Clouds of Deceit (6 page)

British scientists had been trying to work out a way of making a bomb from uranium, the heaviest naturally occurring element. To understand the problems to which Frisch and Peierls now suggested answers, we have to return to our model of an atom as a miniature solar system consisting of a central nucleus of protons and neutrons, with a number of electrons in its outer structure.

Which element an atom belongs to is determined by the number of protons in its nucleus - an atom of carbon, for instance, always has six - and this number is balanced by an equal number of electrons. But an element can occur in different forms, known as isotopes, which behave slightly differently from each other. What differentiates one isotope from another is the number of neutrons in the nucleus, the number of protons remains constant, and they acquire their names by the addition of the protons and the neutrons.

The two isotopes of uranium which were exercising the minds of scientists at the outbreak of the war were Uranium 235 and Uranium 238. U235 atoms split much more readily when bombarded by neutrons but form only 0.7 per cent of naturally occurring uranium, the remainder being U238.

Scientists believed that bombarding natural uranium with
neutrons would split insufficient atoms to start the chain reaction necessary for a nuclear explosion. Even if the problems could be overcome, very large amounts of rare uranium, running into tons, would be needed. The Frisch-Peierls Memorandum suggested that a much smaller amount of uranium - as little as a kilogram - would be needed if the U235 could be separated out from the U238. They also came up with a possible method of carrying out the separation.

The paper ended with a prophetic description of the horrors of the bomb that might be made from this process. They estimated that, one day after the explosion, the radiation would be equal to that from one hundred tons of radium. A cloud of radioactivity would kill everybody ‘within a strip estimated to be several miles long'. Rain would make the situation worse by carrying radioactive material firmly down to the ground, where it would linger. ‘Effective protection is hardly possible,' they wrote. ‘Houses would offer protection only at the margins of the danger zone.' Deep cellars might be comparatively safe, but even this protection would depend on access to uncontaminated air.

As a result of the Frisch-Peierls Memorandum a subcommittee of the Committee for the Scientific Survey of Air Warfare was set up. The sub-committee, whose brief was to look into the possibility of a uranium bomb, was given an uninformative title - The Maud Committee.

The name, deliberately intended to obscure its activities, was based on a misreading of a telegram from Niels Bohr to Otto Frisch. Bohr sent the telegram to England as Germany invaded Denmark; it ended with the curious phrase, ‘TELL COCK CROFT AND MAUD RAY KENT'. The reference to John Cockcroft, a scientist working in the Ministry of Supply, was comprehensible, but the last part of the message was a puzzle. Frisch and Cockcroft worked out that it might be a garbled anagram of RADIUM TAKEN, a message that the Germans had snatched Denmark's radium stocks. For this reason, a former governess called Maud Ray, who lived in Kent, never received the reassurring message Bohr had sent her about the safety of his family. The phrase preyed on the scientists' minds, however, and the
committee ended up with the name Maud. (Much later, it turned out that the name had been ingeniously interpreted by civil servants as an acronym for Military Application of Uranium Detonation.)

Under the supervision of the Maud Committee, work on the feasibility of the bomb project began in April 1940. Many of the scientists who made important contributions at this time were later to carry on their work in the US as part of the Manhattan Project.

The nerve centres for the work were Oxford, Liverpool, Cambridge and Birmingham. A team based at Oxford worked on the separation of U235 from natural uranium. Frisch joined Chadwick at Liverpool, leaving Peierls behind in Birmingham. Peierls's team was soon joined by the German, Klaus Fuchs, who played an important role in work on the size of the bomb. The importance of all this work cannot be overstressed. Robert Jungk, in his history of the first atomic scientists,
Brighter than a Thousand Suns,
wrote: ‘The countless administrative and technical obstacles which blocked the road to the release of atomic energy were finally overcome simply and solely by the determination and obstinacy of the scientists resident in the Anglo-Saxon countries… They repeatedly took the initiative in bringing that mighty weapon into the world.'

