Fabrication and physical properties of lanthanide oxide glass wasteform for the immobilization of lanthanide oxide wastes generated from pyrochemical process

Development, characterization and dissolution behavior of calcium-aluminoborate glass wasteforms to immobilize rare-earth oxides

“…Concentrations of Nd in solution from CAB20 glass were below the detection limit of ICP-AES (<0.1 ppm) that corresponds to NL Nd ~10 −5 g·m −2 . This value is comparable to that of competitive REO-containing borosilicate glasses (Table 4 ) 7 , 8 , 25 . The normalized elemental release of boron from CAB20 ( NL B = 0.067 g·m −2 ) was significant smaller than that from alkali-borosilicate glass containing REO (36–46 g·m −2 ) 8 .…”

“…These values were obtained from PCT procedures and measured by ICP-AES. Two other glasses reported previously were included for a comparison 7 , 8 . Error: ± 0.1%.…”

“…Waste loading represents the amount of waste that can be incorporated in a wasteform and processability determines the feasibility of large scale and economical fabrication; relevant parameters are melting temperature T M , viscosity, electrical conductivity and crystallization tendencies of the melts. Several wasteforms have been reported for REO immobilization; each has advantages and disadvantages 7 – 11 . For example, ceramic wasteforms synthesized using solid-state sintering have low leaching rate of ~10 −5 g·m −2 d −1 for RE, but can only achieve REO loading of ~20 wt% by using a relatively complex synthesis processes 11 .…”

An evaluation of the design and performance for a new neutron absorber based on an artificial rare-earth compound

“…To design a neutron absorber with chemical and physical durability and stable control of criticality, using the borosilicate glass materials mixed with artificial rare earth compounds was proposed. The optimum composition of the neutron absorber was defined through trial fabrication (Choi et al, 2014). The neutron absorber density and the mass ratio of materials constituting the absorber are as follows:…”

“…In a previous study, the physical and chemical properties of the neutron absorbers were evaluated in their glass radioactive waste-form (Choi et al, 2014). Therefore, in this chapter, a summary of the physical and chemical properties of the neutron absorber for use in spent fuel storage is described.…”