JAPAN - The plant was crippled by the 2011 earthquake and tsunami.
The disaster knocked out cooling systems to the reactors, three of which melted down.
Now, with an estimated 400 tonnes of groundwater flowing from the mountainside to the damaged Fukushima reactor basements daily, Japan is to invest hundreds of millions of dollars into building a frozen wall around the nuclear plant to stop radioactive water from leaking.
Water is now being pumped in to cool the reactors, but storing the resultant large quantities of radioactive water has proved a challenge for plant operator Tokyo Electric Power Company (Tepco).
Under the government plan, estimated at 47-billion yen (S$604m), a wall of frozen earth will be built around the reactors, using pipes filled with coolant to prevent groundwater from coming into contact with contaminated water used to cool fuel rods.
Damage to the plant has necessitated the constant pumping of water to cool the reactors - a process which creates an extra 400 tonnes of contaminated water every day.
That water is being stored in temporary tanks at the site.
In August, Tepco said 300 tonnes of highly radioactive water had leaked from one of the tanks, in the most serious incident to date.
Meanwhile Japanese Prime Minister Shinzo Abe on Sept 19 ordered Tepco to work out a schedule for stemming radioactive leaks, as he toured the facility.
During Japan's 2020 Olympic bid process last month, Mr Abe assured the International Olympic Committee that the situation at Fukushima was "under control".
The remark, delivered as part of Tokyo's successful bid to host the 2020 Summer Games, sparked criticism at home, as Tepco was struggling to control the flow of mildly contaminated groundwater and was encountering problems with highly radioactive waste water making its way into the sea.