Robots have been essential to cleanup efforts since the 2011 earthquake and tsunami destroyed the Fukushima Daiichi nuclear power facility. Tokyo Electric Power Company (TEPCO) is advancing the next stage of robotics application: the extraction of melted nuclear fuel.
Fifteen thousand nine hundred people lost their lives in the Tohoku region on March 11, 2011, when a powerful earthquake and ensuing tsunami struck, devastating Japan’s Fukushima Daiichi nuclear power facility. The plant’s diesel generators, which ran the coolant-circulating pumps, were destroyed by the 50-foot waves that flooded it. This resulted in widespread radioactive contamination, three nuclear meltdowns, and three hydrogen explosions.
TEPCO significantly reduced the radiation exposure of engineers by using robots to navigate the reactor buildings and send pictures back to them after the incident. The quadruped robot Spot, created by Boston Dynamics, is one prominent example. The Spot has been helpful in obtaining debris samples for radiation testing, record video, monitor radiation levels, and gather statistics. Spot is more appropriate for these delicate operations than drones, whose rotor blades can scatter dust and debris.
Despite Spot’s effectiveness, TEPCO realized early on that a specialized robot was needed to remove fuel debris and clean up high-radiation locations within the reactor buildings. After two years of delays, engineers have finally created such a bot, ready for the next crucial stage of the cleanup.
This week, TEPCO unveiled a robot with tongs to extract small fragments of melted fuel debris from the three damaged reactors. The demonstration showed the robot carefully lowering itself from a telescopic pipe to grab a stone from a gravel pile.
Workers will install This robot in one of the reactors later this year, which will be the first attempt to clear the site of melted fuel pollution since the 2011 accident. At Fukushima Daiichi, almost 880 tonnes of highly toxic melted nuclear fuel are still there. The cleanup crew will remove less than 3 grams of debris during the first test at reactor 2. Researchers plan to examine this melted fuel waste to help TEPCO with its upcoming decommissioning efforts.