As the fifth anniversary of Japan's massive earthquake and nuclear disaster approaches, the country's former prime minister said it was time to do without nuclear power.
"If you look at the reality of these last five years, Japan spent two years without a single nuclear plant on line. There are now a few active reactors, but still, that's only a handful," Naoto Kan, who was prime minister when the Great East Japan Earthquake struck, told CNBC. His comments were translated from Japanese.
"These five years have demonstrated that we can secure enough power without nuclear plants. That's why I believe we should stay away from the large risk posed by nuclear plants and focus instead on renewable energy by changing our sources of power," Kan added.
Kan isn't alone in his opposition to nuclear power; opinion polls have showed that a majority of Japanese people agree. But he blamed the current ruling party, the Liberal Democratic Party the recent restart of four reactors, which had been shuttered in aftermath of the disaster. Kan is a member of the Democratic Party of Japan.
"The Liberal Democratic Party, which ran on a platform of returning to nuclear power, won all the major elections," Kan said. "The main reason is the [Shinzo] Abe administration focused the elections on economic policy. Now these economic policies are at a dead end, while the people's anti-nuclear sentiment remains strong." Kan was referring to Abe's economic stimulus program, known as Abenomics, which has a mixed track record in its aim to kick start the long-moribund economy out of deflation.
On March 11, 2011, a magnitude 9.0 earthquake struck Northeast Japan. It was one of the most powerful quakes on record, unleashing a tsunami along 700 kilometers (435 miles) of coastline.
The earthquake and tsunami triggered a meltdown at the Fukushima Daiichi nuclear plant, which contaminated nearby towns in what was the world's worst nuclear disaster since Chernobyl in 1986.
According to the latest estimate, 15,894 people were killed in the combined disasters; an additional 2,562 others are still listed as missing, and more than 450,000 people were forced from their homes.
Five years on, the decommissioning effort at Fukushima Daiichi is still in its early stages, and is expected to take 30 to 40 years. Just last month, three former executives from Tokyo Electric Power (Tepco), the company that operated Fukushima Daiichi, were indicted for failing to take safety measures to prevent a nuclear disaster. They are the first Tepco officials to charged over the meltdown.
The government's immediate response to the disasters was "very complicated," Kan told CNBC.
"The natural disaster and the nuclear accident occurred and unfolded at the same time. That was the most difficult aspect," he said.
"If it had only been the earthquake and tsunami, the first stages would have been difficult. There were lots of victims, but there were previous examples of how to respond," he said. "In the case of the nuclear crisis, we didn't know how serious it would become. The situation kept escalating."
Kan cautioned that the nuclear disaster was not yet over.
"There is still contaminated water coming out of the buildings of reactor one to four. Tepco says it is storing it in tanks, but part of it is leaking out into the ocean," he said, adding that radioactive particles were also still leaking, while nuclear debris remained in the reactors that melted down.
Additionally, the human cost of the disaster was ongoing, he noted.
"There are still more than 100,000 evacuees from Fukushima who are unable to return home. Even if the government and Fukushima prefecture say they will, there are still many women with young children who have decided to leave the area," he said.
—Reuters contributed to this article
—By CNBC.Com's Leslie Shaffer; Follow her on Twitter @LeslieShaffer1