ML19186A449
| ML19186A449 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde, 07201031  |
| Issue date: | 07/05/2019 |
| From: | Lacal M Arizona Public Service Co |
| To: | Document Control Desk, Division of Spent Fuel Management |
| References | |
| 102-07946-MLL/MDD | |
| Download: ML19186A449 (10) | |
Text
10 CFR 72.7 MARIA L. LACAL Senior Vice President, Nuclear Regulatory & Oversight Palo Verde Nuclear Generating Station 102-07946-MLL/MDD P.O. Box 52034 July 05, 2019 Phoenix, AZ 85072 Mail Station 7605 Tel 623.393.6491 ATTN: Document Control Desk Director, Division of Spent Fuel Management Office of Nuclear Material Safety and Safeguards U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
Dear Sirs:
Subject:
Palo Verde Nuclear Generating Station Units 1, 2, and 3 and Independent Spent Fuel Storage Installation Docket Nos. STN 50-528/529/530 and 72-44 Renewed Operating License Nos. NPF-41, NPF-51, NPF-74 Request for Exemption from NAC-MAGNASTOR Certificate of Compliance 72-1031 In accordance with the provisions of 10 CFR 72.7, Specific Exemptions, Arizona Public Service Company (APS) requests an exemption from the provisions of 10 CFR 72.212(a)(2),
72.212(b)(3), 72.212(b)(5)(i), 72.212(b)(11), and 10 CFR 72.214 for the Palo Verde Nuclear Generating Station (PVNGS) Independent Spent Fuel Storage Installation. Specifically, an exemption is requested for the fuel pellet outside diameter (OD) requirement in the NAC-MAGNASTOR Certificate of Compliance (CoC).
The requested exemption would allow APS to deviate from the NAC-MAGNASTOR CoC Appendix B, Table B2-3, Bounding PWR Fuel Assembly Loading Criteria, assembly type CE16H1 fuel (CE 16x16, nominal, cold, and unirradiated), pellet OD requirement of 0.325 inches by implementing, instead, the requirement of 0.3255 inches. The requested exemption would apply to NAC-MAGNASTOR dry casks that will be used by APS at PVNGS under the CoC Amendment 7 listed in 10 CFR 72.214 (72-1031). Prior to this first campaign using the NAC-MAGNASTOR dry cask storage system, APS used the NAC-UMS Universal Storage system, Certificate number 72-1015. A change to the pellet OD requirement in the NAC-UMS system was previously requested and approved for the pellet OD requirement of 0.3255 inches.
This exemption is needed because the current pellet OD requirement of 0.325 inches for assembly type CE16H1 fuel in the MAGNASTOR CoC Appendix B does not bound the pellet diameter of 0.3255 inches applicable to fuel assemblies in the Unit 3 spent fuel pool that are planned to be loaded into a NAC-MAGNASTOR dry cask. APS needs to load at least two NAC-MAGNASTOR dry casks in order to ensure full core offload capability is reserved for operation subsequent to the Unit 3 refueling outage this fall. Additional information for this exemption request is provided in the enclosure to this letter.
APS has notified NAC International, Inc., the certificate holder for the MAGNASTOR system, of this exemption request. NAC International, Inc. is in the process of preparing a supplement to an existing amendment request, which will incorporate this pellet OD requirement change.
A member of the STARS Alliance LLC Callaway
- Diablo Canyon
- Palo Verde
- Wolf Creek
102-07946-MLL/MDD ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Request for Exemption from NAC-MAGNASTOR CoC 72-1031 Page 2 Based upon the anticipated review schedule, the 10 CFR 72.214 rulemaking required to implement the proposed NAC-MAGNASTOR CoC amendment with this pellet OD requirement change would not be completed in time for APS to load spent fuel in Unit 3 in August 2019.
APS requests approval of this exemption request by August 12, 2019 in order to have it approved in time for the scheduled NRC MAGNASTOR inspection that starts August 12, 2019. However, as discussed with the NRC staff in a teleconference on Wednesday, July 3, 2019, approval of this exemption request prior to August 19, 2019, would allow sufficient time for APS to complete the documentation and not impact the scheduled start of MAGNASTOR dry cask loading on August 26, 2019.
No new commitments are being made in this submittal. If you have any questions about this request, please contact Michael D. DiLorenzo, Department Leader, Nuclear Regulatory Affairs, at (623) 393-3495.
