The World and Nuclear Fission

Purely as a physical phenomenon nuclear fission offers ample scope for intellectual
problem-solving. If it implied nothing further it could be left to those specialists who
might find satisfaction in its intellectual challenge; the rest of us could busy ourselves
with other more pressing concerns. Unfortunately, nuclear fission  - as everyone knows  -
implies much more than abstruse mathematical argument and donnish hairsplitting.
Almost from the time it was first recognized, in 1938, nuclear fission has implied not
merely articles in learned journals but major decisions of public policy. The social,
economic and political context of nuclear fission has been from the beginning an
essential factor in its development; in turn, it has exerted an extraordinary range of social,
economic and political influence. To foresee with any clarity the shape of the nuclear
future, a historical perspective is imperative. It is necessary to know not only how nuclear
fission occurs, but also who makes it occur, under what circumstances and for what
purposes. We have already alluded, in a preliminary way, to these aspects of the subject.
It is now time to step back and examine them in much more detail. As we shall see,
nuclear activities from the outset have been characterized by unpredictability and secrecy.
Throughout nuclear history, either too little has been known, or enough has been known
but too little said.
In 1896, Henri Becquerel discovered radioactivity. Shortly after, by carrying a vial of
radium in his pocket and burning himself, he also discovered the most troublesome
attribute of radioactivity: its biological effects, actual and potential. An episode which
occurred more than fifty years later characterizes the situation that has prevailed since
Becquerel's discoveries. Interested organizations were debating the design of an
international symbol to convey the warning 'DANGER: RADIATION'. One group of
participants, including labour union representatives, favoured the design of a grinning
skull with an aura of wavy lines emanating from it. But spokesmen for government and
industry groups flatly refused to sanction such a design, which they considered too
frightening. As a result the design finally adopted was a circle with three leaves fanning
out from it  - intelligible  only to those to whom it has been explained beforehand, and
utterly devoid of prior associations, either benevolent or malevolent.
This is a succinct instance of the schism which divides viewpoints about radiation. As
indicated earlier the very biological essentials of the issue are hotly controversial,
increasingly so; but we shall confine discussion of them mainly to Appendix B. What is
in some ways yet more controversial is the developing social context of radiation,
especially that produced by radioactivity. (A good case can be made for concern about
other forms of ionizing radiation, especially diagnostic  X-rays; but we shall here
comment only that diagnostic X-rays should be used only when clearly indicated by 76
medical evidence, and should be generated only by well-shielded apparatus for as brief an
exposure as possible.) Before plunging into the tumult of nuclear controversy it is
important to stress - since it may later be easy to overlook  - that the main health problem
is that created by radiation; that the radiation is inherently invisible and detectable only
by special instruments; that different forms of radiation present different hazards (see
Appendix B); and that the deleterious result of exposure to radiation may not manifest
itself for many years. For these reasons it is far from easy to be confident of
understanding the effects of radiation. Accordingly, human undertakings involving
radioactivity may be peculiarly difficult to evaluate from a public-health standpoint. They
may also, as we shall see, be difficult to evaluate by a variety of other criteria, not least
the economic.
After Becquerel's discovery came those by Pierre and Marie Curie, who isolated from the
uranium ore pitchblende the powerfully radioactive elements polonium and radium. It
now appears that the Curies were, paradoxically, fortunate in their poverty. Their
laboratory was a draughty attic, and its otherwise undesirable ventilation probably saved
Marie Curie from an early death brought on by inhalation of radon from her experimental
materials. (The draughty attic did not save her husband, who died of quite another
technology, under the wheels of a cart in a Paris street.)
Scientific fascination with the newly discovered radioactive substances was almost at
once paralleled  by a search for practical application. Roentgen's X-rays were, within
months of their discovery, applied in medicine; but within three years the X-rays - which
of course required apparatus to generate them - were meeting competition from the
radiation of radium and its relatives. Alas for the early successes of radiotherapy: its
pioneers, and Marie Curie herself, were among the first to experience the insidious
delayed consequences of radiation. So were their patients, some of whom died not from
cancer or other afflictions but from radiation burns inflicted with the aim of healing.
