Naoto Kan, who was Japanese PM when the March 2011 Great East Japan Earthquake hit and crippled the Fukushima nuclear plant, remains in politics but has only one aim now: to see every last atomic energy plant shut down.
In the dark days of late March and April 2011, when the crisis at the Fukushima nuclear plant threatened to escalate into an even more dramatic catastrophe, the entire nation hung on Naoto Kan's words as he addressed televised press conferences with the latest updates from the wrecked plant.
Today he speaks to groups of maybe a couple of dozen people at small-scale town-hall meetings around the country. But his theme at these talks is consistent: He is asked to appear to encourage local people and town councils to stand firm in their opposition to utility companies restarting nuclear power plants in the neighborhood.
Resisting the return of nuclear power has become his sole aim in politics now, he said suring an interview in Tokyo on Thursday, December 12.
"I was recently in Hakodate, in Hokkaido, to take part in a meeting of people opposed to the restart of the Oma nuclear plant and after that I went to Ikata to speak to people in Ehime Prefecture about the reactors there," Kan said.
Network of citizens
"I am trying to increase the network of citizens who are speaking out against nuclear power.
"And when I meet the people in the towns where these reactors are based, I see just how many voices are against the plants," he said. "That makes me think it will not be possible for the government and the power companies to go over the heads of the people and forcibly restart the plants."
All 50 of Japan's commercial reactors are currently off-line, a measure that Kan ordered in the immediate aftermath of the Fukushima disaster and until thorough safety checks could be carried out. Under law, they can only be restarted with the approval of local authorities and while two reactors were briefly operated earlier this year, no community has so far granted a power company to put their facilities back into full operation.
And Kan wants to keep it that way.
Cannot be controlled
"The reason that I am against nuclear energy is because it is a technology that human beings cannot control 100 percent," he said. And while he agrees that there are similar risks associated with travelling by airplane, for example, the impact of a severe accident at a nuclear plane - as Japan has already seen - is "potentially enormous."
At one point shortly after the Fukushima disaster, Kan and his government was giving serious consideration to issuing an order to evacuate 50 million people living within a 250-km radius of the plant, which would have included Tokyo.
"The worst case scenario was that one-third of Japan would no longer be able to be used and more than 40 percent of the population would have to be moved," he said. "That was the situation that we were facing and we only escaped it by a hair's breadth."
In those early days of the crisis, the true gravity of the problem was not clear and experts were largely guessing at what had happened within the reactors. It now appears that molten fuel burned through the 20-cm-thick metal casing of the pressure vessels in three of the reactors and pooled in the concrete shell of the basement level.
"If things had got worse and the fuel had gone through the concrete, then we would not be sitting in this room in Tokyo today," he said.
A similar stroke of luck prevented the spent fuel rods in reactor four being exposed to the air when the water they are meant to be stored in evaporated. A gate designed to stop water flowing through a channel was displaced by the shockwaves of the earthquake, enabling more water to flow into the pool.
'Intervention from God'
Naoto Kan resigned from office five months after the nuclear disaster in Fukushima
"I still consider this to have been divine intervention from God," he said.
Kan stepped down as prime minister in August 2011 and his Democratic Party of Japan (DPJ) lost the December 2012 general election to the Liberal Democratic Party (LDP) - a strongly pro-business and pro-nuclear energy party.
Even though he is no longer in government - and has been suspended by the DPJ for supporting a rival to the party's candidate in a recent by-election - Kan continues to push his belief that humankind cannot completely control nuclear energy and that we therefore need to harness power from renewable sources to ensure our future.
"When I was still head of the DPJ, we set an official policy of having no nuclear plants in Japan within 30 years," he said. "We took a strong position and I hope to be able to continue to express my thoughts clearly and loudly in the Diet in the future.
"I intend to pursue Prime Minister Shinzo Abe and his administration and to show them that their policies are wrong," he added.