Development of dismantling method for liquid waste tanks lined with rubber in "Joyo" waste treatment facility

not registered; not registered; Kondo, Hitoshi; Tanimoto, Kenichi

Dismantling methods of liquid waste tanks lined with flammable natural rubber for decommissioning of Joyo Waste Treatment Facility. In this development, we researched common mechanical and heat cutting methods and chose appropriate one that was effective to decrease exposure and had no risk to fire the natural rubber lining. We next carried out dismantling tests using the chosen method with rubber lined mock-ups ofthe tanks to obtain cutting conditions and removal conditions of the lining to minimize secondary wastes. Results are follows. (1)We chose abrasive water jet that has an ablity to remove the rubber lining and to be controllable remotely with ease as a cutting method for the natural rubber lined tanks. (2)As a result of cutting tests under parameters of a cutting nozzle speed and a abrasive feed rate, cutting conditions minimizing secondary wastes are 0.4 kg/min abrasive feed rate and 300 mm/min nozzle speed. (3)As a result of a removing test under a parameter of a removing nozzle speed, a removing condition minimizing secondary wastes is 60 mm/min nozzle speed, thus removing speed is 3720 mm/min. (4)Improving the removing method, especially decreasing water feed, and general design of a dismantling system including treatment with secondly waste are required.