Scoping assessment of groundwater doses to biota at the Sellafield site, UK

Westlakes Scientific Consulting Ltd., The Princess Royal Building, Westlakes Science and Technology Park, Moor Row, CA24 3LN Cumbria, UK

Abstract

In investigating the impact of discharges from the nuclear industry on non-human biota, much attention has been given to biota in marine and terrestrial environments. Relatively little attention to date has been given to the exposure of biota to groundwater containing man-made radionuclides. This area of interest is growing especially in the field of nuclear waste repositories. A scoping assessment has been performed to determine the impacts due to radiological contamination on organisms living within or coming into contact with groundwater at the Sellafield site, UK. for time periods up to 2120, modelling of contaminant release from in-ground inventories and transport in groundwater was carried out using a relatively simple assessment methodology with the MONDRIAN modelling suite. Calculated equivalent dose rates to freshwater and marine biota were significantly higher at groundwater sites within the Sellafield boundary than at locations offsite. In general, the total weighted absorbed dose rates calculated in this scoping assessment were of no radiological significance in relation to the England and Wales Environment Agency freshwater ecosystem trigger level (40 µGy h^-1). The one exception to this was for bacteria, although the calculated exposure rate is believed to be inconsequential due to the very small size of bacteria.