C05036: ADMS-STAR Development: A Short Range Emergency Response Atmospheric Dispersion Model

Study Duration: February 2005 to March 2006.

Contractor: Cambridge Environmental Research Consultants (CERC) Limited.

The Agency currently uses the R91STAR model to help determine its response to accidents. R91STAR predicts atmospheric dispersion and is a first generation model, which requires staff to be specifically trained in its use. The project will develop the commercially available ADMS model for use in predicting accidental releases. ADMS is a second generation system, which explicitly models the physical characteristics of the atmosphere. The model has many enhanced features compared to R91STAR and is used in several parts of the Agency.

The project will combine the accidental data and output features of R91STAR with the software coding of the ADMS model. A sensitivity comparison between the two models will be included in the work, along with the production of a users guide.

It is anticipated that this project will produce a standard accidental release model for replacement of the R91STAR model. The advanced features and flexibility of the ADMS model is such that it is envisaged that further development may be possible to increase the functionality of the new ADMS-STAR model beyond that currently available to the Agency.

In the event of an accidental release of a pollutant to the atmosphere, such as radioactivity or a chemical, the Agency currently uses an atmospheric dispersion model called R91STAR to help predict deposited levels of contamination. For radionuclides, the model can also help predict where levels may exceed statutory limits. However, the R91STAR model is a first generation model which uses statistical representations of the atmosphere and so may fail to represent the conditions specific to the time and location of the modelled release.

The commercially available ADMS model is a second generation atmospheric dispersion model which is able to model the atmosphere from basic meteorological and surface data, and so provides improved predictions. This project modified the current version of the ADMS model (version 3.1) to give it the same specialist emergency response capabilities as the older R91STAR, while making use of the more advanced features of ADMS. This new model has been called ADMS-STAR.

The ADMS-STAR model is expected to improve the Agency�s ability to predict the possible impact on the food chain and food safety from a radioactive or chemical release to the atmosphere. ADMS-STAR has also been designed so that it is possible to further develop the model, such as enabling it to include the effects of topography and variable meteorological conditions. Additionally, as the ADMS model is commercially supported, the maintenance cost of ADMS-STAR are expected to be significantly less than those of R91STAR.

In addition to the development of the ADMS-STAR software, the project deliverables also included the production of an ADMS-STAR users guide and a sensitivity study of ADMS-STAR, comparing its predictions with those of the R91STAR model.

Copies of the Users Guide and sensitivity report are available from the Agency's Information Centre. To obtain a copy, please contact the Enquiry Desk, Information Services, Food Standards Agency (tel: 020 7276 8181/8182 or email: infocentre@foodstandards.gsi.gov.uk)

Contact: For any enquiries concerning this research project, please contact the relevant Programme contact or email: science@foodstandards.gsi.gov.uk www.cerc.co.uk