PLA-8107, Request for Exemption from Certain Requirements of 10 CFR 72.212 and 10 CFR 72.214 Resulting from Fuel Basket Design Control Compliance

Request for Exemption from Certain Requirements of 10 CFR 72.212 and 10 CFR 72.214 Resulting from Fuel Basket Design Control Compliance

ML24079A070
Person / Time
Site:	Susquehanna
Issue date:	03/19/2024
From:	Casulli E Susquehanna
To:	Office of Nuclear Material Safety and Safeguards, Office of Nuclear Reactor Regulation, Document Control Desk
References
PLA-8107
Download: ML24079A070 (1)

Text

Edward Casulli Site Vice President March 19, 2024 Attn: Document Control Desk Susquehanna Nuclear, LLC 769 Salem Boulevard Berwick, PA 18603 Tel. 570.542.3795 Fax 570.542.1504 Edward.Casulli@talenenergy.com Director, Division of Fuel Management Office of Nuclear Material Safety and Safeguards U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 SUSQUEHANNA STEAM ELECTRIC STATION REQUEST FOR EXEMPTION FROM CERTAIN REQUIREMENTS OF 10 CFR 72.212 AND 10 CFR 72.214 RESULTING FROM FUEL BASKET DESIGN CONTROL COMPLIANCE PLA-8107 TALEN~

ENERGY 10 CFR 72.7 Docket Nos.

50-387, 50-388 and 72-28

References:

1) NRC letter to Holtec, "U.S. Nuclear Regulatory Commission Inspection Report 07201014/2022-201, Holtec International," dated September 12, 2023 (ADAMS Accession No. ML23145Al 75).

2) NRC letter to Holtec, "Holtec International Inc. -Notice of Violation; The U.S. Nuclear Regulatory Commission Inspection Report No. 07201014/2022-201," dated January 30, 2024 (ADAMS Accession No. ML24016A190).

Pursuant to 10 CFR 72.7, "Specific Exemption," Susquehanna Nuclear, LLC (Susquehanna), is requesting exemption from ce1iain requirements of 10 CFR 72.212(a)(2), 72.212(b)(3),

72.212(b)(5)(i), 72.212(b)(l 1), and 72.214 for the Susquehanna Steam Electric Station (SSES).

These regulations require, in part, that a licensee store its in-adiated fuel in compliance with the terms and conditions of the spent fuel storage cask's Certificate of Compliance (CoC). This exemption request is specific to the conditions of Holtec International, Inc. (Holtec) CoC Number 1032 (hereafter, CoC No. 72-1032). CoC No. 72-1032 is issued for the Holtec International Storage Module Flood and Wind (HI-STORM FW) Multi-Purpose Canister (MPC)

Storage system which contains the Susquehanna-utilized model MPC-89, including the continuous basket shim (CBS) variant, MPC-89CBS.

As documented in Reference 1, the NRC identified three apparent violations during an inspection of a Holtec manufacturing facility in December 2022. As required by 10 CFR 72.48(c)(2)(viii), "Changes, tests, and experiments," Holtec failed to obtain CoC amendments pursuant to 10 CFR 72.244, "Application for amendment of a certificate of compliance," prior to Document Control Desk PLA-8107 implementing the proposed CBS design changes to MPCs for spent fuel cask designs. This resulted in a departure from the methods of evaluation described in the HI-STORM FW Final Safety Analysis Report used in establishing the design bases. As required by 10 CFR 72.48(d)(l), Holtec failed to maintain records of changes that included written evaluations that provided adequate bases for the determination that changing to the MPC CBS basket variants did not require CoC amendments pursuant to 10 CFR 72.48( c )(2). As required by 10 CFR 72.146(c), "Design control," Holtec failed to subject design changes for the MPC CBS basket variants to design control measures commensurate with those applied to the original design.

As documented in Reference 2, the NRC made a final determination and issued a Notice of Violation for the inspection findings. The NRC determined that three Severity Level IV violations of regulatory requirements occurred, and Holtec did not demonstrate objective evidence of plans to restore compliance within a reasonable period of time.

The condition described above has been entered into the Susquehanna Corrective Action Program.

