Tokyo Electric Power Company Holdings

The tsunami-wrecked Fukushima Daiichi nuclear power plant 's operator says it began releasing its first batch of treated radioactive water into the Pacific Ocean on Thursday — a controversial step, but a milestone for Japan's battle with the growing radioactive water stockpile.

Japan's new prime minister on Oct. 17 said the planned mass disposal of wastewater stored at the tsunami-wrecked Fukushima nuclear plant cannot be delayed, despite concerns from local residents.

The "decision has already been made" to release radioactive material from the Fukushima plant into the ocean, according to its owners. Fishermen have reacted with fury to the decision, claiming it will devastate their already struggling industry.