Radioecological risk analysis of ANSTO's monthly effluent releases, 2006-07

Abstract

In line with its ISO 14000 initiatives, ANSTO endeavours to identify its environmental impacts. Part of this process includes the assessment of its releases of radioactivity into the wider environment. Liquid effluent with low levels of radioactivity is routinely released via Sydney Water's sewerage system, treated to tertiary standard in the Cronulla Sewage Treatment Plant (CSTP) and finally discharged into the marine environment at Potter Point (Figure 1). These releases occur approximately four times a week and, given the delay and mixing that occurs in transit before discharge into the ocean, can be considered to be a relatively constant release. This raises the question as to whether the releases have the potential to cause unintended environmental impacts in the receiving environment. A comprehensive overview of the potential adverse effects of enhanced environmental radioactivity is given in Copplestone et al. (2001). In this study, the possible radiological dose-rates to biota arising from the radioactivity in the ANSTO effluent have been evaluated and compared to international criteria of acceptability to assess the potential ramifications of release.