The amount of ¹⁸F dispersed from a cyclotron-attached ¹⁸F production target was measured, and the ratio to the production amount (dispersal ratio) was obtained. The target was covered with a collection bag, the air inside was sucked in with a dust sampler, and the 511 keV gamma ray emitted from the ¹⁸F adsorbed onto the filter was measured with an NaI spectrometer. Similarly, the amount of adhesion of ¹⁸F to the inner surface of the bag, the surface of the target body, and the inner surface of the suction tube was evaluated. Combining these results, the dispersal ratio of ¹⁸F from the target was found to be less than 6.1 × 10⁻⁷.

The Radiation Worker Certificate is used as a powerful tool when there is joint use of Radioisotope (RI) facilities or when there are job changes. The Radiation Hazards Prevention Act, which was revised in September 2019, introduced the concept that the responsibility for safety lies primarily with the licensee (business responsibility) based on the IAEA’s fundamental safety principles. Currently, the Radiation Worker Certificate is certified by the head of the organization or the Radiation Protection Supervisor. However, based on the idea of business responsibility, it was thought that the head of the organization was more suitable than the Radiation Protection Supervisor as the certifier. On the other hand, if a certificate was issued by an organization that was not an RI business operator, the certificate lacks persuasiveness because the organization did not have business responsibility. Now that business responsibility has been introduced, we once again discussed the ideal form of radiation worker certificates, together with the sender and certifier of the certificate.