Abstract: A scraping blade for use in a thin film dryer adapted for processing radioactive substances comprises a main body, a hing member rigidly attached to one side of the body and pivotably connected to a rotor in the dryer, a blade chip attached to the other side of the body for engaging the radioactive substance, and a screw member engaged with the body to secure the blade chip to the body. The blade chip is made of a material more than 1.2 times harder than the radioactive substance. The blade may further comprise an engaging member for screw engagement with the screw having edge portions to be engaged with recesses formed on the blade chip and the main body.

Abstract: In a process for treating radioactive liquid waste having an evaporation concentration device, including a concentration vessel, and a steam heater having steam inlet and outlet lines and operating to heat, with heating steam, radioactive liquid waste in the evaporation concentration device so as to concentrate the waste, contamination of the entire steam heater system in the event of leakage is prevented or greatly reduced by the provision of: (1) a sluice valve in the steam outlet line near the heater; (2) a discharge line with a drain valve for discharging any waste fluid between the heater and the sluice valve; and (3) means for receiving radioactive waste discharged through the discharge line. In accordance with the process of the present invention, when the pressure within the steam heater is less than that within the concentration vessel, and the operation of the evaporation concentration device is to be resumed, the sluice valve is first closed and the drain valve is opened.