The clean up of Japan's Fukushima Daiichi nuclear plant, which suffered catastrophic damage after an earthquake and tsunami in 2011, may take up to 40 years to complete.

Tokyo Power Electric Company (TEPCO), the utility company that runs the now damaged plant, has been a victim of harsh scrutiny over the clean-up process due to ridiculous stunts like using adhesive tape to perform repairs and the flow of reports detailing the dumping of radioactive waste water into the ocean.

According to TEPCO official, Akira Ono, the decommission process has been painfully slow but is moving forward.

"If I may put this in terms of mountain climbing, we've just passed the first station on a mountain of 10 stations," said Akira Ono, who heads the Fukushima plant.

The biggest obstacle to closing down the plant permanently is removing all the melted nuclear fuel debris from three reactors, Ono told reporters after a press tour of the plant this week.

Ono believes that the possible 40-year-long decommission process is rolling ahead with many obstacles still in the way.

TEPCO is still unsure about the state of the debris inside the reactor.

The company is also still battling the build up of 300 to 400 tons of contaminated water that fills the plant on a daily basis.

TEPCO pumps the contaminated water into storage tanks, adding a fresh tank every three or four days. Currently there are 1,000 tanks containing 750,000 tons of radioactive water.

Comment: This radioactive water is being released into the Pacific Ocean. According to Dr. Helen Caldicott: "There is no way to prevent the radioactive water [from] reaching the western shores of the North American continent and then circulating around the rest of the Pacific Ocean. At the moment, it seems like this is going to occur for the rest of time."

TEPCO claims that the containment of radioactive water has progressed as equipment required to create an "ice wall" around the stricken nuclear power plant is finally in place.

Over the years leaks have been reported from the radioactive water containers while efforts to filter the water have taken place.

In May of last year TEPCO claimed that 620,000 tons of radioactive water it stored in Fukushima plant no. 1 had been treated to lower its radiation levels.

The latest move to aid in the decommission process comes from Toshiba who in January unveiled a remote-control robot that's expected to remove fuel-rod assemblies from the spent fuel pool in the plant's reactor 3 building.

The robot features arms that can be used to manipulate and dismantle debris, and to retrieve rods from the reactor cooling pool.

The work involving Toshiba's robot, which is expected to begin next year, is a big endeavor, with 566 fuel-rod assemblies that need to be removed from just this one reactor, reports Science Alert.