Fukushima nuclear plant operators prepare for dangerous procedure
Hundreds of radioactive rods must be removed at Fukushima without exposing them to air
Julian Ryall in Tokyo
The operator of the Fukushima Dai-ichi nuclear plant is making final preparations before starting the most delicate and dangerous procedure attempted at the plant since three reactors were wrecked in the March 2011 earthquake and tsunami.
Engineers from Tokyo Electric Power Co (Tepco) need to remove 1,533 rods of highly irradiated spent fuel from the damaged storage pool alongside the Number 4 reactor without exposing them to the air. The rods must then be carefully transported to a safer location for longer-term storage.
The 18-month project is due to start in early November.
Nothing remotely similar has been attempted before and while everyone - nuclear experts, government officials, environmental groups and the public - agrees that the rods must be moved to more secure storage, it is feared that any error of judgment could lead to a massive release of radiation into the atmosphere.
Tepco says the building surrounding the reactor has been reinforced and a crane has been constructed that will be used to lift the rods from the pool - which is 30 metres above the ground - and lower them to the ground.
Unit 4 at the plant contains an alarming 10 times as much caesium-137 as was at Chernobyl, experts say.
"We have taken a number of security measures before starting the procedure, including strengthening the tolerance of the storage pool by reinforcing the bottom, monitoring the building to make sure that it is not tilting, conducting visual checks for any hazards and carrying out inspections of the integrity of the building four times a year," a spokesman for Tepco said.
He admitted, however, that it was not clear whether any of the rods were damaged or if debris in the pool would complicate the recovery effort. But the company was taking every measure to ensure safety, he said.
That promise cuts little ice with Aileen Mioko Smith, of Kyoto-based Green Action Japan, who points out that Tepco has presided over a catalogue of errors, miscalculations and failures since the disaster.
And that is without looking into the shoddy safety and operational procedures at the plant before March 2011.
"They're incompetent," she said. "For example, how could they not realise that a typhoon was going to bring rain that was going to flood the areas around the storage tanks for radioactive water? A child could have comprehended that."
Mioko Smith has a number of fears about the recovery process, the biggest of which is that another major earthquake brings down the building or causes the storage pool to fall, exposing the rods to the air and triggering a release of radiation that could be catastrophic and extremely difficult to remedy.
Others have made even more strident warnings, including Charles Perrow, a professor emeritus at Yale University.
"Conditions in the unit 4 pool, 100 feet from the ground, are perilous, and if any two of the rods touch it could cause a nuclear reaction that would be uncontrollable," said Perrow.
"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," he said. "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."
As well as the technical and engineering problems that Tepco is facing, it has been suggested that corporate pride is preventing the company from accepting meaningful outside advice and assistance.
"I would prefer to have had some US companies that are experts on spent fuel decommissioning brought in to assist," said a nuclear energy expert who has been monitoring Tepco's handling of the crisis.
The problem of 400 tonnes of radioactive water leaking from the site every day could be fixed in a matter of days if the company would listen to external experts, he said.
"The issues are not primarily technological, they are political," he added.
When asked for giving advice to anyone living in Tokyo should the worst happen at the Fukushima plant, he said the winds were unlikely to blow most of the radiation towards the capital.
But the winds can be fickle and some of the contamination would undoubtedly reach Tokyo, he said.
"If so, go up to a very high floor," he said. "Radioactive particles are heavy, so keep out of basements."