"MEISTeR" Remote Control Robot Completes Demonstration Testing At Fukushima Daiichi Nuclear Power Station

The MEISTeR is an enhanced version of a disaster response robot initially developed by MHI after the criticality accident at the nuclear fuel processing facility in Tokai-mura, Ibaraki Prefecture, in 1999. The improvements incorporated, which were based on MHI's abundant maintenance technologies cultivated at nuclear power facilities, aimed to enable the new robot's use at the Fukushima Daiichi Nuclear Power Station, and they were implemented in cooperation with TEPCO and the International Research Institute for Nuclear Decommissioning (IRID) as part of a project funded by the Japanese Ministry of Economy, Trade and Industry (METI). Under this initiative the robot was significantly improved in terms of radioactive resistance and remote control capability, making it adaptable to performing a variety of tasks in highly radioactive locations.

Whereas most disaster response robots available until now have primarily performed inspection, maintenance and similar tasks relying on cameras, etc., the MEISTeR can handle a broad array of tasks by changing the tools attached to its arm ends. In addition to inspection and maintenance, the MEISTeR can perform decontamination work, concrete core sampling, cutting of obstacles blocking pathways, etc.

Each robot arm has seven freely articulating joints. By attaching a different tool to the left and right arms, two types of work can be performed simultaneously: for example, grasping an item with one arm and cutting with the other. Inside a nuclear power plant, the MEISTeR is capable of tasks including concrete drilling, cutting of handrails and piping, removal of obstacles, decontamination, repair work, etc.

Inside the Unit 1 plant at the Fukushima Daiichi Nuclear Power Station, the MEISTeR carried out demonstration testing of two decontamination processes since late last month: one whereby radioactive material in the plant is sucked up through a dedicated nozzle, and another in which a jet of abrasive blast material is used to scrape off a thin layer of a contaminated surface. It also confirmed travel capability inside the plant's narrow passageways, and performed concrete core sampling aimed at investigating the level of contamination inside the reactor building. The latter process involved taking concrete samples from the structure's walls and floor, at a depth of approximately 70 millimeters (mm) from the surface; this was carried out by remotely controlling the robot's arms, to which a specially developed drill and hand were attached. Concrete core sampling is now also scheduled for the Unit 2, to determine the level of contamination of the operating floor.

Going forward, MHI intends to proceed with development of even more sophisticated remote control robots and tool attachments of various kinds, to meet the diverse needs of the Fukushima Daiichi Nuclear Power Station and other plants.