The use of metal hydrides, especially the zirconium hydride (ZrHx), as high-performance moderators in advanced reactors has long-term precedent. However, the application of ZrHx in nuclear system required careful management of the moderator temperature to avoid hydrogen desorption at elevated temperatures. Yttrium hydride (YHx) is more attractive for high temperature moderator application, attributed to its superior thermal stability. The successful deployment of high temperature YHx moderator in advanced reactors requires development of a consistent and affordable production pathway along with the establishment of a complete database of the thermomechanical and neutronics properties and irradiation response. In this presentation, we will demonstrate the successful fabrication of crack-free bulk YHx and discuss the detailed characterization of the as-fabricated YHx, including hydrogen concentration determination, crystal structure, thermal stability, thermophysical and mechanical properties, and thermal neutron scattering properties. In addition, the impact of neutron irradiation on the thermomechanical properties will also be discussed.