U3Si2 and UO2 composites densified by spark plasma sintering for accident-tolerant fuels

Understanding xenon and vacancy behavior in UO2, UN and U3Si2: a comparative DFT+Ustudy

“…1,2 Different from UO 2 , UN and U 3 Si 2 can lower the centreline temperature during operation and increase the melting margin. 3 In particular, UN exhibits low fission gas release and good irradiation stability, [4][5][6][7] and U 3 Si 2 may have favourable swelling characteristics 8,9 due to its long potential fuel cycle benefit. However, rapid oxidation of UN and U 3 Si 2 occurs when they are exposed to a steam/water environment, leading to fuel dispersal along with cladding integrity loss.…”

Survey of Uranium Nitride and Mixed Oxide Fuels for Microreactor Applications

“…Thus, not only liquid metals can be used as coolant that will enable run-beyond-cladding-breach (RBCB), but also be used as thermal bonding medium to lower the temperature jump caused by the fuel-cladding gap. As UN reacts with high temperature water/steam, mitigation approaches such as UN-U3Si2 and UO2-U3Si2 composite fuels [35,36], protective coating, and dopants [37],…”

Self-contained dual-scale composite architectures in spray dried zirconium diboride

“…A candidate composite nuclear fuel concept consists of fissile ceramic microspheres dispersed in a fissile matrix, to boost thermophysical and thermochemical fuel stability during normal operation and in the event of anticipated operational occurrences (AOOs) or design-basis accidents [1], [2]. Ceramic materials like uranium diboride (UB2) [3], uranium silicide (U3Si2) [4] and uranium nitride (UN) [5], [6] are embedded in the parent nuclear fuel, typically uranium oxide (UO2). However, non-fissile ceramics, such as zirconium diboride (ZrB2) are also potential microsphere materials for accident tolerant composite fuels.…”