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Visit to the Fukushima Daiichi Nuclear Power Plant

It has been quite some time since I added anything to this blog, though quite a lot has happened in the intervening weeks and months. In March I spent the best part of three weeks covering a trial for an Irish newspaper, which related to the murder last May (2012) of an Irish student in Tokyo. There are a few other projects I have been working and hopefully I will get around to adding posts to update this blog in the near future.

On to more recent assignments, on June 12 I  part in a tour of the Fukushima Daichi nuclear power plant, which suffered triple meltdowns following the March 2011  earthquake and tsunami in Japan’s northeast. My plan is to write up a more personal account of the experience but for the time being here is the story that I wrote up for the New Scientist, which appeared in the magazine last week.

Photo shows the steel canopy arching over Unit 4 of the Fukushima Daiichi Nuclear Power Plant. The now completed structure will be used to support a overhead crane strong enough to lift 100-ton vessels into which will be placed the 1533 pent fuel assemblies that are still residing inside the unit's spent fuel pool on the 3rd floor. they will be moved to a common spent fuel pool

 

 

By Rob Gilhooly at Fukushima Daiichi Nuclear Power Plant

 

An alarm lets off a shrill beep as a dosimeter on the bus hits 1500 microsieverts of radiation. “Do not open the windows,” an official warns. We are inside the Fukushima Daiichi nuclear power plant, driving by one of the three reactors that went into meltdown following the earthquake and tsunami that struck north-eastern Japan on 11 March 2011.

The place is a mess, with mangled containers and vehicles scattered around crumbling buildings – but the fact that I’m even here is testament to the now relative safety of the plant. However, much remains to be done and the clean-up operation is starting to look never-ending.

The group I’m with is ushered into a quake-proof building, the plant’s nerve centre since the disaster, by staff from the Tokyo Electric Power Company (Tepco), the plant’s operator. Inside, the only sign of the post-disaster panic and stabilisation operations, undertaken by 3,000 workers a day, is a line of unmade bunk beds, indicating that the clean-up operation is still a round-the-clock affair.

The walls are decorated with messages of encouragement to embattled workers from school children. “We’re rooting for you,” reads one, a bright red heart drawn above. Many of the messages were penned during more ominous times, when tens of thousands of residents living near the plant were evacuated from their homes, and plant workers struggled to secure  water to cool the compromised containment vessels housing the reactor fuel.

Water shortages are no longer the problem – quite the opposite. Today, the main issue is what to do with all the water used to cool the fuel that melted through the containment vessels. This is exacerbated by the 400 tonnes of groundwater that are flooding into the basements of the cracked reactors every day and mingling with leaked nuclides.

rest of story available at New Scientist website here

 

Fukushima Fuel Extracted

Workers undertaking fuel extraction operations at Fukushima Daiichi Nuclear Power Plant

Rob Gilhooly

Tokyo

Operations commenced July 18 to remove nuclear fuel assembiles from the storage pool of one of the reactors at Fukushima Daiichi nuclear power plant, some 16 months after the worst nuclear disaster since Chernobyl struck northeastern Japan.

Despite plant operator Tokyo Electric Power Co. (TEPCO) requesting media outlets to refrain from filming the delicate and highly dangerous operations, aerial images aired on TV and online showed cranes lifting two of the 1,535 fuel units, each of which holds 60 fuel rods, from the No. 4 reactor building.

The procedure marked the first stage of a program that could go on for years to remove both unused and used fuel from the reactor in order to counter the risk of further radiation leakage.

Experts, including nuclear engineer Arnie Gundersen of Fairwinds Energy Education, have long argued that structural weaknesses in the reactor building, which was severely damaged by an explosion last March that exposed spent fuel to the atmosphere, could cause a large-scale catastrophe should another large quake strike the area.

Hiroaki Koide of Kyoto University’s Department of Reactor Safety Management, says that the biggest concern remains the sheer volume of fuel in the pools, which if exposed to the air would cause massive radioactive releases.

The amount of cesium 137 in the fuel in the pools is equivalent to 5,000 times the amount that was spread by the Hiroshima atomic bomb,” says Koide. “The government has said that the amount of radioactivity released by the three affected reactors following 3.11 was 168 times that of Hiroshima, so it is clear that we would be looking at a considerably worse outcome should the (rector 4) structure be compromised.”

The government used exactly such an outcome in its worse-case scenario analysis following the disasters, concluding that residents in Greater Tokyo – home to around 35 million people — would need to be evacuated in such an eventuality.

TEPCO has announced that repair work has sufficiently stabilized the structure, and while Koide is doubtful such operations could have been properly executed under the still high levels of radiation at the plant, others are less skeptical.

My understanding is that now they do have some redundancy in the cooling systems and have buttressed the fuel ponds themselves,” said Malcolm Grimston, a nuclear expert at Imperial College London. “So things are reasonably stable even against another earthquake, though obviously it depends upon where and how strong.”

The first fuel to be removed are among some 204 units that had yet to be used, meaning it posed little danger because unused fuel emits low levels of radiation, Tepco was reported as saying. Operations to remove the 1,331 more dangerous used fuel units will not be manageable until a much larger crane has first been installed. This will be used to haul out mammoth 100-ton metal casks that will be required to house the fuel units to ensure they not exposed to the air, says Kyoto University’s Koide.

TEPCO, which declined to comment on the latest maneuvers due to their “sensitive” nature, estimates that such operations will commence in December 2013, though Koide believes that is ambitious. “It’s a process that carries with it an immense amount of danger,” he says.

Some experts decry Wednesday’s maneuvers as further proof that the utility has no concern for public safety. University of Tokyo professor Ayumu Yasutomi says the removal of the unused fuel was merely a “demonstration” to give the impression it is working in the public’s best interests.

The aim of this is not to protect the people but to protect Nuclear Power Plants in Japan,” says Yasutomi. “This latest procedure is horrifying – just one small mistake and we could be subjected to  something unimaginable. I personally doubt TEPCO has the technical knowhow to carry out these procedures and we should leave it to a capable team of international experts.”

Meanwhile on the same day, a second reactor went back online at the Oi Nuclear power Plant in Fukui Prefecture, just two months after another reactor reached criticality at the same plant in May. The government justified the move in the name of supplying sufficient energy in the steamy summer months, bringing public sentiment to simmering point in Tokyo on July 16, when an estimated 170,000 people took to the streets to voice their disapproval.

Version of above story published in New Scientist magazine here

Photo courtesy of TEPCO

 

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