Transfer Rates of ²²⁵Ac to Exhaust Air, Surface, and Waste Water under Chemical Operations

Abstract

 Actinium-225 is one of the most promising nuclides in the field of nuclear medicines for treatments of cancers, whereas the transfer rate of ²²⁵Ac during chemical treatments, required for the radiological protection of the radiation workers, has not been determined. In this study, firstly, the chemical operations and the chemical status required for dealing with ²²⁵Ac for nuclear medicines were selected, and secondly, the dispersal rate, the surface contamination, and the concentrations of radionuclides in the waste water of ²²⁵Ac were determined. The total dispersal rates were determined as low values (2～4) × 10⁻⁶ h⁻¹ and high values (2～4) × 10⁻⁵ h⁻¹, depending on the classes of operations, and that in the exhaust as 1 × 10⁻⁷ h⁻¹. These values are about an order of magnitude smaller than that of the “in surface” for normal chemical operations.