Work

An analytical review of the problem of improving VVER-1000 reactor absorber rods (AR) has been done. It has been found that absorber rod efficiency and reliability will be enhanced by using dysprosium hafnate being a radiation-resistant and highly effective neutron absorber at the absorber rod lower part. A patent search and information analysis regarding the dysprosium hafnate neutron absorbing compositions, their properties, characteristics, manufacturing techniques and results of reactor testing has been done. It has been found that the most promising and efficient technology for mass-production of dysprosium hafnate pellets is the technology based on sintering in air. There have been established and optimized the process operation modes enabling to produce high-quality pellets with high density: ~ 8.2 ... 8.3 g/cm3. By means of chemical deposition, hafnium oxide and dysprosium hafnate nanopowders with crystallite dimensions of less than 100 nm and dysprosium hafnate pellets based on them with a density of ~ 8.0 ... 8.1 g/cm3 have been obtained. The results on the characteristics and properties of pellets hafnate dysprosium are obtained and situated in level known foreign achievements such centers as JSC “SSC RIAR” and JSC "Chepetsky Mechanical Plant" (Russian Federation).