Calling all Mechanical Engineers! We need tougher robots.
A clean-up and decommissioning of three of the Fukushima Daiichi nuclear reactors, that fell victim to meltdowns after a powerful earthquake and subsequent tsunami in 2011, is underway. The clean-up will cost the equivalent of USD$190 billion.
The first step to decommissioning is locating the spent, melted nuclear fuel. No human can withstand the radiation levels in the reactors. As a result, radiation-resistant robots are being sent down to locate the fuel. But they’re not working as planned.
The team sent their Scorpion Robot down to the No. 2 Reactor on February 16th, 2017. Unfortunately, the high levels of radiation caused the robot to falter and eventually be rendered useless. The radiation caused a belt on the robot’s wheel mechanisms to fail.
The Robot that failed due to radiation in Nuclear Reactor #2 at Fukushima Daiichi
Credit: The Tokyo Electric Power Company
Two other robots were also abandoned after one became stuck on its way to where they think the radioactive spent fuel is, and the other after failing to find the fuel. One of the robots’ cameras actually began to malfunction due to the high levels of radiation on one of the attempts.
Tokyo Electric Power Company Holdings, Incorporated, Scorpion Robot: https://www.facebook.com/OfficialTEPCOen/videos/1348040575255238/
The reality is, the Tokyo Electric Power Company (Tepco) needs smarter and tougher robots - a fact the Director of Decommissioning has admitted.
Toshiba manufactured the Scorpion Robot and are now purportedly developing the robot that is needed to probe the most damaged reactor, Reactor No. 3. The company will have to go back to the drawing board to ensure this new robot will withstand and survive the radioactive material.
Toshiba’s engineers initially thought their Scorpion robot had the capacity to weather the radiation but realised more work to make them radiation-proof is needed. The engineers must perform a more rigorous process of ‘radiation hardening’ to ensure these next iterations do not succumb to the same pitfalls.
Despite being abandoned, the failed robots have provided engineers with some indication of where their weaknesses were - the location of the melted material. To fully ascertain why they miscarried, without having them at hand, would be difficult and will prove challenging when designing the tougher and smarter versions.
President of Decommissioning, Naohiro Masuda, said: “We should think out of the box so we can examine the bottom of the core and how melted fuel debris spreads out.” Tepco wants to have the decommissioning process completed by 2021.
The Daily Mail has released drone footage of the abandoned town. This year would mark the sixth year since the earthquake and tsunami.
Wehner, Mike. "Japan’s Failed Nuclear Reactor Is Still so Radioactive It Almost Killed a Robot." BGR. 14 Feb. 2017. Web. 08 Mar. 2017.
Yamaguchi, Mari. "Fukushima Cleanup Chief Urges Better Use of Probe Robot." Japan Today. Web. 08 Mar. 2017.