Former Prime Minister Naoto Kan said Tuesday the nuclear disaster at the Fukushima No. 1 power plant is not over five years since a massive earthquake and tsunami triggered the meltdowns.

“There is no doubt” radioactive materials have been seeping into the sea after mixing with groundwater, Kan, who has been a vocal critic of nuclear energy since the crisis started, told the National Press Club in Washington.

Prime Minister Shinzo Abe has repeatedly said the issue of water contaminated with radioactive substances at the Fukushima plant is “under control,” including when he was making a pitch for Tokyo as host of the 2020 Olympic Games.

Kan disputes this. “The accident is still unfolding,” he said.

Kan was prime minister when the world’s worst nuclear crisis since Chernobyl occurred following the massive earthquake and tsunami on March 11, 2011.

Kan, a lawmaker of the Democratic Party of Japan, also criticized Abe’s decision to raise the ratio of electricity produced by atomic energy to 20-22 percent of the nation’s total output by 2030.

“The goal is not achievable” unless Japan extends the maximum legal period of reactor operations or builds a new nuclear plant, Kan said.

Most nuclear reactors remain off line in Japan, but various operators are seeking restarts.

Kansai Electric Power Co. is set to reactivate a reactor at its Takahama plant in Fukui Prefecture on Friday, in what would be the third restart since new safety standards were put in place.