Japan's nuclear power industry, which once ignored opposition, now finds its existence threatened by women angered by official opaqueness on radiation from the Fukushima Daiichi nuclear plant after it was struck by an earthquake-driven tsunami in March.

"Mothers are at the forefront of various grassroots movements that are working together to stop the operation of all nuclear plants in Japan from 2012," Aileen Miyoko Smith, head of Green Action, a non- governmental organisation (NGO) that promotes renewable energy told IPS.

More than 100 anti-nuclear demonstrators, most of them women, met with officials of the Nuclear Safety Commission this week and handed over a statement calling for a transparent investigation into the accident and a permanent shutdown of all nuclear power plants.

Currently six of Japan's 56 nuclear plants are closed, some for stress tests after the Fukushima accident exposed serious breaches of safety precautions in the nuclear power industry.

More than 150,000 people remain unable to return home because of high levels of radiation in the Fukushima vicinity. There is now evidence that contamination has spread to rice and vegetables grown in nearby farming areas, and found its way into baby food products on supermarket shelves.

Japanese authorities announced last week that the devastated Fukushima Daiichi complex has been brought down to a state of cold shutdown.

"The first stage of controlling the terrible accident has been achieved. The government will follow a road map which in 30–40 years will make Fukushima safe again," said Goshi Hosono, minister of state for nuclear power policy and administration.

Speaking to the press, he explained that there is now no nuclear activity in the Fukushima nuclear reactors emitting radiation.

Power companies and government officials have also pledged to enforce safety regulations strictly and to ensure transparency.

Smith views the latest announcements as a warning. "We are stepping up our activism to ensure that the government and power industries, now eager to create a notion of security, will not restart nuclear plants," she said.

Indeed, groups of women, braving a cold winter, have been setting up tents since last week preparing for a new sit-in campaign in front of the ministry of economic affairs.

The women have pledged to continue their demonstration for 10 months and 10 days, traditionally reckoned in Japan as a full term that covers a pregnancy.

"Our protests are aimed at achieving a rebirth in Japanese society," said Chieko Shina, a participant, and a grandmother from Fukushima. "There is a need to change the way the authorities have run the country by putting economic growth ahead of protecting the lives of people."

Experts view the ongoing protests as a landmark in Japan's fledgling social movements long consigned to the sidelines of a prosperous and hardworking society that puts a premium on achievement and success.

"The ongoing demonstrations symbolise the determination of ordinary people who do not want nuclear power because it is dangerous. There is also the bigger message that we do not trust the government any more," said Takanobu Kobayashi, who manages the Matsudo network of citizens' movements.

Distrust stems primarily from the fact that the meltdown of the Fukushima reactors was not reported to the public immediately, causing huge health risks to the local population from radiation leaks.

Internet sites have recorded hundreds of thousands of comments by people expressing disbelief over assurances put out by the government or officials from the Tokyo Electric Power Company (TEPCO), operator of the Fukushima plant, on nuclear safety.

The accident also broke the myth of safety of nuclear power plants that authorities had maintained for decades to gain public support as the country embarked on massive nuclear power programmes.

Faced with public anger, the government and TEPCO have acknowledged mismanagement and promised major reforms.

Prof. Hideo Nakazawa, a sociologist at Chuo University, describes the ongoing protests as both a display of resentment against authority as well the use of nuclear power.

"Demonstrations have reached cities, taking the nuclear issue to the forefront of civil movements in Japan," he told IPS. He added that the lack of involvement of political parties in the anti-nuclear movement contrasts with the older pattern that had strong leftist leanings.

The leadership of women in civic movements is also unprecedented. Mothers have been leading the demonstrations, with many of them coming out for the first time to gain sympathy and support for their campaign to prevent exposing children to the dangers of radiation.

"Japanese civic movements have languished on the margins mostly because of the cold shoulder treatment they have received in society. These barriers are being broken now," explained Nakazawa.

Parliamentarian Mizuho Fukushima, one of Japan's leading female politicians and an active participant in the anti-nuclear demonstrations, told IPS that the protests against nuclear power are not going to die down.

"Forcing changes to stop nuclear power in Japan is very possible," said Fukushima, chair of the Social Democratic Party of Japan since 2003.