Robot discovers suspected melted nuke fuel at Fukushima reactor

In the world’s worst nuclear calamity since Chernobyl in 1986, three reactors at the Fukushima Daiichi plant melted down after a magnitude 9 natural disaster struck off the coast of Japan in March 2011, triggering a tsunami that devastated a large area and killed more than 15,000 people.The lumps are scattered at the bottom of the containment vessel of the No. 3 reactor at the Fukushima No. 1 nuclear power plant.A three-day probe of Unit 3 by the Little Sunfish was concluded Saturday.Due to the highly radioactive nature of the damaged power plant, only specially designed robots are allowed to investigate the facility, and the company is developing new technology to remove the melted fuel from the reactors – technology that Japan Times said could be completed as early as next summer and usable sometime during the 2018 fiscal year ending March 2019.Last week, technicians from the plant’s operator, the Tokyo Electric Power Company (TEPCO) revealed their initial findings from three days of exploration.Removing the fuel debris is one of the most hard parts of the decommissioning project, which is expected to take at least 30 to 40 years. “In that sense, it is possible that the melted objects found this time are melted fuel debris or probably around it”.TEPCO spokesman Takahiro Kimoto said it was the first time a robot camera has captured what is believed to be the melted fuel. “This is a big step towards the decommission process”.The Little Sunfish was co-developed by Toshiba, which has been charged with helping clean up the power plant, and the International Research Institute for Nuclear Decommissioning (IRIND), a government-funded consortium. It should be realized here that the extremely high radiation levels in the other two reactors have to date destroyed any robots that have been sent in – so, as or right now, the melted down nuclear fuel in those reactors has yet to be located. Three reactors sank into 20 feet of water, allowing the release of radioactive material.Images taken by the robot showed what is likely melted fuel attached to control rod devices extending to the bottom of the reactor’s pressure vessel.