ML23089A014
| ML23089A014 | |
| Person / Time | |
|---|---|
| Issue date: | 05/30/2023 |
| From: | Matthew Learn NRC/NMSS/DFM/IOB |
| To: | |
| Shared Package | |
| ML23033A113 | List: |
| References | |
| RG 3.77 Rev 0 DG-3057 | |
| Download: ML23089A014 (3) | |
Text
REGULATORY ANALYSIS DRAFT REGULATORY GUIDE DG-3057 WEATHER-RELATED ADMINISTRATIVE CONTROLS AT INDEPENDENT SPENT FUEL STORAGE INSTALLATIONS (New Regulatory Guide 3.77)
- 1.
Statement of the Problem The U.S. Nuclear Regulatory Commission (NRC) is considering issuing a new regulatory guide (RG) to provide guidance to the industry on an additional option for complying with certain requirements for spent fuel storage licensees in Title 10 of the Code of Federal Regulations (10 CFR) Part 72, Licensing Requirements for the Independent Storage of Spent Nuclear Fuel, High-Level Radioactive Waste, and Reactor-Related Greater than Class C Waste. Specifically, this new guidance would address 10 CFR 72.122(b) and 10 CFR 72.236(l) requirements and would provide an additional method that the NRC staff considers acceptable in certain limited situations for a licensee (specific or general) of an independent spent fuel storage installation (ISFSI) and certificate of compliance (CoC) holders to comply with protection against environmental conditions and natural phenomena.
During its inspections, the NRC found that some ISFSI licensees had not performed the necessary evaluations required by 10 CFR 72.48, Changes, tests, and experiments; 10 CFR 72.122(b); and 10 CFR 72.212(b)(6) to demonstrate that their site-specific parameters with respect to severe weather events, including tornadoes, were enveloped by the design bases of the dry storage system (DSS) during outdoor DSS handling activities (ODHAs). In response to the issues identified during these inspections, the NRC issued Enforcement Guidance Memorandum (EGM) 22-01, Enforcement Discretion for Noncompliance of Tornado Hazards Protection Requirements at Independent Spent Fuel Storage Installations, issued April 2022 (Agencywide Documents Access and Management System Accession No. ML22087A496), to provide guidance to the NRC staff on exercising enforcement discretion when an ISFSI licensee does not comply with these requirements. As a condition of the EGM, licensees were allowed to demonstrate, through the use of administrative controls rather than engineering analysis, that a structure, system, or component (SSC) important to safety would not be exposed to severe weather that would exceed its tornado accident design bases.
Additionally, since the identification of the issue, multiple CoC holders have submitted CoC amendment requests to make the same demonstration through the use of administrative controls in lieu of an engineering analysis.
In parallel with NRC efforts, the Nuclear Energy Institute (NEI) developed industry guidance in NEI 22-02, Revision 2, Guidelines for Weather-Related Administrative Controls for Short Duration Outdoor Dry Cask Storage Operations, issued November 2022 (ML22339A035). Subsequently, the NRC proposed developing a RG to endorse NEI 22-02, Revision 2, with clarifications and exceptions. This RG would provide the industry with staff positions based on formally documented administrative controls that form an appropriate basis for demonstrating compliance with 10 CFR 72.122(b) and 10 CFR 72.236(l) in lieu of engineered analysis solely for weather-related wind and tornado events during ODHAs.
2
- 2.
Objective The objective of this regulatory action is to provide the NRC staff and the industry with guidance regarding an additional method of compliance, in certain limited situations, where licensees and CoC holders may use administrative controls to ensure that SSCs important to safety (ITS) are designed to withstand the effects of weather-related wind and tornado natural phenomena without impairing their capability to perform their intended design functions during ODHAs. This RG would endorse NEI 22-02, Revision 2, with clarifications and exceptions.
- 3.
Alternative Approaches The NRC staff considered the following alternative approaches:
(1)
Do not issue the RG.
(2)
Issue the RG.
Alternative 1: Do not issue the RG Under this alternative, the NRC would not issue new guidance. This alternative is considered the no-action alternative and provides a baseline condition from which any other alternatives would be assessed. If the NRC does not take action, there would be no changes in costs or benefit to the public, licensees, CoC holders, or the NRC.
However, the no-action alternative would not address the identified need for clear NRC staff positions based on formally documented administrative controls that staff has determined could, in certain limited situations, form an appropriate basis for demonstrating compliance with 10 CFR 72.122(b) and 10 CFR 72.236(l) in lieu of engineered analysis solely for weather-related wind and tornado events during ODHAs. Many licensees are currently using administrative controls in contradiction to their design bases to meet regulatory requirements under the enforcement discretion provided by EGM 22-01.
