ML23095A101

Tn Americas LLC, Third Supplemental Response to Request for Additional Information – Application for Amendment 18 to Standardized NUHOMS Certificate of Compliance No. 1004 for Spent Fuel Storage Casks, Revision 6

ML23095A101
Person / Time
Site:	07201004
Issue date:	04/05/2023
From:	Narayanan P TN Americas LLC
To:	Office of Nuclear Material Safety and Safeguards, Document Control Desk
Shared Package
ML23095A100	List: ML23095A101 ML23100A002
References
E-62170
Download: ML23095A101 (1)

Text

April 5, 2023 E-62170

Columbia Office U. S. Nuclear Regulatory Commission 7160 Riverwood Drive Attn: Document Control Desk Columbia, MD 21046 One White Flint North Tel: (410) 910-6900 11555 Rockville Pike

@Orano_USA Rockville, MD 20852

Subject:

Third Supplemental Response to Request for Additional Information

- Application for Amendment 18 to Standardized NUHOMS Certificate of Compliance No. 1004 for Spent Fuel Storage Casks,

Revision 6 (Docket No. 72-1004, CAC No. 001028, EPID: L-2022-LLA-0079)

Reference:

[1] E-61864, Response to Request for Additional Info rmation -

Application for Amendment 18 to Standardized NUHOMS Certificate of Compliance No. 1004 for Spent Fuel Storage Casks, Revision 2 (Docket No. 72-1004, CAC No. 001028, EPID: L-2022-LLA-0079),

dated January 20, 2023

TN Americas LLC (TN) hereby submits a supplement to Reference [ 1], above, that provides additional clarifying information associated with the responses to certain structural RAIs.

The NRC and TN held a clarification call on March 6, 2023 for the purpose of clarifying TNs responses to certain structural Requests for Additional In formation (RAIs). As a result, TN is providing supplemental information associated with RAIs 4.4 and 4.5.

Enclosure 2 provides a proprietary version of the aforementione d RAIs and supplemental responses as a result of the clarification call. Enclosure 3 provides a public version of the supplemental responses to the RAIs.

The proprietary version of the Updated Final Safety Analysis Re port (UFSAR) changed pages associated with Amendment 18 are included as Enclosure 4, with a footer on each changed page annotated as 72-1004 Amendment 18, Revision 6, April 2023, and changes indicated by italicized text and revis ion bars. The changes are further annotated with gray shading or a gray box enclosing an added section, as well as a footer to distinguish the Amendment 18, Revision 6 ch anges from previous Amendment 18 changes. The public version of these UFSAR change d pages is provided as Enclosure 5.

Enclosure 6 provides a listing of computer files contained on the Enclosure 7 hard drive being submitted in support of this submittal. Enclosure 7 contains file formats and sizes not allowed by the NRC EIE application process, so they are provided separately on one computer drive.

Document Control Desk E-62170 Page 2 of 2

Certain portions of this submittal include proprietary informat ion, which may not be used for any purpose other than to support the NRC staffs review of the app lication. In accordance with 10 CFR 2.390, TN Americas LLC is providing an affidavit, Enclos ure 1, specifically requesting that this proprietary information be withheld from public discl osure.

Should you have any questions regarding this submittal, please do not hesitate to contact Mr. Douglas Yates at 434-832-3101, or me, at 410-910-6859.

Sincerely,

Prakash Narayanan Chief Technical Officer

cc: Chris Allen (NRC), Project Manager, Storage and Transportation Licensing Branch Division of Fuel Management

Enclosures:

1. Affidavit Pursuant to 10 CFR 2.390

2. RAIs and Responses (Proprietary)

3. RAI and Responses (Public)

4. Proposed Amendment 18, Revision 6 Changes to the Standardize d NUHOMS System Updated Final Safety Analysis Report (Proprietary Version)

5. Proposed Amendment 18, Revision 6 Changes to the Standardize d NUHOMS System Updated Final Safety Analysis Report (Public Version)

6. Listing of Computer Files Contained in Enclosure 7

7. Certain Computer Files Associated with Certificate of Compli ance 1004 Amendment 18, Revision 6 (Proprietary) (contained on one hard drive)

Enclosure 1 to E-62170

AFFIDAVIT PURSUANT TO 10 CFR 2.390

TN Americas LLC )

State of Maryland) SS.

