The airborne release of radon and particulates from seven different source types can be analyzed:
Plume rise is considered for point and drying and packaging sources. A wind-blown dust (erosion) model is available for area sources to address ore pads and tailings piles. Downwind air concentrations are estimated using a Gaussian plume model with dry and wet deposition to estimate ground concentrations for particulates. The ground concentrations are used in turn to estimate resuspended air concentrations and plant uptake with subsequent consumption by humans and animals. Dose to humans is calculated for the following pathways — inhalation of downwind and resuspended radionuclide air concentrations, external exposure from contaminated ground and air concentrations, and ingestion of plants, meat, and milk.
Releases of particulates explicitly considered are limited to the radionuclides U-238, Th-230, Ra-226, and Pb-210 for the U-series decay chain and Th-232, Ra-228, and Th-228 for the Th-series decay chain. Other radionuclides in these series are implicitly accounted for under the secular equilibrium assumption. Gaseous releases are limited to consideration of Rn-222 and Rn-220 plus in growth of decay products.
As of version 4, the code was revised to run natively on Windows 7 to 10. Updates include an improved user interface, support for uranium ores containing Th‑232 and its daughter radionuclides, a revised area source model, and the ability to perform sensitivity analysis on specific input parameters.
The improved user interface includes geographic information system (GIS) functionality to aid in visualization of the scenario to be assessed, including the proper consideration of area source shapes and positioning of receptors and sources.
Use current local meteorological data provided by the National Centers for Environmental Information. A pre‑processor was added to import recent meteorological data (for the U.S. and abroad) for use in air dispersion calculations.
MILDOS 4 is maintained at Argonne National Laboratory for the Office of Nuclear Regulatory Research at the U.S. Nuclear Regulatory Commission under the Radiation Protection Computer Code Analysis and Maintenance Program (RAMP).
Register at the RAMP web site to download MILDOS 4.
|4.02||April 2018||Incremental release. MILDOS has gone from a 32-bit to a 64-bit application. As a 64-bit application, version 4.02 allows for a greater number of source terms, receptors, and time steps and eliminates most of the previous issues associated with the use of larger map files. Added features include the ability to re-project raster map data, a map ruler, sorting of meteorological joint frequency data, and additional output of intermediate calculated values such as source – receptor distance and outdoor radon equilibrium fractions.|
|4.01||September 2016||Maintenance release. Fixed a number of user interface issues. Faster report generation at the end of a run.|
|4.0||March 2016||Last major release|