© GRS
Mit ARTM berechnetes Strömungsfeld
Radiation Protection

Atmospheric Radionuclide Transport Model – ARTM

GRS has developed the atmospheric dispersion code ARTM on behalf of the Federal Ministry for the Environment and the Federal Office for Radiation Protection. ARTM simulates the dispersion of airborne radioactive substances and their deposition on the ground.

Atmospheric dispersion models are used in many ways today. Meteorologists or traffic planners use them, for example, to determine the distribution of pollutants in the air. The use of simulations has various advantages in this respect. They can be used to test different scenarios in which any weather conditions or pollutant concentrations can be postulated. The spatial scale or the temporal sequence can be adapted according to the issue under consideration. The simulations of the dispersion codes complement the on-site measurements and provide a basis for predictions and analyses.

Dispersion modelling for airborne radioactive particles or gases 

Atmospheric dispersion models are also used to simulate the dispersion of very small, airborne particles or gases. In nuclear power plants, industry, research or medicine, for example, radioactive substances can enter the atmosphere in a planned or accidental manner. After release, the radioactive particles disperse with the wind, are subject to radioactive decay and can partly – depending on their physical and chemical form – also be deposited on the ground. An atmospheric dispersion model for radionuclides makes it possible to simulate these processes and thus to make statements on the concentration of radionuclides in the air we breathe and on the ground or on the gamma cloud radiation caused by the radionuclides in an exhaust cloud.

At GRS, the atmospheric radionuclide transport model ARTM has been developed on behalf of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) since 2004. It is based on the AUSTAL2000 code package for conventional air pollutants (e.g. nitrogen oxides, sulphur dioxide, PM10), which had been developed by Janicke Consulting in the early 2000s on behalf of the Federal Environment Agency (UBA). ARTM has been validated and further developed in follow-up projects. Among other things, it now features the graphical user interface GO-ARTM. 

ARTM is based on a Lagrangian particle model where the simulation particles represent radionuclides. With ARTM, it is not only possible to analyse pollutant concentration at a certain point but also to calculate the dispersion spatially and over time. The behaviour of radioactive substances depends on various factors. ARTM therefore not only takes into account when, where and how many radioactive substances were released. In addition to meteorological data such as wind direction, wind speed and precipitation, the code also includes parameters such as the shape of the terrain (plain vs. mountains) and the surface structure (water surface, building area, forest) in the calculation. Various boundary layer models and the diagnostic wind field model TALdia are available as standard in the ARTM code package for simulating wind and turbulence conditions.

Since the physical-chemical properties of the substances also play an important role in dispersion, these are also taken into account in the modelling. In addition to the concentration of radionuclides in the air and on the ground, ARTM also simulates gamma cloud radiation.

Based on the results of an ARTM simulation, the organ doses and the effective dose for persons in the simulation area can be calculated using the DARTM dose module developed by the Federal Office for Radiation Protection (BfS). Since June 2020, the calculation rules of the General Administrative Provision on the determination of exposure of members of the public through activities requiring a permit or notification (AVV-Tätigkeiten) apply in this respect. 

The ARTM code is freely available as an open source program including source code. The Federal Office for Radiation Protection provides the download package with numerous tools.
 

Project highlights Radiation Protection

Virus fliegt in einem Aerosol-Tröpfchen durch die Luft
AeroCoV - Predicting infection routes of SARS-CoV-2 aerosols in indoor environments
2020 - 2021

In the current Covid 19 pandemic, airborne aerosols that contain viruses are considered to be an important transmission route, especially in insufficiently ventilated rooms. To be able to make a sound assessment of the related risk of infection and to derive appropriate recommendations for action, the aerosol behaviour as well as representative ambient conditions must be considered in detail and realistically. Within the framework of the AeroCoV research project, scientists of GRS have applied the COCOSYS simulation code – which was developed and validated for the analysis of accidents and severe accidents in containments of nuclear power plants – for the first time for calculating the dispersion of SARS-CoV-2 aerosols.

Environment and Energy