Decontamination Plan for the Concrete of the Activated Accelerator Room and Its Implementation: A Case Study in the Decommissioning of the PET Cyclotron Room at the Medical and Pharmacological Research Center Foundation

Herein, we present the case study of the decontamination of highly activated concrete in the accelerator room. The activated cyclotron room for pharmaceutical for the positron emission tomography (PET) in the Medical and Pharmacological Research Center Foundation (Ishikawa, Japan) was decontaminated. The contact dose rates of the concrete walls, floor, and ceiling were measured at 50 cm mesh using a NaI survey meter. The depth profiles of spe cific activity in the concretes were obtained by core boring at seven different places. The activated concrete regions were estimated in detail based on the relationship between the measured contact dose rates and depth profiles of the specific activity. The activated concrete was chipped and