A Modeling and Neutron Diffraction Study of the High Temperature Properties of Sub-Stoichiometric Yttrium Hydride for Novel Moderator Applications
Low-enriched-uranium (LEU) reactor systems utilize moderators to improve neutron economy. Solid yttrium hydride is one of the primary moderator candidates for high-temperature (>700 °C) nuclear reactor applications. This is due to its ability to retain hydrogen at elevated temperatures compared t...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-01-01
|
| Series: | Metals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-4701/12/2/199 |
| _version_ | 1797478074119356416 |
|---|---|
| author | Vedant K. Mehta Sven C. Vogel Dan Kotlyar Michael W. D. Cooper |
| author_facet | Vedant K. Mehta Sven C. Vogel Dan Kotlyar Michael W. D. Cooper |
| author_sort | Vedant K. Mehta |
| collection | DOAJ |
| description | Low-enriched-uranium (LEU) reactor systems utilize moderators to improve neutron economy. Solid yttrium hydride is one of the primary moderator candidates for high-temperature (>700 °C) nuclear reactor applications. This is due to its ability to retain hydrogen at elevated temperatures compared to other metal hydrides. For reactor modeling purposes, both neutronic and thermos-mechanical modeling, several high-temperature properties for sub-stoichiometric yttrium hydride (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Y</mi><msub><mi>H</mi><mrow><mn>2</mn><mo>−</mo><mi>x</mi></mrow></msub></mrow></semantics></math></inline-formula>) are needed. In this paper, we present an atomistics and a neutron diffraction study of the high-temperature properties of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Y</mi><mo> </mo></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo> </mo><mi>Y</mi><msub><mi>H</mi><mrow><mn>2</mn><mo>−</mo><mi>x</mi></mrow></msub></mrow></semantics></math></inline-formula>. Specifically, we focus on the thermal lattice expansion effects in yttrium metal and yttrium hydride, which also govern bulk thermal expansion. Previously reported physical and mechanical properties for sub-stoichiometric yttrium hydride at ambient conditions are expanded using lattice dynamics to take into account high-temperature effects. Accordingly, an array of newly generated properties is presented that enables high-fidelity neutronics, and thermomechanical modeling. These properties include various elastic moduli, thermal expansion parameters for yttrium and yttrium hydride, and single-phase (<i>YH</i><sub>2</sub><sub>−</sub><sub><i>x</i></sub>) and two-phase (<i>Y</i> + <i>YH</i><sub>2</sub><sub>−</sub><sub><i>x</i></sub>) density as a function of stoichiometry and density. |
| first_indexed | 2024-03-09T21:26:52Z |
| format | Article |
| id | doaj.art-b3fdec7acd3c4ae0b83aab877ab4f11c |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-03-09T21:26:52Z |
| publishDate | 2022-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Metals |
| spelling | doaj.art-b3fdec7acd3c4ae0b83aab877ab4f11c2023-11-23T21:06:32ZengMDPI AGMetals2075-47012022-01-0112219910.3390/met12020199A Modeling and Neutron Diffraction Study of the High Temperature Properties of Sub-Stoichiometric Yttrium Hydride for Novel Moderator ApplicationsVedant K. Mehta0Sven C. Vogel1Dan Kotlyar2Michael W. D. Cooper3Nuclear Engineering & Nonproliferation Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USAMaterials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USADepartment of Nuclear Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USAMaterials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USALow-enriched-uranium (LEU) reactor systems utilize moderators to improve neutron economy. Solid yttrium hydride is one of the primary moderator candidates for high-temperature (>700 °C) nuclear reactor applications. This is due to its ability to retain hydrogen at elevated temperatures compared to other metal hydrides. For reactor modeling purposes, both neutronic and thermos-mechanical modeling, several high-temperature properties for sub-stoichiometric yttrium hydride (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Y</mi><msub><mi>H</mi><mrow><mn>2</mn><mo>−</mo><mi>x</mi></mrow></msub></mrow></semantics></math></inline-formula>) are needed. In this paper, we present an atomistics and a neutron diffraction study of the high-temperature properties of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Y</mi><mo> </mo></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo> </mo><mi>Y</mi><msub><mi>H</mi><mrow><mn>2</mn><mo>−</mo><mi>x</mi></mrow></msub></mrow></semantics></math></inline-formula>. Specifically, we focus on the thermal lattice expansion effects in yttrium metal and yttrium hydride, which also govern bulk thermal expansion. Previously reported physical and mechanical properties for sub-stoichiometric yttrium hydride at ambient conditions are expanded using lattice dynamics to take into account high-temperature effects. Accordingly, an array of newly generated properties is presented that enables high-fidelity neutronics, and thermomechanical modeling. These properties include various elastic moduli, thermal expansion parameters for yttrium and yttrium hydride, and single-phase (<i>YH</i><sub>2</sub><sub>−</sub><sub><i>x</i></sub>) and two-phase (<i>Y</i> + <i>YH</i><sub>2</sub><sub>−</sub><sub><i>x</i></sub>) density as a function of stoichiometry and density.https://www.mdpi.com/2075-4701/12/2/199DFTneutron diffractionhigh-temperature propertiesyttrium hydridethermal expansion |
| spellingShingle | Vedant K. Mehta Sven C. Vogel Dan Kotlyar Michael W. D. Cooper A Modeling and Neutron Diffraction Study of the High Temperature Properties of Sub-Stoichiometric Yttrium Hydride for Novel Moderator Applications Metals DFT neutron diffraction high-temperature properties yttrium hydride thermal expansion |
| title | A Modeling and Neutron Diffraction Study of the High Temperature Properties of Sub-Stoichiometric Yttrium Hydride for Novel Moderator Applications |
| title_full | A Modeling and Neutron Diffraction Study of the High Temperature Properties of Sub-Stoichiometric Yttrium Hydride for Novel Moderator Applications |
| title_fullStr | A Modeling and Neutron Diffraction Study of the High Temperature Properties of Sub-Stoichiometric Yttrium Hydride for Novel Moderator Applications |
| title_full_unstemmed | A Modeling and Neutron Diffraction Study of the High Temperature Properties of Sub-Stoichiometric Yttrium Hydride for Novel Moderator Applications |
| title_short | A Modeling and Neutron Diffraction Study of the High Temperature Properties of Sub-Stoichiometric Yttrium Hydride for Novel Moderator Applications |
| title_sort | modeling and neutron diffraction study of the high temperature properties of sub stoichiometric yttrium hydride for novel moderator applications |
| topic | DFT neutron diffraction high-temperature properties yttrium hydride thermal expansion |
| url | https://www.mdpi.com/2075-4701/12/2/199 |
| work_keys_str_mv | AT vedantkmehta amodelingandneutrondiffractionstudyofthehightemperaturepropertiesofsubstoichiometricyttriumhydridefornovelmoderatorapplications AT svencvogel amodelingandneutrondiffractionstudyofthehightemperaturepropertiesofsubstoichiometricyttriumhydridefornovelmoderatorapplications AT dankotlyar amodelingandneutrondiffractionstudyofthehightemperaturepropertiesofsubstoichiometricyttriumhydridefornovelmoderatorapplications AT michaelwdcooper amodelingandneutrondiffractionstudyofthehightemperaturepropertiesofsubstoichiometricyttriumhydridefornovelmoderatorapplications AT vedantkmehta modelingandneutrondiffractionstudyofthehightemperaturepropertiesofsubstoichiometricyttriumhydridefornovelmoderatorapplications AT svencvogel modelingandneutrondiffractionstudyofthehightemperaturepropertiesofsubstoichiometricyttriumhydridefornovelmoderatorapplications AT dankotlyar modelingandneutrondiffractionstudyofthehightemperaturepropertiesofsubstoichiometricyttriumhydridefornovelmoderatorapplications AT michaelwdcooper modelingandneutrondiffractionstudyofthehightemperaturepropertiesofsubstoichiometricyttriumhydridefornovelmoderatorapplications |