The simulating technetium (Tc) separated from HLW was immobilized in perovskite-rich and rutile-rich synroc which contained 85wt% of perovskite or rutile, and 20, 25, 30 or 35wt% waste loading, respectively. The synro...The simulating technetium (Tc) separated from HLW was immobilized in perovskite-rich and rutile-rich synroc which contained 85wt% of perovskite or rutile, and 20, 25, 30 or 35wt% waste loading, respectively. The synroc was prepared by hot pressing under reducing condition. The fabricated samples have good physical properties (density and open porosity). The XRD analyses show that the major phase is perovskite or rutile and the minor phases are zirconolite, hollandite and metal alloy. At higher waste loading the metal alloy phase appeared, particularly in the rutile-rich synroc. The scanning electron microscopy (SEM) and backscattered electron images (BEI) show the samples to be homogeneous and densified. The MCC-1 leaching tests (90℃, 28 d) results show that: mass losses are at the level of 10-3 G·m-2·d-1,and the nominal element leaching rates are 10-5-10-3 G·m-2·d-1.It indicates that the fabricated samples have good leach resistance. According to their physical properties and leach resistance, the perovskite-rich and rutile-rich synroc can immobilize Tc up to 35 wt%. In comparison, Tc immobilization by using perovskite-rich synroc is more favorable.展开更多
Heavy-ion irradiation is commonly used to study radiation damage of high level radioactive waste (HLW) forms, but S ion was never used before. In this investigation, 100 MeV 32S ions produced by tandem accelerator was...Heavy-ion irradiation is commonly used to study radiation damage of high level radioactive waste (HLW) forms, but S ion was never used before. In this investigation, 100 MeV 32S ions produced by tandem accelerator was used to study radiation effects on pyrochlore-rich synroc which contained simulated actinides. The amorphization and amorphous doses were determined by X-ray diffractometer (XRD) and transmission electron microscopy /select area electron diffraction (TEM/SAED). The vacancy defects induced by heavy-ion irradiation were characterized by using positron annihilation technique (PAT). The experimental results show that the amorphous dose is 0.5 dpa, the defects produced by heavy-ion irradiation are mainly voids, and irradiation could continue to intensify the vacancy defects even after the amorphous dose was reached.展开更多
基金This work is one part of Research Coordination Program of International Atomic Energy Agency(No.10637)
文摘The simulating technetium (Tc) separated from HLW was immobilized in perovskite-rich and rutile-rich synroc which contained 85wt% of perovskite or rutile, and 20, 25, 30 or 35wt% waste loading, respectively. The synroc was prepared by hot pressing under reducing condition. The fabricated samples have good physical properties (density and open porosity). The XRD analyses show that the major phase is perovskite or rutile and the minor phases are zirconolite, hollandite and metal alloy. At higher waste loading the metal alloy phase appeared, particularly in the rutile-rich synroc. The scanning electron microscopy (SEM) and backscattered electron images (BEI) show the samples to be homogeneous and densified. The MCC-1 leaching tests (90℃, 28 d) results show that: mass losses are at the level of 10-3 G·m-2·d-1,and the nominal element leaching rates are 10-5-10-3 G·m-2·d-1.It indicates that the fabricated samples have good leach resistance. According to their physical properties and leach resistance, the perovskite-rich and rutile-rich synroc can immobilize Tc up to 35 wt%. In comparison, Tc immobilization by using perovskite-rich synroc is more favorable.
基金Supported by International Atomic Energy Agency under Contract No.10637
文摘Heavy-ion irradiation is commonly used to study radiation damage of high level radioactive waste (HLW) forms, but S ion was never used before. In this investigation, 100 MeV 32S ions produced by tandem accelerator was used to study radiation effects on pyrochlore-rich synroc which contained simulated actinides. The amorphization and amorphous doses were determined by X-ray diffractometer (XRD) and transmission electron microscopy /select area electron diffraction (TEM/SAED). The vacancy defects induced by heavy-ion irradiation were characterized by using positron annihilation technique (PAT). The experimental results show that the amorphous dose is 0.5 dpa, the defects produced by heavy-ion irradiation are mainly voids, and irradiation could continue to intensify the vacancy defects even after the amorphous dose was reached.
