ML23074A105
| ML23074A105 | |
| Person / Time | |
|---|---|
| Site: | 07201032 |
| Issue date: | 03/23/2023 |
| From: | Storage and Transportation Licensing Branch |
| To: | Holtec |
| Shared Package | |
| ML23074A101 | List: |
| References | |
| Download: ML23074A105 (1) | |
Text
Request for Additional Information Batch 5 Docket No. 72-1032 Certificate of Compliance No. 1032 Amendment No. 7 to the HI-STORM Flood/Wind Multipurpose Canister Storage System The staff identified additional information needed in connection with its review of the application of Amendment No. 7 to the Certificate of Compliance No. 1032 for HI-STORM Flood/Wind (FW)
Multipurpose Canister Storage System as provided in the request for additional information (RAI) discussed below. Each question describes information needed by the staff to complete its review of the application and to determine whether the applicant has demonstrated compliance with regulatory requirements in Title 10 of the Code of Federal Regulations (10 CFR), Part 72.
Structural RAI RAI 3-4 Clarify throughout the final safety analysis report (FSAR) which Multi-Purpose Cannister (MPC) and basket combinations are being referenced when discussing an MPC.
It does not appear that the designation Continuous Basket Shim (CBS) is always used when referring to CBS designs. With baskets that have a standard, loose shim version and a CBS version, it is unclear at times which model or both is being discussed.
For example, there are mentions of the MPC-44 in SAR section 3.4.4.1.4a, Load Case 4: Non-Mechanistic Tipover of Standard Basket Design. However, the staffs understanding is that MPC-44 does not have a standard basket design version, and it appears these statements should refer to the MPC-44CBS and be moved to safety analysis report (SAR) section 3.4.4.1.4b or 3.4.4.1.4c.
This information is needed to determine compliance with the regulatory requirements in 10 CFR 72.230(a).
RAI 3-5 Clarify, in the SAR, which combinations of MPC vessels, basket designs, and overpacks are acceptable for the HI-STORM FW.
The SAR does not clearly state which MPCs, baskets, and overpacks are permitted to be used with one another. For example, SAR table 1.0.1 contains a note that MPC-37P, referring to MPC-37P-CBS, is qualified for storage in the HI-STORM FW Version E overpack. This table does not include the UVH among the list of overpacks for the HI-STORM FW. SAR section 3.4.4.1.4a states that the tipover of MPC-44, referring to the MPC-44CBS, is only postulated in the Version E overpack; while table 1.I.1.2 lists MPC-44 as a principal component of the HI-STORM FW UVH system with a tipover analysis in HI-2210313, Analysis of the Non-Mechanistic Tipover Event of the Loaded HI-STORM FW Version UVH Storage Cask.
This information is needed to determine compliance with the regulatory requirements in 10 CFR 72.230(a).
Enclosure
RAI 3-6 Provide a description and the results of the finite element analyses of the MPCs with CBS basket designs in the SAR.
The SAR merely refences other reports in lieu of describing the finite element models, input data, and results of these analyses. For example, sections 3.4.4.1.4b and 3.4.4.1.4c state that the details of the finite element models with CBS baskets, input data, and results are archived in HI-2094353, Analysis of the Non-Mechanistic Tipover Event of the Loaded HI-STORM FW Storage Cask and HI-2200503, Analysis of the Non-Mechanistic Tipover Event of the Loaded HI-STORM FW Version E Storage Cask. The staff requests descriptions of these analyses be added to the SAR.
This information is needed to determine compliance with the regulatory requirements in 10 CFR 72.230(a).
RAI 3-7 Include the size of the bolt holes in the CBS and basket panel extensions in drawings for the CBS basket designs.
HI-2200503, appendices C and D, state that bolt holes in the CBS and basket panel extensions are sized to allow the shims to slide up against the basket panels without subjecting the bolts to shear loads. Neither the drawings nor SAR mention the size of the bolt holes which are necessary to achieve the behavior assumed in the tipover analyses.
This information is needed to determine compliance with the regulatory requirements in 10 CFR 72.150.
RAI 3-8 Provide HI-2094353, Analysis of Non-mechanistic Tipover and Drop Events of Loaded HI-STORM FW Storage Cask, Revision 18 or later.
SAR section 3.4.4.1.4b states that details of the tipover analyses for the CBS basket designs are archived in this calculation package. Revision 18 includes analyses of MPC-37CBS, which is needed for the staffs review of MPC-37P-CBS for this amendment.
This information is needed to determine compliance with the regulatory requirements in 10 CFR 72.236(l).
RAI 3-9 Provide the maximum total deflection of the fuel basket from the tipover analyses performed for the MPC-37CBS and MPC-44CBS basket designs and the HI-STORM FW UVH baskets. Include these results in the safety analysis report (SAR).
As described in chapter 2 of the SAR, the structural design criterion for the fuel basket is to limit the deflection of the basket panels to 0.5% of the cell width.
