Tepco prepares to remove nuclear fuel at Fukushima plant — The Asahi Shimbun

” OKUMA, Fukushima Prefecture–The 1,533 nuclear fuel assemblies were lined up in neat rows in the storage pool of the No. 4 reactor building amid new equipment and a clean environment.

But in stark contrast was the scene around the No. 4 reactor building at the Fukushima No. 1 nuclear power plant.

Concrete walls were still missing from the third and fourth floors of the No. 4 reactor building, raising questions among onlookers if the structure could withstand a huge earthquake.

On the sea side of the building, a piping system and metal rods were exposed behind collapsed walls of a former boiler building.

A truck swept up by the 2011 tsunami remained upside down by the side of the turbine building.

Amid these surroundings, Tokyo Electric Power Co. plans to start removing the nuclear fuel assemblies from the No. 4 storage pool as early as next week. The work would represent a new stage in the overall plan to end the nuclear crisis that started 32 months ago.

“It is a big step in the process to decommission the reactor,” Nuclear Regulation Authority Commissioner Toyoshi Fuketa said.

The entire decommissioning plan for the plant is expected to take 30 to 40 years to complete, and the strategy could change at any moment.

Workers still do not know the location of melted nuclear fuel in the No. 1, No. 2 and No. 3 reactors. High radiation levels are preventing entry to some areas. And contaminated water leaks continue to plague the site.

And removing the nuclear fuel from the No. 4 pool will require delicate procedures, considering the state of the building and the dangers involved.

NRA Chairman Shunichi Tanaka told TEPCO President Naomi Hirose to use extreme caution in removing the assemblies.

“The process involves a very large risk potential,” Tanaka told Hirose. “In a sense, it is more risky than the radioactive water crisis.”

TEPCO on Nov. 6 allowed reporters to see the spent fuel storage pool of the No. 4 reactor building and other areas of the stricken nuclear plant.

An elevator took the reporters to the top floor of the five-story building. A steel frame had been assembled near the pool, and a new fuel hoist and a new crane had been installed.

The No. 4 reactor building itself was covered by a canopy to replace the roof that was blown off in an explosion on March 15, 2011.

TEPCO plans to transfer the 1,533 nuclear fuel assemblies to a “storage pool for common use” 100 meters west of the No. 4 reactor.

The removal and transfer is expected to be completed at the end of next year.

The assemblies contain both spent and unused fuel. Some bundles were moved to the pool from the reactor core because the No. 4 reactor was undergoing a regular safety check when the Great East Japan Earthquake and tsunami struck the plant on March 11, 2011.

The disaster knocked out the cooling system for the storage pool, sparking fears that it would dry up, leaving the fuel exposed and allowing huge amounts of radioactive substances to spew into the air.

That didn’t happen. However, the explosion four days after the tsunami left large chunks of debris in the storage pool.

Those chunks have been cleared, but a number of smaller pieces remain in the storage pool.

The fuel removal process will use a cask receptacle that is 5.5 meters long, weighs 91 tons and can hold 22 fuel assemblies. It will be submerged in the pool and receive one fuel assembly at a time to prevent a nuclear reaction from occurring.

A crane will lower the receptacle to the ground, where a vehicle will pick it up and take it to the common-use storage pool.

TEPCO plans to use two receptacles to speed up the transfer process and finish removing all the fuel in just over a year.

In addition to uranium, spent nuclear fuel contains highly toxic plutonium and other radioactive substances, which could be released if the fuel assemblies are damaged during the removal or transfer process.

TEPCO has taken measures to check for deformed fuel assemblies and to prevent the remaining debris from causing damage when the fuel is pulled out.

The company has also decided to use double wires to ensure the receptacles are not dropped by mistake.

The canopy covering the No. 4 reactor building is designed to contain radioactive materials in the event of an accident. The bottom of the storage pool has also been strengthened with concrete and other materials.

The reinforced storage pool could withstand shaking as strong as the magnitude-9.0 Great East Japan Earthquake, TEPCO officials said. … ”

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Fukushima trial run begins dangerous reactor 4 clean-up — Common Dreams

” Clean-up workers begin recommended test run before embarking on ‘humankind’s most dangerous moment since the Cuban Missile Crisis’

Preparations to begin the potentially catastrophic decommissioning of the crippled Reactor 4 at the Fukushima nuclear power plant will begin this week with a test run.

The test, which could push back the beginning stages of fuel rod removal by two weeks, includes moving a “protective fuel cask” into and out of the No. 4 storage pool with a crane—before attempts are made to move the spent fuel rods, the Japan Times reports. 

Japan’s Nuclear Regulation Authority gave the final go-ahead last week for TEPCO to begin the decommissioning process, the entirety of which watchdogs say could take decades.

The most dangerous step in the process will include the removal of the 1300 “bent, damaged and embrittled” spent fuel rods from the unstable Unit 4 pool. The fuel rod removal, which has never been done before on this scale, could take up to one year, and has been described by anti-nuclear expert and activist Harvey Wasserman as “humankind’s most dangerous moment since the Cuban Missile Crisis.”

While the fuel removal at reactor 4 presents possible dangers, there is also urgency to complete the task. Natural disasters such as earthquakes remain a major threat to the stability the damaged building, and should it be damaged further before it is decommissioned, there could be a global catastrophe, many experts have warned.

