Thirty seconds into what may ultimately be regarded as one of the defining speeches of his career, Prime Minister Shinzo Abe slowly raised his hands chest high, then spread them out sideways in a gesture of confidence.
“Let me assure you,” he said, addressing members of the International Olympic Committee on Sept. 7. “The situation is under control.”
The prime minister was attempting to convince his audience in Buenos Aires that the multiple meltdowns at the Fukushima No. 1 nuclear power plant, initiated by tsunami triggered by the Great East Japan Earthquake on March 11, 2011, should not be a cause of concern for Tokyo hosting the Summer Olympic Games in 2020.
The nuclear accident, he said, “has never done and will never do any damage to Tokyo.”
However, cleaning up the crippled nuclear power plant certainly won’“t be plain sailing, with decommissioning plans believed to include the removal of spent nuclear fuel rods from a cooling pool littered with debris, the creation of a permafrost wall around the four damaged reactors in order to prevent the spread of radioactive isotopes and the discovery of the precise location of the melted nuclear fuel in the highly toxic containment vessels.”On a scale of zero to 10, I’d say the decommissioning process has advanced by about 0.1 (since the nuclear accident),“said Michio Ishikawa, president of the Association for Nuclear Decommissioning Study.”I think the prime minister was right in saying that things are under control now,“Ishikawa said, but”predicting what the situation will be in 2020 is still very difficult."
According to the latest road map released by the government and the Tokyo Electric Power Co. in June, decommissioning Fukushima’s four damaged nuclear reactors is expected to take up to 40 years to complete. The first – and most pressing – item on Tepco’s to-do list is stem the flow of contaminated water leaks from the on-site facilities.
The government has earmarked roughly \30 billion on an unprecedented project to freeze the ground around the reactors to prevent groundwater from leaking into the plant. Under a plan proposed by Kajima Corp. in April and endorsed by the Ministry of Economy, Trade and Industry on Oct. 9, a frozen wall spanning 1.4 km will be formed by coolant tubes drilled into the ground at 1-meter intervals around the plant. The government expects to finish the project by the end of the country’s fiscal 2014.
The annual running cost of the permafrost wall hasn’t officially been revealed yet. However, several critics have suggested that it could total up to \3 billion annually based on current estimates. Critics have also expressed concern that the system will require an abundant electricity supply around the clock, despite the nationwide shortages that have continued since the country’s nuclear reactors have been taken offline for maintenance in the wake of the Fukushima catastrophe.
In addition to the proposed permafrost wall, Tepco hopes to remove most radioactive materials from contaminated water on the site by employing the Advanced Liquid Processing System at full capacity soon.
However, creating an artificial permafrost of this scale has never been attempted before, while the filtration system that commenced trial operations in June has already been suspended three times after malfunctions were detected.
Despite the ongoing setbacks, the government only officially reached out to nuclear experts worldwide in September for advice on how to handle the contaminated water issue. The government has been notably slow to act on several occasions, which has even left pro-nuclear advocates scratching their heads in bewilderment.
“It isn’t completely clear that freezing the soil will contain the radioactive water,” University of Tokyo professor Satoru Tanaka said.
In June 2011, Tanaka was named head of the Atomic Energy Society of Japan, which boasts a membership of 7,000 nuclear experts nationwide. He was involved in designing the Fukushima No. 1 nuclear power plant, and issued apologies after the crisis for not being able to handle the calamity better.
When asked about the ongoing problems hampering the cleanup, Tanaka noted that none of the proposed solutions had ever been successfully implemented anywhere else in the world on such a massive scale.
“The whole process will be trial and error, and then fixing the error and trying again. It’s the only way things will move forward,” Tanaka said. “It is crucial that everyone involved anticipate what may go wrong and be ready to implement countermeasures quickly.”
Presuming Tepco is able to control the spread of contamination beyond 2015, it would still have only scratched the surface of the issue. The mammoth task of removing the melted nuclear fuel and debris from the reactors lies ahead.
In mid-November, the embattled utility is preparing to remove 400 tons of spent fuel from the damaged reactor 4, 21/2 years after a hydrogen explosion damaged the structure’s exterior.
According to the Nuclear Regulation Authority, there are 1,533 spent and unused fuel rod bundles in the cooling pool that contain radiation equivalent to 14,000 times the amount released in the atomic bomb attack on Hiroshima in 1945.
To remove the rods, Tepco has erected a 273-ton mobile crane above the building that will be operated remotely from a separate room.
Up to 22 spent fuel rods will be pulled from the racks they are stored in and inserted one by one into a heavy steel chamber while the assemblies are still under water. Once the chamber is removed from the pool and lowered to the ground, it will be transported to another pool in an undamaged building on the site for storage.
Under normal circumstances, such an operation would take little more than three months, but Tepco is hoping to complete the complicated task within fiscal 2014.
The plan has received mixed reviews regarding its safety from nuclear experts. Removing the fuel rods is a task usually assisted by computers that know their exact location down to the nearest millimeter. Working virtually blind in a highly radioactive environment, there is a risk the crane could drop or damage one of the rods – an accident that would heap even more misery onto the Tohoku region. The more alarmist critics out there have even argued that residents in Tokyo, located more than 200 km away, could be forced to evacuate if another earthquake flattened the reactor 4 building.
