ML25332A103
| ML25332A103 | |
| Person / Time | |
|---|---|
| Issue date: | 01/14/2026 |
| From: | Andrew Barto NRC/NMSS/DFM/NARAB |
| To: | Roman C Division of Fuel Management |
| References | |
| Download: ML25332A103 (0) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 MEMORANDUM TO:
Cinthya Román, Deputy Director Division of Fuel Management Office of Nuclear Material Safety and Safeguards FROM:
Andrew Barto, Sr. Nuclear Engineer Nuclear Analysis and Risk Assessment Branch Division of Fuel Management Office of Nuclear Material Safety and Safeguards
SUBJECT:
SUMMARY
OF AUGUST 27, 2025, U.S. DEPARTMENT OF ENERGY/U.S. NUCLEAR REGULATORY COMMISSION COLLABORATION FOR CRITICALITY SAFETY SUPPORT FOR COMMERCIAL-SCALE HIGH-ASSAY LOW-ENRICHED URANIUM FUEL CYCLES AND TRANSPORTATION CALL #2 WORKSHOP
Background:
On August 27, 2025, the U.S. Nuclear Regulatory Commission (NRC) sponsored a joint workshop with the U.S. Department of Energy (DOE) in Germantown, Maryland, on the DOE/NRC Collaboration for Criticality Safety Support for Commercial-Scale High-Assay Low-Enriched Uranium (HALEU) Fuel Cycles and Transportation (DNCSH) Project. This workshop, the second in a series co-hosted by the NRC and DOE, described the NRC and DOE collaboration initiated by the 2020 Energy Act and as funded by the Inflation Reduction Act to develop publicly available data to support the NRC in initiating, executing, and completing activities that will reduce the uncertainty associated with approving commercial-scale facility and transportation operations for the HALEU fuel cycle. Reaffirming this need, recent executive orders, Deploying Advanced Nuclear Reactor Technologies and Reinvigorating America's Nuclear Industrial Base, both issued on May 23, 2025, have mandated rapid advanced reactor deployment and supporting infrastructure development. This project, through the development of publicly available data and collaboration with the NRC, will support industry innovation and reduce the uncertainty associated with assessing commercial-scale facility and transportation operations for the HALEU fuel cycle, directly supporting those executive orders.
The meeting notice and agenda are located at Agencywide Documents Access and Management System Accession No. ML25191A097. The presentation slides from the NRC and CONTACT:
Andrew Barto, NMSS/DFM 301-415-6941 January 14, 2026 Signed by Barto, Andrew on 01/14/26
C. Román 2
DOE staff, as well as National Laboratory partners, are available at ML25252A200. A list of in-person meeting attendees is provided in the enclosure.
A full list of in-person and virtual attendees will be provided in the full meeting report to be posted on the DNCSH website (https://www.ornl.gov/dncsh)
Discussion:
The DNCSH Project is a result of the 2020 Energy Act (Public Law No. 116-2601) and the Inflation Reduction Act (H.R. 53762) to support the availability of HALEU for civilian domestic research, development, demonstration, and commercial use. Part of the rationale for making HALEU material available is to enable commercial use through efficient economies of scale, innovative designs, and demonstration of safe performance. This effort is made possible through the availability of quality data and modern methods. The law provides direction for this area, executed as a collaboration between DOE and NRC.
Work under the DNCSH Project progresses via a series of calls for Experiment and Analysis Work Packages (EAWs), which identify key validation gaps for HALEU fuel cycle and transportation licensing and solicit industry and National Laboratory proposals for experiments and data to fill the identified gaps. The first call for EAWs focused on filling validation gaps for HALEU transportation, uranium hexafluoride (UF6) enrichment and deconversion, and fabrication of HALEU fresh fuel in various fuel forms. This call was officially announced in May 2024 and resulted in 16 proposals being awarded for benchmarks and data measurements.
The focus of the second DNCSH workshop conducted on August 27, 2025, was to: 1) share progress on the DNCSH-funded projects from Call #1; 2) identify validation gaps related to fuel cycle facility criticality analyses for HALEU fuel; and 3) discuss the proposal opportunity to be announced for Call #2 for EAWs related to the identified validation gaps.
Shana Helton, Director, Division of Fuel Management, NRC, and Florie Knauf, Acting Deputy Assistant Secretary for the Nuclear Fuel Cycle, DOE, gave opening remarks. Shana Helton emphasized the importance of code validation for licensing HALEU and non-light water reactor (non-LWR) systems. She highlighted that while the NRC can currently license such systems, improved benchmarking data will reduce conservatism and regulatory burden, enabling safer and more efficient designs. Florie Knauf reiterated DOEs commitment to supporting public data generation and innovation. She noted that the DNCSH program aligns with national priorities to reinvigorate the nuclear industrial base and improve licensing efficiency.
Walid Metwally, Oak Ridge National Laboratory (ORNL), presented results from a pre-workshop stakeholder survey. The survey had 51 responses, mostly from criticality safety practitioners and researchers. Survey results indicated high interest in enrichment, fabrication, transportation, and storage among the respondents. Key needs identified included more benchmarks, improved methods, and nuclear data. The survey results also indicated a strong interest in training on validation methods. Feedback on a fuel cycle gap assessment, discussed later in the meeting, suggested additional focus areas, including burnup credit, absorber materials, and public data availability.
Catherine Percher, Lawrence Livermore National Laboratory, and Theresa Cutler, Los Alamos National Laboratory, outlined several ongoing funded projects from Call #1.
