Japan is accurately monitoring occupational radiation exposure of workers involved in handling ALPS-treated water at the Fukushima Daiichi Nuclear Power Station (FDNPS), the International Atomic Energy Agency (IAEA) said in a recent report.
The report presents findings from the IAEA’s two-year interlaboratory comparison (ILC) programme, conducted at the request of Japan to verify the accuracy of radiation monitoring services provided by Tokyo Electric Power Company (TEPCO), the operator of the FDNPS. This review focused on confirming external radiation exposure monitoring and evaluating the analytical methods used by relevant dosimetry services.
ILCs involve different laboratories separately testing and analyzing dosimeters and then comparing results and procedures to determine their reliability and accuracy.
Consistent with the relevant IAEA Safety Standards, TEPCO is responsible for the protection of workers against occupational exposure to radiation. This includes the use of quality-assured dosimetry services to assess and record workers' exposure. The ILC assessed the quality of TEPCO’s measurement results from whole-body, extremity and eye-lens dosemeter monitoring. The corroboration work involved IAEA Radiation Safety Technical Services laboratories at the IAEA headquarters in Vienna, Austria, along with laboratories in Japan. Reference metrology laboratories in Germany and Spain supported the ILC by providing reference irradiations in different radiation qualities for the dosimeters.
In the report, the IAEA found that TEPCO’s laboratories have demonstrated a high level of accuracy in their measurements and technical competence.
The work is part of the Agency’s extensive monitoring and assessment activities that support its ongoing safety review of the Advanced Liquid Processing System (ALPS) treated water discharge.