Application of a Simple Model to Predict Environmental Radionuclide Levels and Consequential Dose Rates on the South Welsh Coast, U.K.

The impact of liquid effluent discharges, from both existing nuclear power stations and from a possible future pressurized water reactor (PWR), on the levels of radioactivity in Welsh Severn coastal waters has been addressed in this study through the use of a simple box model. If a PWR was in operation at Hinkley Point, and assuming that the existing discharges into the estuary remained the same as in 1989, the levels of the most radiologically significant radionuclide, 137Cs, in seawater along the Welsh shoreline are predicted to increase by 7% (inner estuary), 7% (Welsh outer estuary) and 5% (inner channel) and in sediment by 0•3, 1•3 and 2% respectively. The radiation dose rate from 137Cs to members of the coastal population alone would show only a marginal increase due to these changes, and would remain less than 1% of the internationally recognized limit.