However, the results reported in the SAR and calculation packages for the tipover analyses do not include the maximum total deflection of the fuel baskets. SAR sections 3.4.4.1.4b, 3.4.4.1.4c, and 3.I.3.8 and calculation packages HI-2200503, HI-2210313, and HI-2094353 all make the conclusion that the deflections in basket panels are less than the deflection limit, but results are not provided to support this conclusion. This information is necessary to support a finding that the storage system will satisfy the design criteria with an adequate margin for safety.
This information is needed to determine compliance with the regulatory requirements in 10 CFR 72.236(c).
RAI 3-10 Clarify what parameter is measured to demonstrate that the maximum total deflection design criterion for the fuel basket is met and describe how it is measured in the finite element models for the tipover event. Update the SAR as necessary.
A variety of different terms for the parameter are used in different calculations and SAR sections. HI-220503 and HI-2210313 refer to permanent deformation adversely affecting fuel assemblies spacing. SAR section 2.2.3b refers to the maximum plastic deformation sustained by the fuel basket panels. SAR section 2.2.8 and SAR table 2.2.11 refer to maximum total deflection. The term total deflection would seem to refer to elastic and plastic deformation, whereas permanent and plastic deformation would seem to discount the elastic deflection.
Holtecs position paper, DS-331, Structural Acceptance Criteria for the Metamic-HT Fuel Basket, which is cited in SAR section 2.2.4 as the basis for the lateral deflection limit, states, To prevent excessive plastic deformation, the maximum total deflection of the Metamic-HT panel under the most limiting condition of lateral loading expressed as the dimensionless factor theta is set equal to 0.005. DS-331 suggests that the design criteria of 0.005 in SAR table 2.2.11 should be for the maximum total deflection, not just plastic deformation.
This information is needed to determine compliance with the regulatory requirements in 10 CFR 72.236(c).
RAI 3-11 Provide results from the tipover analyses to justify the conclusion that the basket shims remain attached to the baskets and maintain their physical integrity for the MPC-37CBS and MPC-44CBS basket designs and the HI-STORM FW UVH.
SAR sections 3.4.4.1.4b, 3.4.4.1.4c, and 3.I.3.8 state this conclusion. However, the SAR sections and the calculation packages describing the finite element analyses of the tipover event do not include results for the basket shims and the bolts or welds connecting the baskets to the shims.
This information is needed to determine compliance with the regulatory requirements in 10 CFR 72.236(c).
RAI 3-12 Justify the assumption that the basket panels transfer shear load to the shims without inducing shear in the bolts and justify the lack of a bolt analysis for the bolts connecting the shims to the basket panel extensions for the continuous basket shim (CBS) basket designs.
The calculation packages for the tipover analyses of the CBS basket designs state that the CBS bolt holes allow basket panels to slide up against shims without subjecting bolts to shear loads. This assumed behavior should be described and justified in the SAR. It is unclear if the size of the bolt holes, the displacement of the basket panel extension relative to the shims needed to transfer load without engaging the bolts, or the bolt torque and friction resisting sliding of the components will allow the assumed behavior; particularly in locations where the basket panels are
not continuously supported by hollow CBS basket shims. Additionally, discuss if there are any other loads observed in the bolts from the tipover or other normal, off-normal, or accident conditions requiring a bolt analysis.
This information is needed to determine compliance with the regulatory requirements in 10 CFR 72.236(c).
RAI 3-13 Justify the modeling assumption to use nodal constraints to tie the basket shims to the basket panel extensions at the bolt hole locations in tipover analysis of the CBS basket designs, instead of explicitly modeling the CBS basket bolts. Update the SAR as necessary.
The calculation packages for the tipover analyses of the CBS basket designs state the above assumption. Using a nodal constraint to tie the basket shims to the basket panel extensions would seem to conflict with previously mentioned assumptions that loads will not form in the bolts. Additionally, this assumption should be discussed in the SAR.
This information is needed to determine compliance with the regulatory requirements in 10 CFR 72.236(c).
RAI 3-14 Demonstrate that the combined radial gap between the basket, shims, and enclosure vessel is sized to ensure that no significant thermal stresses develop that would cause distortion in basket panels. Include a description of this evaluation in the SAR.
The application sections 3.1.1(i) states, a small, calibrated gap designed to prevent significant thermal stressing associated with the thermal expansion mismatches between the fuel basket, the basket support structure, and the MPC shell. However, it is not clear if this was assessed for the CBS basket designs.
Additionally, explain why drawings for the MPC-44CBS and MPC-37P-CBS do not include the language from Note 4 regarding the sizing of the basket panel extensions to allow for unrestrained differential thermal expansion that drawings for other CBS designs contain.
This information is needed to determine compliance with the regulatory requirements in 10 CFR 72.236(l).
ML23074A101; ML23074A105 OFFICE NMSS/DFM/STLB NMSS/DFM/STLB NMSS/DFM/MSB NMSS/DFM/MSB WWheatley NAME YChen YC PKoch PK TBoyce TB JCurry for JC DATE Mar 20, 2023 Mar 22, 2023 Mar 21, 2023 Mar 22, 2023 OFFICE NMSS/DFM/STLB NMSS/DFM/STLB NAME YDiaz-Sanabria YD YChen YC DATE Mar 22, 2023 Mar 23, 2023