Radionuclide uptake in vegetables & herbs cultivated within the ANSTO Buffer Zone

Gedz, A; Loosz, T; Corry, M; Hoffmann, EL

Radionuclide uptake in vegetables & herbs cultivated within the ANSTO Buffer Zone

Date

2018-11-06

Authors

Publisher

South Pacific Environmental Radioactivity Association

Abstract

The Australian Nuclear Science and Technology Organisation (ANSTO) operates the production OPAL research reactor for the production of medical radioisotopes, scientific research, and the irradiation of silicon for use in microelectronics and other specialised irradiations for research and industry. During routine operations, small amounts of radionuclides are released through filtered emissions to air and treated liquid effluent discharged to the Sydney Water sewer. Airborne emissions from licenced facilities are bound by regulatory limits for radioactivity set by ARPANSA and are continuously monitored. Analysis of local environmental media provides confirmation as to the radionuclides released. including radioiodines from medical isotope production and low levels of tritium from the OPAL reactor. The effective dose to the local population from ANSTO’s authorised airborne releases is modelled quarterly as meteorology and stack emission data. At less than 5 uSv/year. the maximum potential airborne dose to the pus : residing at the 1.6 km Buffer Zone boundary remains well below the 1 mSv/year dose limit recommended by ARPANSA, As there is no longer any commercial food production within the Buffer Zone, sampling of foodstuffs has not been part of the ANSTO Environmental Monitoring program since the last dairy was closed in the 1980's. However, the construction of a new nuclear medicine facility and a childcare centre at ANSTO, in addition to proposed housing developments in the local community, has highlighted the need for renewed testing of locally-grown foodstuffs. In November 2017 and January 2018, two separate sampling campaigns were conducted at ANSTO as part of a scoping study to investigate potential radionuclide uptake in vegetation cultivated on-site, in particular radioiodine. Following these investigations, a working garden was established to determine seasonal radionuclide uptake in common vegetable and herb varieties, and to assess the potential dose from consumption of this produce. Results will be presented from gamma spectrometry analysis conducted to date, as well as a short discussion on the methodology and challenges associated with quantifying the radionuclides of interest and determining detection limits. The World Health Organisation General Standard for Contaminants and Toxins in Food and Feed (CODEX STAN 193-1995) will be applied for the calculation of potential dose associated with the ingestion of vegetables and herbs containing radioactivity.

Keywords

Radioactivity, Uptake, ANSTO, OPAL Reactor, Radioisotopes, Herbs, Vegetables, Emission, Contamination, Toxins

Citation

Gedz, A., Loosz, T., Corry, M., & Hoffmann, E. (2018). Radionuclide uptake in vegetables & herbs cultivated within the ANSTO Buffer Zone. Paper presented to the SPERA Conference 2018, "Bringing environmental radioactivity research to Western Australia, Perth, Western Australia, 6 - 9 November 2018. (pp. 43).