CP-201201212, Spent Fuel Pool Criticality Analysis
| ML12292A193 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 10/09/2012 |
| From: | Madden F Luminant Power, Luminant Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| CP-201201212, GL-91-018, TXX-12148 | |
| Download: ML12292A193 (3) | |
Text
Rafael Flores Luminant Power Senior Vice President P 0 Box 1002
& Chief Nuclear Officer 6322 North FM 56 rafael.flores@Luminant.com Glen Rose, TX 76043 Luminant T 254 897 5550 C 817 559 0403 F 254 897 6652 REF: 10CFR50.68 CP-201201212 TXX-12148 October 9, 2012 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
SUBJECT:
COMANCHE PEAK NUCLEAR POWER PLANT (CPNPP)
DOCKET NOS. 50-445 AND 50-446 SPENT FUEL POOL CRITICALITY ANALYSIS
REFERENCES:
- 1. NRC Regulatory Issue Summary 2005-20, Rev. 1, Revision to Guidance Formerly Contained in NRC Generic Letter 91-18, "INFORMATION TO LICENSEES REGARDING TWO NRC INSPECTION MANUAL SECTIONS ON RESOLUTION OF DEGRADED AND NONCONFORMING CONDITIONS AND ON OPERABILITY" April 16, 2008
- 2. Meeting between Luminant Power and the NRC regarding revised analysis to support a License Amendment Request for Spent Fuel Pool Criticality, dated September 13, 2012 (ML12216A299)
Dear Sir or Madam:
Luminant Generation Company, LLC (Luminant Power) is currently developing a request for a License Amendment (LAR) for submittal to the NRC to revise Technical Specification (TS) 3.7.17, "Spent Fuel Assembly Storage." TS 3.7.17 describes storage configurations allowed in Region II high density storage racks based on burnup verses enrichment curves generated from a spent fuel pool (SFP) criticality analysis. The current Analysis of Record (AOR) supporting TS 3.7.17 is not bounding for fuel discharged from the current licensed power level. Luminant Power has entered this condition into the Comanche Peak Nuclear Power Plant (CPNPP) corrective action program and imposed administrative controls.
These administrative controls will remain in place until the LAR currently being prepared is approved for use by the NRC and implemented. Furthermore, Luminant Power is submitting this letter to inform the NRC that procedural administrative controls have been implemented for the Region II high density storage racks based on an operability determination (described below) as required by Reference 1 to assure the safety margins required by 10CFR50.68 are maintained.
A member of the STARS Alliance Callaway
- Comanche Peak
- Diablo Canyon
- Palo Verde - San Onofre - South Texas Project
- Wolf Creek PC bc l
U. S. Nuclear Regulatory Commission TXX-12148 Page 2 October 9, 2012 In order to establish the administrative controls, Luminant Power used the methodology utilized in the current spent fuel pool criticality AOR to quantify the impact of post-uprate power operation on the storage requirements for discharged fuel. This analysis was used as the basis to establish "burnup penalties" which were implemented into CPNPP procedures. For fuel operated in post-uprate conditions, a penalty is applied to each fuel assembly's actual burnup value prior to evaluating which configurations are allowable for storage per TS 3.7.17. The burnup penalties establish more conservative limits to maintain the margin of safety in the original AOR. This administrative control ensures the margin of safety established in the AOR supporting the current TS,3.7.17 was not reduced for the Region II high density storage racks.
In addition to quantifying the impact of the power uprate'on fuel reactivity, Luminant Power evaluated bounding conditions for "as stored" fuel in the Region II high density spent fuel storage racks. This evaluation conservatively demonstrated the amount of uncredited excess margin based on the actual assembly loading in the SFP.
Luminant Power established two additional administrative controls which will be in place until a new criticality analysis is reviewed and approved by the NRC. First, CPNPP committed to maintain the Spent Fuel Pool boron concentration above 2400 ppm to provide additional margin (note that the Technical Specification 3.7.16 limit is 2000 ppm). Second, since the Operability Determination evaluating the margin of safety credited excess margin in the then-current SFP configuration, CPNPP committed to maintaining this same margin. Maintaining the safety margin in the Operability Determination has been implemented into the fuel movement planning procedures, and evaluated as part of the fuel planning process. This commitment effectively prevents CPNPP from eroding the safety margin in the Region I1 storage cells, even if fuel movement would be allowed by Technical Specifications (including the burnup penalty applied to fuel discharged from uprate power conditions).
In summary, the administrative controls currently in place at CPNPP ensure that the levels of margin required by 10CFR50.68 are maintained in the SFP, and include considerations for both fuel discharged from uprate operation and known NRC questions with industry practices regarding spent fuel pool analysis. Luminant Power will request a License Amendment to revise TS 3.7.17. These controls will be in place until a revised criticality analysis is implemented in the CPNPP Technical Specifications.
Luminant Power's efforts to submit a LAR to revise TS 3.7.17 are currently ongoing and a schedule for the planned submittal was provided to the NRC at the SFP analysis Pre-Submittal meeting (Reference 2).
U. S. Nuclear Regulatory Commission TXX-12148 Page 3 October 9, 2012 This communication contains the following new licensing basis commitments regarding CPNPP Units 1 and 2.
Commitment No. Commitment Description 4486409 A burnup penalty using the analysis of record will be applied to the fuel assembly's actual burnup value prior to evaluation of allowed storage configuration per TS 3.7.17 for each fuel assembly which was irradiated at the current licensed power level.
4416027 Luminant Power will ensure that the current level of excess margin is maintained in the SFP. The excess margin will be determined prior to fuel movement within the Region II high density storage racks, using the same method used in the Operability Determination of Condition Report CR-2012-005311. Fuel movement will not be permitted if the determination demonstrates that planned fuel movement results in a reduction in excess margin as provided in the Operability Determination.
4408996 Luminant Power will maintain Spent Fuel Pool boron concentration at or above 2400 ppm, above that required for operability as allowed in Technical Specification 3.7.16 (2000 ppm).
4486411 Luminant will request a License Amendment to revise TS 3.7.17, "Spent Fuel Assembly Storage." The schedule for submittal of this license amendment is March 31, 2013.
The administrative controls described in the above commitments are incorporated into CPNPP procedures and will be in effect until the Analysis of Record for Spent Fuel Criticality is revised, and a revision to TS 3.7.17 is approved by the NRC and implemented at CPNPP.
Should you have any questions, please contact J. D. Seawright at (254) 897-0140.
Sincerely, Luminant Generation Company LLC Rafael Flores By: /* 2K2Qa --
Fred W Madden Director, Oversight & Regulatory Affairs c- E. E. Collins, Region 1V B. K. Singal, NRR Resident Inspectors, Comanche Peak