VOA常速英语:日本考虑将福岛核电站含氚污水排入太平洋

Month by month, year by year, the huge storage tanks surrounding the crippled Fukushima Daiichi plant grow in number.It is estimated they contain more than 750 thousand metric tons of water contaminated with tritium.Local media reported last month that plant owner TEPCO planned to release the water into the Pacific Ocean,prompting an outcry from environmental groups and local fishermen, TEPCO says it has yet to make a decision.

“One option is to release the tritium-contaminated water into the ocean.However, there are other options such as vaporizing it, but we have not decided yet which option to take to dispose of the water.Since there may be an influence on the environment,and because there have been harmful rumors about what effects it may have on people and the environment,we are still consulting with various stakeholders before finally deciding on the solution.”

TEPCO points out that all nuclear power plants around the world release tritium into the environment.It is considered one of the less dangerous radioactive isotopes,says marine radiochemist Ken Buesseler of the Woods Hole Oceanographic Institute in Massachusetts.

He spoke to VOA via Skype, “there are natural sources up in cosmic rays interacting in the atmosphere.And the biggest source by far was the weapons’ testing back in the 1960s, so you’re talking about adding to what’s already there.If it’s all released on one day, that’s a very different scenario for the oceans than if it’s released sequentially over the course of several years.”

A purification system known as ALPS is designed to remove other more harmful isotopes from the contaminated water.Buesseler says more oversight is needed.

“Independently, I want to see for each tank, what are the levels not only of the tritium, which dominates by far the radioactivity,but all those minor elements, cesium, strontium, that are still there to some degree.”

Longer-term, authorities face the task of trying to remove the nuclear fuel.Robots have recorded footage of what appear to be melted fuel rods inside one of their reactors.

“Around the fall of this year, we are hoping to reveal a big plan on our future policy,and the method which we will use to remove this fuel.”

The Japanese government estimates the total cleanup cost, including compensation, decommissioning and decontamination,will reach 190 billion dollars in a process likely to take at least 40 years.

Henry Ridgwell, for VOA News, Tokyo.