UN燃料耐腐蚀性能及掺杂改性的研究进展

王明江, 王晓敏, 肖红星

Research Progress on Corrosion Resistance of UN Fuel and Its Doping Modification

WANG Mingjiang, WANG Xiaomin, XIAO Hongxing

表3 掺杂物对UN燃料耐腐蚀性能的影响汇总

Table 3 Summary of the influence of additives on the corrosion resistance of UN fuel

Additive Form Influence Conclusion UO2 Dual-phase The onset temperature decreases and the corrosion rate accelerates The doping of UO2 will cause corrosion to occur throughout the entire core block, providing more diffusion channels and intensifying the corrosion of the fuel U3Si2 Dual-phase The onset temperature rises, and the corrosion rate accelerates in the later stage. The weight gain decreases within a short period of time The doping of U3Si2 transforms the corrosion mechanism into intergranular corrosion, thereby inhibiting crack propagation UB2 Partial solid solution The onset temperature increased while the corrosion rate remained basically the same, and the integrity after corrosion was better The UB2 at the grain boundaries may have inhibited the occurrence of corrosion through the grain boundary modification method, and enhanced the integrity after corrosion Zr Complete solid solution The onset temperature and corrosion rate vary depending on the experimental method The sensitivity of solid solutions to air and steam may vary Al、Ni Dual-phase The sintering process is difficult. The addition of Al will lower the initial temperature The differences between the UN and Al in terms of density and thermal expansion coefficient result in significant internal stress, which further aggravates the corrosion Cr Partial solid solution The initial temperature rises, and it further increases after annealing Solid solutions play a significant role in enhancing corrosion resistance. The effects of suppressing segregation and increasing the strength of grain boundaryneed to be further verified