Robots readied to decontaminate Japanese nuclear plant

By THE JAPAN NEWS/YOMIURI Published: December 17, 2015

A new four-device system to decontaminate nuclear reactor buildings was unveiled at a Chiba, Japan, factory on Wednesday by the International Research Institute for Nuclear Decommissioning (IRID) and other entities.

IRID is in charge of decommissioning at Tokyo Electric Power Co.'s Fukushima No. 1 nuclear power plant. The system is expected to be introduced to clean the plant from as early as next spring. The new system's remotely controllable devices are capable of sweeping the second and third floors, where radiation levels are relatively high.

Nuclear decontamination robots are already in use at the plant, but they are not able to go to the second floor or above.

The new system, developed mainly by nuclear reactor makers Mitsubishi Heavy Industries Ltd., Hitachi-GE Nuclear Energy, Ltd. and Toshiba Corp., comprises four units, each with specific functions. They can be carried to upper floors using a lift. The lead unit is equipped with two arms, and can decontaminate interior spaces by scraping away at walls contaminated with radioactive materials. The devices that follow collect the debris from the scraped walls.

The new system is designed to lower the radiation dose for people entering the site, from current levels of over tens of millisieverts per hour (mSv/h) to less than 3 mSv/h, below which humans can enter to perform further decontamination work.

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