Personnel from the NSW Environment Protection Authority raided the Lucas Heights nuclear facility in Sydney on June 11, and claimed to have found radioactive waste leaking from drums, and safety equipment that had not been functioning for up to two years. The raid was the latest incident in an ongoing dispute between the state and federal governments over storage of nuclear wastes at the site. JOHN R. HALLAM, of Friends of the Earth, Sydney, describes the dilemma posed by radioactive leftovers.
There are about 1300 highly radioactive spent fuel elements kept on site at Lucas Heights. There's no consensus on what to do with these high-level wastes, though the Australian Nuclear Science and Technology Organisation has wanted to export them either to the Idaho National Engineering Laboratory in the US for reprocessing or to Dounreay in the UK.
Then there is a varied assortment of low to intermediate wastes at a variety of sites around Australia, about 50% of it at Lucas Heights. It varies from obsolete reactor components to luminous radium dials for World War II aircraft instruments to slightly radioactive monazite sands processing waste.
The largest single batch is 536 cubic metres of "low-level solid wastes" stored in 200 litre drums at ANSTO.
The next largest batch by volume is also stored on the ANSTO site. It includes activated material from the HIFAR reactor, including the ends of fuel elements. This should qualify as high to intermediate level waste, rather than low level, under which category it is proposed to dispose of it. Stored with it at are also high-level liquid wastes from the production of radiopharmaceuticals.
In a concrete bunker at St Mary's are 17 cubic metres of low-level waste which ANSTO wanted to move to its site but was prevented from doing by a court decision in February.
Another 20 cubic metres are held at Lidcombe in a concrete blockhouse and a further 60 cubic metres in an old air-raid shelter. Various smaller quantities are held by the UNSW Department of Health, the Navy, Army and Air Force. Smaller quantities are held in Victoria, SA and Qld.
The total, about 1000 cubic metres, is being added to at approximately 100 cubic metres per year. This figure does not include the high-level waste stored at ANSTO, the "lightly contaminated soil" that ANSTO wanted to import from CSIRO in Victoria nor large quantities of waste from monazite sand processing.
The National Health and Medical Research Council (NHMRC) produced in 1990 a "Draft Code of Practice and Guidelines for the Disposal of Low Level Waste by Shallow Land Burial in Arid Areas" and in 1992 another draft. Both are sadly deficient.
The major problem pointed out in submissions by both Friends of the Earth and Greenpeace has been the selection, without discussion, of shallow land burial as a disposal method.
The residents of Sutherland Shire quite rightly object not only to more waste being bought onto the ANSTO site from St Mary's and elsewhere. They also point out that the top of a highly permeable sandstone plateau in an area of high rainfall next to high quality sources of water in a rapidly growing suburban area on the edge of Australia's largest city is a terrible location for even a temporary waste repository, let alone the largest concentration of waste in the country. Even the highest level waste, spent reactor fuel, is kept simply in concrete-lined holes in the ground.
In the US, shallow land burial sites have been strongly criticised for leakages resulting in up to 400 times the EPA standards for radioactive contamination in drinking water. In the UK, NIREX has abandoned shallow land disposal. Other methods of disposal are being pursued elsewhere.
There is also a great deal of uncertainty as to exactly what the waste repository will contain. For example, the 1992 and 1990 drafts mention obsolete reactor components. One would have presumed that these were high, or at least intermediate level, waste, and thus quite unsuitable for disposal as low level waste.
Waste is supposed to be classified into four categories: A, B, C and S. The NHMRC guidelines include concentration limits for the different waste categories.
Many of the limits for category A and B wastes have been quietly raised between the 1990 and the 1992 draft guidelines. For example, in the case of Category A wastes, the limit for tritium has been raised by a factor of two, carbon 14 by a factor of 1.5 and alpha emitting radionuclides by slightly more than two. The limit for thorium and uranium has been raised wastes by five times, and the limit for radium by 2.5 times. In Category B wastes, tritium has had its limit removed altogether, carbon 14 has gone up by 2.5 times, and the limit for radium has been raised to 50 times the limit in the 1990 guidelines! Are we to assume that radium has become 50 times less harmful in the last two years?
The drafts claim that Australian limits for the concentration of various radionuclides in low level waste are comparable to, or better than, international standards. This is not the case. According to their own figures, the Australian limit for tritium is now over two orders of magnitude higher than the US limit, four orders of magnitude greater than the UK limit, and seven orders of magnitude greater than the Italian limit.
These anomalies form the basis for a parliamentary question on notice by Senator Karin Sowada.