ML12068A437
| ML12068A437 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 03/08/2012 |
| From: | Joel Wiebe Division of Operating Reactor Licensing |
| To: | Bauer J, Gullott D, Mathews M Exelon Generation Co |
| References | |
| Download: ML12068A437 (7) | |
Text
NRR-PMDAPEm Resource From: Wiebe, Joel Sent: Thursday, March 08, 2012 9:53 AM To: Joseph Bauer; Mitchel Mathews Cc: David Gullott
Subject:
Redacted Draft Quad Cities Units 1 and 2 SLMCPR Safety Evaluation for Proprietary Information Review Attachments: image001.jpg; Redacted Draft Quad Cities Units 1 and 2 SLMCPR Safety Evaluation.docx
- Joe, Attached is the redacted draft Quad Cities Unit 1 and 2 SLMCPR Safety Evaluation. In accordance with NRR Office Instruction LIC-204, Revision 3, Handling Requests to Withhold Proprietary Information from Public Disclosure (ADAMS Accession No. ML062200530), this is provided for review for proprietary information, only. To meet our schedule for issuance of the related amendment, submit the results of your review for proprietary information to me by c.o.b March 8, 2012.
Joel 1
Hearing Identifier: NRR_PMDA Email Number: 296 Mail Envelope Properties (Joel.Wiebe@nrc.gov20120308095300)
Subject:
Redacted Draft Quad Cities Units 1 and 2 SLMCPR Safety Evaluation for Proprietary Information Review Sent Date: 3/8/2012 9:53:22 AM Received Date: 3/8/2012 9:53:00 AM From: Wiebe, Joel Created By: Joel.Wiebe@nrc.gov Recipients:
"David Gullott" <David.Gullott@ExelonCorp.com>
Tracking Status: None "Joseph Bauer" <Joseph.Bauer@exeloncorp.com>
Tracking Status: None "Mitchel Mathews" <Mitchel.Mathews@exeloncorp.com>
Tracking Status: None Post Office:
Files Size Date & Time MESSAGE 523 3/8/2012 9:53:00 AM image001.jpg 11907 Redacted Draft Quad Cities Units 1 and 2 SLMCPR Safety Evaluation.docx 39279 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:
Recipients Received:
Page 1 of 1 file://c:\EMailCapture\NRR_PMDA\296\attch1.jpg 3/8/2012
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 250 TO RENEWED FACILITY OPERATING LICENSE NO. DPR-29 AND AMENDMENT NO. 245 TO RENEWED FACILITY OPERATING LICENSE NO. DPR-30 EXELON GENERATION COMPANY, LLC AND MIDAMERICAN ENERGY COMPANY QUAD CITIES NUCLEAR POWER STATION, UNITS 1 AND 2 DOCKET NOS. 50-254 AND 50-265
1.0 INTRODUCTION
By letters to the U.S. Nuclear Regulatory Commission (NRC, the Commission) dated June 7, 2011 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML111590206 ), and November 22, 2011 (ADAMS Accession No. ML113260347), as supplemented by letters dated September 21, November 22, 2011, and January 9, 2012 (ADAMS Accession Nos. ML112650398 and ML113070430, and ML120090250, respectively),
Exelon Generation Company, LLC, (the licensee) requested changes to the technical specifications (TS), for the Quad Cities Nuclear Power Station (QCNPS), Units 1 and 2. The proposed changes would revise the value of the single (Units 1 and 2) and two (Unit 2) recirculation loop operation safety limit minimum critical power ratio (SLMCPR) in TS Section 2.1.1, Reactor Core SLs.
The September 21, 2011, November 22, 2011, and January 9, 2012, supplements, contained clarifying information and did not change the NRC staff=s initial proposed finding of no significant hazards consideration.
2.0 REGULATORY EVALUATION
The purpose of the SLMCPR is to ensure that specified acceptable fuel design limits (SAFDLs) are not exceeded during steady state operation and analyzed transients. The fuel cladding is one of the physical barriers that separate the radioactive materials from the environment. The integrity of this cladding barrier is related to its relative freedom from perforations or cracking.
Fuel cladding perforations can result from thermal stresses which can occur from reactor operation significantly above design conditions. Since the parameters that result in fuel damage Enclosure 3
are not directly observable during reactor operation, the thermal and hydraulic conditions that result in the onset of transition boiling have been used to mark the beginning of the region in which fuel cladding damage could occur.
The NRC staff finds that the licensee, in Section 4.1 of its submittals, identified the applicable regulatory requirements. The regulatory requirements and guidance for which the NRC staff based its acceptance are identified below.
General Design Criteria (GDC)-10, Reactor Design, of Appendix A, GDC for Nuclear for Nuclear Power Plants, to Title 10 of the Code of Federal Regulations (10 CFR Part 50) states, in part, that the reactor core and associated coolant, control, and protection systems shall be designed with appropriate margin to assure that SAFDLs are not exceeded during any condition of normal operation, including the effects of anticipated operational occurrences.