Susquehanna is requesting an exemption from certain requirements in Holtec CoC No. 72-1032 for the HI-STORM FW system. The enclosure to this letter provides the site-specific exemption request for SSES. If approved, the exemption will allow the loading of new canisters of the CBS style. Susquehanna requests approval of the enclosed exemption request by May 31, 2024, in order to avoid delays to the planned spent fuel loading campaign beginning in August 2024.

Susquehanna is providing a copy of this application, with enclosure, to the designated Commonwealth of Pennsylvania state official.

Both the Plant Operations Review Committee and the Nuclear Safety Review Board have reviewed the exemption request.

There are no new or revised regulatory commitments contained in this submittal.

Should you have any questions regarding this submittal, please contact Ms. Melisa Krick, Manager-Nuclear Regulatory Affairs, at (570) 542-1818.

E. Casulli

Enclosure:

Request for Specific Exemption from Certain Requirements of 10 CFR 72.212 and 10 CFR 72.214

Document Control Desk PLA-8107 Copy: NRC Region I Mr. R. Lorson, Region I Administrator Ms. J. England, NRC Senior Resident Inspector Ms. A. Klett, NRC Project Manager Mr. M. Shields, PA DEP/BRP

Enclosure to PLA-8107 Request for Specific Exemption from Certain Requirements of 10 CFR 72.212 and 10 CFR 72.214

1.

DESCRIPTION

2.

BACKGROUND

3.

TECHNICAL JUSTIFICATION

4.

REGULATORY ANALYSIS 4.1 Applicable Regulatory Requirements / Criteria 4.2 Authorized by Law 4.3 Will Not Endanger Life, Property, or Common Defense and Security 4.4 Otherwise in the Public Interest 4.5 Conclusion

5.

ENVIRONMENTAL CONSIDERATION 5.1 No Significant Hazards Consideration Analysis 5.2 Evaluation of Categorical Exclusion 5.3 Environmental Impacts of the Proposed Action 5.4 Adverse Environmental Effects Which Cannot be Avoided Should the Exemption be Approved 5.5 Alternatives to the Proposed Action 5.6 Environmental Effects of the Alternatives to the Proposed Action 5.7 Environmental Conclusion

6.

CONCLUSION

7.

REFERENCES

Enclosure to PLA-8107 Page 1 of 13

1.

Description The Holtec International Storage Module Flood and Wind (HI-STORM FW) dry cask storage system is designed to hold and store spent fuel assemblies for independent spent fuel storage installation (ISFSI) deployment. The system is listed in 10 CFR 72.214 as Certificate of Compliance (CoC) Number 1032 (hereafter, CoC No. 72-1032). This system is used by Susquehanna Nuclear, LLC (Susquehanna), at the Susquehanna Steam Electric Station (SSES) in accordance with 10 CFR 72.210, General license issued.

Pursuant to 10 CFR 72.7, Specific Exemptions, Susquehanna requests an exemption from certain requirements of 10 CFR 72.212(a)(2), 10 CFR 72.212(b)(3), 10 CFR 72.212(b)(5)(i),

10 CFR 72.212(b)(11), and 10 CFR 72.214 for SSES. These regulations require, in part, that a licensee store its irradiated fuel in compliance with the terms and conditions of the spent fuel storage casks CoC. Specifically, Susquehanna is requesting an exemption from certain requirements in Amendment No. 5 of the Holtec International, Inc. (Holtec) CoC No. 72-1032 for the HI-STORM FW System (Reference 1). If approved, the exemption will allow the loading of new canisters of the Continuous Basket Shim (CBS) style, as shown in Table 1 below.

The exemption is needed because although Holtec originally performed a tip-over analysis with favorable results and subsequently implemented the CBS design variants under 10 CFR 72.48, Changes tests, and experiments, the NRC issued Severity Level IV violations (Reference 2) that indicated that these design variants should have resulted in an amendment to the CoC No.

72-1032. Specifically, the tip-over analysis performed for the CBS design included changes to elements of a previously approved method of evaluation (MOE) as well as the use of new or different MOEs thus requiring prior NRC approval via an amendment, which is not expected to be approved prior to Susquehannas 2024 loading campaign.

Susquehanna requests approval of this exemption request by May 31, 2024, to support the loading of the next MPC-89CBS canisters beginning in August 2024.

