Build a wall of ice with hundreds of pipes, which should stop the contaminated water
Five years after the nuclear accident at the Fukushima Daiichi plant, located in the province of the same name, Japanese still suffer the consequences. The reactors did not melt still overheating and needing to be cooled with water, which then becomes contaminated. But Japan wants to change that with a wall of ice (no, not the Game of Thrones ).
It is planned a few years ago by Tokyo Electric Power (Tepco), but only on Wednesday (30) they got permission from the NRA (Nuclear Regulatory Agency, its acronym in English) to activate it. The purpose is to prevent groundwater is contaminated, barring their contact with the reactor. It is expected that it also prevents water contamination in the Pacific Ocean.
The wall is 30 meters deep and 1.5 km long, frozen at 30 ° C negative. In total, it cost $ 312 million. The result is long-term: the Japanese hope to solve the problem of contaminated water in time for the 2020 Olympics, which will take place in the Japanese capital of Tokyo. Tepco engineers hope to draw water seeping underneath the turbines before the games.
Despite being compared to the Wall of Game of Thrones at the beginning of the matter, the Japanese ice wall is made up of hundreds of pipes that were placed in theunderground , around four damaged reactors. The water to cool three damaged reactors becomes contaminated and leaking after passing through them, mixing with ground water.
With the pipes at a temperature of -30 ° C, engineers say the surrounding soil will be frozen and a kind of wall will be formed within a few months to clean ground water is not infected. If the power fails to feed the pipes, the wall can keep frozen for up to two months.
The entire cooling system will be closely monitored by responsible, being connected in stages to break monitoring. For years, the project has been criticized for its high cost of production and uncertainty as to its fully effective operation. Some say that the pipes can freeze both the ground that the amount of groundwater may decrease significantly.
It could be a plausible problem, since the temperature of the wall can not be adjusted rapidly if something goes wrong. The temperature can only be changed in a matter of weeks, which also costs a lot of money.
When asked if the wall would be worth the investment, the spokesman of Tepco Toshihiro Imai said only that “the effect is still uncertain, since the expected result is based on simulations.”
Considering all the rich and likely outputs, do not know what might happen; all the simulations suggest that the system has enough capacity to stop contaminated water. However, the president of the NRA, Shunichi Tanaka warned not to have too high expectations, because of the success of the project depends on natural causes. And we know that not always nature works as expected.
A similar method had been tested before in the United States, but not in such a large scale as the wall. In an interview with The Associated Press , Tanaka said a controlled release of the treated water is the best option to treat the infected water, but it is no use if it leaks into the ocean.
Recalling the Fukushima Accident
Caused by an earthquake measuring 9.0 on the Richter scale, the Fukushima disaster happened because three of the six reactors could no longer be refrigerated for damage caused by tsunami more than 40 meters high. He was considered the largest nuclear disaster since Chernobyl in the area now covered by the territory of Ukraine.
On his birthday five years, CNN did a special report on the disaster, which left 20,000 dead and wounded. Radiation leaks to date, with 400 tons of contaminated water being added daily to the storage tanks. So far, more than 800 tons (!) Of infected water. They were also spending more than $ 1.5 billion to join the contaminated soil in hundreds of industrial plastic bags.
Until today, who lives in a nearby area of the accident take daily precautions to ensure their health. A school in the province measures radiation in soil and foods distributed in lunch every day. The World Health Organization (WHO) estimates that residents near the plant have a risk 4 to 7% greater risk of developing cancer.
Japan, a country that has had more than 30% of all its energy from 50 nuclear reactors shut down its last reactor in 2012. Japanese were not without nuclear power for 45 years. Now the country imports 80% of its fuel. The shutdown has power bills increase 19% and carbon dioxide emissions increase significantly.