Japan pictures show melted Fukushima fuel for first time

If confirmed, substance would be first discovery of fuel that melted during accident at Fukushima

New images show what is likely to be melted nuclear fuel hanging from inside one of Japan’s wrecked Fukushima reactors, a potential milestone in the cleanup of one of the worst atomic disasters in history.

Tokyo Electric Power, Japan’s biggest utility, released images showing a hardened black, grey and orange substance that dripped from the bottom of the No 3 reactor pressure vessel at Fukushima, which is likely to contain melted fuel, according to Takahiro Kimoto, an official at the company. The company sent a Toshiba-designed robot, which can swim and resembles a submarine, to explore the inside of the reactor for the first time on July 19.

“Never before have we taken such clear pictures of what could be melted fuel,” Kimoto said at a press briefing that began at 9 pm Friday in Tokyo, noting that it would take time to analyse and confirm whether it is actually fuel. “We believe that the fuel melted and mixed with the metal directly underneath it. And it is highly likely that we have filmed that on Friday.”

If confirmed, the substance — which has the appearance of icicles — would be the first discovery of the fuel that melted during the triple reactor accident at Fukushima six years ago. For Tokyo Electric, which bears most of the clean-up costs, the discovery would help the utility design a way to remove the highly-radioactive material.

The robot, which is about 12 inches long, will search for melted fuel at the bottom of the reactor on Saturday. It is possible that the company will take more pictures of what could be melted fuel spread across the floor and lower levels, according to Tokyo Electric’s Kimoto. Fuel from a nuclear meltdown is known as corium, which is a mixture of the atomic fuel rods and other structural materials.

“It is important to know the exact locations and the physical, chemical, radiological forms of the corium to develop the necessary engineering defuelling plans for the safe removal of the radioactive materials,” said Lake Barrett, a former official at the US Nuclear Regulatory Commission who was involved with the cleanup at the Three Mile Island nuclear power plant in the US. 

Bloomberg