Table 1: List of Affected Canisters Scheduled for Loading MPC Serial Number HI-STORM Serial Number CoC No. 72-1032 Amendment No.

306 395 5

307 396 5

308 397 5

309 398 5

310 399 5

311 400 5

Enclosure to PLA-8107 Page 2 of 13 The technical justification supporting continued use of the MPC-89CBS is provided in the following sections.

2.

Background

Susquehanna currently utilizes the HI-STORM FW System under CoC No. 72-1032, Amendment No. 5 and Final Safety Analysis Report, Revision 8 (Reference 3) for dry storage of spent nuclear fuel in specific MPCs (i.e., MPC-89 canisters). All design features and contents must fully meet the HI-STORM FW CoC, all operations must occur within the Limiting Conditions for Operations, and the site must demonstrate that they meet all site-specific parameters.

Holtec is the designer and manufacturer of the HI-STORM FW system. Holtec developed a variant of the design for the MPC-89 known as MPC-89CBS. The MPC-89CBS basket, like the previously certified MPC-89, is made of Metamic-HT. The only enhancements implemented through the new variant pertain to the external shims which are between the basket periphery and the MPC shell, and the elimination of the friction-stir-weld seams joining the raw edges of the basket panels.

The CBS variant calls for longer panels of Metamic-HT. The projections of the Metamic panels provide an effective means to attach the shims to the basket using a set of stainless-steel fasteners. These fasteners dont carry any primary loads, except for the dead weight of the shims when the MPC is oriented vertically, which generates minimal stress in the fasteners. The fasteners are made of Alloy X stainless material, which is a pre-approved material for the MPCs in the HI-STORM FW system. This method of attaching the shim to the basket has the added benefit of improving the heat transfer path from the stored fuel to the external surface of the MPC.

Susquehanna currently has six (6) loaded storage casks with the MPC-89CBS canisters as listed in Table 2 below.

Table 2: List of Affected Canisters Currently Loaded MPC Serial Number HI-STORM Serial Number Date Placed in Storage 205 364 10/14/22 200 363 10/21/22 201 361 10/28/22 203 362 11/04/22 202 360 11/10/22 204 359 11/18/22 Holtec originally implemented these design variants under the provisions of 10 CFR 72.48.

However, the NRC has issued Severity Level IV violations that indicated that these variants

Enclosure to PLA-8107 Page 3 of 13 should have been submitted for review and approval, and therefore this exemption request is necessary.

3.

Technical Justification The MPC-89CBS basket assembly features the same fuel storage cavity configuration as the standard MPC-89 configuration. The manner in which the inter-panel connectivity is established and by which the aluminum shims are held in place outside the basket is improved with the CBS variant. This improvement is made such that the loose aluminum shims around the basket periphery used in the original MPC-89 design are replaced with integrated aluminum shims that are mechanically fastened (bolted) to basket panel extensions that protrude into the annular region between the basket and the enclosure vessel. The addition of these bolted shims eliminates the need for the friction stir welds located in the external periphery of the Metamic-HT fuel basket. All other design characteristics of the fuel basket are unchanged by the use of the CBS variant.

Regardless of their design, the primary design functions of the basket shims are to facilitate heat transfer away from the fuel basket and spent fuel assemblies and to provide lateral support of the fuel basket during the non-mechanistic tip-over accident. The primary design functions of the Metamic-HT fuel basket itself, regardless of shim configuration, are to provide structural support of the fuel assemblies and perform the criticality control design function for the system.

The MPC enclosure vessel provides structural support of the fuel basket, as well as assisting in the overall heat transfer process. The MPC enclosure vessel also acts as the confinement boundary for the system.

On January 31, 2024, the NRC issued a Safety Determination of a potential structural failure of the Holtec fuel basket with the CBS design variant during accident conditions for the HI-STORM 100 and HI-STORM FW dry cask storage systems (Reference 4). The results of this safety determination are addressed below for the critical parameters or basic nuclear safety criteria as identified within the 10 CFR 72.48 process.

Thermal The NRC used the structural assessment to confirm there was no loss of confinement integrity.