NUREG-0800, Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants, provides guidance on the acceptability of the reactivity control systems, the reactor core and fuel system design. Specifically, Section 4.2, Fuel System Design, specifies all fuel damage criteria for evaluation of whether fuel designs meet the SAFDLs, and Section 4.4, Thermal Hydraulic Design, provides guidance on the review of thermal-hydraulic design in meeting the requirement of GDC-10 and the fuel design criteria established in Section 4.2.
3.0 TECHNICAL EVALUATION
The NRC staff has reviewed the licensee=s technical and regulatory analyses in support of its proposed license amendment which are described in Sections 3.0 and 4.0 of the licensee=s submittal. The detailed evaluation below will support the conclusion that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission=s regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
The licensee requested to change the QCNPS Technical Specifications (TS) 2.1.1.2 Unit 1 SLMCPR for single recirculation loop operation (SLO) from 1.13 to 1.14 and proposed no change to the current value of 1.11 for two recirculation loop operation (TLO). The licensee proposed to change the QCNPS TS 2.1.1.2 Unit 2 SLMCPR for SLO from 1.13 to 1.14 and for TLO from 1.11 to 1.12. These SLMCPR values are for the reactor steam dome pressure 785 psig and core flow 10 percent of rated core flow.
The licensee describes the methodology to calculate the new SLMCPR values for the TS in its submittals and supplements. The staff determined from the licensees description that the QCNPS Unit 1 and Unit 2 Cycle 22 SLMCPR analyses were performed by Westinghouse Electric Company (Westinghouse) using the plant - and cycle-specific fuel and core parameters, U.S. Nuclear Regulatory Commission (NRC) approved methodologies including CENPD-300-P-A, Reference Safety Report for Boiling Water Reactor Reload Fuel, CENPD-300-P, 10x10 SEVA Fuel Critical Power Experiments and CPR Correlation: SEVA-96+, and associated codes related to application of CENPD-300-P-A to this minimum critical power ratio calculation including the McSLAP code.
The staff determined from the licensees submittals that the McSLAP computer code system is the code system that implements the Monte Carlo process in CENPD-300-P-A to determine the SLMCPR[
]in order to determine that the safety limit was not to exceed 0.1 percent of all fuel rods in the reactor core subject to the onset of transition boiling or dryout.
[
]
McSLAP processes the inputs from[
]. The relationship of these codes to McSLAP and the roles of these codes in CENPD-300-P-A are described in the January 9, 2012, supplement but not listed in CENPD-300-P-A. The staff has determined that while the McSLAP code is not specifically referenced in CENPD-300-P-A it is an implementation of the staff approved methodology described in CENPD-300-P-A. As part of the staff review of revisions to CENPD-300-P-A, the staff will ensure that this ambiguity is clarified. The staff notes that supplement 1 to CENPD-300-P-A has been submitted to the NRC (ADAMS Accession No. ML102850344) and has been accepted for staff review (ADAMS Accession No. ML103500217).
The licensee also addressed in their submittals: (1) the final core loading pattern selection for the QCNPS, Units 1 and 2, Cycle 22, operation with respect to the combination of the reload control procedure, reload design review criteria, cycle design inputs and requirements (CDIR) including input parameters such as cycle energy requirements, thermal limit margins, reactivity margins, discharge exposure limitations and other limits, desired control rod patterns, and channel distortion; (2) the SLMCPR calculation process with respect to the uncertainties associated with[
](3) the reason to have a higher SLMCPR value for SLO only and the application of a 1 percent penalty due to errors found in the McSLAP code for QCNPS Unit 1; and (4) the backup stability protection scram and controlled entry regions in the power to flow map using approved method CENPD-295-P-A.
The NRC staff reviewed the information presented in the licensee submittals and responses to the NRC staff requests for additional information (RAI) including the NRC staff audit conducted on October 19 and November 10, 2011, on the SLMCPR calculations using the McSLAP code and determined that:
(1) approved methodologies are used; (2) qualitative and quantitative descriptions of the final core loading pattern and critical power analysis are provided; (3) the SLMCPR value increase for QCNPS Unit 1 SLO only is justified due to a 1 percent penalty of McSLAP code error; and (4) the SLMCPR value increase for QCNPS Unit 2 is due to[
]
used in the previous cycle.
Based on the above discussion the staff concluded that the SLMCPR analysis for QCNPS, Units 1 and 2, Cycle 22, operation using the plant- and cycle-specific calculation with the approved method is acceptable. The Cycle 22 SLMCPRs will ensure that 99.9 percent of the fuel rods in the core will not experience boiling transition which satisfies the requirements of GDC-10 of Appendix A to 10 CFR Part 50, regarding acceptable fuel design limits.
4.0 STATE CONSULTATION
In accordance with the Commission=s regulations, the Illinois State official was notified of the proposed issuance of the amendment. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendment changes the requirements with respect to installation or use of a facility=s component located within the restricted area as defined in 10 CFR Part 20 [or changes a surveillance requirement]. The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (76 FR 50762; August 16, 2011 and 77 FR 140; January 3, 2012).
Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.
6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission=s regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: Tai Huang Date of issuance: