ML24198A087
| ML24198A087 | |
| Person / Time | |
|---|---|
| Site: | HI-STORM 100 |
| Issue date: | 08/05/2024 |
| From: | Melendez-Colon D Storage and Transportation Licensing Branch |
| To: | Elzahri A Holtec |
| References | |
| EPID L-2023-LLA-0176 | |
| Download: ML24198A087 (1) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Ali Elzahri, Licensing Project Engineer Holtec International Krishna P. Singh Technology Campus 1 Holtec Blvd.
Camden, NJ 08104
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION FOR REVIEW OF THE HOLTEC MODEL NO. HI-STORM UMAX STORAGE SYSTEM, AMENDMENT 5 - COST ACTIVITY CODE/ENTERPRISE PROJECT IDENTIFICATION NUMBERS 001028/L-2023-LLA-0176
Dear Ali Elzahri:
By letter dated December 14, 2023 (Agencywide Documents Access and Management System
[ADAMS] Accession No. ML23348A302), as supplemented on April 18, 2024 (ADAMS Accession No. ML24136A189), Holtec International (Holtec or the applicant) requested the U.S.
Nuclear Regulatory Commission (NRC) amend Certificate of Compliance (CoC) No. 1040 for the Model No. HI-STORM UMAX. The application proposes to add new versions of the UMAX with lid features that will provide protection for colder canisters.
In connection with our review, we need the information identified in the enclosed request for additional information (RAI). To assist us in scheduling the NRC staffs review of your response, we request that you provide this information 45 calendar days from the date of this letter. Inform us at your earliest convenience, but no later than two weeks before the response date if you are not able to provide the information by that time frame. If you are unable to provide a response by the stated date, our review may be delayed.
Please reference Docket No. 72-1040 and Cost Activity Code/Enterprise Project Identification Nos. 001028/L-2023-LLA-0176 in future correspondence related to this review. The NRC staff is available to clarify these questions, and, if necessary, to meet and discuss your proposed responses.
In accordance with Title 10 of the Code of Federal Regulations (10 CFR) Section 2.390, Public inspections, exemptions, requests for withholding, a copy of this letter will be available electronically for public inspection in the NRC Public Document Room (PDR) or from the Publicly Available Records component of the NRCs ADAMS. ADAMS is accessible from the NRC website at http://www.nrc.gov/reading-rm/adams.html. The PDR is open by appointment.
To make an appointment to visit the PDR, please send an email to PDR.Resource@nrc.gov or call 1-800-397-4209 or 301-415-4737, between 8:00 a.m. and 4:00 p.m. eastern time (ET),
Monday through Friday, except Federal holidays.August 5, 2024 A. Elzahri 2 If you have any questions regarding this communication, please contact me at (301) 415-7295, or via e-mail to Daneira.Melendez-Colon@nrc.gov.
Sincerely, Daneira Meléndez Colón, Project Manager Storage and Transportation Licensing Branch Division of Fuel Management Office of Nuclear Material Safety and Safeguards Docket No.: 72-1040 EPID No.: L-2023-LLA-0176
Enclosure:
Request for Additional Information Signed by Melendez-Colon, Daneira on 08/05/24
ML24198A087 OFFICE NMSS/DFM NMSS/DFM NMSS/DFM NMSS/DFM NMSS/DFM NAME DMelendez-Colon WWheatley JTapp JSolis BPatel DATE 07/18/2024 07/22/2024 07/22/2024 07/22/2024 07/23/2024 OFFICE NMSS/DFM/ NMSS/DFM/ NMSS/DFM NMSS/DFM NMSS/DFM NAME HRodriguez ASotomayor-Rivera TBoyce YDiaz-Sanabria DMelendez-Colon DATE 07/23/2024 07/24/2024 07/24/2024 07/29/2024 08/05/2024 Request for Additional Information Docket No. 72-1040 Certificate of Compliance No. 1040 Amendment No. 5 Model No. HI-STORM UMAX
This request identifies additional information that is needed by the U.S. Nuclear Regulatory Commission (NRC) staff in connection with its review of the application. The NRC staff used NUREG-2215, Standard Review Plan for Spent Fuel Dry Storage Systems and Facilities, in its review of the application.
Each question describes information needed by the NRC staff to complete its review of the application and to determine whether the applicant has demonstrated compliance with the regulatory requirements of Title 10 of the Code of Federal Regulations (10 CFR) Part 72.
