Abstract
The High Flux Isotope Reactor (HFIR) is a versatile research reactor that provides one of the highest steady-state neutron fluxes of any reactor in the world. The HFIR reactor physics team investigated the conversion of the current 93 wt% highly enriched uranium U3O8 -Al dispersion fuel to a 19.75% low-enriched uranium (LEU) U3Si2-Al dispersion fuel. The team continuously develops a Python module to streamline the analysis steps required for an LEU core design to ensure reproducible and agile design iteration. The Python module automates the data processing between analysis steps and automates the input perturbation for branch calculations and design changes. The automated framework has proven to significantly increase the efficiency and reproducibility of the reactor physics team to design High Flux Isotope Reactor (HFIR) LEU cores and thoroughly analyze performance metrics, safety metrics, and thermal safety margins. Consequently, the team can now respond rapidly to fuel fabrication engineer and thermal-hydraulic-structural analyst requests. Numerous combinations of LEU fuel designs are explored, of which two LEU fuel designs are presented in this paper: a low density silicide design, and a high-density silicide design. Results show that both designs meet or exceed safety and performance metrics with exception for minor differences caused by the hardened spectrum from LEU.
| Original language | English |
|---|---|
| Article number | 112193 |
| Journal | Nuclear Engineering and Design |
| Volume | 405 |
| DOIs | |
| State | Published - Apr 15 2023 |
Funding
This material is based upon work supported by the US Department of Energy’s National Nuclear Security Administration Office of Material Management and Minimization . Brian J. Ade is the originator of PHAME; he built the automated explicit geometry model building functions that are still present in the tool. The authors also thank Joseph Burns, Kara Godsey, and Carol Sizemore for their technical review of this paper. This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE) . The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ). This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).This material is based upon work supported by the US Department of Energy's National Nuclear Security Administration Office of Material Management and Minimization. Brian J. Ade is the originator of PHAME; he built the automated explicit geometry model building functions that are still present in the tool. The authors also thank Joseph Burns, Kara Godsey, and Carol Sizemore for their technical review of this paper. ORNL is funded by the US DOE National Nuclear Security Administration (NNSA) Office of Material Management and Minimization (M3) to perform HFIR conversion activities. The conversion from highly enriched uranium (highly enriched uranium (HEU)) (93 wt% 235 U) to low-enriched uranium (LEU) (19.75 wt% 235 U) aligns with M3’s mission to convert civilian research reactors and medical isotope production facilities for nonproliferation purposes. Initial studies to convert HFIR from its current HEU dispersion fuel to LEU fuel explored uranium-molybdenum (U-10Mo) monolithic alloy fuel because of its high uranium density (15.318 gU/cm) ( Renfro et al., 2014; Betzler et al., 2017 ). However, HFIR’s unique fuel design and requirements result in a more complex fuel design relative to the other high-performance research reactors (e.g., radial and axial contouring), which presented significant project risk. In 2017, HFIR LEU efforts were refocused on fuel design studies with LEU uranium-silicide dispersion (U 3 Si 2 -Al) fuel ( Chandler et al., 2018 ); this work was officially rebaselined to U 3 Si 2 -Al in 2019. For example, the National Institute of Standards and Technology (NIST) is considering these fuel forms for a proposed LEU research reactor to replace the National Bureau Standards Reactor (NBSR) ( Turkoglu et al., 2019 ).
| Funders | Funder number |
|---|---|
| DOE Public Access Plan | |
| National Nuclear Security Administration Office of Material Management and Minimization | |
| U.S. Department of Energy | |
| National Nuclear Security Administration |
Keywords
- HEU
- High Flux Isotope Reactor
- LEU
- ORIGEN
- Reactor physics
- Shift