Sincerely, Weber, Thomas Digitally signed by Weber, Thomas N(Z00499)
DN: cn=Weber, Thomas N(Z00499)
N(Z00499) Reason: Thomas N. Weber for Maria L. Lacal Date: 2019.07.05 16:43:13 -07'00' MLL/MDD
Enclosure:
Request for Exemption from NAC-MAGNASTOR CoC 72-1031 cc: S. A. Morris NRC Region IV Regional Administrator S. P. Lingam NRC NRR Project Manager for PVNGS M. M. OBanion NRC NRR Project Manager B. H. White NRC NMSS Project Manager C. A. Peabody NRC Senior Resident Inspector for PVNGS B. Goretzki Arizona Department of Health Services - Bureau of Radiation Control A member of the STARS Alliance LLC Callaway
- Diablo Canyon
- Palo Verde
- Wolf Creek
Enclosure Request for Exemption from NAC-MAGNASTOR Certificate of Compliance 72-1031
Request for Exemption from NAC-MAGNASTOR Certificate of Compliance 72-1031 1.0 Description 2.0 Proposed Exemption 3.0 Background 4.0 Technical Analysis 5.0 Regulatory Safety Analysis 6.0 Environmental Considerations 7.0 Conclusion 8.0 References
Enclosure Request for Exemption from NAC-MAGNASTOR Certificate of Compliance 72-1031 1.0 Description This letter is a request for exemption from certain provisions of 10 CFR 72.212, Conditions Of General License Issued Under 10 CFR 72.210, and 10 CFR 72.214, List Of Approved Spent Fuel Storage Casks, for the Palo Verde Nuclear Generating Station (PVNGS) Independent Spent Fuel Storage Installation (ISFSI).
The requested exemption would allow Arizona Public Service Company (APS) to deviate from the NAC-MAGNASTOR Certificate of Compliance (CoC) Appendix B, Table B2-3, Bounding PWR Fuel Assembly Loading Criteria, assembly type CE16H1 fuel (CE 16x16, nominal, cold, and unirradiated), pellet outside diameter (OD) requirement of 0.325 inches by implementing, instead, the requirement of 0.3255 inches. The requested exemption would apply to NAC-MAGNASTOR dry casks that will be used by APS at PVNGS under the CoC Amendment 7 listed in 10 CFR 72.214 (72-1031). Prior to this first campaign using the NAC-MAGNASTOR dry cask storage system, APS used the NAC-UMS Universal Storage system, Certificate number 72-1015. A change to the pellet OD requirement in the NAC-UMS system was previously requested and approved for the pellet OD requirement of 0.3255 inches.
This exemption is needed because the current pellet OD requirement of 0.325 inches for assembly type CE16H1 fuel in the MAGNASTOR CoC Appendix B does not bound the pellet diameter of 0.3255 inches applicable to fuel assemblies in the Unit 3 spent fuel pool that are planned to be loaded into a NAC-MAGNASTOR dry cask. APS needs to load at least two NAC-MAGNASTOR dry casks in order to ensure full core offload capability is reserved for operation subsequent to the Unit 3 refueling outage this fall.
APS has notified NAC International, Inc., the certificate holder for the MAGNASTOR system, of this exemption request. NAC International, Inc. is in the process of preparing a supplement to an existing amendment request, which will incorporate this pellet OD requirement change.
Based upon the anticipated review schedule, the 10 CFR 72.214 rulemaking required to implement the proposed NAC-MAGNASTOR CoC amendment with this pellet OD requirement change would not be completed in time for APS to load spent fuel in Unit 3 beginning in August 2019.
2.0 Proposed Exemption In accordance with the provisions of 10 CFR 72.7, Specific Exemptions, APS requests an exemption from the provisions of 10 CFR 72.212(a)(2), 72.212(b)(3), 72.212(b)(5)(i),
72.212(b)(11), and 10 CFR 72.214 for the PVNGS ISFSI. Specifically, an exemption is requested for the fuel pellet OD requirement in the NAC-MAGNASTOR CoC. The requested exemption would allow APS to deviate from the NAC-MAGNASTOR CoC Appendix B, Table B2-3, Bounding PWR Fuel Assembly Loading Criteria, assembly type CE16H1 fuel (CE 16x16, nominal, cold, and unirradiated), pellet OD requirement of 0.325 inches by implementing, instead, the requirement of 0.3255 inches.
The requested exemption would apply to all NAC-MAGNASTOR dry casks that will be used by APS at PVNGS under the CoC amendments listed in 10 CFR 72.214 prior to an amendment that revises the pellet OD requirement in the CoC.
