A new 300-ton water leak from Japan nuclear plan

Japan's tsunami-crippled Fukushima Dai-ichi nuclear power plant has leaked this week about 300 tons of highly radioactive water from one of the hundreds of storage tanks. Four other tanks of the same design have had similar leaks since last year.

It is believed that because the tank is about 330 feet from the coastline, the leak does not pose an immediate threat to the sea. However, it is unknown if the leakage will reach the sea through a drain gutter. The leaked water seeped into the ground after escaping piles of sandbags near the concrete barrier around the tank.

The leaked water's radiation level was about 100 millisieverts / hour — the maximum cumulative exposure allowed for plant workers over five years. The leak is considered to be a level 1 incident, the second-lowest on an International Nuclear and Radiological Event Scale of eight.

The plant had multiple meltdowns after the massive earthquake and tsunami in March 2011. Hundreds of tanks were constructed around the plant to store the contaminated water coming from the three melted reactors, as well as underground water running into reactor and turbine basements.

Contaminated water continues to enter the Pacific Ocean at a rate of hundreds of tons per day. Much of that is ground water that has mixed with untreated radioactive water at the plant. To reduce leaks plant workers are using measures such as building chemical underground walls along the coastline, but have made little improvement so far.

Inspection the construction of the shore barrier designed  to  stop radioactive water from leaking into the sea