NSUF 23-4648: Hydrogen quantification in neutron irradiated monolithic metal hydrides compacts
Metal hydrides are an essential component for designing and building advanced small modular nuclear reactors. Small-modular reactors require neutron moderators that minimize the core weight and volume by increasing the neutron slowing-down power and lowering the neutron absorption. An ideal component with these qualifications is hydrogen, and it has been used extensively as a moderator in light and heavy water reactors. Metal hydrides are an improvement over liquid water because of the increased hydrogen density and ability to build these moderators into unique solid shapes. However, fabricating metal hydrides has been challenging as hydrogen distribution gradients cause internal stresses that make these metals prone to cracking and failures. Only recently have new hydrogenation techniques been developed to control and minimize the residual stresses within metal hydrides. Despite these advancements, the hydrogen distribution within metal hydrides can change under extreme conditions such as those experienced by neutron moderators and lead to failures. Therefore, we propose to investigate the effect of irradiation under elevated temperatures of YH2 rods using neutron imaging.
We have previously irradiated YH2 rods with a temperature gradient ranging from 150 °C to 300 °C and propose to employ neutron imaging to spatially quantify changes in the hydrogen content. Specimens will be prepared utilizing NSUF sample preparation and post-irradiation examination facilities located at MIT. We will specifically use the dicing capabilities located within the Hot Sample Preparation Facilities at MITR and the 4DH4 beamline at the MIT Research Reactor with a 2D scintillator-based imaging detector with a resolution of 20 μm to image the specimens. The period of performance for this project is anticipated to be 3-4 months. This time frame will be sufficient to prepare the samples (dicing) and transport them to the 4DH4 imaging beamline at the MITR. These measurements will be critical to understanding the stability of metal hydrides under extreme conditions that will guide the development of new metal hydrides capable of withstanding the conditions within advanced nuclear reactor cores.
Additional Info
| Field | Value |
|---|---|
| Abstract | Metal hydrides are an essential component for designing and building advanced small modular nuclear reactors. Small-modular reactors require neutron moderators that minimize the core weight and volume by increasing the neutron slowing-down power and lowering the neutron absorption. An ideal component with these qualifications is hydrogen, and it has been used extensively as a moderator in light and heavy water reactors. Metal hydrides are an improvement over liquid water because of the increased hydrogen density and ability to build these moderators into unique solid shapes. However, fabricating metal hydrides has been challenging as hydrogen distribution gradients cause internal stresses that make these metals prone to cracking and failures. Only recently have new hydrogenation techniques been developed to control and minimize the residual stresses within metal hydrides. Despite these advancements, the hydrogen distribution within metal hydrides can change under extreme conditions such as those experienced by neutron moderators and lead to failures. Therefore, we propose to investigate the effect of irradiation under elevated temperatures of YH2 rods using neutron imaging. We have previously irradiated YH2 rods with a temperature gradient ranging from 150 °C to 300 °C and propose to employ neutron imaging to spatially quantify changes in the hydrogen content. Specimens will be prepared utilizing NSUF sample preparation and post-irradiation examination facilities located at MIT. We will specifically use the dicing capabilities located within the Hot Sample Preparation Facilities at MITR and the 4DH4 beamline at the MIT Research Reactor with a 2D scintillator-based imaging detector with a resolution of 20 μm to image the specimens. The period of performance for this project is anticipated to be 3-4 months. This time frame will be sufficient to prepare the samples (dicing) and transport them to the 4DH4 imaging beamline at the MITR. These measurements will be critical to understanding the stability of metal hydrides under extreme conditions that will guide the development of new metal hydrides capable of withstanding the conditions within advanced nuclear reactor cores. |
| Award Announced Date | 2023-06-01T09:03:52.17 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Gordon Kohse |
| Irradiation Facility | None |
| PI | Lance Snead |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | None |