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Enclosure Request for Exemption from NAC-MAGNASTOR Certificate of Compliance 72-1031 3.0 Background APS is the operator of PVNGS Units 1, 2, and 3, and currently stores spent fuel in dry cask storage at an ISFSI under the general license provisions of 10 CFR 72. The dry cask spent fuel storage system currently used by APS is the NAC-UMS Universal Storage System, certificate number 72-1015, as listed in 10 CFR 72.214. APS plans to start loading the NAC-MAGNASTOR System, certificate number 72-1031, also listed in 72.214.
The ISFSI general license provisions in 10 CFR Part 72 require each general licensee to comply with the conditions of the CoC for each dry cask used to store spent fuel under the general license. (See section 5.0 Regulatory Safety Analysis, for a discussion of the specific regulatory requirements). The NAC-MAGNASTOR CoC is conditioned upon fulfilling the requirements of its Appendix A, Technical Specifications, and Appendix B, Approved Contents.
This requested exemption would allow APS to deviate from Table B2-3, Bounding PWR Fuel Assembly Loading Criteria, pellet OD requirement for assembly type CE16H1 fuel.
Currently the fuel characteristics in Table B2-3 for assembly type CE16H1 fuel have a maximum nominal pellet OD for cold and unirradiated pellets of 0.325 inches. APS would only be able to load fuel assemblies with pellets of 0.325 inches nominal OD or less in the NAC-MAGNASTOR system. The majority of the spent fuel at PVNGS contains pellets with a nominal OD of 0.3255 inches. There is not a sufficient number of fuel assemblies in the PVNGS Unit 3 spent fuel pool qualified to fully load a NAC-MAGNASTOR system.
APS plans to load three NAC-MAGNASTOR canisters beginning August 26, 2019, out of the Unit 3 spent fuel pool. The Unit 3 refueling outage is scheduled to begin on October 5, 2019.
In order to ensure full core offload capability is reserved for operation subsequent to the Unit 3 refueling outage this fall, at least two NAC-MAGNASTOR canisters must be loaded out of the Unit 3 spent fuel pool before the outage. Therefore, APS requests approval of this exemption to support the scheduled loading campaign and scheduled NRC MAGNASTOR inspection while maintaining full core offload capability in Unit 3.
The NAC-UMS Universal Storage System CoC that is currently in use at PVNGS originally required a Max Pellet OD for assembly type CE16H1 fuel of 0.325 inches. The 72-1015 CoC for the NAC-UMS system was amended to allow a Max Pellet OD for assembly type CE16H1 fuel of 0.3255 inches prior to implementing the NAC-UMS storage system at PVNGS. NAC-UMS CoC Amendment 2 is the amendment that implemented the 0.3255 inches requirement.
PVNGS currently stores the NAC-UMS system under Amendment 5.
4.0 Technical Analysis APS is requesting authorization to use a maximum nominal pellet OD of 0.3255 inches for cold, unirradiated assembly type CE16H1 fuel instead of 0.325 inches as required by the NAC-MAGNASTOR CoC, Appendix B, Table B2-3. The NAC-MAGNASTOR Final Safety Analysis Report (FSAR) Table 6.1.1-1 shows the baseline pellet diameter used for analysis of the assembly type CE16H1 fuel is 0.325 inches. As documented in Section 6.7.2 of the FSAR, an increase to 0.3255 inches does not impact the safety conclusion of the system (i.e., k eff 0.95).
NAC International, Inc. analyzed the pellet OD of 0.3255 inches for assembly type CE16H1 fuel in the course of conducting their criticality safety analysis as documented in NAC calculation 71160-6001. Specifically, FSAR Section 6.7.2, Table 6.7.2-3, presents the analytical results of the reactivity impact for a change in pellet diameter from 0.3255 inches (case 2) to 0.3245 inches (case 4) which brackets the evaluated nominal dimension of 0.325 2
Enclosure Request for Exemption from NAC-MAGNASTOR Certificate of Compliance 72-1031 inches. As documented, the change in reactivity between the evaluated values is not statistically significant to demonstrating the criticality safety of the system.
