Modelling radioactivity in the Irish Sea: from discharge to dose

Area of Science:

• Environmental Science
• Radiological Protection
• Mathematical Modeling

Background:

• Authorised discharges of low-level radioactive liquid effluent require robust impact prediction models.
• Understanding long-term dispersion and transport is crucial for assessing radiological impacts on coastal populations.

Purpose of the Study:

• To develop and present a mathematical grid model for simulating radioactivity dispersion from the Sellafield site.
• To predict the radiological impacts on critical groups in Cumbria and Northern Ireland due to current and proposed liquid discharges.

Main Methods:

• A fine-grid mathematical model simulating long-term dispersion and transport of radioactivity.
• Incorporation of seabed sediment distribution for accurate contamination source prediction.
• Comparison of model predictions with environmental data for validation.

Main Results:

• The model effectively simulates long-term dispersion and transport of radioactivity from Sellafield.
• High resolution of seabed sediment distribution improves predictions, especially for low discharge periods.
• Predicted doses for the Cumbria critical group align well with environmental data during low discharge phases.

Conclusions:

• The developed grid model provides robust predictions of radiological impacts from liquid radioactive discharges.
• The model's ability to account for sediment dynamics enhances its accuracy in assessing long-term contamination.
• This tool supports informed decision-making for authorised discharges in coastal regions.