by Joan Smith
We have already seen how part of the fallout from Operation Hurricane drifted across the mainland at 10,000 feet instead of the much more innocuous 25,000 feet predicted. During the Royal Commission’s hearings in London, Peter McClellan, the barrister assisting the commission, read out comparisons between the cloud paths predicted for various tests and where they actually went.
The cloud from the third test in the Buffalo series at Maralinga, for instance, was supposed to go just north of Brisbane, on the east coast of Australia. Where it actually went was just north of Sydney, about 400 miles further south. When it came to the fourth Buffalo test, fallout was intended to go north of Brisbane again. What actually happened became clear in this exchange between McClellan and Penney:
MCCLELLAN The observed pattern -
PENNEY (interrupting) Goes everywhere!
MCCLELLAN Half to three-quarters of Australia. At the time, did it become known that the cloud had behaved so differently … was any concern expressed?
PENNEY When that was known, to my knowledge, no concern was expressed.
The cloud from the biggest British bomb tested in Australia, the 98-kiloton blast known as Mosaic II, was supposed to drift harmlessly out to sea from the Monte Bello Islands. Instead, the wind changed and blew fallout across the small towns on the coast of nearby Western Australia - Onslow, Roebourne, Dampier and Port Hedland. This event was the cause of the frantic signal to the British from the Australian government which demanded to know what was going on.
Other clouds - Operation Hurricane and the second Totem test - simply got lost. The overall picture, in which radioactive clouds can be seen drifting unpredictably across populated areas of Australia, is hard to reconcile with claims that the Australian population was never put at risk.
The extent to which the population of Australia was exposed to radiation from the tests is difficult to assess because of the inadequacy of the efforts made to measure it. No information at all is available on long-range fallout from the first three tests - Operations Hurricane and Totem - because no aerial surveys were made to look for it.
At the later tests, aerial surveys were carried out to check for fallout at considerable distances from the tests; from Totem onwards, monitoring stations were set up on the ground to collect fallout. Evidence given to the Royal Commission cast doubt on the effectiveness of all these systems in giving accurate measurements. But the spirit in which the monitoring was done is clear, and explains the confidence with which rather inadequate data was used as the basis of assurances to the Australian people about the safety of the tests.
The purpose of setting up the monitoring systems was revealed quite clearly during exchanges between Peter McClellan and Lord Penney during the Commission’s London hearings. McClellan said the monitoring stations were set up specifically to check fallout from the tests. ‘Was that done’, he asked, ‘because of concern [that] there may be some safety problems?’
‘No,’ said Penney, dismissing the notion that there could be any danger to the Australian people. ‘It was done to confirm it was all right.’ (My italics.) When McClellan pressed him, Penney expanded on the theme in a way which stressed the public relations nature of the exercise. ‘It was to demonstrate it was safe,’ he insisted, adding, ‘We were sure, but there’s nothing like being doubly sure.’
It seems a curious departure-point for a scientific investigation. It may also explain why the exercise was carried out with rather unreliable equipment. Ground monitoring was done by festooning the countryside with sticky paper, which was supposed to catch particles of fallout. McClellan suggested to Penney that the sticky-paper method hadn’t worked very well at all. ‘Well,’ said Penney, ‘I can’t really say yes or no. They don’t look as if they’d be too good but they did give a reading.’
The problem with the sticky-paper method was that it was adversely affected by rain. Unfortunately, the other system used for monitoring on the ground, air pumps which measured airborne contamination passing through them, was also unreliable. McClellan raised these problems with Donald Stevens, an Australian scientist who was director of the Australian Radiation Laboratory from 1956 to 1977 and a member from 1956 of the Australian committee set up to look after the safety of the civilian population during the British bomb tests.
MCCLELLAN You were also involved in the monitoring of fallout in Australia outside the declared area [the official danger zone]. In this programme, two types of equipment were used, air pumps and sticky-paper samplers. You recall the air pumps ran into some problems, however, particularly in outback Australia - for example, dust clogged some filter papers and inhibited the standard flow of air through them, with the result that in some areas there may have been an underestimate of airborne contamination at ground level. Are you able to give me any idea of the order of underestimate that would have been involved?
STEVENS No, I could not.
MCCLELLAN Could it be in the order of hundreds or thousands of per cent? What sort of range would you expect?
STEVENS No, I would be completely guessing, Your Honour.
McClellan then asked what happened to the sticky-paper samplers when it rained. ‘Well, the sticky paper was a gum form on a plastic base, as it were,’ said Stevens, ‘and under heavy rain conditions this became … lost its tackiness … lost its ability to hold the deposit on it.’
MCCLELLAN Well, have we reached the position then, sir, [that] by 1958 it was recognized by the Atomic Weapons Tests Safety Committee [the Australian safety committee] that there were problems in the collection of fallout information from both the air-pump method and the sticky-paper method?
STEVENS There were some uncertainties, yes.