Others, meanwhile, say the reactor 4 building is more straightforward to work with than those housing other reactors since the pressure vessel didn’t contain fuel rods at the time of the earthquake and tsunami. The cooling pool has also been made substantially stronger than it was before the accident, with Tepco saying that reinforced concrete measuring up to 18.5 cm is structurally sound on all sides, and the entire pool is shielded by a 6-mm stainless steel sheet.
While successfully removing the spent fuel rods from the reactor 4 cooling pool will probably go some way to allaying the fears of those living in Tohoku, it merely puts Tepco and the government on a collision course with the hitherto great unknown: finding the melted nuclear fuel in the remaining three reactors.
Tepco is planning to submerge the entire pressure vessel of each reactor in water in order to reduce radiation levels. Exactly how the utility is going to fill the 32-meter-high light-bulb-shaped containment vessel – in addition to sealing any cracks or holes it stumbles across along the way – is expected to be decided within fiscal 2016.
Subsequent steps regarding the pressure vessels are not expected to be decided until fiscal 2018, paving the way for the actual removal of the fuel in the remaining three reactors in the first half of fiscal 2020 – about the same time the Olympic torch is being relayed across the country.
Bearing all of this in mind, it’s extremely hard to predict exactly how far along the decommissioning schedule the Fukushima plant will have come by 2020.
Ishikawa, whose career has also included stints at the International Atomic Energy Agency, is one of the few people who can claim to have an insight into the process.
“First, I would like to explain that decommissioning a nuclear power plant is not as complicated as it sounds,” the 79-year-old told The Japan Times On Sunday. “It’s all about removing the nuclear fuel, which contains 99.9 percent of the radioactive material. After that, it’s basically the same as deconstructing any other building.”
Employed at the Japan Atomic Energy Research Institute, Ishikawa was involved in designing Japan’s first nuclear reactor. And then, toward the end of his career, he was tasked with creating technology in the 1980s to decommission the first nuclear plant in Japan.
“The first time, it was strenuous,” Ishikawa said. “We needed ways to operate machines remotely and we had to build them from scratch.”
He said he was excited by the prospect of creating a brand new form of technology to clean up nuclear waste.
But the Fukushima No. 1 cleanup remains a different story, even in his eyes. Nuclear fuel inside reactors 1, 2 and 3 is believed to have breached the inner containment vessels and accumulated in the outer steel containment vessels – what experts describe as a “melt-through.”
Assuming the reactor pressure vessels are submerged before the Olympics, as Tepco plans, still won’t help much in figuring out where the nuclear fuel is located.
“It could be mixed with other metal, it could be as hard as iron or as breakable as a concrete block,” Ishikawa said. “There is no way to know such factors and, without them, removal isn’t a possibility.”
Ishikawa believes that designing a specialized robot to locate the melted fuel is probably going to be required. If that doesn’t work, easing the upper limit of radiation exposure for decontamination workers at the Fukushima No. 1 power plant is going to be essential, as laborers would need to work in close proximity to the vessels.
“If a sample of the nuclear fuel lying at the bottom of a vessel is extracted for study within the next four to five years, I’d call it a success,” Ishikawa said.
Forecasting the cleanup timetable in the aftermath of a nuclear crisis is also complex because there are few precedents that can provide an accurate guidance.
The Chernobyl disaster in 1986, which along with Fukushima remains the only level 7 incident to occur since the International Nuclear Event Scale was created, is very much an ongoing effort as of 2013.
Nine years after the plant exploded and caught fire, the World Health Organization linked nearly 700 cases of thyroid cancer among children and adolescents in the region to the accident. Some believe that radioactive iodine released in the calamity was deposited in pastures and eaten by cows who then concentrated it in their milk – a favorite source of nourishment for young children.
The Russian government is still in the process of strengthening Chernobyl’s containment structure, and reports say that more than 95 percent of the nuclear fuel that sat in the pressure vessel at the time of the accident remain under the sarcophagus today. A new containment shelter over whatÅfs left of the devastated power plant in the Ukraine is scheduled to be completed in 2015.
By comparison, workers cleaning up the site of Three Mile Island were in the middle of shipping critical debris components to an off-site storage facility using specialized chambers and rail carriages nine years after America’s worst nuclear accident. The debris shipments began in 1986 and continued until 1990. The accident, however, was substantially easier to mop up compared to Fukushima or Chernobyl, as it was only a level 5 incident on the International Nuclear Event Scale.
Ishikawa does not believe the reactors at Fukushima No. 1 will be in a state that would worry the International Olympic Committee seven years from now in 2020.
While several radioactive materials that were released following the 2011 accident have half lives that will render much of the surrounding countryside unusable for many decades, there is no reason to believe that Fukushima will become an issue in hosting the Olympics, he said.
Tanaka of the University of Tokyo went further, saying it was virtually senseless to debate whether Abe’s claim that “the situation is under control” is true.
And he agreed that at least in terms of hosting the Olympics, the nuclear plant posed no obvious risk to Tokyo.
“Look around, people are living in the city without any serious risk today,” Tanaka said.
“Trying hard to convince the world that Japan is safe isn’t enough,” he said.
“What counts now is that the government makes it easier for everyone to understand – in tangible numbers – that it is, in fact, safe,” Tanaka said.
“For example, we need to explain the leaks more clearly to the public and what it means. That is the responsibility of the government now”as Japan gears up for 2020, Tanaka said.
Jun Hongo, Japan Times Staff Writer, October 19, 2013