@article{ffda635b821949048c703bef26bf7789,
title = "Advancements in Yttrium Hydride Moderator Development",
abstract = "As microreactors evolve to become a more affordable and efficient worldwide energy source, the development of moderator material within the system to decrease the required mass of low-enriched uranium fuel is important. The use of low- instead of high-enriched uranium in small nuclear reactors stems from recent national policies associated with nonproliferation. New designs are being developed for a range of applications and nuclear space systems in particular. Using system geometries such as those described in this paper, the next step is to advance the technology readiness level of moderator material such as delta-yttrium hydride (YHx,x = 1.6–2.0) so that it can be qualified for use in a microreactor system. Although characterization of unirradiated material has been documented previously, to fully understand the performance of this material, behavior in relevant irradiation environments must occur. This paper describes the fabrication of yttrium hydride samples through innovative techniques and how these samples were tested in two relevant neutron environments. These two experiments include (1) a critical experiment performed at the National Criticality Experiments Research Center (NCERC) to evaluate reactivity changes in a neutron-critical environment and (2) irradiation in the Advanced Test Reactor (ATR) to assess structural integrity/material form, thermophysical data, hydrogen permeability, and other features post irradiation. For this purpose, hundreds of samples were fabricated for the NCERC and ATR experiments and are described within this paper.",
keywords = "ATR, NCERC, Yttrium hydride, microreactors, moderator",
author = "Holly Trellue and Chase Taylor and Erik Luther and Theresa Cutler and Aditya Shivprasad and Jewell, \{J. Keith\} and Rao, \{Dasari V.\} and Michael Davenport",
note = "Funding Information: The work submitted for this special issue was supported by the DOE-NE under the Advanced Reactor Technology portfolio{\textquoteright}s Microreactor Program. The content represents ongoing efforts by the Microreactor Program to enable accelerated development and demonstration of microreactor technology. The critical experiment was supported by the DOE Nuclear Criticality Safety Program and was funded and managed by the National Nuclear Security Administration (NNSA) for the DOE. Los Alamos National Laboratory (LANL) is operated by Triad National Security, LLC, for the NNSA of the DOE (contract no. 89233218CNA000001). The Hypatia experiment was planned and YHX discs manufactured under the LANL Laboratory Directed Research and Development-Directed Research project 20150058DR, “Multi-Scale Kinetics of Self-Regulating Nuclear Reactors.” We would like to thank Changhu Xing, Dong Choe, and Douglas E. Stacey (Idaho National Laboratory) for their contributions in the thermal, neutronic, and structural analysis and design of the ATR irradiation experiment and David Wootan at Pacific Northwest National Laboratory for providing input on the FFTF experiments. MCNP{\textregistered} and Monte Carlo N-Particle{\textregistered} are registered trademarks owned by Triad National Security, LLC, manager and operator of Los Alamos National Laboratory. Any third party use of such registered marks should be properly attributed to Triad National Security, LLC, including the use of the designation as appropriate. Funding Information: The work submitted for this special issue was supported by the DOE-NE under the Advanced Reactor Technology portfolio{\textquoteright}s Microreactor Program. The content represents ongoing efforts by the Microreactor Program to enable accelerated development and demonstration of microreactor technology. The critical experiment was supported by the DOE Nuclear Criticality Safety Program and was funded and managed by the National Nuclear Security Administration (NNSA) for the DOE. Los Alamos National Laboratory (LANL) is operated by Triad National Security, LLC, for the NNSA of the DOE (contract no. 89233218CNA000001). The Hypatia experiment was planned and YH discs manufactured under the LANL Laboratory Directed Research and Development-Directed Research project 20150058DR, “Multi-Scale Kinetics of Self-Regulating Nuclear Reactors.” We would like to thank Changhu Xing, Dong Choe, and Douglas E. Stacey (Idaho National Laboratory) for their contributions in the thermal, neutronic, and structural analysis and design of the ATR irradiation experiment and David Wootan at Pacific Northwest National Laboratory for providing input on the FFTF experiments. MCNP{\textregistered} and Monte Carlo N-Particle{\textregistered} are registered trademarks owned by Triad National Security, LLC, manager and operator of Los Alamos National Laboratory. Any third party use of such registered marks should be properly attributed to Triad National Security, LLC, including the use of the designation as appropriate. X Publisher Copyright: {\textcopyright} This work was authored as part of the Contributor{\textquoteright}s official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.",
year = "2022",
month = apr,
day = "29",
doi = "10.1080/00295450.2022.2043088",
language = "English",
volume = "209",
pages = "S123--S135",
journal = "Nuclear Technology",
issn = "0029-5450",
publisher = "Taylor and Francis Ltd.",
number = "sup1",
}