With respect to the thermal impacts of a postulated non-mechanistic tip-over accident, the NRC considered fuel debris that could potentially cause hot spots near the bottom of the MPC (on its side from a postulated tip-over). The NRC noted that there might be some local increase in temperatures, but no temperatures that would challenge the MPC confinement integrity based on its stainless-steel material. The thermal review concludes, the containment will remain intact and therefore the non-mechanistic tip-over accident condition does not result in significant safety consequences for the HI-STORM FW and HI-STORM 100 storage systems.

Enclosure to PLA-8107 Page 4 of 13 Structural and Confinement The hypothetical tip-over accident is the most significant challenge of the structural performance of the basket. The primary safety function is to prevent a criticality event, and as stated below, the criticality assessment determined no safety concerns under a hypothetical tip-over including basket failure.

The NRC assessment (Reference 4) concluded that the MPC, which is the confinement boundary, maintains its structural integrity during a tip-over event and therefore no water is able to enter the interior of the MPC during accident conditions. The NRC also acknowledged that consistent with the HI-STORM FW FSAR (Reference 3), there is no requirement to demonstrate structural integrity of the cladding. Retrievability requirements continue to be met, since as stated above, the MPC maintains its integrity.

The NRC also considered natural phenomena hazards (NPH) and concluded, the structural failure of the fuel baskets during these NPH accident conditions is unlikely. However, even if a basket failure occurs, the criticality evaluation below demonstrates that the fuel will be maintained subcritical. Therefore, the [NRC] concludes that the NPH accident conditions do not result in significant safety consequences for the HI-STORM FW and HI-STORM 100 storage systems with the CBS fuel basket designs, (Reference 4).

Finally, the structural assessment considered the handling operations for the dry cask storage systems. The system is either handled with single failure proof devices where a drop is considered non-credible or held to a lift height which has been demonstrated acceptable via a drop analysis. The drop analysis shows that there are no significant loads on the basket that would challenge the structural integrity. The NRC concluded that, a similar conclusion to that for the non-mechanistic tip-over can be made for dry cask handling accident conditions. The MPC confinement boundary maintains its structural integrity and no water can enter the interior of the MPC. Should the fuel basket fail to maintain its structural integrity during stack-up the fuel will be maintained in a subcritical condition, (Reference 4).

In regard to the handling operations, as noted in Table 2, Susquehanna previously completed a load campaign where six (6) storage casks with the MPC-89CBS canisters were loaded and stored, demonstrating the adequacy of the established administrative controls for safe handling of the MPC-89CBS variant. The handling procedures utilized by Susquehanna comply with the requirements of Appendix A of CoC No. 72-1032, Amendment 5. These administrative controls include features such as (1) the Holtec-fabricated lift yoke and HI-TRAC VW lift lugs designed in accordance with ANSI N14.6 (Reference 6), which together with the SSES Reactor Building crane, constitute a single failure proof lifting system in accordance with NUREG-0612 (Reference 7); and (2) the vertical cask transporter, designed as single failure proof and integrating redundant drop protection features through the use of hydraulic check valves and wedge locks, used to lift the loaded HI-STORM FW from the HI-PORT and place it on the

Enclosure to PLA-8107 Page 5 of 13 ISFSI, as well as to lift an empty HI-STORM FW from the ISFSI pad and place it on the HI-PORT.

The applicable procedures governing these activities are listed below and available for inspection if required. Note that these procedures were reviewed by the NRC, as documented in NRC Inspection Report No. 07200028/2022001 (Reference 5), during the 2022 loading campaign.

SSES-HPP-3032-0200, MPC Loading at SSES SSES-HPP-3032-0300, MPC Processing (FHD) at SSES SSES-HPP-3032-0400, MPC Stack-up and Transfer at SSES SSES-HPP-3032-0500, HI-STORM Operations and Transport at SSES Shielding and Criticality and Radiation Protection In Reference 4, the NRC assessed the potential for a criticality incident under a complete failure of the basket, which could result in basket material and fuel debris at the bottom of the MPC.

The NRC relied on documented studies related to the enrichment of uranium needed to achieve criticality in an unmoderated, unreflected environment. The allowable contents have enrichment limits well below that in the studies and would also still have the neutron absorbing material present. Therefore, the NRC concluded, there is no criticality safety concern for the CBS basket variants for both the HI-STORM 100 and FW casks under the assumption of fuel basket failure.

