Almost two years after a deadly tsunami crashed into the Fukushima Dai-ichi nuclear power plant, crippling its backup power supply and triggering the world’s worst nuclear crisis for a quarter of a century, the gravest danger has passed.
However, on a rare trip to the atomic facility, for all the signs of progress since I last visited a year ago the most complex nuclear decommissioning operation ever carried out has barely begun.
Radiation levels in the abandoned communities near the power plant have fallen 40 percent in the past year. Inside the wrecked facility, construction workers rush to complete state-of-the-art equipment that will remove dozens of dangerous radioactive nuclides from cooling water. Soon, a steel shield will be driven into the seabed to prevent contamination from the plant from leaking into the Pacific.
The pipes, cables and other equipment strewn across the plant’s grounds this time last year are now functioning components in a complex, technologically fraught mission to cool the crippled reactors, while experts struggle to figure out how to extract the melted nuclear fuel lying deep inside their basements.
The three reactors struck by meltdown and hydrogen explosions two years ago were brought to a safe state known as “cold shutdown” in December 2011, nine months after the tsunami left almost 20,000 dead or missing along Japan’s northeast coast.
Now, Japan is about to embark on a cleanup that could cost at least US$100 billion — on top of the cost of compensating evacuees and decontaminating their abandoned homes.
Fukushima Dai-ichi’s manager, Takeshi Takahashi, conceded that decommissioning the plant could take between 30 and 40 years.
“Even though we are still faced with a difficult task, we’ll keep pushing on with the decommissioning process,” he told a small group of visiting foreign journalists on Wednesday. “It will take a long time to complete our work, especially on the three reactors that suffered meltdown, but we’ll do our best to keep them stable.”
The cleanup operation will begin at reactor No 4, where the fuel rods inside survived unscathed after it was hit by the tsunami, then badly damaged by a hydrogen explosion.
By the end of this year Tokyo Electric Power Co (TEPCO) says it will begin removing fuel assemblies from the reactor and placing them in a nearby cooling pool, where they will remain for four years before being stored in dry casks in a purpose-built facility on higher ground.
In total, workers will have to extract more than 11,000 new and used fuel assemblies from seven badly damaged storage pools. Work to remove melted fuel will not begin until 2021, and the entire decommissioning project is expected to take up to 40 years.
Managers from firms contracted by TEPCO to help decommission the 40-year-old plant say they are confident progress is being made, despite the radiation hazards faced by their employees.
Perhaps the most dangerous job on the site has fallen to Hiroshige Kobayashi and his colleagues. As a manager at Kajima Corp, Kobayashi is responsible for clearing and processing the rubble and debris from reactor No. 3, where radiation levels easily outstrip those at other parts of the site.
The dangers associated with working in highly radioactive areas of Fukushima Dai-ichi prompted the WHO to warn last week that one-third of the plant’s workers face an increased risk of developing thyroid cancer, leukemia and all solid cancers during their lifetimes.