ML23138A146
| ML23138A146 | |
| Person / Time | |
|---|---|
| Site: | 07201042 |
| Issue date: | 05/16/2023 |
| From: | Office of Nuclear Material Safety and Safeguards |
| To: | |
| Shared Package | |
| ML23138A145 | List: |
| References | |
| EPID L-2022-LLA-0017, CAC 001028 | |
| Download: ML23138A146 (3) | |
Text
Supplementary Requests on TN Americas LLC NUHOMS EOS Amendment 4 Structural Request for Supplemental Information Responses The staff requests that the applicant 1) provide information that was omitted from their March 30, 2023, responses to the Requests for Supplemental Information (RSIs), and
- 2) provide explanations and revised material, as required, to clarify apparent discrepancies between the responses and the safety analysis report (SAR). This information is required to establish the design basis of the horizontal storage module steel-plate composite (HSM-SC),
such as design codes, load combinations, and acceptance criteria which will allow staff to assess the acceptability of the application.
Omissions:
- a. (Proprietary)
- b. (Proprietary)
- c. (Proprietary)
- d. (Proprietary)
- e. RSI 3-8 requested that the thicknesses and lengths be provided for those portions of the HSM-SC being evaluated for global response to tornado missile effects. The RSI also requested that a summary of the resulting ductility ratios be provided, as well as an explanation as to why the computed response values tabulated in the SAR for the HSM-SC were so disparate from those tabulated for the horizontal storage module reinforced concrete (HSM-RC).
The response to RSI 3-8 provided component thicknesses, but no lengths employed in the global response calculations, nor any summary of ductility ratios. No explanation was offered as to why the tabulated global response values of the yield resistance capacities for the HSM-RC and HSM-SC vary by as much as 500 percent.
The response did provide an example of intermediate results for a schedule 40 pipe missile; however, staff is unable to recreate the reported CR and CT values using the following values from the SAR:
The Ry value of 1648 kips from the table in SAR section 3.9.8.10.6.2 is divided by the peak force, F, of 718 kips from section 3.9.4.10.6.2.C to obtain the resistance to force ratio, CR, of 2.29. This value does not agree with the value of CR that was provided within Item c of the initial response to RSI 3-8.
Provide the requested information in the SAR as well as the associated calculation report as part of the submittal package, if not included in the final evaluation document.
Update the SAR as required to reference it.
Response: TN Americas LLC (TN) understands the clarification and will provide a supplemental response to the RSI.
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- f. RSI 3-8 requested that if credit is taken for the shield walls to act as missile barriers to protect the end and rear walls of the HSM-SC, this fact be clearly documented in the SAR. Although the response verified that the shield walls also serve as missile barriers, the staff is unable to find a clear statement within the SAR documenting this fact. Update the SAR with this information.
Response: TN understands the clarification and will provide a supplemental response to the RSI.
- g. (Proprietary)
- h. (Proprietary)
- i. RSI 3-10 requested that the design Code and load combinations employed for the various steel components be identified. The response does not address the design load combinations; however, it does identify that the Code is the American Institute of Steel Construction (AISC) Specification. It does not identify whether the items are designed employing the Allowable Strength or Load and Resistance Factor Design methodology.
Provide the requested information as well as the calculation report documenting the same, if not included in the final evaluation document. Update the SAR to reference it.
Response: TN understands the clarification and will provide a supplemental response to the RSI.
- j. RSI 3-11 requested that the design Code and load combinations employed for the steel heat shield plates and bolts be identified. The response does not address the design load combinations; however, it does identify that the Code is the AISC Specification. It does not identify whether the items are designed employing the Allowable Strength or Load and Resistance Factor Design methodology. Provide the requested information as well as the calculation report documenting same, if not included in the final evaluation document. Update the SAR as required to reference it.
Response: TN understands the clarification and will provide a supplemental response to the RSI.
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Clarifications:
- k. (Proprietary)
- l. (Proprietary)
- m. (Proprietary)
- n. (Proprietary)
- o. RSI 3-6 requested information regarding the stability analyses performed for the HSM-SC. The response stated that the stability analysis methodology employed for the HSM-SC is identical to that employed for the HSM-RC in SAR section 3.9.7. However, the applicant goes on to explain that, as some HSM-SC stability values were not explicitly recalculated, engineering judgment was employed to validate the stability of some analyses. This was based on the increased weight of the HSM-SC as compared to that of the HSM-RC. Verify the change in methodology and update the SAR accordingly.
- p. RSI 3-10 requested design basis information for various steel connectors, including concrete embedments. The response states that there is supplementary reinforcement provided for embedments, but none can be found on the drawings. Clarify response and update drawings as required.
The response also states that the design load combinations for the concrete and steel components are based on American Concrete Institute and AISC Codes, respectively.
The response references SAR table 3.9.4-5, which only provides load combinations for concrete component design, but none for steel component design. The response also does not address whether the steel items are designed employing the Allowable Stress or Load and Resistance Factor Design methodology. Provide this information and update the SAR to include the steel design load combination reference and steel design methodology.
Additionally, the staff requests that the applicant verify that the intended reference in response to RSI 3-10 for the steel component design is not the AISC Manual of Steel Construction (Ref. 3.9.8-5), but rather the AISC Specification for Structural Buildings (Ref. 3.9.8-6). Update SAR section 3.9.8.10.7 accordingly.
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