The evaluations shown in Table 6.7.2-3 consider changes in uranium loading (MTU) and moderation associated with the pellet diameter modification. These evaluations are performed with unborated water in the pellet to clad gap. The change in this exemption request does not include a change to the MTU, so the increased diameter pellet would have a fixed MTU. This would be modeled as an increase in pellet diameter along with a revised density that leaves the MTU unchanged. The neutronic impact of a larger pellet diameter at a fixed MTU is limited to reducing the amount of moderator in the under moderated lattice - the amount of unborated water in the gap is decreased. Reducing the amount of moderator in an under moderated system while keeping the MTU constant would result in a reduced k eff. A reduced keff is further from criticality and thus a safer configuration.
In conclusion, assembly type CE16H1 fuel has been analyzed for use in the NAC-MAGNASTOR system with a pellet OD of 0.3255 inches. As documented in Section 6.7.2 of the FSAR, there is not a statistically significant difference in reactivity between a pellet OD of 0.3255 inches and a pellet OD of 0.3245 inches (which bounds the current value of 0.325 inches listed in the MAGNASTOR CoC Appendix B). Additionally, if the pellet OD was increased to 0.3255 inches while keeping the MTU constant, the result would be a reduced keff due to reducing the amount of moderator in an under moderated system.
5.0 Regulatory Safety Analysis 5.1 Applicable Regulatory Requirements/Criteria 10 CFR 72.7, states the following:
The Commission may, upon application by any interested person or upon its own initiative, grant such exemptions from the requirements of the regulations in this part as it determines are authorized by law and will not endanger life or property or the common defense and security and are otherwise in the public interest.
The proposed exemption is authorized by law since regulation 10 CFR 72.7 authorizes the NRC to grant exemptions from the requirements of the Part 72 regulations.
The proposed exemption will not endanger life or property or the common defense and security. The proposed exemption would allow APS to store fuel assemblies with a larger pellet OD than currently specified in the CoC. This has been analyzed by the dry cask certificate holder within the design analyses of the NAC-MAGNASTOR system to have a reduced keff which is a safer configuration.
The proposed exemption is in the public interest. The proposed exemption would allow APS to load spent fuel on schedule, maintain full core offload capability and would not affect power plant operations or refueling outages for the three PVNGS units.
10 CFR 72.212(a)(2) states the following:
This general license is limited to storage of spent fuel in casks approved under the provisions of this part.
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Enclosure Request for Exemption from NAC-MAGNASTOR Certificate of Compliance 72-1031 10 CFR 72.212(b)(3) states the following:
The general licensee must: Ensure that each cask used by the general licensee conforms to the terms, conditions, and specifications of a CoC or an amended CoC listed in § 72.214.
10 CFR 72.212(b)(5)(i) states the following:
The general licensee must: Perform written evaluations, before use and before applying the changes authorized by an amended CoC to a cask loaded under the initial CoC or an earlier amended CoC, which establish that: The cask, once loaded with spent fuel or once the changes authorized by an amended CoC have been applied, will conform to the terms, conditions, and specifications of a CoC or an amended CoC listed in § 72.214 10 CFR 72.212(b)(11) states the following:
The general licensee must: Maintain a copy of the CoC and, for those casks to which the licensee has applied the changes of an amended CoC, the amended CoC, and the documents referenced in such Certificates, for each cask model used for storage of spent fuel, until use of the cask model is discontinued. The licensee shall comply with the terms, conditions, and specifications of the CoC and, for those casks to which the licensee has applied the changes of an amended CoC, the terms, conditions, and specifications of the amended CoC, including but not limited to, the requirements of any AMP put into effect as a condition of the NRC approval of a CoC renewal application in accordance with § 72.240.
10 CFR 72.214 States the following:
"The following casks are approved for storage of spent fuel under the conditions specified in their Certificates of Compliance.
Certificate Number: 1031.
Initial Certificate Effective Date: February 4, 2009, superseded by Initial Certificate, Revision 1, on February 1, 2016.
Initial Certificate, Revision 1, Effective Date: February 1, 2016.
Amendment Number 1 Effective Date: August 30, 2010, superseded by Amendment Number 1, Revision 1, on February 1, 2016.
Amendment Number 1, Revision 1, Effective Date: February 1, 2016.
Amendment Number 2 Effective Date: January 30, 2012, superseded by Amendment Number 2, Revision 1, on February 1, 2016.
Amendment Number 2, Revision 1, Effective Date: February 1, 2016.
Amendment Number 3 Effective Date: July 25, 2013, superseded by Amendment Number 3, Revision 1, on February 1, 2016.
Amendment Number 3, Revision 1, Effective Date: February 1, 2016.
Amendment Number 4 Effective Date: April 14, 2015.
