Tatsuhiko Kodama's voice shakes as he addresses volunteers at Ishigami Daini Kindergarten in the city of Minamisoma, 15 miles from the troubled Fukushima Daiichi Nuclear Plant.
The director of the University of Tokyo's Radioisotope Center is training people how to decontaminate a school filled with radiation spewed from the nuclear reactors. He has explained the process a dozen times before, yet tears well up every time Kodama sees mothers donning masks, fathers taking notes with dosimeters in hand.
"All of this is to protect your health," he tells them. "We want to make sure there's no negative impact on you or your health. We must protect our children."
Kodama is leading a joint project with the local government to decontaminate neighborhoods just outside the government-mandated exclusion zone. His volunteers are carrying out an ambitious undertaking to lower radiation levels at all nurseries and schools, so children, the most vulnerable residents, can return this fall.
The plan calls for aerial monitoring devices to determine radiation levels on the ground, mapping the contamination, and training volunteers to decontaminate the areas accordingly. It's a painstaking process that requires hours of pressure washing walls and playground equipment, and shoveling highly radiated soil from school grounds. Workers scrub down the roof with brooms, take radiation measurements at every step, then repeat the process until the number on the radiation counter falls below 0.1 microsievert per hour, the level of exposure considered safe for children.
That doesn't come easily.
"The area itself is relatively highly contaminated," Kodama says. "Many small children playing around the ground might touch some mud or in some case, eat some sand, which would result in internal radiation. [That's why] we would like to remove this highly contaminated material first."
Volunteers Scrubbing Nuke Effects From Playgrounds, Schools
For the 67,000 residents of Minamisoma, it is a critical step toward returning life back to normal. Five months after Japan's worst nuclear crisis, the coastal city once considered a "ghost town" has slowly sprung back, as stores reopen and residents return home after months in temporary shelters. Yet half the population remains evacuated. A third of the city still sits inside the 12-mile, government-mandated exclusion zone, deemed too dangerous for people to live in.
The government has announced plans to lift evacuation advisories for areas outside that zone. But it has yet to come up with a blueprint to decontaminate areas where radiation exposure exceeds 20 millisieverts a year, the maximum dosage allowed for average nuclear workers.
Tired of waiting, Minamisoma has drawn up a multimillion-dollar plan that largely relies on volunteers such as Yukari Kowata to cleanup, with the help of Kodama's team. Her home is 10 miles from the Fukushima plant. She and her elderly parents have been living in temporary housing since the government forced them to evacuate in March.
Cleaning Nuclear Contamination at the Edge of Japan's No-Go Zone
On a recent Saturday, Kowata braved the rain with three dozen other volunteers, wearing parkas, gloves and face masks as they measured for radiation. Under the playground slide, the counter read "4.7 microsieverts" per hour, 40 times the level considered safe for children.
The group removed the top soil with shovels, placed the mud in a small bag, washed down the slide, then measured again. The level had dropped to 3.4.
"I wonder if the rainwater is having an effect," one woman said, as others continued to shovel dirt, and remove another layer of soil.
"If this radiation is going to stick around here for five to 10 years, we have to learn to live with it," said Kowata, who also oversees kindergartens and nurseries for the city. "If we want our children to return, then we have to find a way to make it safe for them again."
Neither the central government nor local officials have set official radiation safety standards for schools, leaving volunteers such as Kowata or Kodama to make that determination on their own. Nearly 300 schools in the Fukushima prefecture have already removed radiated top soil from playgrounds, a critical first step in decontamination. But only a handful of cities have adopted plans similar to Minamisoma.
University of Georgia professor Cham Dallas, who spent a decade studying the effects of the Chernobyl nuclear disaster, says overall radiation levels have dropped in Fukushima schools, but the "hot spots" remain. While decontamination methods used in Minamisoma are effective in the short-term, Dallas says, pressure washing and scrubbing aren't proper solutions for areas with dangerously high levels.
"That's what they did at Chernobyl, and it didn't work," Dallas said. "Radionuclides just keep moving around. Then you have to deal with it five years later, you have to deal with it 10 years later. Then it is 25 years later and you're still dealing with radionuclides that could have been removed in the initial year, instead of just letting it move around."
Volunteers Wear Dosimeters to Measure Radiaton as They Work
There are other concerns: where to store all the radioactive dirt and water removed from school grounds. Contaminated sludge has piled up at waste treatment centers in recent months, as the government mulls over its final resting place.
Kodama says it will take a multi-pronged approach to make Minamisoma's schools radiation-free once again. But his project is the first step, one more step than the government has taken.
In a recent testimony before a parliamentary committee, Kodama ripped into the government's slow response to the nuclear accident, and demanded that it immediately come up with a decontamination plan, saying, "What the hell are you, the government doing?"
The testimony was so emotional it quickly went viral on YouTube.
Back in Minamisoma, Kodama measures the radiation levels inside empty classrooms after volunteers complete their work. He points the Geiger counter toward the ceiling, waits for the deflection needle to stop moving, then smiles. The counter reads "0.12," a 60 percent drop in radiation dosage, compared with levels two weeks ago.
One small victory in a fight Kodama expects will take decades.
"In the case of Minamisoma, we are very optimistic," Kodama said. "But in the case [of cities] just outside the Fukushima plant, some areas may not be livable for up to 50 years."