The NRC reviewed the shielding impact and concluded, as the damage is localized and the vast majority of the shielding material remains intact, the effect on the dose at the site boundary is negligible. Therefore, the site boundary doses for the loaded HI-STORM FW overpack for accident conditions are equivalent to the normal condition doses, which meet the Title 10 of the Code of Federal Regulations (10 CFR) Section 72.106 radiation dose limits.

Consistent with the NRCs assessment and as required by 10 CFR 72.104 and 10 CFR 72.106, Susquehanna has demonstrated that the combined dose produced by the storage systems on the SSES ISFSI will not result in annual doses at the ISFSI controlled area boundary in excess of the limits specified in 10 CFR 72.104(a) during normal operations and anticipated operational occurrences or in excess of the limits specified in 10 CFR 72.106 during design basis accidents; these conclusions are documented in the Susquehanna 72.212 Evaluation Report (Reference 8).

The Susquehanna 72.212 Evaluation Report and associated analyses were reviewed by the NRC, as documented in NRC Inspection Report No. 07200028/2022001 (Reference 5), during the 2022 loading campaign detailed in Table 2.

Regarding compliance with 10 CFR 72.106, the HI-STORM FW FSAR Section 11.4.3 (Reference 3) demonstrates that there are no accidents which would significantly affect shielding effectiveness of the HI-STORM FW system, including the postulated tip-over event described in FSAR Section 12.2.3.

Enclosure to PLA-8107 Page 6 of 13 Based on the above and the NRCs conclusion that damage is localized and the vast majority of the shielding material remains intact, compliance with 10 CFR 72.104 and 10 CFR 72.106 is not impacted by a non-mechanistic tip-over event resulting in basket failure. As there is no adverse effect on the shielding or confinement functions, there is no effect on occupational or public exposures as a result of this accident condition.

Materials There is no change in the materials used in the CBS variant of the basket compared to the original design of the MPC and basket. Therefore, there is no new material related safety concern.

Safety Conclusion The above analysis demonstrates that structural failure of the CBS basket resulting from a tip-over event does not endanger life or property or the common defense and security. As such, the safety significance of not having an approved tip-over analysis, demonstrating the structural integrity of the CBS design during the postulated tip-over event, is bounded by the analysis assuming structural basket failure.

4.

Regulatory Analysis 4.1 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.

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.

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

Enclosure to PLA-8107 Page 7 of 13 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.

4.2 Authorized by Law This exemption would allow Susquehanna to load additional canisters of the MPC-89CBS variant design. 10 CFR 72.7 gives the NRC the authority to grant exemptions from the requirements of 10 CFR 72 provided they do not endanger life or property, or the common defense and security, and are otherwise in the public interest. This exemption request documents that these criteria are met. Therefore, the exemption is authorized by law.

4.3 Will Not Endanger Life, Property, or Common Defense and Security The NRC has performed a safety assessment (Reference 4) to evaluate the loading and storage of the MPC-89CBS variant without an approved tip-over analysis. This evaluation, detailed in Section 3, assumed basket failure due to the tip-over event, but concluded that the consequences of a basket failure have a very low safety significance provided the confinement boundary is maintained and the fuel is kept in a dry storage condition. As these conditions are demonstrated to be met during a tip-over event, the [NRC] determined that there was no need to take an immediate action with respect to loaded HI-STORM 100 and HI-STORM FW dry cask storage systems with the continuous basket shim (CBS) fuel basket designs. Based on the NRC safety assessment, the proposed exemption does not endanger life or property or the common defense and security.

Enclosure to PLA-8107 Page 8 of 13 4.4 Otherwise in the Public Interest It is in the publics interest to grant an exemption, since dry storage places the fuel in an inherently safe, passive system. This exemption would allow the upcoming loading campaign to proceed on time to move fuel into the dry storage condition and maintain the ability to offload fuel from the reactor, thus allowing continued safe reactor operation. Specifically, if the 2024 loading campaign is canceled or deferred, then in 2025 when the next new fuel batch is received followed by the refueling outage core discharge, Susquehanna will be challenged to support a full core offload until the deferred dry fuel storage campaign is performed, or the storage in the fuel pools is otherwise optimized.

