Decommissioning procedure and induced activation levels, calculations and measurements in an 18 MeV medical cyclotron

The present article describes the decommissioning of a self-shielded 18 MeV medical cyclotron IBA
Cyclone 18/9 after 14 years of operation. A Monte Carlo simulation of the possible nuclear reactions
was performed in order to plan the decommissioning activities. During the cyclotron dismantling, the
activities of the cyclotron components, concrete wall and floor samples were measured. Residual
activities were analysed by means of an HPGe detector and liquid scintillation counting, and
compared with simulation data. Dosimetry of the staff involved in the decommissioning procedure was
monitored by individual TL dosimeters and/or digital dosimeter. The cyclotron component analysis
confirmed the presence of gamma and pure beta emitters, 22 Na, 54 Mn, 60 Co, 65 Zn, 207 Bi, 55 Fe,
63 Ni at different values of specific activity, depending on the positioning of the sample point and
on the alloy of the sampled part. In ...

Source: Journal of Radiological Protection - December 6, 2021 Category: Physics Authors: Riccardo Calandrino, Simone Manenti, Flavia Groppi, Francesco Broggi, Carlo Bergamaschi, Andrea Ferrari, Simona Manenti, Massimiliano Nizzi, Alessandro Loria and Antonella del Vecchio Source Type: research