Possible melted fuel seen for first time at Fukushima plant

TOKYO — An underwater robot captured images of solidified lava-like rocks Thursday inside a damaged reactor at Japan's crippled Fukushima nuclear plant, spotting for the first time what is believed to be nuclear fuel that melted six years ago.

Plant operator Tokyo Electric Power Co. said the robot found large amounts of lava-like debris apparently containing fuel that had flowed out of the core into the primary containment vessel of the Unit 3 reactor at Fukushima. The plant was destroyed by a massive earthquake and tsunami in March 2011.

Cameras mounted on the robot showed extensive damage caused by the core meltdown, with fuel debris mixed with broken reactor parts, suggesting the difficult challenges ahead in the decades-long decommissioning of the destroyed plant.

Experts have said the fuel melted and much of it fell to the chamber's bottom and is now covered by radioactive water as deep as 6 meters (20 feet). The fuel, during meltdown, also likely melted its casing and other metal structures inside the reactor, forming rocks as it cooled.

TEPCO spokesman Takahiro Kimoto said it was the first time a robot camera has captured what is believed to be the melted fuel.

"That debris has apparently fallen from somewhere higher above. We believe it is highly likely to be melted fuel or something mixed with it," Kimoto said. He said it would take time to analyze which portions of the rocks were fuel.

In an earlier survey Wednesday, the robot found severe damage in the vessel, including key structures that were broken and knocked out of place.

The robot, nicknamed "the Little Sunfish," on Friday went inside a structure called the pedestal for a closer look. TEPCO plans to send the robot farther down on Saturday in hopes of finding more melted fuel and debris.

Experts have said the melted fuel is most likely to have landed inside the pedestal after breaching the core.

Kimoto said the robot probe in its two missions has captured a great deal of useful information and images showing the damage inside the reactor, which will help experts eventually determine a way to remove the melted fuel, a process expected to begin sometime after the 2020 Tokyo Olympics.

"It's still just the beginning of the (decades-long) decommissioning. There is still a long way to go, including developing the necessary technology," he said. "But it's a big step forward."

Locating and analyzing the fuel debris and damage in each of the three wrecked reactors is crucial for decommissioning the plant. The search for melted fuel in the two other reactors has so far been unsuccessful because of damage and extremely high radiation levels.

The submersible robot, about the size of a loaf of bread, is equipped with lights, maneuvers with five propellers and collects data with two cameras and a dosimeter. It is controlled remotely by a group of four operators. It was co-developed by Toshiba Corp., the electronics, nuclear and energy company charged with helping clean up the plant, and the International Research Institute for Nuclear Decommissioning, a government-funded consortium.

___

Follow Mari Yamaguchi on Twitter at twitter.com/mariyamaguchi

Her work can be found at https://www.apnews.com/search/mari%20yamaguchi

Related News

Activist discovers iPhone spyware, sparking security update

Aug 26, 2016

Apple has issued a security update after powerful espionage software was discovered targeting an activist's iPhone in the Middle East

Judge: Kim Dotcom can livestream legal fight against the US

Aug 30, 2016

A New Zealand judge on Tuesday decided to allow internet entrepreneur Kim Dotcom to livestream his latest legal bid to halt his extradition to the United States

In drought, drones help California farmers save every drop

Aug 29, 2016

In the drought-stricken West, where every drop of water counts, some California farmers are using advanced drone technology to save the scarce resource

You may also like these

Google to expand Waze carpooling service in San Francisco

Aug 30, 2016

Google is set to expand a San Francisco carpooling program that could morph into a showdown with its one-time ally, the popular ride-hailing service Uber

Samsung updates smartwatch, Lenovo ditches laptop keyboard

Aug 31, 2016

Samsung's next smartwatch will come with GPS capabilities and the ability to call for help by triple-tapping a side button

Samsung recalls Galaxy Note 7 after battery explosions

Sep 3, 2016

Samsung Electronics recalled all of its Galaxy Note 7 smartphones on Friday after finding batteries of some of the flagship gadgets exploded or caught fire

Search
Financial Markets

About Us

Science Tech Today is all about the present with what’s new in the Science and Technology world. “Keep up with today, and don’t be left behind.”

Contact us: sales@sttcom.com