ML21063A213
| ML21063A213 | |
| Person / Time | |
|---|---|
| Site: | 07201025 |
| Issue date: | 03/23/2021 |
| From: | Christopher Markley Storage and Transportation Licensing Branch |
| To: | Fowler W NAC International |
| Markley C | |
| Shared Package | |
| ML21063A211 | List: |
| References | |
| CAC 001028, CoC No. 1025, EPID L-2019-RNW-0029 | |
| Download: ML21063A213 (3) | |
Text
Enclosure REQUEST FOR ADDITIONAL INFORMATION NAC International Certificate of Compliance (CoC) No. 1025 Renewal Application Docket No. 72-1025 By letter dated December 18, 2019, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML19357A178), NAC International (NAC) submitted an application for renewal of Certificate of Compliance (CoC) No. 1025 for the NAC-Multi-Purpose Canister (NAC-MPC). In my letter dated, May 4, 2020, I acknowledged acceptance of your application for a detailed technical review and provided a proposed schedule for the U.S. Nuclear Regulatory Commission (NRC) review (ADAMS Accession No. ML20125A133). This request for additional information (RAI) identifies information needed by the NRC staff in connection with its technical review of the renewal application. The requested information is listed by chapter number and title in the renewal application. The staff used NUREG-1927, Revision 1, Standard Review Plan for Renewal of Specific Licenses and Certificates of Compliance for Dry Storage of Spent Nuclear Fuel and NUREG-2214, Managing Aging Processes In Storage (MAPS) Report in its review of the renewal application.
Each individual RAI describes information needed by the staff for it to complete its review of the renewal application and to determine whether the applicant has demonstrated compliance with the regulatory requirements.
RAI-1
Revise the UFSAR supplement and changes (Appendix C of the renewal application) to clarify the expectations related to use of transfer casks and transfer adapters.
The renewal application states that fuel transfer and auxiliary equipment are addressed in site-specific reviews by general licensees. The renewal application further states that a majority of this equipment was disposed of following completion of the spent fuel loading operations and decommissioning of the reactor plant. The renewal application clarifies that, when required for operations for removing the loaded NAC-MPC transportable storage canisters (TSCs) from these independent spent fuel storage installations (ISFSIs), new or refurbished equipment will be provided to complete those fuel transfer operations. These expectations are not reflected in the UFSAR supplement and changes related to aging management.
This information is needed to determine compliance with 10 CFR 72.240(c).
RAI-2
Justify that galvanic corrosion is not credible for VCC, transfer cask and transfer adapter assemblys steel subcomponents exposed to sheltered, air-indoor air-outdoor environments, or, provide aging management activities that address aging effects due to this aging mechanism.
2 The renewal application presents the applicants aging management reviews results for the VCC configurations and transfer cask/transfer adapter configurations (Tables 3.2-4 through 3.2.8). These tables identify steel subcomponents exposed to sheltered, air-indoor and air-outdoor environments. NUREG-2214 identifies galvanic corrosion of steel subcomponents to be credible in steel subcomponents where dissimilar material galvanic couples exist. The applicant is asked to justify which of the steel subcomponents for the VCC, transfer cask and transfer adapter assembly are exposed to galvanic couples that may lead to galvanic corrosion.
If galvanic couples may be present, the applicant is asked to provide aging management activities that address aging effects due to galvanic corrosion in these subcomponents.
This information is needed to determine compliance with 10 CFR 72.240(c).
RAI-3
Justify that radiation embrittlement and thermal aging are not credible for the VCCs silicone foam exposed to a sheltered environment, or, provide aging management activities that address aging effects due to this aging mechanism.
The renewal application does not provide a technical basis to address potential aging effects due to radiation embrittlement and thermal aging of the VCCs silicone foam (insulation subcomponent), which is needed for the staff to make a safety finding on the adequacy of the aging management activities for the VCC.
This information is needed to determine compliance with 10 CFR 72.240(c).
RAI-4
Clarify if the NS-3 neutron shielding material contains the optional boron filler. If so, justify that aging effects due to boron depletion are not credible for the VCCs neutron shielding in a fully-encased environment, or, provide aging management activities that address aging effects due to this aging mechanism.
The renewal application does not provide a technical basis to address potential aging effects due to boron-10 depletion of the VCCs NS-3 shielding, which (if applicable) is needed for the staff to make a safety finding on the adequacy of the aging management activities for the VCC.
This information is needed to determine compliance with 10 CFR 72.240(c).
RAI-5
Justify that aging effects due to fatigue are not credible for the stainless steel cladding in a helium environment, or, provide aging management activities that address aging effects due to this aging mechanism.
The renewal application does not provide a technical basis to address fatigue of the stainless-steel cladding of the spent fuel contents, which is needed for the staff to make a safety finding on the adequacy of the aging management activities for the spent fuel.
3 This information is needed to determine compliance with 10 CFR 72.240(c).
RAI-6
Provide a justification for the option in the Localized Corrosion and Stress Corrosion Cracking of Welded Stainless-Steel Transportable Storage Canisters aging management program (AMP) that allows a general licensee to choose not to conduct the canister inspections. Otherwise, revise the renewal application to remove that option.
The AMP for the canister inspections, including the proposed FSAR Summary of the AMP, provides an ISFSI site the option of not conducting inspections if the site provides a justification.
The AMP does not provide any criteria for that justification. In addition, the staff notes that, if the site does not perform the canister inspections, the site would also not perform the activities under the Internal Vertical Concrete Casks (VCC) Metallic Components Monitoring AMP. The inspections under the VCC AMP occur only when canister inspections are conducted.
Provide additional information that justifies this approach, addressing the following:
The canister AMP provides the option for not conducting inspections in a manner that does not appear to require a general licensee to evaluate such a deviation under the provisions of 10 CFR 72.212 and 72.48 (see RIS 2012-05). The staff notes that the guidance in NUREG-1927 Appendix E and NEI 14-03 Section 2.2.3 cite the use of the 72.212 and 72.48 processes as the appropriate means to make changes to aging management programs, as articulated in NEI 14-03:
10 CFR 72.48 provides the appropriate set of public health and safety-based criteria for determining whether NRC review and approval of revised TLAAs and AMPs is required prior to implementation.
Absent this change control process, it is unclear to the staff how deviations from the AMP canister inspection activities will be appropriately evaluated by the general licensee and be inspectable by the NRC.
The guidance in NUREG-1927 states that, if an AMP may not be applicable to certain general licensees, the AMP should specify this. The canister AMP does not provide any details for either the general licensee or the NRC staff to evaluate if the option for not performing inspections is appropriate. In addition, the staff has previously noted its concern for the use of surrogates (inspections conducted at another site) as a basis for not conducting inspections until such time when there is sufficient operating experience to justify that approach (see Draft Regulatory Guide DG-3055).
The staff requires this additional information to understand what constitutes an adequate technical basis to justify a general licensees decision to not follow the canister AMP (and by extension, the VCC AMP) and how this process provides an adequate opportunity for NRC oversight.
This information is needed to demonstrate compliance with 10 CFR 72.240(c).