PACE is an application for performing probabilistic assessments of the off-site consequences of accidental release of radioactive material to the atmosphere (otherwise termed level-3 PSA) . PACE is used to estimate the probability distributions of such consequences as

  • Individual doses from exposure to radioactive material in the air and on the ground and collective doses from ingestion of contaminated terrestrial food.
  • Numbers of health effects both fatal and non-fatal arising from exposure.
  • Costs of disruption on agriculture, industry and society.

Consequences can be mitigated by countermeasures and PACE considers the following:

  • Evacuation
  • Sheltering
  • Stable iodine prophylaxis
  • Long term population relocation
  • Decontamination of the environment
  • Restriction of food

PACE incorporates both a Gaussian dispersion model and the UK Met Office NAMEIII lagrangian particle model. PACE is embedded within the ArcGIS(TM) Geographic Information System software enabling high quality map output to be produced.


  • Ability to handle short and long duration multi-phase releases
  • Embedded within ArcGIS(TM) software to allow sophisticated spatial data handling functionality and high quality map production.
  • Incorporates the advanced UK Met Office NAMEIII lagrangian particle model. This model can use 3-D Numerical weather prediction (NWP) data or single site meteorological data.
  • A complete set of default input data for the UK

Online services and support

  • Web-based knowledge base (coming soon)
  • Web-based and telephone support with web-based logging (coming soon)
  • Download software from web (coming soon)
  • Account and purchase history (coming soon)

Some of the ways you can use PACE

PACE has been designed for assisting in the process of planning and licensing of new nuclear power stations but it can also be used for assessing the consequences of hypothetical accidents at existing facilities and improve emergency planning.


Licensing example

For the planning process a typical PACE analysis would follow from a Level-2 analysis which looks at accident sequences that might breach the containment of the facility. The Level-2 analysis would establish a suitable source term (the quantities of different radionuclides released) which would be used as the input to the PACE Level-3 analysis. By running PACE you can establish the probability of certain consequences such as fatalities and compare these against the regulatory licensing criteria.


Emergency planning example

Given a source term, PACE can indicate the likely extent of evacuation, sheltering and stable iodine administration and how many people might be affected. It can estimate the likely duration of relocation and restriction on food marketing. This information can then be used as a basis for a review of the adequacy of existing emergency plans. It also allows you to quantify when the limits of current emergency planning may be exceeded, for example when urgent countermeasures may be required outside the existing emergency planning zone.