Despite the objections of local fishermen, the tritium-tainted water stored at the Fukushima No. 1 nuclear plant will be dumped into the sea, a top official at Tokyo Electric says.

“The decision has already been made,” Takashi Kawamura, chairman of Tokyo Electric Power Company Holdings Inc., said in a recent interview with the media.

Tritium typically poses little risk to human health unless ingested in high amounts, and ocean discharges of diluted volumes of tritium-tainted water are a routine part of nuclear power plant operations. This is because it is a byproduct of nuclear operations but cannot be filtered out of water.

As of July 6, about 777,000 tons were stored in about 580 tanks at the Fukushima plant, which is quickly running out of space.

Tepco’s decision has local fishermen worried that their livelihood is at risk because the radioactive material will further mar public perceptions about the safety of their catches.

Kawamura’s remarks are the first by the utility’s management on the sensitive matter. Since the March 2011 meltdowns were brought under control, the Fukushima No. 1 plant has been generating tons of toxic water that has been filling up hundreds of tanks at the tsunami-hit plant.

Kawamura’s comments came at a time when a government panel is still debating how to deal with the tritium issue, including whether to dump it all into sea.

Saying its next move is contingent on the panel’s decision, Kawamura hinted in the interview that Tepco will wait for the government’s decision before actually releasing the tainted water into the sea.

“We cannot keep going if we do not have the support of the state” as well as Fukushima Prefecture and other stakeholders, he said.

Toxic water at the plant is being treated by a complex water-processing system that can remove 62 different types of radioactive materials except tritium.

Shunichi Tanaka, chairman of the Nuclear Regulation Authority, has been urging Tepco to release the water. Kawamura says he feels emboldened to have the support of the NRA chairman.

But fishermen who make their livelihoods from sea life near the plant are opposed to the releases because of how the potential ramifications will affect their lives.

“Releasing (tritium) into the sea will create a new wave of unfounded rumors, making our efforts all for naught,” said Kanji Tachiya, head of a local fishermen cooperative.

Tachiya, of the cooperative that includes fishermen from the towns of Futaba and Okuma, which host the plant, took a swipe at Tepco’s decision, saying there has been “no explanation whatsoever from Tepco to local residents.”

On March 11, 2011, tsunami inundated the six-reactor plant, situated 10 meters above sea level, and flooded the power supply, causing a station blackout. The cooling systems of reactors 1, 2 and 3 were thus crippled, leading to core meltdowns that became the world’s worst nuclear disaster since Chernobyl in 1986.

Water is being constantly injected into the leaking reactors to keep the molten fuel cool, creating tons of extremely toxic water 24/7. Although it is filtered through a complex processing system, extracting the tritium is virtually impossible.