The calculation of collective radiation exposure arising from discharges of activity into an estuary or sea in the British Isles

A model is described for the calculation of collective radiation exposure for releases of activity to an estuary or sea. The model is based on methods described by the Commission of the European Communities with the main exposure pathways being via the ingestion of seafood and external exposure on beaches. For tritium the most important pathway arises from the transfer of activity from the marine to the atmospheric environment. The model is best suited for calculations for fairly long-lived nuclides which do not become dispersed globally and for which the seafood ingestion pathway is dominant. Dose calculations for short-lived nuclides or nuclides where the external exposure pathway can be important will have greater uncertainty associated with them. A computer code CODAR is being developed which incorporates this model. (author)