Thursday 10 March 2016

THE ROBOTS SENT INTO FUKUSHIMA HAVE "DIED"




BY Frank

A member of the media, wearing a protective suit and a mask, looks at the No. 3 reactor building at Tokyo Electric Power Co's (TEPCO) tsunami-crippled Fukushima Daiichi nuclear power plant in Okuma town, Fukushima prefecture, Japan.
TORU HANAI/FILES/REUTERS
(Reuters) - The robots sent in to find highly radioactive fuel at Fukushima's nuclear reactors have “died”: a subterranean "ice wall" around the crippled plant meant to stop groundwater from becoming contaminated has yet to be finished. And authorities still don’t how to dispose of highly radioactive water stored in an ever mounting number of tanks around the site.


Five years ago, one of the worst earthquakes in history triggered a 10-meter high tsunami that crashed into the Fukushima Daiichi nuclear power station causing multiple meltdowns. Nearly 19,000 people were killed or left missing and 160,000 lost their homes and livelihoods.

Today, the radiation at the Fukushima plant is still so powerful it has proven impossible to get into its bowels to find and remove the extremely dangerous blobs of melted fuel rods.

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The plant's operator, Tokyo Electric Power Co (Tepco), has made some progress, such as removing hundreds of spent fuel rods in one damaged building. But the technology needed to establish the location of the melted fuel rods in the other three reactors at the plant has not been developed.


A member of the media, wearing a protective suit and a mask, looks at the No. 3 reactor building at Tokyo Electric Power Co's (TEPCO) tsunami-crippled Fukushima Daiichi nuclear power plant in Okuma town, Fukushima prefecture, Japan.
TORU HANAI/FILES/REUTERS
“It is extremely difficult to access the inside of the nuclear plant," Naohiro Masuda, Tepco's head of decommissioning said in an interview. "The biggest obstacle is the radiation.”

The fuel rods melted through their containment vessels in the reactors, and no one knows exactly where they are now. This part of the plant is so dangerous to humans, Tepco has been developing robots, which can swim under water and negotiate obstacles in damaged tunnels and piping to search for the melted fuel rods.

But as soon as they get close to the reactors, the radiation destroys their wiring and renders them useless, causing long delays, Masuda said.

Each robot has to be custom-built for each building. “It takes two years to develop a single-function robot,” Masuda said.

IRRADIATED WATER

Tepco, which was fiercely criticized for its handling of the disaster, says conditions at the Fukushima power station, site of the worst nuclear disaster since Chernobyl in Ukraine 30 years ago, have improved dramatically. Radiation levels in many places at the site are now as low as those in Tokyo.

More than 8,000 workers are at the plant at any one time, according to officials on a recent tour. Traffic is constant as they spread across the site, removing debris, building storage tanks, laying piping and preparing to dismantle parts of the plant.

Much of the work involves pumping a steady torrent of water into the wrecked and highly radiated reactors to cool them down. Afterward, the radiated water is then pumped out of the plant and stored in tanks that are proliferating around the site.

What to do with the nearly million tonnes of radioactive water is one of the biggest challenges, said Akiro Ono, the site manager. Ono said he is “deeply worried” the storage tanks will leak radioactive water in the sea - as they have done several times before - prompting strong criticism for the government.

The utility has so far failed to get the backing of local fishermen to release water it has treated into the ocean.

Ono estimates that Tepco has completed around 10 percent of the work to clear the site up - the decommissioning process could take 30 to 40 years. But until the comp

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