ADMSSTAR

Advanced software for modelling short-term accidental releases

What is ADMSSTAR?

ADMSSTAR is a model for the analysis of Short-Term Accidental Releases based on the ADMS methodology. ADMSSTAR has been developed specifically to estimate air concentration and deposition rate for radiological or chemical emissions to the atmosphere.

ADMSSTAR can be used either in situations where the source details are known or it can perform a back calculation and estimate the source strength based on sample data. In both cases ADMSSTAR will calculate air concentrations and deposition rates. These can be compared against regulatory or other levels (e.g. EU maximum permitted levels in foodstuffs). ADMSSTAR may be linked with ESRI's ArcGIS (Geographical Information System) and used to display contours of concentration and/or deposition overlaid on a map of the area where the incident occurred.

ADMSSTAR is underdevelopment to use a Lagrangian puff methodology to enable complex terrain along with temporally and spatially varying meteorology to be incorporated into the model.

Who uses ADMSSTAR?

The model was developed with financial support from the UK Food Standards Agency who use ADMSSTAR as part of their emergency response modelling capability.

Why use ADMSSTAR?

ADMSSTAR has a user-friendly Windows interface, making it easy to set up the model and view results. The input data is arranged in a series of screens with default values provided for much of the information. This makes the model ideal for rapid data entry and use by non-specialists, e.g. in emergency situations.

The system has a number of distinct features:

• Advanced dispersion model in which the boundary layer structure is characterised by the height of the boundary layer and the Monin-Obukhov length, a length scale dependent on the friction velocity and the heat flux at the surface.
• Samples of air concentration or deposited material may be entered and the model will apply a back calculation to calculate the source strength. This can be useful in emergency scenarios where the actual characteristics of the source are not known.
• The model has a built in list of isotopes along with their half-life and daughter products allowing for the consideration of the effects of radioactive decay. This radio active decay is also taken into account in the back calculation to determine the source strength.
• The model has a built in list of EU maximum permitted levels in foodstuffs which allows for easy comparison to regulatory levels. Contours showing where these levels are exceeded can be simply plotted over a map of the area using the link to ESRI's ArcGIS.