ML25090A288
| ML25090A288 | |
| Person / Time | |
|---|---|
| Site: | University of New Mexico |
| Issue date: | 05/06/2025 |
| From: | Edward Helvenston NRC/NRR/DANU/UNPL |
| To: | |
| Shared Package | |
| ML25090A285 | List: |
| References | |
| EPID L-2025-NFA-0000 | |
| Download: ML25090A288 (1) | |
Text
Enclosure 2 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 8 TO FACILITY OPERATING LICENSE NO. R-102 UNIVERSITY OF NEW MEXICO UNIVERSITY OF NEW MEXICO AGN-201M REACTOR DOCKET NO. 50-252
1.0 INTRODUCTION
The University of New Mexico (UNM) requested an amendment to Facility Operating License No. R-102 for the UNM Aerojet-General Nucleonics-201 Modified (AGN-201M) Reactor (UNMR) by letter to the U.S. Nuclear Regulatory Commission (NRC, the Commission) dated January 14, 2025 (Agencywide Documents Access and Management System Accession No. ML25027A371), as supplemented by letter dated March 26, 2025 (ML25085A117). The proposed amendment would revise License Condition (LC) 2.B.2.a of Facility Operating License No. R-102 to more accurately describe the special nuclear material (SNM) allowed to be possessed under the UNMR operating license by clarifying the material in which the SNM (in the form of uranium dioxide (UO2)) in the UNMR core fuse is embedded. Specifically, the LC would be revised to indicate that the SNM in the core fuse is embedded in polystyrene, rather than the polyethylene in which SNM is embedded in other fueled reactor components (the fuel disks and the fueled control rods).
UNMs January 14, 2025, letter states that UNM submitted the license amendment request (LAR) pursuant to previous NRC inspection reports. During an NRC security inspection conducted at the UNMR on November 30 through December 2, 2020, as documented in NRC Security Inspection Report No. 05000252/2020202, dated December 23, 2020 (ML20352A452 (transmittal letter only; the enclosed report is Official Use Only - Security-Related Information)),
the NRC staff opened an Unresolved Item that relates to this LAR.
2.0 REGULATORY EVALUATION
The NRC staff reviewed UNMs LAR and evaluated the proposed changes based on the following regulations and guidance:
Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Domestic Licensing of Production and Utilization Facilities, including Section 50.54, Conditions of licenses, paragraph (b), which states that no right to SNM shall be conferred by a 10 CFR Part 50 reactor license except as may be defined by the license, and Section 50.52, Combining licenses, which states that [t]he Commission may combine in a single license the activities of an applicant which would otherwise be licensed severally.
Part 70, Domestic Licensing of Special Nuclear Material, of 10 CFR, which establishes procedures and criteria for the issuance of licenses to receive title to, own, acquire, deliver, receive, possess, use, and transfer SNM; and to establish and provide for the terms and conditions upon which the Commission will issue such licenses.
NUREG-1537, Guidelines for Preparing and Reviewing Applications for the Licensing of Non-Power Reactors, Part 1, Format and Content, and Part 2, Standard Review Plan and Acceptance Criteria (ML042430055 and ML042430048, respectively),
including section 9.5, Possession and Use of Byproduct, Source, and Special Nuclear Material, of Parts 1 and 2. Section 9.5 of NUREG-1537, Part 2, provides guidance that 10 CFR Part 50 reactor licenses should explicitly state which materials used at a licensee facility are covered by the 10 CFR Part 50 license.
3.0 TECHNICAL EVALUATION
UNMR LCs 2.B.2.a and 2.B.2.b are the LCs which allow possession of SNM under the 10 CFR Part 50 UNMR operating license pursuant to 10 CFR Part 70. Current LC 2.B.2.a allows receipt, possession, and use of reactor fuel, including the UNMRs fueled control rods. LC 2.B.2.b (which would not be revised by the proposed amendment) allows possession and use of other SNM (e.g., plutonium) that may be produced by UNMR operation.
As discussed in sections II.A and V.A of the UNMR safety analysis report (SAR), submitted to the NRC by letter dated February 21, 2007 (ML092170540), the UNMR core fuse is a polystyrene plug that supports the bottom half of the reactor core. There is a uranium loading in the fuse that is double (by volume) that of the nominal uranium density of the reactor fuel, such that more heat is generated in the fuse during reactor operation than in the core. If the temperature of the fuse rises excessively (e.g., due to a reactor transient), the fuse will melt and the lower part of the core will drop approximately 2 inches, shutting the reactor down to help ensure the core fuel disks are not damaged.
