The tritium concentration in the eighth batch of treated water, which the Tokyo Electric Power Company (Tepco) has begun discharging from the Fukushima Daiichi NPP site is far below Japan’s operational limit, according to International Atomic Energy Agency (IAEA) experts.
Contaminated water, used to cool the melted reactor cores in the aftermath of the 2011 nuclear disaster at Fukushima, is stored in around 1,000 huge tanks at the plant containing more than 1.3m tonnes and total storage capacity has been reached. The contaminated cooling water and groundwater is treated by the Advanced Liquid Processing System (ALPS), which removes most of the radioactive contamination, with the exception of tritium.
The treated water is then stored in tanks before being diluted with seawater to one-fortieth of the concentration permitted under Japanese safety standards before being released one kilometre off the power plant. The water is being discharged in batches over a period of approximately 30 years beginning in August 2023. The IAEA’s independent on-site analysis has confirmed that the tritium concentrations in the previous seven batches, totalling approximately 54,700 cubic metres of water, were also far below operational limits.
IAEA experts stationed at the Agency’s office at the Fukushima site sampled the treated water and conducted an independent on-site analysis and confirmed that the tritium concentration is in line with international safety standards.
In a comprehensive report issued in July 2023, the IAEA’s safety review found that Japan’s plan for handling the treated water was consistent with international safety standards and that the release as planned would have a negligible radiological impact to people and the environment. Last month, the IAEA Task Force established to review the safety of the water discharge plan said in a new report that the discharge has continued to comply with international safety standards.
