Hitachi, Ltd.

Kazuhiko Kudo

Koichi Chino

Masami Matsuda

Yoshiyuki Takamura

Akira Oda

Hideichi Mura

In a treatment system of radioactive waste solution including sodium sulfate generated from a boiling water type nuclear reactor, waste solution is fed into a thin film evaporator where the waste solution is evaporated and made into powder while precipitating in a peripheral surface of the evaporator vessel. The surface of the precipitated solid is wiped by rotating wiper blades and removed off as radioactive solid powder. The rotational speed of a rotor to which the wiper blades are secured is controlled at a minimum and necessary rotational speed which contributes to make the waste solution into the powder so that the rate of worn out of the wiper blade is decreased.

Process and system for treatment of radioactive waste

A granulating apparatus comprising a device which adds a binder of an epoxy resin or the like into a powder to-be-treated, a screw feeder which conveys the powder to-be-treated containing the binder, and rolls which compression-molds it. By rotating the screw feeder and the rolls, the powder to-be-treated is caused to induce internal friction and to generate heat, thereby to temporarily dissolve the binder, whereupon the powder to-be-treated is pelletized. In order to temporarily dissolve the binder, the granulating apparatus is equipped with a device for measuring the temperature of the powder to-be-treated, and a controller for controlling the stirring speed of the screw feeder and the molding speed of the rolls on the basis of the measured value so as to establish a desired temperature.

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Hitachi, Japan

Kazuhiko Kudo