![]() ‘Most of it is being stored in interim facilities in the vicinity of the plant until 2045,’ reports Evrard. It also generated a significant amount of waste, about 20 million m 3. Topsoil removal was effective but expensive, costing the Japanese state about £21 billion. ‘Removing this layer therefore led to very significant – around 80% – reduction in the contamination levels found in soils under cropland.’ There has also been a 90% reduction in caesium levels in flood deposits from rivers in 2020 compared with 2011 as cropland was the main source of contaminated material, Evrard says. ‘Radiocaesium is known to be rapidly and strongly bound to clays was concentrated in the upper 5cm layer of the soil after fallout,’ Evrard explains. 1 ‘The Japanese authorities decided in August 2020 that the remaining contaminated area will progressively be reopened without remediation.’ ‘The initial remediation stage has been completed in the priority areas,’ reports Olivier Evrard of the Laboratory of Climate and Environmental Sciences, Université Paris-Saclay, and coordinator of a review of land contamination studies around Fukushima. In areas further from the power plant, they applied substances known to fix or substitute caesium such as potassium fertilisers and zeolite powders. In cultivated areas, they removed the surface layer of soil down to 5cm and replaced it with crushed granite. The Japanese authorities focused mainly on radioactive caesium, particularly caesium-137 because of its relatively long half-life of 30 years. Ten years on, decontamination efforts appear to have been effective, but concerns remain about disposal of contaminated soil and water, as well as the need for long-term future monitoring.ĭecontamination of soil in a 9000km 2 region surrounding the power plant began in 2013. The damage to the power station resulted in the release of a range of radionuclides, including caesium-134, caesium-137 and iodine-131 into the atmosphere. The subsequent tsunami devastated the eastern seaboard of Japan’s Tōhoku region and led to disaster at the Fukushima Daiichi Nuclear Power Station. On 11 March 2011 a massive earthquake struck just off the eastern coast of Japan.
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