Research Of Decontamination Technology For Radioactive Contamination On Metal By DEDM

The Stripping-Ultrasonic-Electrolysis (SUE) method is a new decontamination method. Based on mixing solid super-acid in original stripping and taking out ultrasonic, the dry electrolysis decontamination method(DEDM) for radioactive contamination on metal was studied.The SO₄^2- /TiO₂ solid super-acid whose acid strength was to be -13.20 0<-11.99 was prepared. Used PYA/PVAc as main ingredient, poly-aniline which adulterated with HC1 and SO₄^2-/TiO₂ solid super-acid as electric component, the electric stripping was prepared. Result in experiment indicated that electro-conductibility was 20.5S/m and the mechanical property can be satisfactory to application when the contents of poly-aniline and SO₄^25-/TiO₂ solid super-acid were 5% and 1.5% respectively.Infrared spectroscopy analysis showed that the conductive structure of poly-aniline which adulterated with HC1 and SO₄^2-/TiO₂ solid super-acid didn't change when they were mixed into stripping.The result in simulative experiment show: the decontamination efficiency (DF) of directness coating method on the surface of metal was from 99% to 87% with processing temperature increasing; the DF of SUE was more than 98%;The D F o f D EDM w as a ccording w ith S UE w hen e lectrolytic v oltage was 2.1 V, drying time of stripping was 8h and electrolytic time were 25³0 min.The result in practical experiment show: the DF of DEDM for stainless steel was more than 96% when origin contaminated level was less than 8Bq/cm2, the contaminated level after contamination was about 0.2Bq/cm2; the D F o f D EDM for alnico w as m ore t nan 9 6% w hen t he r ange o f o rigin contaminated level were 10 Bq/cm2 to 16Bq/cm2, the contaminated level after contamination was about 0.4Bq/cm2; the DF of DEDM for corrosion carbon steel was more than 93% when the range of origin contaminated level were 20 Bq/cm2 to 70Bq/cm2, the contaminated level after contamination was max 4.87Bq/cm2.Because of excellent decontamination efficiency, less secondary waster, and simple handle, the dry electrolysis decontamination method can be applied to decontamination in the decommissioning project of nuclear facility.