TOKYO — Over 60 percent of some 15,200 tons of spent nuclear fuel in Japan could be stored in metal casks in the future as the cooling pools that currently keep them are filling up, a Kyodo News survey showed Wednesday.
The survey into the plans of utilities revealed the potential volume, at a time when each company is looking at dry casks to boost storage capacity of the ever-increasing highly radioactive by-product of nuclear power generation.
They believe the leak-tight canisters will be safer than storing the spent fuel in pools.
But keeping them in dry cask storage facilities, which do not need water or electricity to keep spent nuclear fuel cooled, will only be a temporary solution.
Analysts say it remains uncertain whether the waste will be taken out for reprocessing and recycling as planned amid technical difficulties and lingering safety concerns following the 2011 Fukushima nuclear crisis.
Residents near the storage sites of spent nuclear fuel are worried that the use of dry casks would lead to prolonged storage of the radioactive material.
Currently, the fuel storage capacity of 10 utilities owning commercial nuclear reactors totals 25,500 tons, with 60 percent already filled up. If unspent fuel is included, 69 percent will be occupied.
The 10 utilities’ plans for future storage of spent fuel using dry casks showed that their combined capacity could increase by up to 10,000 tons in the future.
Among them, Tokyo Electric Power Company Holdings Inc., whose Fukushima Daini complex holds 1,650 tons of spent nuclear fuel, has decided to build a new storage facility within its premises, while Kansai Electric Power Co. which owns 11 reactors in Fukui Prefecture plans to find a site to store some 2,000 tons by around 2030.
The Nuclear Regulation Authority has also encouraged utilities to shift storage of nuclear waste from cooling pools to dry casks in consideration of safety.
In the 2011 Fukushima nuclear disaster triggered by a powerful earthquake and tsunami, reactors temporarily lost the cooling functions in their spent fuel pools, putting a massive amount of fuel at risk of overheating and exposure.
Meanwhile, a dry cask storage facility, located within the premises of the Fukushima Daiichi plant remained safe, including the containers and the nuclear fuel inside, even though it was flooded by the tsunami.