International Atomic Energy Agency (IAEA) experts have confirmed that the tritium concentration in the tenth batch of diluted ALPS treated water, which the Tokyo Electric Power Company (TEPCO) began discharging 17 October, is far below Japan’s operational limit.

IAEA experts stationed at the Agency’s office at the site of the Fukushima Daiichi Nuclear Power Station (FDNPS) conducted an independent on-site analysis of samples from the treated water. The IAEA confirmed that the tritium concentration in the diluted water is far below the operational limit of 1500 becquerels per litre and is in line with international safety standards.

In line with Japan’s plans, the ALPS-treated water is being released from FDNPS in a series of batches over the next decades, following the start of the discharge in August 2023. The IAEA confirmed?that the tritium concentrations in the previous nine batches, totalling approximately 72 000 cubic meters of water, were also far below operational limits.

In a comprehensive?report?issued on 4 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.

Earlier this month, the IAEA, with experts from third-party laboratories, performed sampling for interlaboratory comparisons (ILCs) to corroborate environmental monitoring conducted by TEPCO and relevant Japanese authorities. Samples of seawater, sediment, fish and seaweed were collected from coastal and offshore locations and a fish market close to FDNPS. The IAEA also initiated the first steps of additional measures at sea near FDNPS.

Reports on sampling, independent analysis, data evaluation, as well as timeline, are available on the IAEA?website.