Defence Department sources have disclosed that about 40 kilograms [almost certainly an over-estimate] of radioactive plutonium was buried in a shallow pit at Maralinga, which was fenced and guarded for a time. Mr Killen ordered the top-level inquiry into tests after the Deputy Opposition Leader, Mr Uren, alleged in Parliament on December 9 last year that nuclear devices were exploded during an international moratorium on nuclear weapons testing.
The story ended with a throw-away line alluding to the fact that unguarded radioactive waste ‘might be suitable for use in nuclear weapons’. But other media did not pick this up, at least not yet.
The rumblings continued and a thunderstorm seemed about to break. On 16 February 1977, Whitlam asked Killen if earlier assurances from the British that they had not flown radioactive waste to Australia for burial were still valid. Killen replied that they were. On 31 March, Killen answered a question on notice from Labor MP and later leader Bill Hayden, who had asked on 9 March if he could ‘provide a full list of all nuclear explosions which have taken place in Australia giving the date, the size, location and purpose of each?’ Killen replied with a basic list of the major trials at the three test sites from October 1952 to October 1957. He included Antler but provided no correction to his earlier suggestion that the major trials had ended in 1956, and he gave no indication that he was aware of the minor trials. Killen then ordered his department to take a closer look. The top-secret Pearce Report that had been in government hands for 10 years showed that plutonium was at the site, even if it underestimated how much was above ground. The full report had not been made public (an edited version was published in May 1979 and tabled in the House of Representatives on 7 June), but it was available to senior government ministers. From the content of public statements by Killen, Garland and others, it appears that few people had read it.
In response to Killen’s request, Defence produced the secret Cabinet submission no. 2605, prepared for the Foreign Affairs and Defence Committee and tabled on 11 September 1978. Titled ‘Plutonium Buried near Maralinga Airfield’, it raised an alarming spectre, that ‘a small party of determined men’ could recover plutonium ‘in a single quick operation if they were willing to take large risks to themselves’ and threaten to exploit its ‘extremely toxic properties… against the population of a major city’. In other words, the aftermath of the minor trials at Maralinga could be used for terrorism, a horrifying prospect. Killen wanted permission from Cabinet to seek British co-operation in removing a half-kilogram ‘discrete mass’ of plutonium buried near the Maralinga airfield. He was not seeking remediation of the plutonium at Taranaki, which the submission conceded was ‘practicably irrecoverable’ because it was so dispersed. (The extent of Vixen B contamination had not yet come out.) The airfield plutonium, noted in the Pearce Report, had been used in a Tims minor trial at TM101 in 1961.
Members of the Foreign Affairs and Defence Committee accepted the recommendation of the submission that the government should avoid public scrutiny and actively attempt to limit media knowledge. The committee specifically asked Killen to ‘arrange for a reconnaissance to determine what would be entailed in exhuming the discrete mass of recoverable plutonium buried at Maralinga on an assumption that it would then be removed from Australia by the British’. The submission advised against announcing the purpose for the reconnaissance, suggesting, if necessary, that it be described as a ‘review of physical security measures and possible need for maintenance work’. The committee acknowledged the need for a public statement ‘about the exhumation/repatriation operation’, but the ‘timing and text would require discussion with the British’. The long-established method of stonewalling media scrutiny, or diverting attention with a bland and uninformative public statement, still operated, but not for much longer.
The secret submission also noted that the Maralinga plutonium might compromise Australia’s international obligations. The prevailing international agreement was the Treaty on the Non-Proliferation of Nuclear Weapons, also known as the Non-Proliferation Treaty. Since ‘some of the nuclear material buried at Maralinga may be safeguardable’, this meant it had to be declared ‘to the International Atomic Energy Agency (IAEA) on Australia’s inventory of materials’. The problem wouldn’t go away by itself: ‘The IAEA is aware of the possible presence of undeclared safeguardable material at Maralinga’.
The submission put forwards three options for dealing with the plutonium. It favoured asking the British to dig it up and take it home, which was, eventually, enforced. The Foreign Affairs and Defence Committee formally responded to Killen’s submission on 28 September 1978 confirming that it would approach the British. The nuclear affairs division of the Department of Foreign Affairs found that the plutonium in question was buried in six containers in ‘relatively shallow’ pits. Despite the term discrete mass, it was not a single lump but dispersed through salt packed into the containers. The British, after initially refusing, recovered the Tims plutonium in 1979 and took it back to Britain.
Despite their desire to keep the story out of the public domain, Killen and his department reckoned without the efforts of one of Australia’s leading investigative journalists. Brian Toohey, then 33 years old, had been a political correspondent for the Australian Financial Review since 1973 and later became Washington correspondent and then editor of the National Times. He was well known for his unwillingness to stick to official versions of events. Fellow political correspondent Mungo MacCallum noted in a 1989 feature, ‘As a journalist of unrivalled application and extraordinary contacts, Toohey dedicated himself to opening up things that politicians (and more particularly bureaucrats) wanted to keep secret, irrespective of what they were’. Fatefully, Toohey got his hands on the secret Defence submission. While he had to maintain confidentiality, he identified his source as ‘someone in the government who thought the information should be public, without being motivated by either a strong environmental, or nuclear disarmament, perspective’.
Finally the ticking time bomb of Maralinga was revealed to a large audience. Toohey used the leaked Cabinet submission as the basis of his story in the Australian Financial Review on 5 October 1978, under the headline ‘Killen warns on plutonium pile’. The sub-heading was even more compelling: ‘Terrorist threat to British atomic waste’. It was a factual account of the contents of the submission, with commentary on the consequences. For example, the second option outlined by the submission for dealing with the plutonium involved Australian authorities extracting and analysing the plutonium at the site, a task described in the submission as potentially beyond the limits of Australia’s capacity to deal with radio-active materials. ‘Although the submission does not make this point, the public is hardly likely to be reassured by the revelation that despite all the money spent on nuclear research within Australia, half a kilogram of plutonium is possibly too hot for the authorities to handle in line with IAEA requirements.’ Toohey noted that the Menzies government in particular had not demanded sufficient safeguards at Maralinga: ‘The submission… makes clear that Australian Governments in the past have taken an extremely lenient attitude towards the existence of the Maralinga plutonium through its nuclear weapons tests in Australia in the 1950s’. He concluded, ‘It is now 20 years since the tests finished. The fall-out, however, is still a very live issue in British–Australian relations however much both Governments want to keep the negotiations entailed in last Thursday’s Cabinet submission a closely guarded secret’.