4.5 Conclusion The proposed exemption is authorized by law as 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 as described in this section. The proposed exemption is in the public interest. The proposed exemption would allow Susquehanna to load spent fuel on schedule, support long term full core offload capability, facilitate efforts to reduce the spent fuel pool inventory, and would not affect power plant operations or refueling outages for the SSES Units 1 and 2.

5.

Environmental Consideration 5.1 No Significant Hazards Consideration Analysis Susquehanna has evaluated the proposed exemption to determine whether a significant hazards consideration is involved by focusing on the three standards set forth in 10 CFR 50.92(c) as discussed below. The No Significant Hazards Consideration (NSHC) analysis is being performed in accordance with 10 CFR 50.92, insofar as 10 CFR 72 does not establish separate criteria.

1.

Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No The NRCs assessment conservatively assumes that the fuel basket fails under the non-mechanistic tip-over load case. However, the multi-purpose canister (MPC) confinement boundary is maintained; therefore, no fuel is released from the MPC, and no water is able to enter the interior of the MPC during accident conditions. The proposed exemption has no effect on facility structures, systems, and components (SSCs) and no effect on the capability of any facility SSC to perform its design function.

Enclosure to PLA-8107 Page 9 of 13 Since the MPC will continue to perform the intended safety function even with a postulated basket failure, the proposed exemption does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2.

Does the proposed amendment create the possibility of a new or different kind of accident from any previously evaluated?

Response: No The proposed exemption does not involve a physical alteration of the facility. The proposed exemption will not physically change any SSCs involved in the mitigation of any accidents. Thus, no new initiators or precursors of a new or different kind of accident are created. Furthermore, the proposed exemption does not create the possibility of a new accident as a result of new failure modes associated with any equipment or personnel failures. No changes are being made to setpoints which initiate protective or mitigative actions, and no new failure modes are being introduced.

Therefore, the proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.

3.

Does the proposed amendment involve a significant reduction in a margin of safety?

Response: No The proposed exemption does not impact facility operation or any SSC that is relied upon for accident mitigation. The NRC assessment concluded that the MPC, which is the confinement boundary, maintains its structural integrity during a postulated tip-over event and the consequences of a basket failure is of very low safety significance provided the confinement boundary is maintained and the fuel is kept in a dry storage condition.

Therefore, the proposed change does not involve a significant reduction in a margin of safety.

Based on the above, Susquehanna concludes that the proposed change presents NSHC under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of "no significant hazards consideration" is justified.

Enclosure to PLA-8107 Page 10 of 13 5.2 Evaluation of Categorical Exclusion While the proposed exemption does not meet the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(25), there are no significant environmental impacts associated with the proposed action. The proposed exemption does not:

Increase the probability or consequences of accidents (see NSHC provided in Section 5.1);

Change the types of effluents released offsite; Increase the occupational or public radiation exposure; Involve any construction or other ground disturbing activities; Change the footprint of the existing ISFSI, spent fuel pool, or any other supporting structures; Change the physical aspects of the dry or wet fuel storage features at the facility; Have any impacts on aquatic or terrestrial habitats in the vicinity of SSES; Have any impacts on threatened, endangered, or protected species; or Have the potential to cause effects on historic or cultural properties, assuming such properties are present at SSES.

In addition, as discussed below, the proposed exemption meets the first five criteria of 10 CFR 51.22(c)(25), because it involves: (i) NSHC; (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 or cumulative public or occupational radiation exposure; (iv) no significant construction impact; and (v) no significant increase in the potential for or consequences from radiological accidents.

However, the exemption does not satisfy the requirement of 10 CFR 51.22(c)(25)(vi), because it involves requirements that are not: (A) Recordkeeping requirements; (B) Reporting requirements; (C) Inspection or surveillance requirements; (D) Equipment servicing or maintenance scheduling requirements; (E) Education, training, experience, qualification, requalification or other employment suitability requirements; (F) Safeguard plans, and materials control and accounting inventory scheduling requirements; (G) Scheduling requirements; (H)

Surety, insurance, or indemnity requirements; or (I) Other requirements of an administrative, managerial, or organizational nature.

5.3 Environmental Impacts of the Proposed Action The SSES ISFSI is a radiologically controlled area on site. The area considered for a potential environmental impact as a result of this exemption request is the area in and surrounding the ISFSI.