Structural Evaluation
RAI-St-1
Provide an evaluation for the thermal degradation of self-hardening engineered subgrade (SES) and concrete subgrade material due to increased temperature for the UMAX storage system.
Per Holtec Report HI-2230586, Thermal Evaluation of HI-STORM UMAX at SONGS with Inlet Vent Flow Restrictions, Revision 0, steady-state temperature for normal long term storage condition has increased for the divider shell and cavity enclosure container (CEC) shell of the HI-STORM UMAX Version B. The CEC temperature has increased from 150°F to 400°F. The staff notes that the subgrade material SES or concrete in space A which is in direct contact with the CEC is also expected to experience similar high temperature, which needs to be evaluated.
The impact of sustained high temperatures on SES/concrete subgrade in space A have not been evaluated in the applicable calculations in the Holtec Report HI-2125228 or in the proposed final safety analysis report (FSAR) Revision 8. Per American Concrete Institute (ACI) 349-01, the concrete surface temperatures shall not exceed 150°F for normal operation or any other long-term period. Per ACI 349, the higher than 150°F temperature may be allowed for concrete for normal long-term use if the concrete design properties are adjusted to account for temperature dependence based on tests or sources providing data based on tests of concrete with similar composition, and verification that the increased temperatures do not cause deterioration of the concrete either with or without load.
This information is needed to determine compliance with 10 CFR 72.236(b), (c), (d) and (l).
RAI-St-2
Provide detailed justification for not reanalyzing the soil-structure interaction (SSI) analyses due to the increased long-term temperatures for the UMAX storage system components and subgrade in space A.
Per Holtec Report HI-2230586, Thermal Evaluation of HI-STORM UMAX at SONGS with Inlet
Enclosure Vent Flow Restrictions, Revision 0, steady-state temperatures for normal long term storage condition have increased for divider shell and cavity enclosure container (CEC) shell of the HI-STORM UMAX version B overpack which are explicitly modeled in LS-DYNA model for SSI analysis contained in calculation/supplement 7A/3 of Holtec Report HI-2125228, Revision 17.
The applicant rationalized not re-analyzing the LS-DYNA simulation stating that the finite element model considers these parts as elastic material and therefore higher temperatures will result in lower elastic modulus values resulting in less than 4% change in CEC elastic modulus and in less than 1.5% change in the divider elastic modulus, which will have secondary effects.
This justification does not appear to be adequate. As described in RAI-St-1, also there is no consideration by the applicant of the increased temperature effects on the SES/concrete material in the interstitial space A for this evaluation. A more detailed justification with a rational is needed for accepting the affected design parameters based on consideration of sensitivities of the input parameters such as change in steel and SES/concrete properties on to the SSI analyses, any associated change in seismic demands, and subsequent comparison to the stress and/or strain design margin available in the affected UMAX overpack and other components.
This information is needed to determine compliance with 10 CFR 72.236(b), (c), (d) and (l).
RAI-St-3
Clarify required subgrade material for the most severe earthquake (MSE) vertical ventilated module (VVM) on Drawing 10017 and update drawings as necessary such that they are consistent with the FSAR and documented analyses.
Subgrade material note 24 is referenced in Section A-A of Drawing 10017, sheet 3 of 10 for standard VVM, but no specific note is referenced for subgrade material in Section B-B of Drawing 10017, sheet 7 of 10 for MSE VVM. However, according to Note 36 of Drawing 10017, sheet 1 of 10, the Note 24 also applies to the MSE VVM because Note 36 indicates that for information of the MSE VVM which are not shown on sheets 7 thru 9, refer to similar views of the component/features for the standard VVM. Note 24 of Drawing 10017, sheet 1 of 10, Revision 7 requires that the subgrade material shall be SES meeting the requirements of FSAR Table 2.3.2, which is 1000 psi compressive strength. Supplement 3, calculation 7A, Revision 3 of Holtec report HI-2125228 Revision 17 identifies required subgrade material to be 3000 psi compressive strength concrete for the MSE VVM, which is neither specified on the Drawing 10017 nor listed in the FSAR Table 2.3.2, Design Data for HI-STORM UMAX ISFSI. It appears to the staff that a note should be added for the subgrade shown in Section B-B of Drawing 10017, sheet 7 of 10 for the MSE VVM to specify subgrade material in space A to be concrete per the FSAR Table 2.3.10, to resolve this discrepancy.