County of Howard )

I, Prakash Narayanan, depose and say that I am the Chief Technical Officer of TN Americas LLC, duly authorized to execute this affidavit, and have reviewed or caused to have reviewed the information that is identified as proprietary and referenced in the paragraph immediately below. I am submitting this affidavit in conformance with the provisions of 10 CFR 2,390 of the Commissions regulations for withholding this information.

The information for which proprietary treatment is sought meets the provisions of paragraph (a) (4) of Section 2.390 of the Commission's regulations. The information is listed below:

• Enclosure 2 - Portions of Proposed Amendment 18, Revision 6 Responses to RAIs

• Enclosure 4 - Portions of Proposed Amendment 18, Revision 6 Changes to the Standardized NUHOMS System Updated Final Safety Analysis Report

• Enclosure 7 - Certain computer files associated with Proposed Amendment 18, Revision 6

This document has been appropriately designated as proprietary.

I have personal knowledge of the criteria and procedures utilized by TN Americas LLC in designating information as a trade secret, privileged or as confidential commercial or financial information.

Pursuant to the provisions of paragraph (b) (4) of Section 2,390 of the Commissions regulations, the following is furnished for consideration by the Commission in determining whether the information sought to be withheld from public disclosure, included in the above referenced document, should be withheld.

1) The infonnation sought to be withheld from public disclosure involves portions of the RAI responses, portions of the UFSAR, and analysis computer files, all related to the design of the Standardized NUHOMS dry spent fuel storage system, which are owned and have been held in confidence by TN Americas LLC.

2) The information is of a type customarily held in confidence by TN Americas LLC, and not customarily disclosed to the public. TN Americas LLC has a rational basis for determining the types of information customarily held in confidence by it.

3) Public disclosure of the information is likely to cause substantial harm to the competitive position of TN Americas LLC, because the infonnation consists of descriptions of the design of dry spent fuel storage systems, the application of which provide a competitive economic advantage. The availability of such infonnation to competitors would enable them to modify their product to better compete with TN Americas LLC, take marketing or other actions to improve their products position or impair the position of TN Americas LLCs product, and avoid developing similar data and analyses in support of their processes, methods or apparatus.

Further the deponent sayeth not.

Prakash Narayanan Chief Technical Officer, TN Americas LLC

Subscribed and sworn before me this 30day of March, 2023. MARYANNE D ATIENZA

Notary Public Anne Arundel County

---

1 II----------------------------------------------------- Maryland Notary Public My Commission Expires March 02, 2025 My Commission Expires *3 / ^ cX3

Page 1 of 1 Enclosure 2 to E-62170

RAIs and Responses (Proprietary Version)

Withheld Pursuant to 10 CFR 2.390

RAIs and Responses - Public Enclosure 3 to E-62170

Structural:

RAI 4.4:

Provide buckling evaluations of the 24PTH DSC and Type 3 Basket.

Buckling of the 24PTH DSC and the Type 3 basket were not evaluated. NUREG -2215 suggests that buckling of the fuel basket materials should be considered for normal and off-normal loading (section 4.5.5.1.2 of reference 2) and buckling of the canister should be considered for a load drop (section 4.5.6.1.1 of reference 2). Buckling evaluations of the 24PTH DSC and Type 3 Basket are needed for the staff to complete the evaluations. The resulting basket deformation from these evaluations should be appropriately included in the criticality analys is and shielding analysis since the basket affects axial dose rates.

The above information is necessary to comply with 10 CFR 72.236(c) and (d).

Original Response to RAI 4. 4:

For the 24PTH DSC Shell, the b uckling evaluations of the 24PTH DSC for a postulated 60g end drop are provided in UFSAR Section P.3.7.4.2.4. This section remains unchanged in this submittal since the same DSC Shell is used for all basket types of the 24PTH DSC.

For normal and off-normal loading, the stress in the Type 3 basket compartment plates for the 1g axial handling load due to conservative basket and fuel assembly weights is 0.54 ksi. This stress value is low, such that the DW + 1g axial handling load combination does not control, and no further buckling evaluation is required.

