The Preparation And The Properties Of Anti-erosion Of Simulated Solidified High Level Radioactive Waste

The solid which high-level radioactive waste is solidified by artificial rock matrix is asthe "second-generation solidified high-level radioactive waste". Pyrochlore is a potentialman-made rock matrix which solidifies high level radioactive waste with rich actinidenuclides. Currently preparation methods of solidified pyrochlore commonly include twosteps of high-pressure molding and high-temperature sintering, which restricts the solidifiedpyrochlore practical application. This paper selects cerium element simulating actinidenuclides, and prepares simulated solidified pyrochlore by the gel-solidifying method. Thegel-solidifying method overcomes the shortcomings of traditional method. This papersystematic studies this preparation process. The study found that adding organic monomer and initiator excessive, the sample will produce pores, affecting the density. And studies showthat the sample has cracks and delamination when the green body drying temperature is toohigh. With sintering temperature to1400℃,it forms the glass. sintering temperatur should becontrolled at1250℃to1350℃.In this paper, anti-leaching behavior of simulated solidified pyrochlore is researched.The study indicates that simulated solidified pyrochlore which is prepared by thegel-solidifying method has good chemical stability. In the corrosion test, the soakingtemperature has a greater impact on the corrosion of the sample. With soaking temperatureincreasing, the sample normalized mass loss rate and the normalized leaching rate of Ceelements increase。And they reduce with immersion time prolonged. At present, mostcountries use borosilicate glass as solidification matrix of high-level radioactive waste. Thispaper also studies anti-leaching behavior of borosilicate glass. The silicon normalizedleaching rate in borosilicate glass decreases with the immersion time increasing. And thehigher the soaking temperature, the value of the silicon normalized leaching rate is larger. Inthe soaking test under the low temperature, the concentration of Mg is enriched in the samplesurface. However, Mg in the sample surface is dissolved in the high-temperature soaking test.Meanwhile, crystallization is in the sample surface.