The Nuclear Regulatory Authority (NRA) announced that 300 tonnes of contaminated water have leaked from one of the waste water storage tanks since Monday, rating the disaster as a level three incident on the International Nuclear and Radiological Seven-point Scale.
The leak is the biggest one ever reported. The radioactive water has escaped from one of the steel storage tanks at the site and left flowing unnoticed for almost a week. Initially it was unclear what the volume and density of the contaminated water are.
The Tokyo Electric Power Company (Tepco), the plant operator, is still unclear about the cause of the leak, making authorities doubt the ability of the operator to handle the situation. As it was stated earlier this week by Reuters quoting Shinji Kinjo, head of NRA, Tepco should not be left alone to tackle the emergency.
In a media statement Shunichi Tanaka, a watchdog chairman, announced that Tepco has failed to detect the leak, although they claim that patrols have been checking the site and the storage tanks twice a day.
NRA also reported that workers on the site have left a tap open, allowing waste water to escape through the safety barrier around the leaking storage tank. There are fears that radioactive water has not only contaminated the ground around the Fukushima power plant, but has already traveled to the Pacific Ocean.
Workers are currently trying to absorb the radioactive water around the tank using sandbags, however the danger is that the levels of radiation are so high, that one hour of exposure can give a dose of radiation that is acceptable to accumulate over five years. This makes the cleaning process very dangerous, labor-demanding and questionably effective.
The aim now is to prevent the water from reaching the surface. According to experts at the NRA, this will increase the flow and make it move extremely fast towards the ocean.