The buckling evaluation for the Type 3 basket under accident side drop loading is discussed in UFSAR Section P.3.8.7.3, and results are presented in UFSAR Tables P.3.8-8 and P.3.8-9. The buckling evaluation for the Type 3 basket under end drop loading is provided in UFSAR Section P.3.8.7.4.Both of these evaluations demonstrate that the 24PTH Type 3 basket will not buckle under accident conditions.

Original Impact:

No change as a result of this RAI.

Supplemental Response to RAI 4.4:

Because the bottom grid plates are subjected to a compressive stress of 17.75 ksi during the 75g end drop loading condition, as discussed in UFSAR Section P.3.8.7.4, a buckling evaluation is performed in accordance with NUREG-6322 and added to UFSAR Section P.3.8.7.4.

NUREG-6322 has been added to reference Section P.3.9.

For the buckling evaluation of the bottom grid plates, which are subjected to the greatest compressive stress, two configurations are considered. The first configuration consists of a

[ ] high grid plate representing an [ ] span of a compartment. [

] as

Page 1 of 6 RAIs and Responses - Public Enclosure 3 to E-62170

shown on Sheet 4 of UFSAR Drawings NUH24PTH-L-5012-SAR, NUH24PTH-S-5012-SAR, and NUH24PTH-S-LC -5012-SAR.

Since the plate is connected to adjacent plates through a portion of the unloaded edges, the plate is considered simply supported on that portion of the edge and free on the rest of the edge, in accordance with Section 5.3 of NUREG -6322. To determine the buckling load of such a plate, an eigenvalue buckling analysis is performed by ANSYS using the model shown in new UFSAR Figure P.3.8-9. The buckling stress determined by ANSYS is 102.7 ksi.

Section 6.5 of NUREG-6322 requires the compressive stress to be limited to 2/3 of the value determined by buckling analysis. Therefore, the allowable stress is (102.7)(2/3) = 68.45 ksi, which is substantially greater than the compressive stress of 17.75 ksi.

The second configuration consists of the top cantilever potion of the plate in the first configuration, which is considered as a plate with two free unloaded edges. Per Equation 19 of NUREG-6322, the elastic buckling stress of such a plate is calculated as :

2

=e DK ah22

where D is the plate rigidity, Kis the effective length factor of columns, a is the plate height, and h is the plate thickness. If the most conservative value of K = 2.1 from Figure 6 of NUREG-6322 is used, e = 47.59 ksi. The allowable stress is, therefore, (47.59)(2/3) = 31.73 ksi, which is substantially greater than the compressive stress of 17.75 ksi. As such, no part of the 24PTH Type 3 basket plates will buckle under accident end drop loading.

Supplemental Impact:

UFSAR Sections P.3.8.7.4 and P.3.9 have been revised as described in the response.

UFSAR Figure P.3.8-9 has been added as described in the response.

Page 2 of 6 RAIs and Responses - Public Enclosure 3 to E-62170

RAI 4.5:

Provide justification that the cross-section model approach is appropriate for the 24PTH DSC Type 3 basket.

The interlocking egg-crate design of the Type 3 basket utilizes no welding and relies on attachments at the basket exterior to keep the structure intact. The mechanical interlocking of the plates at the center of the basket likely has clearance gaps for assembly and thermal growth that give the basket add itional flexibility (drawing details were not available to evaluate the gap dimensions). The application has little discussion of the joints and gaps between the basket plate structures and how these are conservatively accounted for in the ANSYS cross -section model. It is not apparent that the short cross -section basket model accounts for the flexibility of the interlocking joints in the series of plates forming the egg-crate design, and the boundary conditions may be artificially stiffening the structure by disallowing any axial motion of the plates under flexure that could occur due to axial clearance gaps. If the cross -section model approach is overly stiff for simulation of an egg-crate design, this could lead to underprediction of the basket compartment relative displacements, which is important for and impacts, among others, the criticality and shielding analyses.

Provide justification that the modeling domain with the cross -section approach appropriately captures the inherent joint flexibility and assembly gaps of the Type 3 basket design to predict maximum compartment displacement. In addition, provide justification for not using the LS -

DYNA approach as done with the Type 1 and Type 2 basket design.

The above information is necessary to comply with 10 CFR 72.236(c) and (d).

