Robot Explores Reactor

After spending four years and a month from the severe Level 7 accident, Tokyo Electric Power Company at last embarked on the investigation inside the Reactor #1 in First Fukushima Nuclear Power Plant on Friday. Who explored in the reactor with extremely high radiation emitted from melted nuclear fuel rods? It was newly invented robot moving like a snake. The robot will research the situation in the broken reactor and send data for the effort of dismantlement of the facility. But, TEPCO has even not decided how to retract melted fuel rods under the bottom of the reactor.

There is a small hole in the Reactor #1 with ten centimeters of diameter. The robot, with sixty centimeters of length and 9.5 centimeters of height, sneaks into the reactor through the hole with a shape of snake. Then it gets down to the first floor and changes its shape to move stably on the floor. The scene may look as letter E moving rightward. It can monitor the situation inside reactor with video camera and measure temperature and radiation there. Forty-three people control the robot from safer place inside the building Reactor #1 exists.

It can move very slowly. It goes around the broken reactor with two days. Melted fuel rods are supposed to have been dropped down to the deep place under the reactor container. Since the hole dug by the melted fuel rods is filled with water for cooling, the robot will need to be invented to move under water. There is no time schedule for the invention will be achieved.

Facing the difficulty of retracting melted fuel rods, or actually a cake of uranium with high harmful radiation, under the water, a governmental agency for dismantling the broken reactors considers options with fewer water. In addition to current plan of retracting from underwater, Nuclear Damage Compensation and Decommissioning Facilitation Corporation, -- bureaucrats believe long and complicated name of organization makes people less interested in their activities --, announced two other options of method of the retracting: one was to catch it from the top of the container and another was to drill a hole on the body of container.

If the container is filled with water, there will be a less possibility of emitting radiation in the process of the dismantlement. But, water may leak out from possible cracks in the containers. If they choose a plan with less water, the risk of the workers of exposition will be raised. Deliberated consideration is still needed.

Besides, no one knows where the melted fuel rods are located now. Without any concrete plan for retracting the rods, TEPCO and the government of Japan assume that they will decide the method for dismantlement by the first half of FY2018 and start retracting by the end of 2021. It is likely that the timeline will be delayed.