The other method of checking fallout on the mainland was through aerial surveys made by planes flying at 500 feet. At the Royal Commission hearings, it emerged that the actual readings made by this method have to be multiplied by ten to give a genuine reflection of the level of contamination on the ground. But the Atomic Weapons Tests Safety Committee used the actual readings to give assurances to the public about the levels of fallout from the tests.
All in all, the systems used for monitoring the mainland are curiously flawed as a basis for the soothing noises made about the lack of danger from fallout from the tests. But, as Penney has revealed, their purpose was less to find out what was going on than to reinforce a preconceived notion that there was no risk to the public.
As well as the twelve atom bomb tests which took place in Australia, Britain also carried out a series of related experiments at Emu Field and Maralinga. The experiments started at Emu in 1953, moved to Maralinga in 1955 and did not end until 1963, long after the last atom bomb test.
They were shrouded in even greater secrecy than the actual bomb tests, and with good reason from the British government’s point of view. They have left large quantities of plutonium at Maralinga to this day, a serious problem since aborigines want to move back into the area. They were also politically sensitive by the end of the 1950s; Britain agreed to a moratorium on weapons testing at the end of 1958 and the minor trials could be interpreted as a breach of the spirit, if not the letter, of the agreement.
Hundreds of experiments were carried out: the exact number is not known, since accurate records have not been kept. Little bits of information have been pieced together, but we still do not have a complete picture of what went on.
Under the innocuous title of ‘Vixens’, a series of experiments took place to determine what would happen to an atom bomb if it was involved in an accident - a plane crash, for example. (‘We always had words that had nothing to do with the subject,’ Penney explained cheerfully to the Royal Commission.) Bombs were exposed to intense fires to see if they could withstand great heat without actually going off.
Another series of minor trials - ‘Tims’ - was intended to test the compressibility of plutonium. The idea was to observe the effect on plutonium of a shock wave caused by high explosives. Would that have involved dispersion of plut
onium, Penney was asked during his evidence to the Royal Commission. ‘Yes,’ he replied. ‘Into the atmosphere?’ ‘Yes.’
Other experiments were designed to try out devices for starting an atomic explosion. We can get some idea of how many experiments took place overall by looking at periods for which we know the dates of the experiments. In 1953, a number of ‘Kittens’ experiments took place at the same time as the two Totem bombs were tested at Emu Field. Five experiments were carried out between 26 September and 17 October. In 1955, ‘Kittens’ trials were held regularly at Maralinga from April to June. In July, they were followed by a series of ‘Tims’ experiments.
In 1959, when the major trials were over and during the voluntary moratorium on nuclear testing, dozens of experiments took place between March and August at Maralinga. There were four separate series of trials - ‘Rats’, ‘Kittens’, ‘Tims’ and ‘Vixens’. In December that year, the Australians were asked to consider a further series of experiments in 1960. The British made clear they were anxious to avoid publicity, because of international discussions on a permanent test ban treaty. The Australians were as accommodating as ever: the 1960 series of experiments included twelve ‘Vixens’ trials, which involved detonations and burnings. The experiments ended in 1963; in September that year, the Atomic Weapons Tests Safety Committee prepared a paper which noted extensive plutonium contamination at Maralinga.
In 1967, when a decision was taken to close the Maralinga range, a team of Royal Engineers and AWRE staff went to Australia to clean up the mess. The exercise, known as Operation Brumby, is described in a secret report by a scientist called Noah Pearce which was leaked to the National Times of Australia in 1984.
The Pearce report shows that tractors were used to churn plutonium into the topsoil over an area of 500 acres at Maralinga. When this had been done, some areas were still so contaminated that they had to be covered with clean topsoil. Since the area is known for its dust storms, it is likely that breaking up the plutonium in this way simply enhanced its chances of being blown across an even wider area.
In 1972, AIRAC 9 reported, there had been ‘heavy loss’ of topsoil at Taranaki, the section of the Maralinga site which had been most heavily contaminated by the minor trials. As well as the plutonium churned into the topsoil, there are nineteen pits at Maralinga which contain 20 kilograms of plutonium mixed in with other material. Plutonium is so dangerous that less than a third of a milligram will give you a 50 per cent chance of getting cancer if it lodges in your lung.
Seventy acres of land have been fenced off at Maralinga, but there is plutonium contamination well outside this area. The scale of the problem posed by the state of Maralinga became clear at hearings of the Royal Commission in Australia in October 1984. Peter McClellan asked Dr Keith Lokan, director of the Australian Radiation Laboratory, how long the area would have to be kept under surveillance if it was allowed to remain in its present state. Lokan’s answer was uncompromising: one million years. The prospect clearly alarmed McClellan.
MCCLELLAN A million years. You keep the Commonwealth police on overtime, six-weekly vacational tours, and you continue to fence. That is what no change means, is that right?
Lokan agreed that it was. McClellan asked him whether the experiments using plutonium should have been carried out at Maralinga. He replied: ‘My view is that they should not have been conducted, because plutonium has a very long half life [the time required for half the substance to lose its radioactivity] and the problem is with us then for a very long time.’