References:

1. Orano TN, Application for Amendment 18 to Standardized NUHOMS Certificate of Compliance No. 1004 for Spent Fuel Storage Casks, Revision 0 (Docket No. 72-1004), May 20, 2022.

2. NUREG-2215, Standard Review Plan for Spent Fuel Dry Storage Systems and Facilities -

Final Report, April 2020.

3. NUREG/CR-3966, Methods for Impact Analysis of Shipping Containers, November 1987.

Original Response to RAI 4. 5:

The mechanical interlocking of the plates at the center of the basket has clearance gaps for assembly and thermal growth, which are considered in the 6-inch cross-section basket model using [ ] elements as described in UFSAR Section P.3.8.6.1. [

] The key basket

dimensions are provided in D rawings NUH24PTH-S-5012-SAR, NUH24PTH-L-5012-SAR, and NUH24PTH-S-LC -5012-SAR in UFSAR Section P.1.5, for the 24PTH-S, -L, and -S-LC DSC, respectively. The drawings show the following basket plate thicknesses.

Page 3 of 6 RAIs and Responses - Public Enclosure 3 to E-62170

Page 4 of 6 RAIs and Responses - Public Enclosure 3 to E-62170

The 24PTH Type 1 and Type 2 basket designs are welded structures for which LS -DYNA was used for structural analysis. However, the 24PTH DSC Type 3 basket egg-crate design is based on the NUHOMS EOS System baskets, so the analysis methodologies including the use of ANSYS for structural analysis for the 24PTH DSC Type 3 basket followed the approach for the NUHOMS EOS basket analysis described in CoC 1042 UFSAR, Section 3.9.2 [1].

Reference:

1. NUHOMS EOS System Updated Final Safety Analysis Report, Docket Number 72-1042, Revision 4.

Original Impact:

No change as a result of this RAI.

Supplemental Response to RAI 4.5:

The clearance gaps discussed in the Original Response were modeled in the handling load analysis, but not in the accident side drop load analysis. Additional sensitivity analysis is performed to appropriately consider the effect of the [ ] gap at the intersecting plate slots in the side drop analysis. The Type 3 basket ANSYS model described in UFSAR Section P.3.8.6.1 is modified in such a way that the gaps at the slots of the intersecting plates are

[ ], and the bounding load case from UFSAR Section P.3.8.7.3 of a 210°, 75g side drop without bolts and tie rods is reevaluated. Side loads, material properties, thermal gaps, dummy DSC displacement and all other criteria are unchanged. UFSAR Figure P.3.8-8 has been added and Table P.3.8-7, Table P.3.8-9, and Table P.3.8-11 have been updated to add the results of this sensitivity analysis.

The maximum strain increased from 0.00673 to 0.01048. Nevertheless, the maximum strain is still significantly less than the allowable strain of 0.03. [

]

Page 5 of 6 RAIs and Responses - Public Enclosure 3 to E-62170

The buckling analysis described in UFSAR Section P.3.8.7.3 is performed for the updated model considering a [ ] gap at the intersecting plate slots. There was still convergence at the maximum applied load of 94g, so the 24PTH Type 3 basket will not buckle under accident side drop loading. The 75g end drop evaluation discussed in UFSAR Section P.3.8.7.4 and the response to RAI 4.4 is not affected by the [ ] gap condition.

Maximum relative perpendicular displacement from one fuel compartment plate to another is determined from the ANSYS results for the accident side drop as described in UFSAR Section P.3.8.7.5. These updated results presented in UFSAR Table P.3.8-11 indicate that the maximum relative displacements between adjacent fuel compartments demonstrated a small increase when the [ ] gap is considered as compared with the case of no gap.

The structural analyses considering the revised finite element model of the 24PTH Type 3 basket with an appropriate [ ] gap at the intersecting plate slots demonstrate that the Type 3 basket is structurally adequate under accident loading conditions. Relevant computer files for the updated analysis are included in Enclosure 7.

Supplemental Impact:

UFSAR Sections P.3.8.6.1, P.3.8.7.3, and P.3.8.7.5have been revised as described in the response.

UFSAR Tables P.3.8-7, P.3.8-9, and P.3.8-11 have been revised as described in the response.

UFSAR Figure P.3.8-8 has been added as described in the response.

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