Progress of Disaster Debris Processing and Soil Remediation - From December 2011 to the 2020s

Progress of Disaster Debris Processing and Soil Remediation - From December 2011 to the 2020s

In the 2011 Great East Japan Earthquake approximately 2800 million tons of debris were generated in Fukushima Prefecture. About 50% of this consisted of wood waste with many other fibrous materials that were difficult to process. The cost of debris processing was estimated at 37800 yen per ton with the total market scale reaching approximately 15000 billion yen. Amid calls for widespread processing experiments were conducted in Fukushima Prefecture using sorghum a grass species to absorb radioactive cesium. The experiments confirmed absorption efficiency up to 200 times higher than sunflowers. Sorghum was also noted for its potential as a bioethanol material and full-scale test cultivation began in spring 2012 in Fukushima Prefecture.

By the 2020s significant progress had been made in processing disaster debris. In March 2020 the full operation of an interim storage facility began and the dismantling of facilities that had completed operations started in fiscal 2022. As of 2022 approximately 1400 million cubic meters of removed soil and waste were stored in the interim facility. Additionally as of 2024 the number of temporary storage sites decreased to about 150 locations with the total volume of stored waste also showing a steady decline.

For agricultural regeneration affected by radioactive contamination phytoremediation using plants showed limited effectiveness. Instead potassium application was promoted to reduce radioactive cesium concentrations in crops achieving over a 90% reduction compared to 2011 levels accelerating farmland recovery.

The removal and decontamination of debris involved major construction companies such as Kajima Corporation Taisei Corporation and Shimizu Corporation. Kajima played a key role in wide-area processing in Fukushima Prefecture. Additionally environmental technology companies supported efficient operations in interim storage facilities through management and sorting.

While the number of temporary storage sites in Fukushima Prefecture has decreased and reductions in total volumes have been progressing as of 2024 securing final disposal sites remains a critical challenge. With a storage deadline of 2045 for the interim storage facility a national-level plan for final disposal is urgently required.

In disaster debris processing and soil remediation significant achievements have been made but sustained technological innovation and consensus building among local residents remain crucial issues for the future.