9 Avril 2015
April 9, 2015
Apr. 9, 2015 - Updated 13:22 UTC+2
New methods may be used to remove melted fuel from the crippled reactors at the Fukushima Daiichi nuclear plant.
The government-backed entity overseeing the plant's decommission says engineers are exploring ways to remove the fuel debris without flooding the containment vessels with water.
In the new methods, the melted fuel could be removed from the top of the reactor - or through a hole made on the side of the containment structure.
The Nuclear Damage Compensation and Decommissioning Facilitation Corporation disclosed its strategic plan for decommissioning technologies on Thursday.
Removal of melted fuel is considered one of the toughest challenges in the decommissioning process, which is expected to take up to 40 years.
The plan says the new methods will be considered in addition to the conventional use of water to shield workers from high levels of radiation.
It says the flooding method faces significant challenges, including plugging leaks in the containment vessel, and ensuring its quake resistance during the process.
The plan also warns that in the new methods, high levels of radiation could affect not just workers but robots and other machines.
And steps must be taken to prevent radioactive materials from spreading in the air.
The Japanese government and the plant's operator, Tokyo Electric Power Company, expect to choose a specific method by March 2017 after further study into the state of the melted fuel.
The plant suffered meltdowns at 3 of its reactors as a result of the 2011 earthquake and tsunami.