Research On Dose Calculation And Visualization For 3D Radiation Field

Nuclear safety and radiation protection are always the focus which the world has paid much attention to during the development of nuclear energy and nuclear technology. How to reduce effectively the radiation exposure of workers during the process of maintenance and decommissioning of nuclear facilities is one of the most important content of radiation protection. Recently, virtual reality technology (VR) is widely applied to radiation protection field due to the rapid development of computer hardware and related techniques. Virtual reality technology utilizes computer to simulate the complex radiation environment of nuclear facilities and takes advantage of computer graphics techniques to display vividly the dose distribution with the virtual scene,so radiation exposure of virtual workers can be assessed in advance and the maintenance and decommissioning scheme of nuclear facilities can be formulated and optimized based on the data of dose distribution.Point kernel method and monte carlo method are the two primary algorithm to calculate the dose rate distribution of radiation field. Point kernel method introduces the buildup factor to consider the influence of scattering photons to the radiation and has a fast computational efficiency, so it is widely used in shielding design and radiation safety analysis. Buildup factors, mass attenuation factors and flux-to-dose conversion factors databases are created using the SQLite database engine, algorithm of calculating mean free path (mfp) is optimized, geometric types of radiation source are augmented, the computational efficiency of dose rate is improved by introducing the parallel computation based on point kernel method in this paper. In addition, dose rate calculation module of 3D radiation field PKShield is developed using C++programming language.Three different solutions of visualizing 3D radiation field dose rate are accomplished in this paper including:(1) plane dose rate rendering based on 2D texture mapping;(2) contour surface rendering of 3D dose rate based on marching cube method;(3 ) volume rendering of 3D dose rate based 3D texture mapping.The 3D dose rate visualization module Dose Visual is developed based on OGRE graphics engine. Finally, radiation calculation and visualization system (RCVS) based on Qt graphics user interface library is developed by integrating the PKShield and DoseVisual module.In order to validating the reliability and effectiveness of RCVS, single layer shield and multi-layer shields are designed to calculate the radiation dose rate distribution with RCVS compared to the MCNP5 program. Then the 3D dose rate visualization is measured with the CAD model of nuclear facilities. The simulation results indicate that dose rate distribution of 3D radiation can be calculated rapidly and visualized graphically by RCVS program that can be applied to the training of radiation protection and the maintenance and decommissioning of nuclear facilities.