Just over a year after the setting up of the Maud Committee, in the summer of 1941, it produced two reports. One was on the use of uranium for power, the other on its use in a bomb. The bomb report showed how far matters had progressed. ‘We have now reached the conclusion that it will be possible to make an effective uranium bomb,' it said, going on to estimate that a 25 pound bomb would produce the effect of 1,800 tons of TNT.

Margaret Gowing has written that ‘there is no doubt that the work of the Maud Committee had put the British in the lead in the race for a bomb.' If it had not existed, she says, ‘the Second World War might well have ended before an atomic bomb was dropped.'

Until the autumn of 1942, there had been considerable cooperation and exchanges of information between Britain and the US about work on the atom bomb. In October 1941,
President Roosevelt had been told of the Maud Committee's conclusion that a uranium bomb was feasible. He decided to speed up the American effort and increase the flow of information to and from Britain. On the day before the Japanese attack on Pearl Harbor, which took place on 7 December 1941, and brought the US into the war, scientists in the uranium section of the Office of Scientific Research and Development were informed of the new programme.

Early in 1942, a British mission visited the US and reported back that the Americans were looking at both the uranium bomb and one based on the recently discovered heavier element, plutonium. Research in the US had clearly raced ahead after its early period in the doldrums. In the autumn of 1942, the American project had reached the point where a major reorganization was needed to cope with its huge industrial requirements. A special group of the US Army Corps of Engineers, known as the Manhattan District, was given charge of the project, under the overall leadership of Leslie Groves. At this point, Britain's problems with her major ally started with a vengeance and provided, if the British had only known it, a foretaste of what was to come immediately after the war. The underlying cause of the trouble was the question as to who would control nuclear energy after the war.

How much the exclusion of Britain from the Manhattan Project between 1942 and 1943, and from the American nuclear energy programme after the war, rankled on this side of the Atlantic can be gauged from Leonard Bertin's history of the period,
Atom Harvest.
‘British scientists who, with full approval of their Government, had been ready to provide the Americans with all the data they wanted, suddenly found doors closed upon them,' he wrote in 1955. ‘There is a popular but mistaken belief that this breakdown in cooperation occurred after the war with the passing of the McMahon Act [the act which forbade US scientists to share information] in 1946. It would be truer to say that it started the day the Americans were persuaded that, despite their own misgivings, the production of atomic weapons before the end of the war was possible.'

The British were informed of the new, restrictive conditions
for collaboration at the beginning of 1943. Effectively, they were told that they would be expected to continue to supply full information on the parts of the bomb effort on which they were working. The information which the British would be given in return was severely limited. For instance, Britain was to receive no information at all on one of the main methods of separating out U235.

According to Bertin, the excuse given to the protesting British was security. But, he writes, ‘subsequent events indicated quite clearly that the question mainly at stake was that of post-war development of atomic power.' The British government certainly seems to have believed this to be the underlying cause of the rift, because the way found out of the impasse conceded to the Americans the final say on post-war developments in nuclear matters with commercial applications.

The Quebec Agreement, signed on 19 August 1943 by Roosevelt and Churchill, agreed that, ‘in view of the heavy burden of production falling upon the United States as a result of a wise division of war effort, the British government recognise that any post-war advantages of an industrial or commercial character shall be dealt with as between the United States and Great Britain on terms to be specified by the President of the United States to the Prime Minister of Great Britain.' Churchill disclaimed any interest in these possible commercial aspects ‘beyond what may be considered by the President of the United States to be fair and just and in harmony with the economic welfare of the world'.

For this high price, collaboration was restored and, towards the end of 1943, teams of scientists from Britain got ready to go to the US, some to work at the nerve centre of the Manhattan Project, the top-secret laboratory set up at Los Alamos, in New Mexico, under the direction of the American physicist, Robert Oppenheimer. The British thought it was worth it because their own resources were severly stretched by the war effort, and sites in Britain would be vulnerable to enemy bombing. They were probably right: the knowledge gained at Los Alamos and elsewhere would prove invaluable after the war.

