Radiological management of air-fed suit work for glovebox dismantling activities

Asakawa, Jun; Kimura, Yasuhisa ; Hirano, Hiroshi*; Kitamura, Akihiro   

During the glovebox dismantling activities, workers wearing air fed suits would have been working in a radioactive environment. Because of the exposure risk, the following radiological control measures have been implemented. First, prior to the glovebox dismantlement activities, we performed a detailed radiological survey of the dose rates in the operation area. Based on the results, we estimated the external exposure doses to the workers in the course of the work. We then applied these estimates to the work plan and defined a management reference value for external exposure. The worker's external exposure dose is limited to this level by continuously monitoring the air dose rate in the operation area and the worker's dosimeters. For the workers internal exposure prevention, we measure the surface density of radioactive materials and the concentration of radioactive materials in the air. We then select respiratory and body protective equipment with a suitable protection coefficient and define the management reference value for internal exposure. The worker's inhalational hazard is managed by continuously monitoring the measurement values that are within the management reference value. In this report, we explain these radiological management activities in detail by showing the concrete procedures and data that we have implemented and obtained through the liquid waste treatment glove boxes dismantlement work previously performed.