This week’s practice run comes per the request of the Japan Nuclear Energy Safety Organization, a government-affiliated nuclear safety agency.

According to Japan Daily, the agency also urged plant operator TEPCO to have the test evaluated by a group of Japanese and overseas experts recommended by the International Research Institute for Nuclear Decommissioning, “a Tokyo-based organization founded by Japanese government agencies, nuclear facility manufacturers and electric power companies.”

However, pressure has been mounting on the Japanese Government and TEPCO to allow an international task force made up of nuclear experts, who are independent of the nuclear power industry, to monitor and assist throughout the entirety of the highly hazardous decommissioning process.

This coming Thursday, Moveon.org and affiliated organizations are presenting a petition of over 150,000 signatures to UN Secretary-General Ban Ki-Moon and Barack Obama, asking for global intervention at Fukushima. The campaign, organized by Wasserman, argues TEPCO does not have the capability to safely go it alone.

TEPCO president Naomi Hirose agreed last week to accept the help of the United States Department of Energy with the fuel rod removal process. ”


Decommissioning Fukushima: how Japan will remove nuclear fuel rods from damaged reactor — The Telegraph

Updated 11/16/13: View Arnie Gundersen’s clarification of Tokyo Electric’s fuel rod removal video, below.

In addition to the article below that contains an overview of the fuel rod removal process, The Telegraph also includes a piece of animated propaganda, seemingly produced by Tepco, that explains the fuel rod removal process under ideal circumstances.

” The operator of Japan’s crippled Fukushima nuclear power plant is soon to begin the delicate and perilous process of removing 1,534 nuclear fuel rods from a storage pool at the site.

In the coming days it will begin a dry run of the procedure at the No. 4 reactor, which experts have warned carries grave risks. The operator had been scheduled to start the actual removal on Friday, but the Japan Nuclear Energy Safety Organisation this week insisted that Tokyo Electric Power Co. carry out a test to ensure that every part of its plan goes smoothly, delaying the operation for some two weeks.

The authorities’ insistence on additional checks suggests there are serious concerns about the ability of the utility to handle the aftermath of the second-worst nuclear accident in history. Tepco’s very public failures in the 32 months since the plant was devastated by the magnitude-9 earthquake and the tsunami that it triggered have shaken confidence in Japan’s nuclear industry, both here and around the world.

And despite the fears of nuclear energy experts, the Japanese public, the government and environmental groups, all agree that the highly irradiated spent fuel must be removed from the damaged storage pool as swiftly as possible.

A key concern is that another major earthquake could cause cracks in the pool, which is nearly 100 feet above the ground, allow the cooling water to escape and expose the rods to the air. That would allow the zirconium alloy cladding to ignite and release radioactive material into the air.

Equally, a misjudgment during the operation to lift the rods out of the pool, transfer them individually to a water-filled cask, lower that to the flat-bed of a truck and then transport the rods to a more secure storage site in the grounds of the power station could lead to another massive release of radiation into the atmosphere.

Tepco says it is confident that the 18-month manoeuvre will go off without a hitch, emphasising that removing rods from a spent fuel pool “is a normal operation that has been done at any nuclear power station, even before the great earthquake.”

The company admits there are risks, however, and has publicly vowed to do everything possible to ensure security “under safety-first principles”.

Tepco has reinforced the pool containing the rods with concrete and steel and says that tests have determined that the building is still sufficiently strong to withstand another earthquake of the same magnitude as the March 2011 tremor.

An external crane to lift the rods out of the pool has been constructed in a way that no extra weight is added to the shell of the No. 4 reactor building, while the entire procedure will be carried out behind a shell to prevent radiation leaking into the surrounding atmosphere.

Despite all the security measures, experts and environmentalists point out that Unit 4 at the plant contains 10 times as much caesium-137 than was at Chernobyl and that nothing remotely similar has ever been attempted before.

“Did you ever play pick up sticks?” asked a foreign nuclear expert who has been monitoring Tepco’s efforts to regain control of the plant. “You had 50 sticks, you heaved them into the air and than had to take one off the pile at a time.

“If the pile collapsed when you were picking up a stick, you lost,” he said. “There are 1,534 pick-up sticks in a jumble in top of an unsteady reactor 4. What do you think can happen?

“I do not know anyone who is confident that this can be done since it has never been tried.”

Even now, it is not clear whether any of the rods, containing transuranic and transplutonic elements, are cracked, he said.

“At the very least, if there was a catastrophic collapse, I assume there will be a major airborne release of radiation,” he said. “But on the other hand, you have to do something.”

Others have issued even more dire warnings, with Charles Perrow, a professor emeritus at Yale University, warning: “The radiation emitted from all these rods, if they are not continually cool and kept separate, would require the evacuation of surrounding areas, including Tokyo.

“Because of the radiation at the site, the 6,375 rods in the common storage pool could not be continuously cooled; they would fission and all of humanity will be threatened, for thousands of years.”

Tepco has focused its efforts on Unit 4 at the plant because it was not operational at the time of the disaster and the reactor did not experience a meltdown. Experts say this makes it the easiest of the four reactors to deal with. ”