The present investigation indicates

The present investigation indicates that during the decomposition of laminate sheeting, the produced gas contains no radioactivity in any run. The distribution of Fe, Co, Cs, I and Sr was determined by radiometric analysis after laminate sheeting was decomposed using supercritical water mixed with RuO2. Iron, cobalt and strontium were recovered as solids after the present supercritical water reaction by the addition of an excessive quantity of iron hydroxide before the reaction. In the case of cesium, iodine and strontium, almost all radioactivities were found in the liquid phase. However, by adding precipitate reagents to the liquid phase obtained in the reaction, cesium, iodine and strontium can be recovered in the solid phase. This method should be a very effective way to decompose the nonflammable organic materials of LLW generated by nuclear power plants.