ML23121A134
| ML23121A134 | |
| Person / Time | |
|---|---|
| Site: | 07109358 |
| Issue date: | 05/15/2023 |
| From: | Storage and Transportation Licensing Branch |
| To: | TN Americas LLC |
| Shared Package | |
| ML23121A132 | List: |
| References | |
| EPID L-2023-LLA-0019 | |
| Download: ML23121A134 (1) | |
Text
Request for Additional Information for the review of the Model No. TN-LC Package Docket No. 71-9358 By letter dated February 15, 2023 (Agencywide Documents Access and Management System Package Accession No. ML23046A179), TN Americas LLC submitted an amendment request for Revision No. 8 to Certificate of Compliance No. 9358 for the Model No. TN-LC package.
The amendment request replaced the use of fuel assembly cans with top and bottom damaged fuel end caps: During fabrication and during fit-up operations it was discovered that the required dimensions for fuel assembly can were so close to the compartment opening dimensions that the can would not reasonably fit into the basket. Therefore, end caps, which are sufficient to fulfill the intended function, are proposed to be used instead.
This request for additional information (RAI) identifies information needed by the staff in connection with its detailed review of the application.
Each individual RAI describes information needed by the staff to complete its review of the application and to determine whether the applicant demonstrated compliance with the regulatory requirements of Title 10 of the Code of Federal Regulations (10 CFR) Part 71.
CHAPTER 2 STRUCTURAL EVALUATION 2.1 Quantify the maximum axial gap that is available between the basket and the cask cavity described in section 1.4.5.2.1 of the safety analysis report (SAR) based on the TN-LC cask maximum cavity length and the 1FA basket minimum length, or specify the axial gap limits on the drawing, so it can be verified.
Paragraph 4 of section 1.4.5.2.1 of the SAR, Rev. 11A, states, neither end cap can come off of the basket compartment once the cask is closed because the axial gap between the basket and the cask cavity is smaller than either the thickness of the top end cap plate, or the combined thickness of the bottom end cap plate and its spacers.
The maximum possible axial gap between the basket and the cask cavity cannot be determined by the staff since only the minimum length (182.5 inches) of the TN-LC cask cavity is provided on Drawing 65200-71-01, sheet 4, and the maximum cavity length is not specified. Although the 1FA basket length provided on Drawing 65200-71-90 is 181.5 inches nominal, the minimum length is not specified or cannot be determined without knowing fabrication tolerances. The maximum possible axial gap needs to be determined so it can be compared against the minimum cover plate thickness to validate the evaluation provided in the SAR.
This information is needed to determine compliance with 10 CFR 71.31(b), 71.33, and 71.43(f).
2.2 Justify the use of American Welding Society (AWS) D1.3 code in lieu of AWS D1.6 code for welding of important to safety (ITS) damaged fuel end cap assemblies.
Enclosure
Note 3 on DWG No. 65200-71-92, Rev. 0B, requires all welding to be performed per D1.3 or American Society of Mechanical EngineersSection IX, as applicable, and all visual inspection of welds per AWS D1.3. The end cap assemblies are made of stainless-steel material of thickness varying from 1.25 to 0.105. AWS D1.6 code contains welding requirements for the fabrication of welded stainless-steel structures and is intended to cover base metal material thickness of 1/16 inch and above. While AWS 1.3 code contains welding requirements for a typical carbon or alloy sheet steel of material thickness less than or equal to 3/16.
This information is needed to determine compliance with 10 CFR 71.119.
2.3 Clarify Note 7 on Drawing 65200-71-90, sheet 1, about fuel gap.
In Note 7 on Drawing 65200-71-90 R8, sheet 1, it states, The fuel gap shall not exceed 1.0 inch. This note does not specify in what direction and between which components this gap needs to be verified. This note needs to be clarified to implement this requirement properly.
This information is needed to determine compliance with 10 CFR 71.55(d) and 71.55(e).
2.4 Justify the quality classification of the studs (Item 3) and the nuts (Item 7) shown on Drawing 65200-71-90, sheet 1, as not important to safety (NITS). Provide the size, material specification, and installation requirements of the studs and nuts (Items 3 & 7) and clarify how they are attached to the basket structure.
The studs and nuts connect the basket tube structure (Items 1 & 2) to the rails (Items 5
& 11) that fill the space between the cask wall and the tube structure; while the poison plate (Item 4) and insert plate (Item 8) are sandwiched between the rail and the tube structure. All these components are classified as ITS, quality category A, while the studs and nuts that keep these components together in their position inside the cask are classified as NITS. Following guidance in NUREG/CR-6407, Classification of Transportation Packaging and Dry Spent Fuel Storage System Components According to Importance to Safety, it appears to the staff that these components should be classified as ITS Category C Items.
The stud size, material specification, and installation requirements are not provided on the drawing. As currently depicted on the drawing, it is not clear how studs are attached to the basket structure (i.e., welded on to the surface of Items 1 & 2 or mechanically fastened with a through thickness holes in Items 1 & 2). It is important to know this for the transport of the damaged fuel, specifically if the studs are mechanically fastened with a through thickness holes in the basket walls.
This information is needed to determine compliance with 10 CFR 71.33 and 71.51.