The clinical value of using fluoroscopy for bronchoscopy is clear, and the evaluation of radiation dose during the procedure is important. In this study, radiation eye dose were measured for one year and were found to potentially exceed the lens equivalent dose limit for occupational exposure. The number of examination, fluoroscopic time, and air kerma were found to be risk factors for dose increase. Therefore, we believe it is necessary to wear Pb glasses and develop new protective equipment that does not interfere with the procedure.

We conducted a basic performance study of the “beta-panel for whole body survey”, a new device for the test of body surface contamination. This equipment is installed in a small number of units, and performance evaluation by users has not yet been done. Five items were examined: sensitivity differences between detectors, the effect of using anti-contamination film, the effect of room temperature, the effect of distance from the detector on measured values, and sensitivity to contamination in the frame area without detectors. We generally obtained good results in terms of sensitivity differences. Although some points require attention in the actual inspection, for instance, position where the subject is standing and contamination in the frame area, the beta-panel can shorten contamination tests, so useful in the event of a nuclear disaster.

When calculating internal exposure dose, a method of extracting and evaluating representatives is recommended. We have developed an evaluation system that calculates internal doses using records of radioisotopes use and radiation workers’ entry into controlled areas. By using this system, it is possible to evaluate internal doses based on correct working hours and to evaluate internal doses of non-representatives, thereby improving the accuracy of radiation safety management.

The AVF cyclotron at Research Center for Nuclear Physics has been used for experiments in nuclear physics and nuclear chemistry since 1973. In the Japanese Fiscal Year 2019, the AVF cyclotron was upgraded to increase beam power. Previous to that, the building which was activated by cyclotron beam was renovated for radiation shielding enhancement. The construction workers who handle the contaminated or activated objects were registered as radiation workers. However, many troubles such as minor-incident or violation of radiation hazards prevention program were occurred. In this report, we introduce difficulties in renewal construction in the activated building and minor incidents those were actually caused by construction workers.

Targeted alpha-particle therapy is attracting attention as a next-generation cancer treatment method. In Japan, research on internal use therapy with ²¹¹At, which can be produced using an accelerator, is underway. However, ²¹¹At has strict concentration limits of 2 × 10^-4 Bq/cm³ in the air and 1 × 10^-6 Bq/cm³ in the exhaust. Therefore, existing radioisotope facilities do not have sufficient exhaust equipment to use large quantities of ²¹¹At that can be used for therapy. Research Center for Nuclear Physics, Osaka University has upgraded its exhaust equipment to handle large amounts of ²¹¹At. Since it was difficult to renew the exhaust pipe from the chemistry laboratory to the roof, the existing duct was diverted. The exhaust air volume from the laboratory was set at 1000 m³/h and diluted with 3000 m³/h of fresh air before the exhaust port to obtain a total exhaust air volume of 4000 m³/h at the exhaust port. As a result, 3 GBq per week and 18 GBq per 3 months of ²¹¹At could be used.