  This article illustrates the development of a software named GoldEnvSim for
simulation of the dispersion of radionuclides in the atmosphere. The software
is written in JavaFX programming language to couple the Weather Research and
Forecasting (WRF) model and the FLEXPART-WRF model. The highlight function of
this software is to provide convenience for users to run a simulation workflow
with a user-friendly interface. Many toolkits for post-processing and
visualizing output are also incorporated to make this software more
comprehensive. At this first version, GoldEnvSim is specifically designed to
analyze and predict the dispersion of radioactive materials in the atmosphere,
but it has potential for further development and applicable to other fields of
environmental science. For demonstration, a simulation of the dispersion of the
Cs-137 that is assumed to be released from the Fangchenggang nuclear power
plant to whole Vietnam territory was performed. The simulation result on
meteorological in comparison to the monitoring data taken from a first-class
meteorological observatory was used to evaluate the accuracy of dispersion
simulation result.
