Characteristics of solidified products containing radioactive molten salt waste

Conference · Sun Jul 01 04:00:00 EDT 2007

OSTI ID:21156438

Kim, In-Tae; Park, Hwan-Seo; Cho, Yong-Zun; Kim, Kwang-Wook; Park, Seong-Won; Kim, Eung-Ho ^[1]

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1. Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yuseong-gu, Daejeon, 305-353 (Korea, Republic of)

For a treatment of molten salt wastes generated from a pyro-processing of oxide spent fuel, we had suggested a stable chemical route, named GRSS (Gel-Route Stabilization and Solidification), and a subsequent consolidation method. By using this method, a series of monolithic wasteforms with different conditions were fabricated, and then their physicochemical properties were investigated. A simulated salt containing 90 wt% LiCl, 6.8 wt% CsCl, and 3.2 wt% SrCl{sub 2} was treated with a gel-forming material system, Si/Al/P=0.4/0.4/0.2 and 0.35/0.35/0.3, and the gel-products were treated at 1100 deg. C after mixing with borosilicate glass powder, where the salt loadings were about 16-20 wt%. The solidified products had a density of 2.3-2.35 g/cm{sup 3}, a micro-hardness of 4.69-4.72 GPa, a glass transition temperature of 528-537 deg. C, and a thermal expansion coefficient of 1.65 X 10{sup -7}-3.38 X 10{sup -5} deg. C. Leaching results by the PCT-A method revealed leached rates, 10{sup -3}-10{sup -2} g/m{sup 2} day and 10{sup -4}-10{sup -3} g/m{sup 2} day for Cs and Sr, respectively. From the long-term ISO leaching test, the 900 day-leached fraction of Cs and Sr predicted by a semi-empirical model were 0.89% and 0.39%. The leaching behaviors indicated that Cs would be immobilized into a Si-rich phase while Sr would be in a P-rich phase. The experimental results revealed that the GRSS method could be an alternative method for a solidification of radioactive molten salt wastes. (authors)

• Research Organization: American Society of Mechanical Engineers (ASME), Three Park Avenue, New York, NY 10016-5990 (United States); Technological Institute of the Royal Flemish Society of Engineers (TI-K VIV), Het Ingenieurshuis, Desguinlei 214, 2018 Antwerp (Belgium); Belgian Nuclear Society (BNS) - ASBL-VZW, c/o SCK-CEN, Avenue Hermann Debrouxlaan, 40 - B-1160 Brussels (Belgium)
• OSTI ID: 21156438
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
BOROSILICATE GLASS
CESIUM CHLORIDES
GELS
GESELLSCHAFT FUER ANLAGEN- UND REAKTORSICHERHEIT
HARDNESS
LEACHING
LITHIUM CHLORIDES
MOLTEN SALTS
OXIDES
SIMULATION
SOLIDIFICATION
SPENT FUELS
STABILIZATION
STRONTIUM CHLORIDES
THERMAL EXPANSION
TRANSITION TEMPERATURE
WASTE FORMS