Overview and Current Status of Analyses of Potential LEU Design Concepts for TREAT

Preliminary Results of Ancillary Safety Analyses Supporting TREAT LEU Conversion Activities

“…For these calculations, it was assumed that the concentration of TU is the same in the LEU core as in the HEU core. Based on the neutronic evaluations of core performance for the Baseline 2.0 core [4], the LEU core was expected to operate at 25% higher power and energy than that of HEU core. The fission rate would thus be higher by 25%, and the total photon source in the HEPA filter would be increased by 25% to 3.43E11 photons/s, which was used to normalize the MCNP6 results.…”

“…The assembly features an approximately 4-ft-long fuel section of 19.75% enriched UO 2 -graphite fuel with a carbon-to-uranium atom ratio of approximately 1500:1, with roughly 2-ft-long graphite axial reflectors above and below the fuel. Additional details on the fuel design can be found in [4]. After setting up the physical model of the cask and fuel subassemblies, the isotropic angular photon source distribution and energy spectrum were determined.…”

“…For each analysis in this report, the LEU design iteration is identified in the text of each section and in Table 1. A description of the LEU design variants, including Baseline 2.0, can be found in [4]. This report begins with a high-level overview of the configuration of TREAT in Section 2.…”

TREAT LEU Conversion Analyses Performed 2016-2018

“…The TREAT LEU Conceptual Design (LEU-CD) was established based on lessons learned in the analysis and fabrication development efforts of the pre-conceptual and conceptual phases of the project [1][2][3]. The baseline design parameters and key assumptions are outlined in the November 2015 revision of the program's analysis guide [7].…”

“…Following pre-conceptual and conceptual phase LEU fuel design analyses [1][2][3], a baseline conceptual LEU fuel design was established in collaboration with INL and Los Alamos National Laboratory (LANL). Detailed analysis of the TREAT LEU conceptual design (LEU-CD) was presented in the March 2016 report ANL/RTR/TM-16/1 [4], with a subset of this information also included in the TREAT convert program's conceptual phase deliverable report.…”