With preparations underway to restart Japan's nuclear plants, writer Keiko Ochiai has pledged to continue a workshop on problems related to atomic power, four years after the Fukushima nuclear disaster began.

The monthly workshop organized by Ochiai in Tokyo was first held in May 2011, two months after a massive earthquake and tsunami hit northeastern Japan, and there have been more than 50 meetings since.

"It's unfortunate but I have to continue the workshop," the 70-year-old writer said in an interview.