Japanese Government Says No Tritium Detected to Date in Fish Samples

One Month on from the release of treated water stored at the Fukushima Daiichi Nuclear Power Station, no detectable amount of tritium has been found in fish samples taken from waters near the damaged plant.

The Japanese government said tritium was not detected in the latest sample of two olive flounders caught on September 24, according to a message on the Japanese Fisheries Agency website. The agency has been providing regular updates since the start of the treated water release, in a bid to counter negative speculation about its impact on the environment.

Samples of local fish have been collected at two points within a 5-kilometre radius of the discharge outlet, except during inclement weather conditions, with the agency announcing its analysis results on an almost daily basis since August 24. To date, no tritium has been detected in 64 fish, which included flounder and six other species, collected since August 8.

The water had been used to cool melted nuclear fuel at the plant but has undergone a treatment process that removes most radionuclides except tritium.

The residual tritium is then diluted to one-40th of the concentration permitted under Japanese safety standards before being released into the Pacific Ocean via an underwater tunnel 1 kilometer from the Daiichi Nuclear plant, the Japanese publication Mainichi reports.