The letter had a handwritten annotation, above Menzies’ initials: ‘Discussed with Mr Townley [Defence minister] and approved as amended’. An attached media statement with handwritten corrections asserted that no nuclear explosions were being carried out on the Maralinga range. More detailed information about the activity at the range was crossed out, in particular a statement that the experimental program involved radioactive or nuclear materials. What remained was the following:
The Range is being used for experiments conducted on behalf of the United Kingdom Energy Authority which has a need to explore systems of safeguards [the previous few words crossed out by hand] to eliminate or to minimise the hazards which could arise from accidents involving radio-active materials. The Australian Government has agreed to the use of Maralinga for these experiments which are carried out in accordance with the requirements of the Safety Committee established by the Australian Government and under carefully controlled conditions to avoid any significant radio-active hazard.
On 20 October, the office of the UK high commissioner in Canberra replied, unhappy with ‘systems of safeguards’, saying it ‘may lead to difficulties and misunderstandings’ because it was similar to terminology being used in negotiations for the new Geneva nuclear weapons treaty. The International Atomic Energy Agency (IAEA) was also using the term in regards to civil uses of nuclear technology. ‘Thus the term “systems of safeguards” has already acquired rather special connotations. It is therefore felt that it would be better if possible to avoid it in the draft press statement.’
After further correspondence, a final version – with ‘systems of safeguards’ removed – was watered down a little more to produce a 100-word media statement. It was never issued, because no journalist ever inquired. Despite growing public disquiet since 1956, the media did not notice the signs that major activities were afoot at Maralinga, overlooking the increases in military personnel and much to-ing and fro-ing. Unless an official media release heralded it, the media seemed to show no interest in the events at Maralinga. Of course, this suited the British test authorities, who consciously sought to maintain secrecy.
The media blackout that descended over Maralinga was extremely successful. Given both the level of previous coverage of the British nuclear tests and the rise of anti-nuclear movements throughout the world, the lack of media activity is conspicuous. Vixen B, a test series that ran for three years and involved hundreds of personnel on site, does not appear to have been covered at all. As Lorna Arnold wrote, ‘Outside official circles, very few people apparently realised that Maralinga was used for these experimental programmes, and that it continued to be used after Antler’.
Arnold claimed that the British authorities were ‘particularly anxious’ not to attract any publicity during international negotiations to limit nuclear weapons testing. Vixen B was the major reason for this anxiety, since it produced nuclear fission, albeit in small amounts, and tested an apparatus that came close to many of the characteristics of an actual nuclear warhead. Vixen B was right on the borderline of international law and may have crossed into illegality. The behaviour of the AWRE authorities at the time suggests that they knew Vixen B was in a grey area and political reasons dictated secrecy.
Intergovernmental moves to find a politically acceptable way to slow the race for nuclear arms had begun in 1958. US president Dwight Eisenhower had proposed that test ban negotiations should begin on 31 October that year, pledging a one-year moratorium on weapons testing, and the Soviet Union had agreed. On that date, the Conference for the Discontinuance of Nuclear Weapons Tests had opened in Geneva. A moratorium on the testing of atomic weapons actually stayed in place until September 1961. In 1963, a permanent partial test ban treaty came into effect.
The Geneva agreement was a complication for the AWRE. The UK weapons authorities had no choice but to comply with the agreement, which was binding on the UK. On the other hand, they had an extensive program at Maralinga and plans to expand it. The easiest thing to do was to behave as though the minor trials were not happening. The attitude of the time was summarised by the Australian chronicler of the tests, John Symonds: ‘There is no reason to believe that these experiments could be regarded as an evasion of a Treaty, whatever the outcome of the present Geneva discussions. While there is no need to raise the point specifically in Geneva, there is no need to deliberately conceal it, but no public statement is to be volunteered’. Without public statements, there was no media coverage.
Vixen B did not produce mushroom clouds. The major trials sent clouds of minute particles of debris into the stratosphere (more than 10 kilometres above the ground) and spread fallout of short-lived radionuclides over most of the Australian continent, with some isotopes found as far east as the Queensland tropics. The impact of the minor trials was more concentrated, more geographically contained, yet significantly more dangerous close to the firing site. The main dangers were to people in that geographical area, primarily service personnel and scientific staff who were conducting the tests, Indigenous people who traversed the land around Taranaki during or after the trials and later visitors to the site who may have unknowingly picked up radioactive materials or inhaled dust containing plutonium.
The dangers were grave, although there is considerable dispute about their extent. Lorna Arnold took the view that the people exposed to the tests were not seriously affected by radiation, doses of which she said were well within the guidelines laid down by the International Commission on Radiological Protection: ‘The people most affected… were the Aboriginals, because of damage to their way of life rather than directly to their health. They had no rights and their interest in the land was not realized or respected; but this was, and had been, their general situation and was neither new nor peculiar to the weapons trials’.
Vixen was initially proposed as one kind of test, but it evolved into two – Vixen A and Vixen B – a year or so after its first formulation. Vixen A, the original form of the experiments, used mostly beryllium and small quantities of plutonium. It involved studying how radioactive and toxic materials including beryllium, uranium and plutonium might behave in an incendiary or explosive accident and specifically examined how weather conditions influenced the spread of such materials. The tests involved burning the substances in a petrol fire or electric furnace, or dispersing them by high explosive. Thirty-one Vixen A experiments were carried out at the Wewak site, about 15 kilometres to the southeast of Taranaki.
The Vixen A experiments were troublesome for several reasons, not least because the balloons used to hoist a variety of monitoring devices aloft before detonating the bundles of radioactive materials kept slipping their moorings and heading off into the open sky. After one such incident in July 1959, a balloon was found the next day about 10 kilometres away from the test site. Another escaping balloon was not found. The balloon accidents associated with Vixen A caused major disruptions to the test program. In fact, these problems turned out to be a foretaste of more serious balloon incidents in September 1960 connected with Vixen B.
During a storm on the night of Friday 23 September 1960, seven of the eight captive balloons that had been placed for the start of the Vixen B experiments broke free. This was before the first Vixen B experiment, so the balloons were not contaminated. One of the balloons was discovered at Hungerford just over the New South Wales–Queensland border, about 1400 kilometres from Maralinga, and another at Cobar in New South Wales. The recovered Cobar balloon was found to have a faulty mooring system. Test authorities were worried that the footloose balloons would provoke media reports, but while some media did report the escaping balloons, none gave much detail.