ML23072A338
| ML23072A338 | |
| Person / Time | |
|---|---|
| Site: | 07109221 |
| Issue date: | 03/15/2023 |
| From: | Storage and Transportation Licensing Branch |
| To: | US Dept of Energy, Naval Reactors |
| Shared Package | |
| ML23072A335 | List: |
| References | |
| Download: ML23072A338 (1) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001
SAFETY EVALUATION REPORT
Docket No. 71-9221 Model No. NRBK-41 Certificate of Compliance No. 9221 Revision No. 9
SUMMARY
By letter dated January 6, 2023 (Agencywide Documents Access and Management System Accession No. ML23025A402), Naval Reactors submitted an application for renewal of Certificate of Compliance (CoC) No. 9221 for the Model No. NRBK-41 package. In addition, the applicant proposed to change the formula for calculating the maximum equivalent Uranium-235 grams authorized for transport in NRBK-41 and updated drawing references. The Nuclear Regulatory Commission staff (staff) reviewed the application using the guidance in NUREG-2216, Standard Review Plan for Transportation Packages for Spent Fuel and Radioactive Material." Based on the statements and representations in the application, as supplemented, the staff agrees that these changes do not affect the ability of the package to meet the requirements of 10 CFR Part 71. The staff concludes that the certificate can be renewed for a five-year term.
1.0 GENERAL INFORMATION
The applicant proposed to add Westinghouse Drawing No. 6235E21 to Condition 5(a)(3). Staff found this acceptable because the drawing was provided with the safety analysis report submitted on November 2, 1995. In addition, the applicant proposed to remove drawing revision letters associated with drawings identified in Condition 5(a)(3) and Condition 5(b)(1).
After discussing this change with Naval Reactors, staff revised the conditions to point to the applications listed in the reference sections since these contain the most recent drawing versions contained in the safety analysis report. Staff considers this change to be administrative and therefore acceptable. Based on a review of the statements and representations in the application, the staff concludes that the package contents have been adequately described to meet the requirements of 10 CFR Part 71.
2.0 STRUCTURAL
The staff reviewed the proposed changes and determined that they did not impact the staffs previous SER findings. Therefore, the staff finds that a new evaluation is not needed.
3.0 THERMAL EVALUATION
The staff reviewed the proposed changes and determined that they did not impact the staffs previous SER findings regarding the package thermal design. Therefore, the staff finds that a new evaluation is not needed.
4.0 CONTAINMENT EVALUATION
The staff reviewed the proposed changes and determined that they did not impact the staffs previous SER findings regarding the package containment design. Therefore, the staff finds that a new evaluation is not needed.
2
5.0 SHIELDING EVALUATION
The staff reviewed the proposed changes and determined that they did not impact the staffs previous SER findings regarding the package shielding design. Therefore, the staff finds that a new evaluation is not needed.
6.0 CRITICALITY
The applicant proposed to revise the equation for calculating equivalent grams of Uranium-235 in certificate condition 5(b)(2) to account for Thorium-232. The staff compared the fission cross sections of Thorium-232 and Uranium-235 and determined that Thorium-232 will effectively reduce the neutron multiplication factor for the package when Thorium-232 is either shipped by itself or in conjunction with other fissile isotopes authorized for transport because theThorium-232 fission cross section is several orders of magnitude below the Uranium-235 fission cross section. In addition, staff performed a confirmatory calculation using the ORIGEN computer code to determine the amount of heat generated by the maximum quantity of Thorium-232 calculated using the Uranium-235 equivalent grams equation in certificate condition 5(b)(2).
Staff determined that the heat output of the maximum quantity of Thorium-232 is orders of magnitude below the maximum decay heat load authorized in certificate condition 5(b)(2).
Based on its review and confirmatory calculations, the staff finds the applicants proposed change is bounded by the existing analyses; therefore, the staff finds the proposed change acceptable.
7.0 PACKAGE OPERATIONS
The staff reviewed the package operations procedures using the guidance in NUREG-2216 and found them to be adequate. Based on a review of the statements and representations in the application, the staff concludes that the operating procedures meet the requirements of 10 CFR Part 71 and that these procedures are adequate to assure the package will be operated in a manner consistent with its evaluation for approval.
8.0 ACCEPTANCE TESTS AND MAINTENANCE PROGRAM REVIEW
The staff reviewed the maintenance procedures for the package using the guidance in NUREG-2216 and found them to be adequate. Based on a review of the statements and representations in the application, the staff concludes that the maintenance procedures meet the requirements of 10 CFR Part 71 and that these procedures are adequate to assure the package will be maintained in a manner consistent with its evaluation for approval.
CONDITIONS
The CoC includes the following condition(s) of approval:
Condition 1(d)(3) in the header on page 2 of 3 was revised to fix typographical errors.
Condition 5(a)(3) was revised to remove drawing revisions and point to the applications in the Reference section.
Condition 5(b)(1) was revised to remove drawing revisions and point to the applications in the Reference section.
3 Condition 5(b)(2) was revised to add Thorium-232 to the Uranium-235 equivalent grams equation.
Condition 9 was revised to reflect the new expiration date.
The references section has been updated to include this request and to reformat an October 4, 2017, entry.
Minor editorial and formatting changes were made.
CONCLUSIONS Based on the statements and representations contained in the application, and the conditions listed above, the staff concludes that the design has been adequately described and evaluated, and the Model No. NRBK-41 package meets the requirements of 10 CFR Part 71.
Issued with Certificate of Compliance No. 9221, Revision No. 9 on.March 15, 2023