Simulation of an Operator´s External Dose using Computer Graphics

An optimization of a dismantling process should be at the beginning of a study for an evaluation of the radioactivity inventory and the safety of the workers. Many countries have been studied an optimization to achieve a shortened dismantling schedule, a reduction of an amount of waste, and cut down on the decommissioning by using computer graphics such as animation, simulation, and virtual reality. In this article, we provided methods for identifying an existence of radioactivity which is contained in the dismantling objects and for estimating a worker´s dose through a simulation. To estimate a worker´s external dose under a virtual dismantling environment which was produced by computer graphics, the shape of the thermal column by 3D CAD was created and the radiation dose surrounding the object was calculated by using MCNP. An animation that can demonstrate a dismantling procedure according to a dismantling scenario was produced. For matching the radiation dose which was calculated by MCNP-4C with an area where workers are dismantling a door on the animation, a simulation module which can show a worker´s external dose in a real-time was developed. The result from the distribution of the radioactivity enables us to distinguish where the most contaminated part of the dismantling objects was. In the animation, a virtual worker demonstrated a dismantling activities procedure as a chosen scenario. In the simulation, a worker´s exposure dose rate in a real-time as an intended in the design stage has been evaluated.