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Rebuilding a Region: Tōhoku Five Years Later
The Fukushima Cleanup Will Take Generations
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The Tōhoku tsunami of March 11, 2011, triggered a series of equipment failures leading to multiple meltdowns, explosions, and releases of radioactive material at the Fukushima Daiichi Nuclear Power Station, operated by Tokyo Electric Power Company. Five years after the second-worst nuclear accident in history (after Chernobyl), the cleanup team is still struggling to halt the buildup of contaminated water, and the techniques and equipment needed to locate, extract, and dispose of the melted fuel have yet to be developed. Given these challenges, many experts are convinced that the decommissioning process will take far longer than the official 40-year timetable—perhaps as long as a century.
TEPCO’s Fukushima Daiichi Nuclear Power Station as photographed in February 2015.
A Five-Year Battle Against Groundwater
One of the first things a visitor will notice upon entering the site is row upon row of massive cylindrical water tanks. Built to store some 800,000 tons of radioactive water, these 1,100 or so tanks bear witness to the epic battle that has absorbed the energies of the cleanup team for the past five years, as it struggled to contain and decontaminate radioactive water and halt its accumulation.
Rows of water tanks, built to hold almost a million tons of radioactive water, occupy much of the plant compound at Fukushima Daiichi Power Station, seen here from the west. Beyond the tanks stand the damaged reactor buildings from which contaminated water continues to flow.
Rainwater and groundwater have continued to pour into the damaged basements of Units 1–4, where it mixes with the highly radioactive cooling water already inside the buildings. To stem the buildup of this contaminated water and prevent it from flowing into the ocean, TEPCO has devised a complicated patchwork of strategies aimed at solving the problem by 2020.
The pillars of TEPCO’s water management efforts to date are two systems for channeling groundwater away from the contaminated basements and releasing it into the ocean relatively free of radioactive contaminants. One, the groundwater bypass system, collects water in wells dug between the reactor buildings and the hills to the west. The water is pumped up from the wells, tested, and eventually released into the ocean. The other, called the subdrain system, uses wells dug around the perimeter of the reactor buildings. So far, TEPCO has discharged some 230,000 tons of water into the ocean using these two methods combined. Even so, groundwater continues to pour into the buildings' basements at the rate of about 150 tons a day.
Some steps TEPCO has taken have generated new problems. An example is the “sea-side impermeable wall” built by sinking close to 600 cylindrical steel piles—each about 30 meters long and a little more than 1 meter in diameter—into the seabed along the waterfront. In October 2015, TEPCO completed the 780-meter barrier. However, the water pumped from the area inside the wall was found to be too radioactive to be released, and as the groundwater level rose, TEPCO was forced to pump it back into the basement of the turbine buildings at the rate of about 550 tons a day. Thus the expensive project has actually exacerbated the accumulation of contaminated water instead of mitigating it, and so far there is no solution to the problem in sight. TEPCO has also installed equipment around the reactor buildings for the purpose of creating an “ice wall” of frozen soil to block the influx of groundwater, but it could be another eight months before the wall is complete.
At a September 2013 meeting of the International Olympic Committee, shortly before Tokyo was selected to host the 2020 Summer Olympics, Prime Minister Abe Shinzō disposed of water-contamination concerns with a breezy “Let me assure you the situation is under control.” This was certainly not the case then, in the wake of revelations that 300 tons of highly radioactive water had leaked into the ground from a storage tank. Today, five years after the 2011 accident, the problem of contaminated water remains a serious challenge. But from a crisis-management standpoint, it is probably fair to say that the situation is finally under control.
Improvements in Working Conditions
Working conditions for the plant’s cleanup workers—who number in the thousands—have improved dramatically over the past few years. Perhaps the most important change in this regard has been the drop in the radiation levels to which workers are routinely exposed. By the end of March 2016, TEPCO expects to meet its target of reducing the effective radiation exposure at the site boundary to less than 1 millisievert per year above natural background levels—about a tenth of the level recorded back when accident debris and the highly radioactive water in storage tanks were still contaminating the air.
One way that TEPCO is reducing radiation exposure at the site is by paving the grounds. The plan, now about 85% complete, is to pave 1.45 million square meters out of the total area of 3.5 million m2. Meanwhile, much of the radioactive water stored in above-ground tanks has undergone initial treatment using advanced liquid processing equipment and other filtration systems.
Thanks to such measures, except for the immediate vicinity of the stricken reactors (where the radiation dose can still be higher than 100 mSv per hour), most of the site is now safe to walk through with no more than a coverall and disposable dust mask for protection. Working at Fukushima Daiichi is no longer a high-risk job, provided one has the sense not to wander unprotected into the radioactive zone around the crippled reactors.
When I visited recently, the work atmosphere was surprisingly pleasant and relaxed. In the cafeteria, employees smiled and laughed easily as they chatted over lunch. The second-floor dining room is part of the nine-story employee “rest house” near the plant’s west entrance. The building, completed in June 2015, features lounges and other common areas along with the cafeteria, which offers a choice of noodles and other hot meals (prepared offsite) at a price of just ¥380. This is another area of dramatic improvement from the early days, when cleanup workers were provided with no more than a bottle of mineral water and some crackers.
“It’s important to make the compound as much like a normal work site as possible,” explained Masuda Naohiro, chief decommissioning officer. Masuda is president of Fukushima Daiichi D&D Engineering Company, set up in April 2014 to “provide optimal focus, expertise, and efficiency” and “clarify the lines of responsibility within TEPCO.”
A red fox made a cameo appearance during my visit to the plant. The creature made no move to flee even when we passed fairly close, and the workers walked on smiling, apparently accustomed to the sight. The almost incongruously pastoral image struck me as another sign of the substantial progress TEPCO has made in improving overall conditions and reducing stress levels at the site of the 2011 accident.
A red fox at the Fukushima Daiichi Nuclear Power Station exhibits little fear of the plant’s human denizens.