This information is needed to determine compliance with 10 CFR 72.146(a), 72.236(b) and (l).
RAI-St-4
Clarify applicability of version B1 and B2 to the Standard UMAX Version B storage system shown on Drawing 10017, sheets 3 thru 6, and provide additional justifications, if applicable.
Drawing 10017, sheets 1 thru 10 provides design details for the Standard and MSE UMAX VVM for Version B, B1 and B2 system. Drawing 10017, sheet 3 thru 6 provides details for Standard Version B UMAX VVM and Drawing 10017, sheet 7 thru 9 provides details for MSE Version B UMAX VVM. Drawing 10017, sheet 10 provides air inlet blocking requirements for Version B1
2 and B2 for the MSE Version B UMAX VVM. However, there is no similar drawing that depicts air inlet blocking requirements for the Standard Version B UMAX VVM. Also, based on the updated structural analyses in Holtec Report HI-2125228, Revision 17 that evaluate changes due to the Version B1 and B2, it appears to the staff that only the analyses affecting the MSE UMAX VVM and associated system components have been evaluated, but the Standard UMAX VVM structural analyses (e.g. calculation/supplement 7/0) have not been evaluated for higher temperatures. On the contrary, in Attachment 1 to Holtec Letter 5021073, Summary of Proposed Changes, under the justification for Proposed Change #1, the applicant states that the Peak Cladding Temperatures for design variants Version B1 and B2 are bounded by the UMAX standard design as reported in Table 4.1.3. Therefore, the Standard UMAX is adopted to perform remaining licensing basis calculations to establish safety for the HI-STORM UMAX system. Due to lack of clarity in the documentation with regards to applicability of B1 and B2 Version to the Standard version B UMAX storage system, and other differences identified in the supporting documents above, it is not clear to the staff whether Version B1 and B2 changes are applicable to the Standard Version B UMAX storage system or not.
This information is needed to determine compliance with 10 CFR 72.236(I) and 72.244.
RAI-St-5
Update FSAR Table 2.4.1 as necessary to address elevated coincident metal temperatures associated with Version B1 and B2 UMAX storage system design.
Load cases and design basis loads applicable to the VVM Components are summarized in Table 2.4.1 of the FSAR Revision 7. This table also lists the Reference Coincident Metal Temperature for different load cases, which no longer be valid for some of the load cases and need to be updated to reflect elevated coincident metal temperatures associated with Version B1 and B2 UMAX storage system design.
This information is needed to determine compliance with 10 CFR 72.236(b) and 72.244.
Thermal Evaluation
RAI-Th-1
Revise the FSAR to include drawings that show details of the outlet vent cover (OVC) used in the HI-STORM UMAX VVM Version B.
As part of the application, the applicant provided thermal analysis models that include an OVC.
However, drawings that show detailed geometry were not included in the application. The staff needs this information to verify that the thermal model is consistent with the design drawings.
This information is needed to determine compliance with 10 CFR 72.236(b), and 72.236(f).
RAI-Th-2
Revise the FSAR to include heat load information in Chapter 2 for HI-STORM UMAX VVM Versions B1 and B2.
Section 4.4 of the FSAR states that heat load limits for the different cask versions and fuel assembly type are provided in Tables 2.1.13 through 2.1.16. The staff reviewed Chapter 2 of
3 the FSAR and did not find these tables. The staff needs this information to verify consistency in the application and thermal analysis models.
This information is needed to determine compliance with 10 CFR 72.236(b), and 72.236(f).
Technical Specifications Evaluation
RAI-TS-1
Clarify the first note in Technical Specifications (TS) Limiting Conditions for Operation (LCO) 3.1.2 to specify the operability determination using the unblocked inlet and outlet vent areas is applicable only to the uncovered areas.
The proposed TS LCO 3.1.2 note on heat removal system operability was not clarified consistent with the revision made to the application in Appendix 13.A, proposed Revision 8A, for LCO B 3.1.2 as part of the response to NRCs Request for Supplemental Information (ADAMS Accession No. ML24136A188). Including the clarification to the TS LCO 3.1.2 as well will ensure consistent and compliant application of the TS by general licensees without the need to review the TS Bases to ensure adequate understanding.
This information is needed to determine compliance with 10 CFR 72.236(l).
4