1 Energy Act of 2020, Public Law 116-260, Division Z (2020).
2 Inflation Reduction Act of 2022, P.L. 117-169, 117th Cong. (2022).
C. Román 3
These included:
1.
UF6 Transportation with Moderator Exclusion - Revisiting historical experiments performed at Y-12 to convert them into benchmarks, 2.
TRISO Fuel Experiments - Using legacy and modern TRISO fuel for new criticality benchmarks, 3.
International Collaboration - Benchmarking experiments at Brazils Institute for Energy and Nuclear Research reactor, 4.
Structural Materials - Experiments at the Sandia Pulsed Reactor Facility - Critical Experiments facility to study the impact of materials like iron on criticality, and 5.
New Fuel Procurement - Plans to acquire modern TRISO and 20 percent enriched uranium dioxide rods for new experiments.
Iyad Al-Qasir (ORNL) discussed gaps in temperature-dependent nuclear data for advanced moderators. Iyad stated that while graphite and zirconium hydride have good data coverage, major gaps still exist for materials like beryllium carbide, silicon carbide, and yttrium hydride.
Ongoing experiments at Oak Ridges Spallation Neutron Source are helping to fill these gaps using modern measurement and modeling techniques.
Andrew Barto (NRC) introduced two new NRC reports on validation that are relevant to DNCSH work on benchmark data. NUREG/CR-7311, Determination of Bias and Bias Uncertainty for Criticality Safety Computational Methods3, provides updated validation recommendations, including statistical methods and documentation practices. NUREG/CR-7308, Sensitivity/Uncertainty Methods for Nuclear Criticality Safety Validation4, provides recommendations on sensitivity/uncertainty methods for criticality safety validation. These documents are not HALEU-specific but are applicable to validation efforts for advanced fuels.
Larry Wetzel (Subcontractor, ORNL) summarized a report presenting a comprehensive analysis of non-LWR fuel cycle facility benchmark gaps using sensitivity/uncertainty methods. Larry Wetzel stated that while good coverage exists for water-moderated TRISO systems, there are significant gaps in fast-spectrum and low-moderation systems, especially for metallic fuels and uranium chloride. The recommended focus areas from the report consisted of unmoderated HALEU systems, low hydrogen-to-fissile ratios, and graphite/silicon carbide moderation.
Cihangir Celik (ORNL) showcased a repository of application models hosted on GitHub. These models include TRISO transportation packages and manufacturing scenarios. Each model includes documentation and similarity assessments using similarity coefficient (ck) metrics.
Future plans for the repository include a web interface for users to upload models and receive similarity evaluations.
Will Wieselquist (ORNL) outlined the upcoming Call #2 for EAWs under the DNCSH Project.
The focus for this upcoming call will be facility and fabrication gaps, including those identified in the fuel facility gap assessment report described earlier, in addition to topics that were identified in Call #1. The second call will be announced by October 1, 2025, with proposals due 3 J. Clarity, W. Marshall, D. Mueller, S. Powers, B. Rearden, and S. Bowman, Determination of Bias and Bias Uncertainty for Criticality Safety Computational Methods, NUREG/CR-7311, Oak Ridge National Laboratory, Oak Ridge, Tennessee (April 2025).
4 W. Marshall, T. Greene, A. Shaw, C. Celik, and M. Dupont, Sensitivity/Uncertainty Methods for Nuclear Criticality Safety Validation, NUREG/CR-7308, Oak Ridge National Laboratory, Oak Ridge, Tennessee (April 2025).
C. Román 4
November 7, 2025, and awards by December 12, 2025. Priority will be given in the rating process to proposals using similarity assessments to demonstrate applicability to application models. The rating process will put an emphasis on experimental data generation; modeling-only proposals are unlikely to be funded.
During the question-and-answer period, participants expressed interest in progress tracking and data availability. DOE and NRC confirmed plans to update the DNCSH website and encouraged early engagement with national labs for proposal development. A follow-up survey was distributed to gather additional feedback on Call #2 priorities.
Enclosure:
In-Person Meeting Attendees
ML25332A103 OFFICE NMSS/DFM NMSS/DFM NMSS/DFM NMSS/DFM NAME ABarto WWheatley DJohnson CRomán DATE 12/3/2025 1/5/2026 1/6/2026 1/13/2026 OFFICE NMSS/DFM NAME ABarto DATE 1/14/2026 Enclosure In-Person Meeting Attendees List
SUMMARY
OF AUGUST 27, 2025, U.S. DEPARTMENT OF ENERGY/U.S. NUCLEAR REGULATORY COMMISSION COLLABORATION FOR CRITICALITY SAFETY SUPPORT FOR COMMERCIAL-SCALE HIGH-ASSAY LOW-ENRICHED URANIUM FUEL CYCLES AND TRANSPORTATION CALL #2 WORKSHOP The U.S. Nuclear Regulatory Commission Shana Helton Andrew Barto Michel Call Dan Frumkin U.S. Department of Energy Florie Knauf Brian Robinson Don Algama National Laboratories Will Wieselquist (Oak Ridge National Laboratory [ORNL])
Walid Metwally (ORNL)
Cihangir Celik (ORNL)
Travis Greene (ORNL)
Theresa Cutler (Los Alamos National Laboratory [LANL])
Nick Thompson (LANL)
Larry Wetzel (Subcontractor, ORNL)