But activists say they are struggling to turn widespread anger toward the government agencies and industry responsible for the disaster into a sustained movement that causes real change.
“[After the accident] parents’ groups sprang up all over the country, and for six months or so they’ve been able to run on pure momentum. But long-term activism is very difficult. We have to turn this into a movement that doesn’t forget, doesn’t give up, and doesn’t stop,” says Emiko Ito, a mother of four and co-founder of the National Network of Parents to Protect Children from Radiation, which has over 275 member organizations from Hokkaido to Okinawa.
The groups are demanding school boards test school lunches, pushing city councils to reject shipments of contaminated soil from Fukushima, and petitioning the central government to give families the right to evacuate from a wider area around the nuclear plant. They have had some success, including a government commitment to pay for devices to measure radiation levels in school lunches in 17 prefectures.
The anti-nuclear movement, too, has surged compared with the last major wave triggered by the Chernobyl accident. Following huge protests last summer and fall, campaigners say they have gathered enough signatures to hold referendums on nuclear power in both Tokyo and Osaka (the number of valid signatures in Tokyo has yet to be verified). Other groups are working to prevent the government from restarting plants shut down for routine inspections and "stress tests" after the Fukushima disaster. In a late-October poll by national broadcaster NHK, 66 percent of respondents said they wanted nuclear power abolished or reduced – an increase of 24 percentage points compared with April.
But long-time environmental activist and conference co-organizer Aileen Mioko Smith says anti-nuclear groups have not experienced the same dramatic growth as radiation-protection groups.
“Masses of people are not calling to say, ‘What can I do?’” she says. “There’s a route where people are worried about [contaminated] food or rubble, then do some petitions, then that leads to, ‘Hey, why is this going on?’ But it’s not everyone.
In fact, many radiation-protection groups have distanced themselves from the anti-nuclear movement in order to broaden membership.
“The one common point for all the groups in our network is protecting children. I think if we made nuclear power a theme some groups would fall away,” said Ito.
How far can the activists go?
That stance has led some to question how much political clout the newly-minted parent-activists can actually have.
“It’s fine to go around with a Geiger counter and see if your child’s playground is radioactive, but how do you go from that to getting the laws to change so that this kind of thing can’t happen again?” asks University of California Berkeley professor Susan Holloway, who studies Japanese families and education.
Tohoku University sociologist Koichi Hasegawa echoes her concern.
“Logically this is a political issue, but the activists don’t have a political strategy. It’s more about expressing anger and improving the [immediate] situation,” says Hasegawa, who has studied the anti-nuclear movement since the late 1980s.
Some parents say keeping the focus personal is a political strategy, however.
“In this country, as soon as you mention the term ‘anti-nuclear,' ” the political system stops working. But everyone can work together on the point that they don’t want their children irradiated,” says Miho Abe, a Web producer and mother of two who founded a radiation-protection group in Yokohama.
Ms. Abe spoke at a Yokohama anti-nuclear conference recently, but said she kept her attendance secret until the event ended for fear local politicians she was working with on radiation issues would drop their support.
Even when it comes to radiation, she tries to keep a low profile.
“I spread information mostly by word of mouth or on the Internet. If you start holding meetings, you’re seen as an extremist,” she said.
Yoshinari Harada, a farmer and teacher who belongs to a radiation-protection group in Miyagi Prefecture, said the social pressure to stay quiet is even stronger in rural areas – including those, like his, with relatively high levels of contamination.
“Before the disaster, people who brought up the issue of nuclear power were considered eccentric. Things haven’t changed much,” he says.
Ito hopes the national network she helped form will allow parents like Harada and Abe gain strength from each other and influence national policy related to radiation.
As for the movement to abolish nuclear power, Mioko Smith says organizers still have to figure out how to tap the undercurrent of political discontent and anti-nuclear sentiment that has spread through mainstream Japan since the disaster.
“11,500 people showed up [at the Yokohama conference] and they weren’t just sitting there bored, ” she said. “We’re talking about what we can do with that energy.”