If Australia decides to remove all the contamination that remains at Maralinga, someone will have to carry out a massive and unpleasant job: the removal of hundreds of acres of topsoil contaminated with plutonium, and the excavation of nineteen pits containing large amounts of plutonium. There is also the question of how to dispose of the resulting quantity of high-level radioactive waste. Peter McClellan made his thinking clear during his questioning of Dr Lokan. ‘Let me ask what some might consider to be the more relevant question,’ he suggested, after a discussion of possible sites for the waste in Australia. ‘Do you know whether or not there is such a site in Great Britain for the disposition of such waste?’ The drift of his question was such that he did not need to mention Windscale by name.
Because they had so little say in the early tests, the Australians decided to set up their own committee to protect the civilian population during the later tests. It came into being in 1955, as the Maralinga Safety Committee, and turned itself into the Atomic Weapons Tests Safety Committee the following year. It was chaired first by Professor Sir Leslie Martin, then by Penney’s former colleague from Los Alamos, Professor Sir Ernest Titterton.
The committee was, to say the least, ineffective; if the British had taken its advice seriously, the tests would probably have ground to an early halt. It was not only ignored but also seems to have failed, on one occasion, to convey to Penney a vital piece of information about the safety of the aboriginal population. In addition the committee seems to have identified with British interests to the point where it worried about the possibility of radioactive rain less because of its possible effect on the mainland than because it might engender publicity harmful to the tests.
On 9 May 1956, the committee held its seventh meeting. Three bomb tests had taken place so far, at Operations Hurricane and Totem. The Mosaic series was well under way in the Monte Bello Islands: the first of the two bombs in the exercise would be tested a week later. The British were now drawing up plans for their first tests at Maralinga - the Buffalo series, which would start in September that year.
The committee was worried about fallout from the tests due to be held at Maralinga. The chances of getting winds blowing into the area of land considered safest for the test were ‘slight’. The committee had sought technical information from Britain on the types of weapons to be tested; because of the amount of fallout the bombs were likely to produce, ‘the tests might have to be restricted to relatively small atomic devices’.
These restrictions - limiting the Maralinga tests to small bombs and only firing the weapons on the rare occasions when the wind was in the right direction - would have made it difficult for the British to go ahead with the tests planned for Maralinga. McClellan asked Donald Stevens, who joined the committee just after this meeting, exactly what the restrictions implied in the memo would have meant.
His reply suggested that the bombs should be no bigger than ten kilotons, and should be exploded in the air or at least on top of high towers to minimize fallout. ‘That memorandum presents a very bleak picture for the future of British nuclear tests in Australia, does it not?’ commented McClellan.
The British, however, either never heard of the committee’s reservations, or ignored them. The first test at Maralinga, the One Tree blast in September, was fifteen kilotons. The final test at Maralinga, the Taranaki test in October 1957, was twenty-five kilotons. And the Marcoo test in October 1956, although it was a small 1.5-kiloton bomb, was actually exploded on the ground – the type of blast which causes the most fallout.
At its sixth meeting, a month before, the committee also received advice which should have prevented the use of Maralinga as a test site at all. The advice, on the risk to aborigines, was never passed on to Penney. When the British were looking for mainland sites to test bombs, Penney had decided any place chosen had to be a hundred miles from inhabited areas. He did this by looking at the distance of Las Vegas from the Nevada site in the US - seventy miles - and adding a bit on for the sake of caution.
But at its sixth meeting, in April 1956, the committee heard a reply from AWRE at Aldermaston to its request for information on the risk from radiation to aborigines living in their tribal state - nearly naked and with bare feet. It said that, because they did not have even the small protection afforded by clothes and shoes, aborigines could be exposed to five times less radiation than people in European dress. Translated into distances, the advice meant that ‘for a nominal [20 kilotons] burst, t
he acceptable level would occur at a distance of about 240 miles’ from the site of the test.
There were thirteen aboriginal settlements within 200 miles of Maralinga, several of them just beyond the hundred-mile limit laid down by Penney. The advice given to the committee made Maralinga a most unsuitable place for the tests: Penney told the Royal Commission he was completely unaware of it. Needless to say, the tests went ahead.
The committee did, however, warn the Australian cabinet about radioactive rain - but not because it thought it was a hazard. On 13 August 1956, it made a top-secret report to the cabinet, pointing out that after the second Monte Bello test, ‘some very low activity was observed in rainwater samples at great distances from the site’. The levels were absolutely harmless, the committee adds, but ‘the results were given publicity and magnified by the press into what became practically a political crisis.’
Instead of looking into ways of preventing radioactive rain, the committee simply warned the Australian government that ‘we appreciate the political difficulties that radioactive rain might stimulate and we have to point out that it is always a possibility’.
The committee goes on in the same report to ask for advice on what it should do if a situation arose in which ‘dangerous’ levels of fallout got into drinking water. This could happen at Oodnadatta, more than 250 miles from Maralinga, if rain washed fallout from a roof into a nearly empty tank containing drinking water.