The British scientist who knew most about the Los Alamos bomb project was William George Penney. Penney was thirty when the war broke out in 1939. Pictures of him in the 1950s, when he was a national hero, show a large, even shambling figure, straight hair brushed sideways across an unusually square head. The man who gave evidence at the Australian Royal Commission hearings in January 1985 was a smaller but equally solid figure. What seemed little affected by age - he was seventy-five at the time - was his curiously slow manner of speech, familiar from thirty-year-old newsreels when excited reporters hung on his every word.

In 1952, Churchill's telegram of congratulation on the success of the first British atom bomb test at the Monte Bello Islands made Penney a knight with the words, ‘Well done, Sir William.' In 1967, he became a life peer, with the title Baron Penney of East Hendred. He now lives in the village of East Hendred, a stone's throw from the atomic research establishment at Harwell.

Penney's statement to the Australian commission deals mainly with the period from 1947 to 1959. His involvement with the Manhattan Project is covered in two laconic sentences: ‘During the war, I was recruited to the US Manhattan District Atomic Weapon Project. I made measurements of the yields of some of the early US tests and visited Japan to report on the damage caused by the two weapons used at Hiroshima and Nagasaki.' But Penney's role was a key one as far as the British were concerned.

At the start of the Second World War, Penney was an assistant professor of mathematics at Imperial College in London. He went to school in Sheerness, Kent, and gained both a BSc and a PhD at London University. Other degrees followed, from the University of Wisconsin, from Cambridge, and from London. At Imperial, Penney had been working on the nature of matter and had published numerous papers on the structure of various elements and compounds.

From 1940, he was on loan from the college to the Admiralty and the Ministry of Home Security to do war work; he was asked to look at the effects of an underwater explosion, particularly
the effect known as the pressure wave. This work later influenced the setting up of Britain's first atom bomb test, since Penney was anxious to discover the effect of an atom bomb explosion on board ship in a harbour.

Penney went on from this work to examine the effects of explosions in air on ships, houses and other vulnerable structures. Next, he advised the Admiralty on the kind of pressures to which the temporary harbour to be used for the Normandy landings would be exposed. In 1944, he went to Los Alamos.

Penney was asked to go to the US, well after the first wave of scientists from Britain arrived, because the project needed someone expert in calculating the effects of explosions. He worked on areas of the project which gave him extensive knowledge of atom bombs - not just the effects of blast but also the planning of the first bomb test, and the flights over Japan when Hiroshima and Nagasaki were bombed. Chapman Pincher, speculating in a book published in 1948 about whether Britain would make its own bomb, wrote that Penney ‘is said to know more about the atom bomb than any other British scientist', making him the most likely candidate to head the project.

When the bomb was dropped on Nagasaki, Penney was in the observer plane with a specially adapted camera to take photographs, in the hope of estimating the size of the bomb, but cloud over the city prevented him. Penney and the other British observer, Group Captain Leonard Cheshire, had wanted to fly in the observer plane over Hiroshima but had been prevented by the local US commander.

So keen were the Americans on Penney that they invited him to attend their first post-war atom bomb tests, an operation called Crossroads, at Bikini Atoll in the Pacific Ocean in 1946. At these tests, in July that year, he was given the title Coordinator of Blast Measurement.

With all this useful experience, Penney was the natural choice to run Britain's post-war bomb project. He was given the task of designing, building and testing the bomb in May 1947, more than two years before the USSR startled the world by testing the first Russian bomb. Leonard Bertin, who interviewed Penney for his book on the early years of the British nuclear
programme, published in 1955, was troubled by an incongruity between Penney's personal charm and the work he was doing: ‘With his boyish face, blue eyes, tousled, sandy hair and ingenuous smile, he looks the last person in the world to develop a fearful weapon of destruction.'