.1% boiling transition criterion for single-loop operation (SLO) and two-loop operation (TLO).
- 2. Core design is an iterative process designed to develop an optimal configuration that meets operational requirements. Please provide: (1) the details of a final core loading pattern as shown in Figure 1, including core design procedures, guidelines, criteria, and approved methodologies used for this Cycle 12 analysis, and (2) a description of the core design process used for Cycle 12, including the Quality Assurance and Quality Control procedures to assure that the final design meets the SLMCPR limits for the fuel used in the core.
- 3. The NRC staff considers GNF2 a new fuel design with regards to the four restrictions identified in the Safety Evaluation of General Electric (GE) Licensing Topical Reports NEDC-32601P, NEDC-32694 and Amendment 25 to NEDE-24011-P-A. All of these topical reports are referenced in the application. Given that LGS, Unit 2, Cycle 12 uses a core loading pattern which includes GNF2 fuel, please provide the following: (1) an evaluation of the four restrictions in NEDC-32601P, 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 the LAR, Attachment 41 are applied to the LGS, Unit 2, Cycle12 analysis, (3) the reason why GNF2 has much higher critical power uncertainty than that of GE14 as shown in Table 6 of, and (4) a clarification for the statement no new GNF fuel designs are being introduced in Limerick [Unit] 2 Cycle 12 in Section 2.5 of the LAR, Attachment 4.
1 to the LAR dated December 15, 2010 is a proprietary document titled, GNF Additional Information Regarding the Requested Changes to the Technical Specification SLMCPR, Limerick 2 Cycle 12. A non-proprietary version of this document can be found as Attachment 5 to the LAR dated December 15, 2010, same title (ADAMS Accession No.ML103500180).
DRAFT
- 4. Please provide an approximation of the correlation for MCPR Importance Parameter (MIP) and R-Factor Importance Parameter (RIP), including applicable fuel related coefficients and constants, leading to the results of TLO SLMCPR Estimate using the MIPRIP Correlation, shown in Table 3.
- 5. In Section 2.1 Major Contributors to SLMCPR Changes, it states that Table 3 presents estimated impacts on the TLO SLMCPR due to methodology deviations, penalties, and/or uncertainty deviations from approved values. Please provide: (1) calculation details and justification that the results listed in Table 3 are conservative related to methodology deviations, penalties, and/or uncertainty deviations from approved values, and (2) justification that all affected factors, including any fuel related issues under Title 10 of the Code of Federal Regulations (10 CFR) Part 21, are included in Table 3.
- 6. Please identify how many of the 10x10 (GE14, GNF2) data points shown in new Figure 5 reflect GNF2 data, because new Figure 5 only shows combined data points for GE14 and GNF2.
- 7. Is the LGS, Unit 2, Cycle 12 operation with GNF2 fuel impacted by the bent spacer wing operating experience (see10 CFR Part 21 report number 2010-19-00, ADAMS Accession No. ML101370065)? If so, please identify the impacts of such operation on fuel thermal performance and evaluation.
- 8. Please provide an updated version of the power/flow map for Cycle 12 operation including stability Option I-D or Option III (if this Option is used) features of the scram region and controlled entry region.