Amendment Number 5 Effective Date: June 29, 2015.
Amendment Number 6 Effective Date: December 21, 2016.
Amendment Number 7 Effective Date: August 21, 2017, as corrected (ADAMS Accession No. ML19045A346).
SAR Submitted by: NAC International, Inc.
Title:
Final Safety Analysis Report for the MAGNASTOR System.
Docket Number: 72-1031.
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Enclosure Request for Exemption from NAC-MAGNASTOR Certificate of Compliance 72-1031 Certificate Expiration Date: February 4, 2029.
Model Number: MAGNASTOR.
Each of these 72.212 and 72.214 regulations require an ISFSI general licensee to comply with the conditions in the dry cask CoC. The NAC-MAGNASTOR CoC is conditioned upon fulfilling the requirements of Appendix A, Technical Specifications, and Appendix B, Approved Contents for the MAGNASTOR System. The requested exemption would allow APS to deviate from the NAC-MAGNASTOR CoC Appendix B, Table B2-3, Bounding PWR Fuel Assembly Loading Criteria, assembly type CE16H1 fuel (CE 16x16, nominal, cold, and unirradiated), pellet OD requirement of 0.325 inches by implementing, instead, the requirement of 0.3255 inches.
6.0 Environmental Considerations It has been determined by the NRC that spent fuel can be stored safely and without significant environmental impact at an onsite ISFSI in the NAC-MAGNASTOR system as evidenced by the issuance of a CoC listed in 10 CFR 72.214. Allowing the use of a maximum nominal pellet OD for cold, unirradiated assembly type CE16H1 fuel of 0.3255 inches instead of 0.325 inches will not increase the probability of an accident and will not increase the consequences of an accident beyond those already presented in the NAC-MAGNASTOR FSAR.
The NAC-MAGNASTOR FSAR already includes the results of the evaluation for the larger pellet OD. This exemption is needed to allow usage of the MAGNASTOR system by APS while the CoC is being corrected.
The proposed exemption does not increase the probability or consequences of accidents; no changes would be made to the types of effluents released offsite, and there would be no increase in occupational or public radiation exposure. Therefore, there are no significant radiological environmental impacts associated with the proposed action. Additionally, the proposed action would not involve any construction or other ground disturbing activities, would not change the footprint of the existing ISFSI, and would have no other significant non-radiological environmental impacts.
The proposed exemption would meet the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(25), because the proposed exemption involves: (i) no significant hazards consideration; (ii) no significant change in the types or significant increase in the amounts of any effluents that may be released offsite; (iii) no significant increase in individual of cumulative public or occupational radiation exposure; (iv) no significant construction impact; (v) no significant increase in the potential for or consequences from radiological accidents; and (vi) the requirements from which the exemption is sought involve (B) reporting requirements, or (C) inspection or surveillance requirements, or (E) training requirements, or (I) other requirements of an administrative, managerial, or organizational nature. Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with this proposed exemption.
Alternative to the Proposed Action:
Since there is no significant environmental impact associated with the proposed action, alternatives with equal or greater environmental impact are not evaluated. The alternative to the proposed action would be to deny approval of the exemption and require compliance with the maximum nominal pellet OD for cold, unirradiated assembly type CE16H1 fuel in the current CoC. Denial of the maximum nominal pellet OD for cold, unirradiated assembly type CE16H1 fuel exemption would unnecessarily delay the loading of spent fuel in dry casks at PVNGS and result in loss of Unit 3 full core offload capability until the rulemaking process is completed for a certificate amendment request.
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Enclosure Request for Exemption from NAC-MAGNASTOR Certificate of Compliance 72-1031 7.0 Conclusion APS has reviewed the requirements in 10 CFR 72 and determined that an exemption to certain requirements in 72.212 and 72.214 are necessary to allow spent fuel from PVNGS to be loaded into the NAC-MAGNASTOR dry casks. The exemption provided herein meets the requirements of 10 CFR 72.7 and also meets the requirements for categorical exclusion set forth in 10 CFR 51.22(c)(25).
8.0 References
- 1. Certificate of Compliance for the NAC-MAGNASTOR System, Docket No. 72-1031, Amendment No. 7, dated August 21, 2017.
- 2. NAC-MAGNASTOR System Final Safety Analysis Report, Revision 10, Docket No. 72-1031, dated February 2019.
- 3. Calculation 71160-6001 NewGen Transfer and Storage Criticality Analysis Rev. 0, dated July 30, 2004.
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