Under this alternative, after EGM 22-01 expires in April 2024, licensees would be required to perform significant reanalysis and potentially perform substantial modifications to SSCs ITS to demonstrate compliance with 10 CFR 72.122(b) and 10 CFR 72.236(l) through engineering analysis, with minor safety benefit.
Alternatively, licensees or CoC holders would be required to submit exemption requests, license amendments, or CoC amendments to modify their design bases to allow administrative controls, which would incur significant costs for licensing actions. The staff believes this alternative approach could lead to inconsistencies in licensing actions received that would lead to prolonged review times. This is because the staff would be required to review licensing actions for each CoC holder and specific licensee desiring to modify the design bases to include administrative controls without consistent NRC guidance on their acceptability.
The NRC regulations in 10 CFR 72.122, Overall requirements, and 10 CFR 72.236, Specific requirements for spent fuel storage cask approval and fabrication, do not differentiate between the requirements for protection during storage operations and short-duration ODHAs.
The current licensing guidance governing weather-related protection contained in section 4.5.5 of NUREG-2215, Standard Review Plan for Spent Fuel Dry Storage Systems and Facilities Final Report, issued April 2020, describes the design-basis loads caused by normal and off-normal winds. Section 4.5.3.3.3 and section 4.5.3.3.4 describe the design-basis loads
3 caused by accident winds and accident tornado missiles accordingly, and section 16.5.2.9 describes the means to evaluate these loads on SSCs ITS. This guidance generally specifies that SSCs ITS will continue to perform their intended safety functions during the maximum credible loads, as demonstrated by engineering analysis.
Further, NUREG-2215, section 4.5.3.3, includes the existing staff guidance that The NRC does not accept the presumption that there will be sufficient warning of tornadoes so that operations, such as transfer between the fuel transfer facility and storage site, may never be exposed to tornado effects.... Ensure that the SAR shows that the cask system will continue to perform its intended safety functions (i.e., criticality, radioactive material release, heat removal, radiation exposure, and retrievability). While this staff position is generally reflected in the vast majority of licenses and CoCs issued, in some specific instances, the NRC has approved administrative controls for short-duration ODHAs for several licensees; for example, the Interim Storage Partners consolidated interim storage facility, and this guidance would provide the additional option of allowing licensees and CoC holders, in certain limited instances, to rely upon administrative controls in complying with these regulatory requirements.
Alternative 2: Issue the RG Under this alternative, the NRC would issue the RG, which would endorse NEI 22-02, Revision 2, with clarifications and exceptions. The RG would provide the industry with the staff position that formally documented administrative controls form an appropriate basis for demonstrating compliance with 10 CFR 72.122(b) and 10 CFR 72.236(l) in lieu of engineered analysis solely for weather-related wind and tornado events during ODHAs. The RG would also provide clear guidance on the appropriate scope and procedural requirements to adequately implement administrative controls to meet regulatory requirements. Licensees and CoC holders would continue to use administrative controls to be fully compliant with NRC regulatory requirements without the need for EGM 22-01. This guidance would ensure regulatory requirements are met both effectively and consistently by ISFSI licensees and CoC holders and would provide the NRC staff with appropriate guidance for reviewing future licensing requests.
The staff anticipates that the impact on the public, licensees, CoC holders, and the NRC of implementing the new guidance would be minimal. The cost would include the voluntary review of the issued RG and the NEI 22-02, Revision 2, guidance. Since licensees desiring to use the RG are already applying administrative controls as conditions of EGM 22-01, the cost to slightly revise these administrative controls following the RG issuance would be minimal, including modification of their Final Safety Analysis Report and evaluating the change under 10 CFR 72.48, evaluation of their SSCs used for ODHAs, and revision of existing procedures.
The impact on the NRC would be the costs associated with preparing and issuing the RG, while the impact on the public would be the voluntary costs associated with reviewing and providing comments to the NRC during the public comment period.
Conclusion Based on this regulatory analysis, the NRC concludes that issuance of a new RG (Alternative 2) is warranted. This action would provide clear guidance based on formally documented administrative controls that would form an appropriate basis for demonstrating compliance with 10 CFR 72.122(b) and 10 CFR 72.236(l) in lieu of engineered analysis solely for weather-related wind and tornado events during ODHAs. The NRC estimates that issuing the RG would lead to cost savings for both the industry and the NRC.