NSUF 25-5368: Free Field Characterization of the Neutron RADiography Reactor Dry Tube with Demonstration of Novel Epithermal Dosimetry Materials

Non-LWR designs often rely on fission caused by neutrons in the epithermal energy range (0.5 eV – 500 keV). Conventional measurement techniques are ill-equipped to monitor these neutron levels. Advanced instrumentation is a critical component to the success of advanced reactor development and demonstration. The validation of new instruments must not necessarily be conducted in a prototypical environment, but the differences in the test environment and the anticipated deployment environment must be assessed. Here it is proposed to demonstrate the determination of epithermal neutron fluence rates using two novel materials (natural europium and enriched tin-117) while concurrently characterizing the free-field neuron flux in the Neutron RADiography (NRAD) reactor dry tube, at a core position relevant to future irradiations. Objectives 1) Measure the activation of conventional neutron dosimetry foils/wires in the NRAD dry tube to characterize the free-field neutron energy profile in the irradiation position. 2) Measure the activation of novel epithermal neutron dosimetry foils/wires in the NRAD dry tube. 3) Compare the effectiveness of industry-standard neutron energy spectrum correction techniques with and without novel epithermal neutron dosimeters to assess the impact of these new measurements. Timeline Q1: Sample Preparation Q2: Sample Irradiation Q3: Sample Measurement and Analysis. The capability to measure several activation paths that have resonances or thresholds in the epithermal neutron energy range will be demonstrated for the first time. Neutron spectrum correction techniques will be used with and without additional measurements from the epithermal neutron dosimeters to assess the impact of these materials for future measurements. Results will be prepared for publication in the journal Nuclear Instruments and Methods in Physics Research Section A. A new standard measurement method will be proposed to ASTM International of epithermal neutron fluence rate with follow-on inter-laboratory studies to validate the method across multiple institutions.

Additional Info

Field Value
Awarded Institution Idaho National Laboratory
DOI 10.46936/NSUF/60015369
Embargo End Date 2027-09-03
Facility Tech Lead Noé Morales
Irradiation Facilities Fuels and Applied Science Building
NSUF Call FY 2025 RTE 2nd Call
PI Michael Reichenberger
PIE Facilities Analytical Laboratory
Prep Facilities Analytical Laboratory
Project Member Dr. Peng Xu - Idaho National Laboratory
Project Member Dr. Michael Reichenberger, Radiation Measurement Scientist - Idaho National Laboratory (https://orcid.org/0000-0001-8749-4645)
Project Member Dr. Tommy Holschuh, Postdoctoral Researcher - Idaho National Laboratory (https://orcid.org/0000-0002-1521-4314)
Project Member Dr. Aaron Craft, Research Scientist - Idaho National Laboratory (https://orcid.org/0000-0002-7092-3826)
Project Member Mr. Kevin Tsai, Nuclear Instrumentation Engineer - Idaho National Laboratory (https://orcid.org/0000-0002-8879-3468)
Project Member Dr. Teancum Quist, Postdoctoral Research Associate - Idaho National Laboratory (https://orcid.org/0000-0002-3862-2230)
Project Type RTE