The Fukushima No 1 nuclear power plant in Okuma town, Fukushima Prefecture in Japan. File pic Photo: AFP
Scientists are calling on Japan to let other countries test wastewater from Fukushima before it is released into the Pacific Ocean.
The Fukushima nuclear plant has begun tests of newly constructed facilities designed to discharge treated nuclear wastewater into the sea.
The water was used to cool the melted reactor of the Fukushima Daiichi nuclear power plant which was destroyed in the 9.0 magnitude 2011 earthquake and tsunami.
But storage is expected to reach capacity early next year, with more than 1000 tanks filled.
Japanese officials have said that the water has been treated to the point where it is no longer harmful.
They now intend to release more than a million tonnes of treated Fukushima wastewater into the Pacific Ocean.
Associate Professor Tony Hooker from Adelaide University said the water would take more than 40 years to dispose of. He was comfortable that the dilution level would be safe and fish from the area would still be able to be eaten.
Hooker said Japanese scientists possibly only knew what was in 40 percent of its 1000 tanks. But he said it was not what was in the tanks that was important, so much as the testing before it was released.
He said at the point of release, the water was being tested for any residual radionuclides (an unstable form of a chemical element that releases radiation as it breaks down and becomes more stable) through the Advanced Liquid Processing System (ALPS).
"We need to, you know, make sure that it's only tritium and carbon 14 that's released," he said.
Hooker believed there were systems in place to ensure that happened.
If there were any residual radionuclides still remaining, he said it would go through the ALPS process again.
Dr David Krofcheck Photo: Supplied
Dr David Krofcheck from the University of Auckland agreed it was necessary to remove "nasty nuclear fission products" such as strontium and iodine.
But he believed dilution and ALPS was the best solution.
He said other proposed options like concrete would corrode in sea water, resulting in the treated particles being put back into the ocean.
Krofcheck would, however, like to see Japanese officials invite scientists from other countries to observe and take samples of their own.
"[So] they can measure and verify that what the Japanese scientists have said is actually correct."
Hooker said Japan being open and transparent would give the community more confidence.
Krofcheck and Hooker believe Japan will begin releasing the treated wastewater some time this year.