Decontamination of soil washing machines in high level radioactive contaminated soil processing by ceramic thin coating with ion plating technique

Ishiyama, Shintaro; Mamitani, Masataka*; Kondo, Mitsunori*; Hiki, Akinori*

Ion plating ceramic coating technique was applied for prevention of radioactive contamination and attrition of chemical interface controlled dispersion and high speed shearing washing machine during water washing with high level radioactive contaminated soil over 570,000 Bq/kg and the following results were obtained. (1) No contamination of AlO courted coupon with 5 m thickness installed in plunger was found after 3 hours water washing process of slurry contained 50% contaminated soil and uniformed attrition of the coating surface was observed, whereas contamination of SUS coupon due to FP particle attack and implantation during washing was observed. This contamination source is attached to SUS surface and not removable. (2) Attrition rate of surface of coated coupon during washing was estimated as 0.14 m/hr in the case of installation on rotor of plunger and attrition of SUS exhibits 7 times higher than that of coated coupon in initial stage of washing process.