In its letter dated January 14, 2025, UNM proposed to revise LC 2.B.2.a to indicate that uranium that may be possessed under LC 2.B.2.a includes both uranium embedded in polyethylene and uranium embedded in polystyrene, such that the LC 2.B.2.a possession allowance would clearly encompass the core fuse material. The NRC staff subsequently suggested additional changes to UNMs proposed LC 2.B.2.a for clarity and conciseness, for consistency with recently issued LCs for other research reactors, and to ensure consistency with the UNMR SAR. By email dated March 17, 2025 (ML25076A605), the NRC staff provided UNM with a draft of the proposed LC 2.B.2.a wording with the suggested NRC staff changes, to provide UNM the opportunity to verify the LC 2.B.2.a was correct and consistent with UNMs LAR. UNM confirmed by letter dated March 26, 2025 (ML25085A117), that the draft LC wording was correct and that it accurately reflected the intent of UNMs LAR.
The current LC 2.B.2.a states:
a.
to receive, possess, and use up to 700 grams of contained uranium-235 enriched to less than 20% in uranium dioxide (UO2) embedded in radiation stabilized polyethylene, in connection with the operation of the reactor; and The revised LC 2.B.2.a would state (added text indicated in bold):
- a.
to receive, possess, and use, but not separate, up to 700 grams of contained uranium-235 enriched to less than 20% in the form of uranium dioxide (UO2) embedded in radiation stabilized polyethylene and nominally doubly-loaded polystyrene, in connection with the operation of the reactor; and The NRC staff reviewed the changes to LC 2.B.2.a. The NRC staff notes that, according to the UNMR SAR as discussed above, the core fuse is a polystyrene plug that is doubly-loaded with uranium compared to the polyethylene reactor fuel. UNMR technical specification (TS) 2.2.b also describes the thermal fuse as made of polystyrene. Therefore, the NRC staff finds the addition of the wording and nominally doubly-loaded polystyrene to be consistent with the UNMR SAR and TSs.
UNM stated in its January 14, 2025, letter that its requested change to LC 2.B.2.a affects only the wording of the operating license, and has no known bearing on any UNMR safety basis.
Based on information in UNMR SAR Table 1, the NRC staff notes that the core fuse uranium-235 (U-235) mass is small compared to either the 700 gram possession limit specified in LC 2.B.2.a, or the total U-235 loading in the polyethylene fuel disks and control rods in the reactor core (approximately 667 grams of U-235 per UNMR TS 5.1.a). Therefore, the NRC staff expects that the revision of LC 2.B.2.a to clearly include the core fuse material is not likely to affect the adequacy of the 700 gram possession limit specified in LC 2.B.2.a. The NRC staff notes that UNM is responsible to continue to ensure that the total quantity of SNM possessed under the UNMR operating license remains within the limits specified in the license. Because the U-235 possession limit quantity and enrichment specified in LC 2.B.2.a are not being changed, because the change does not result in any physical changes to the UNMR or the radioactive material present at the UNMR facility, and because the change is only clarifying the description of the form of the material that may be possessed, the NRC staff also finds that the addition of the wording and nominally doubly-loaded polystyrene does not impact facility safety, nor does it affect the applicability of existing regulatory requirements to the facility. For example, facility security requirements would not change because the SNM possessed under the UNMR operating license would continue to be less than Category III per Section 73.2, Definitions, of 10 CFR Part 73, Physical Protection of Plants and Materials.
As part of the additional suggested NRC staff changes to the LC 2.B.2.a wording discussed above, the NRC staff also added the wording but not separate and the form of to LC 2.B.2.a.
UNM confirmed that these changes were appropriate as discussed above. The NRC staff finds that the addition of but not separate clarifies that UNMR fuel must remain in its licensed form and that the UNMR license does not permit separation of SNM in UNMR fuel, consistent with the LC 2.B.1 designation of the UNMR as a utilization facility licensed under 10 CFR Part 50.
The NRC staff also finds that the addition of the form of specifies that UO2 embedded in radiation stabilized polyethylene and nominally doubly-loaded polystyrene is the form of material in which the SNM described in LC 2.B.2.a may be possessed.
Based on the above, the NRC staff finds that the changes to UNMR LC 2.B.2.a help ensure that SNM on the UNMR operating license, and how the SNM may be used, are clearly identified and described in the license in conformance with 10 CFR Part 50 and 10 CFR Part 70, and consistent with the guidance in and NUREG-1537. Therefore, the NRC staff finds that the changes to LC 2.B.2.a are acceptable.
4.0 ENVIRONMENTAL CONSIDERATION
The amendment relates to changes in editorial, corrective or other minor revisions. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR Section 51.22, Criterion for categorical exclusion; identification of licensing and regulatory actions eligible for categorical exclusion or otherwise not requiring environmental review, paragraph (c)(10)(v). Pursuant to 10 CFR Section 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
5.0 CONCLUSION
The Commission concludes that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) there is reasonable assurance that such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors: E. Helvenston, NRR B. Gallagher, NRR Date: May 6, 2025