|
内容記述 |
Based on lessons learned from the Fukushima Daiichi Nuclear Power Plant accident, efforts are underway to establish a system for monitoring thyroid doses in the public in nuclear emergencies. At QST, drawing on experience gained through a government-commissioned study since FY2012 on estimating initial internal doses—primarily thyroid doses from radioactive iodine intake—among Fukushima residents, we have been developing practical methods for reliable monitoring from the early stages of a nuclear disaster, when human resources may be limited. Our proposed method involves a three-tiered approach: simplified measurements using NaI(Tl) survey meters, detailed assessments using existing spectrometers, and supplementary measurements using mobile whole-body counters—many of which were introduced after the Fukushima accident. These approaches have been partially incorporated into a national thyroid monitoring guideline.To address the difficulty of measuring radioactive iodine in the thyroids of young children with conventional devices, we developed a novel portable thyroid monitor featuring small detectors positioned around the neck. Despite its compact design, the monitor achieves performance comparable to stationary devices installed at designated nuclear emergency hospitals under normal radiation conditions. After further improvements for miniaturization and usability, the monitor was commercialized in January 2024.On the operational side, we have implemented training programs to expand the pool of personnel capable of performing simplified thyroid monitoring. We have also developed educational materials, dose assessment manuals, and guidance for examinees. Since FY2024, QST has partnered with the Japan Association of Radiological Technologists to conduct on-site training in nuclear power plant host prefectures.This presentation will provide an overview of these initiatives at QST and discuss future challenges and directions. |