Enclosure to PLA-8107 Page 11 of 13 The interaction of a loaded HI-STORM FW system with the environment is through the thermal, shielding, and confinement design functions for the cask system. The review herein supports the following conclusions:

The confinement boundary maintains its structural and thermal integrity during accident conditions.

Fuel cladding temperature remains below applicable limits.

Existing radiological evaluations and conclusions in Chapter 5 of the HI-STORM FW FSAR remain valid.

There are no radiological or non-radiological effluents (gaseous, liquid, or solid), radiological exposures (worker or member of the public), or land disturbances associated with the proposed exemption. Therefore, approval of the requested exemption has no impact on the environment.

5.4 Adverse Environmental Effects Which Cannot be Avoided Should the Exemption be Approved Since there are no environmental impacts associated with approval of this exemption, there are no adverse environmental effects which cannot be avoided should the exemption request be approved.

5.5 Alternatives to the Proposed Action In addition to the proposed exemption request, alternative actions have been considered.

Specifically, Susquehanna considered two alternatives: (1) perform the 2024 loading campaign using (currently) compliant canisters or (2) delay performance of the 2024 loading campaign until such time as the MPC-89CBS design is approved or compliant canisters can be obtained.

Due to the lead time needed to support procurement, fabrication and delivery of compliant MPC-89 canisters, the first option is not feasible to support a 2024 loading campaign.

Additionally, as discussed in Section 4.4, canceling or otherwise deferring the scheduled 2024 loading campaign, regardless of which canisters are used, would adversely impact Susquehannas ability to maintain full core offload capability. Thus, the second option subjects Susquehanna to increased risk and challenges to safe plant operation.

5.6 Environmental Effects of the Alternatives to the Proposed Action There are no environmental impacts associated with the alternatives to the proposed action.

Enclosure to PLA-8107 Page 12 of 13 5.7 Environmental Conclusion Based on the environmental assessment, the continued storage and future use of MPC-89CBS at Susquehanna is in the public interest in that it avoids unnecessary operational risks for the SSES Units 1 and 2 that would result from the alternative to the proposed action.

6.

Conclusion As the safety and environmental reviews above demonstrate, the HI-STORM FW system with the MPC-89CBS canister is capable of performing required safety functions and mitigating the effects of design basis accidents, even without an approved tip-over analysis. Therefore, use of an approved non-mechanistic tip-over analysis completed without using NRC accepted methods of evaluation does not present a threat to public and environmental safety.

Susquehanna has reviewed the requirements in 10 CFR 72 and determined that an exemption to certain requirements in 72.212 and 72.214 are necessary. The exemption would allow the loading of new canisters of the CBS style, as shown in Table 1.

Enclosure to PLA-8107 Page 13 of 13

7.

References

1. Certificate of Compliance Number 1032, Amendment Number 5 for HI-STORM Flood/Wind Multipurpose Canister Storage System, dated June 25, 2020 (ADAMS Accession No. ML20163A701).

2. NRC letter to Holtec, Holtec International Inc. - Notice of Violation; The U.S. Nuclear Regulatory Commission Inspection Report No. 07201014/2022-201, dated January 30, 2024 (ADAMS Accession No. ML24016A190).

3. Final Safety Analysis Report on the HI-STORM FW MPC Storage System, Revision 8.

4. NRC Memorandum, Safety Determination of a Potential Structural Failure of the Fuel Basket During Accident Conditions for the HI-STORM 100 and HI-STORM Flood/Wind Dry Cask Storage Systems, dated January 31, 2024 (ADAMS Accession No. ML24018A085).

5. Susquehanna Steam Electric Station - Independent Spent Fuel Storage Installation (ISFSI)

NRC Inspection Report No. 07200028/2022001, dated December 15, 2022 (ADAMS Accession No. ML22307A243).

6. ANSI N14.6-1993, "American National Standard for Radioactive Materials - Special Lifting Devices for Shipping Containers Weighing 10,000 Pounds (4500 Kg) or More, American National Standards Institute, Inc, Washington, DC, June 1993.

7. NUREG-0612, "Control of Heavy Loads at Nuclear Power Plants," United States Nuclear Regulatory Commission, 1980.

8. Susquehanna Steam Electric Station 10 CFR 72.212 Evaluation Report for the HI-STORM MPC Storage System, Revision 0.