Monitoring of ANSTO's environmental performance for 1995 shows it complied by a wide margin with all standards set by State regulatory authorities and recommended by national and international organisations.
A publicly available report, "Environmental and Effluent Monitoring at Lucas Heights Science and Technology Centre, 1995", reports the quantities of radionuclides in authorised discharges to the air and the sewer are the amounts detected in environmental samples around Lucas Heights and Potter Point.
Potential maximum radiation doses to members of the public resulting from the discharges are also presented.
The 1995 results were audited by the Australian Radiation Laboratory, an independent body which is part of the Commonwealth Department of Health and Family Services. As points of reference, the international unit of radiation dose is the sievert.
All Australians receive an annual average radiation dose of 2 millisieverts from natural sources such as the Sun, the earth itself, materials and the food and drink we consume.
The National Health and Medical Research Council recommends that members of the public should not receive an additional annual dose of more than one millisievert from other sources, excluding doses from medical exposures.
The results of the 1995 ANSTO sampling program were:
Air:
Total radioactive airborne emissions from the Lucas Heights site in 1995 resulted in a potential effective dose of just 1% of the annual dose limit of 1 millisievert for members of the public recommended by the National Health and Medical Research Council (NH&MRC).
Liquid:
In 1995 releases from ANSTO to the sewer averaged 22% of the limit for radionuclides specified in the Trade Waste Agreement with Sydney Water Corporation.
Analyses of stormwater drainage from ANSTO showed that the stormwater complied with the NSW Clean Waters Regulations (1972) at the agreed sampling points on the three creeks receiving most of the run-off from the site. Environmental samples collected from the Woronora River and Forbes Creek showed no evidence of radionuclides produced by ANSTO.
Seawater samples were taken from the vicinity of Potter Point, near Cronulla, where treated sewage from Sutherland Shire, including that from ANSTO, is released into the ocean.
Analyses of these samples showed that the tritium, or radioactive hydrogen, level was essentially that of naturally occurring background levels in the upper layer of seawater.
The only gamma radiation emitter detected, potassium-40, was also measured at concentrations similar to naturally occurring background levels in seawater.
ANSTO also conducted biological monitoring at Potter Point, sampling fish, algae, barnacles and particulates. Naturally occurring radionuclides were detected, and in some specimens Iodine-131, Cobalt-60 and Caesium-137 were also detected at or just above the limit of detection.
Caesium-137 was found at levels within the range reported for fish from around other parts of Australia. Based on the trace amounts of cobalt-60 and caesium-137 found by monitoring, a person would have to consume about 77,000kg of fish per year to reach the internationally recommended intake limits.
Other locations
Sensitive thermoluminescent dosimeters, which measure ambient external gamma radiation, were placed at various locations around ANSTOs perimeter and at three private residences, one each in the nearby suburbs of Barden Ridge, Engadine and Woronora. Each dosimeter was supplied by the Australian Radiation Laboratory.
The dosimeters at each of the three private residences registered an average absorbed radiation dose of 1.0 millisievert per year. This is the same dose level reported by the ARL for Australian capital cities as a result of naturally occurring radiation sources.
ANSTO has a policy of continuous upgrade of its facilities to minimise dose exposure to staff and the community.
Published: 29/01/1997