RADIOACTIVE 'HOT PARTICLES': ARE THEY STILL A PROBLEM?

摘要

The evaluation of the hazard posed by very small radioactive sources (diameter < 1 mm) has become popularly known as the 'hot particle' problem. The 'problem' arises both from the difficulty of calculating or measuring the highly spatially non-uniform dose from hot particles and from the difficulty of evaluating the potential biological response. Hot particles are ubiquitous in all nuclear reactor environments but appear to be of particular practical concern in ageing water reactor (PWR and BWR) plants. In recent years the authors have co-ordinated an extensive collaborative dosimetry and radiobiological study to develop improved dosimetry techniques for the measurement of radiation dose from hot particles and to relate exposure to early and late stochastic and deterministic effects, particularly in the skin. The continuing concern regarding the carcinogenic effects of hot particles is discussed in the light of the extensive literature which now exists for hot particle exposures of the lung and on the skin.