Radium became for a time a fashionable material. 'Radium spas' were suddenly
successful in several parts of Europe, and doctors prescribed medicines containing
radium. There was also a vogue for 'luminous dial' wristwatches; the digits on the watch
faces were painted over with a mixture of zinc sulphide and radium, and glowed in the
dark. The women who worked in the watch factory used fine brushes to apply this
luminous paint: and to give a brush a suitably pointed tip its user would lick it. In due
course almost all the 'luminizers' fell sick, with bleeding gums and anaemia, and
eventually most developed bone sarcoma - cancer of the bone - from the accumulation of
radium in their bodies. A small New jersey plant alone produced more than forty victims
from staff employed between 1915 and 1926.
The radium which now seemed so ubiquitous was being produced from mines like the old
silver mine of Joachimsthal, whose uranium ore gave it a  new lease of life. But the
miners of Joachimsthal, as we have described, were prone to  Bergkrankheit - lung cancer,
induced by inhalation of radon and radon daughters. Medical detective work had by 1930
identified the genesis of this disease, and made clear that it could be prevented only by
ensuring thorough ventilation of underground uranium mines, a lesson which was to be
callously ignored in the American uranium rush of the 1950s. There was, throughout the 77
1920s, a growing awareness among medical researchers, biologists, and radiation
workers themselves that radiation had some unpleasant attributes. But there was,
throughout this time, no particular public concern, and no general sense of controversy
about radioactive materials and their uses. It was as if the controversy over radiation had
an even longer latency period than radiogenic disease.
From 1939 to 1945, there was neither opportunity nor inclination to question the
circumstances which might arise in the manufacture and use of radioactive materia ls: no
opportunity, because most of the frantic effort then occurring was under strict conditions
of secrecy, and no inclination, because those involved were preoccupied with the much
more immediate and pressing fear that Nazi Germany would achieve nuclear
weapons-technology first. As all the world now knows, the Nazis did not. The USA
achieved the technology and the weapons, and used them, bringing an abrupt and
devastating end to the Second World War.
In the aftermath of the Hiroshima and Nagasaki bombs, the US government set up the
Atomic Bomb Casualty Commission. Its function was dual. It was - so far as the Japanese
victims were concerned  - a source of medical aid for those who had survived the nuclear
explosions but had already suffered or might subsequently suffer from the effects of the
radiation. It was also  - so far as the USA was concerned  - an agency which could carry
out a large-scale study and documentation of the effects of radiation on human beings. As
may be apparent the two roles were not wholly compatible. Many Japanese grew to
resent deeply the role which they felt they were being forced to play, as guinea-pigs for
the further enlightenment of the world's first and only user of nuclear weapons.
Nonetheless the US medical researchers studying radiation effects also found
opportunities closer to home. Fifteen days after the Hiroshima bomb, on 21 August 1945,
Harry Daghlian, a physicist at Los Alamos, accidentally allowed a sample of fissile
material to reach criticality when he was handling it. His hands and body were raked by a
massive burst of radiation, gamma rays and neutrons. Admitted to hospital within half an
hour, Daghlian lost sensation in his fingers, then complained of internal pains and finally
became delirious. His hair fell out. His white blood cell count surged as his shattered
tissues tried vainly to cope. It took him twenty-four days to die.
Daghlian's death brought home to the entire Los Alamos community the grim ethical
conflict in which nuclear physicists - the 'atomic scientists' - now found themselves. It is
worth stressing, some forty years later, that the first to recognize the dilemma of nuclear
energy - the conflict between its constructive and destructive potentials - were the nuclear
scientists themselves.
Even before the dropping of the Hiroshima bomb a group of those who had helped to
create it signed a memorandum subsequently known as the Franck report, submitted to
the US Secretary of War on 11 June 1945, forecasting with dismaying accuracy the
nuclear arms race, in the event of the use of the bomb against a military target. James
Franck and his colleagues proposed instead that the bomb be demonstrated in a remote
site, desert or island, before representatives of Japan and of the allied United Nations, and 78
that the USA renounce its use thence forth, provided that the rest of the nations of the
world agreed to do likewise. But the Franck proposals, as the world knows, fell on stony
ground - unlike the Hiroshima and Nagasaki bombs. Later in 1945 the initiators of this
report, with colleagues similarly concerned, founded the Bulletin of the Atomic Scientists.
Since its inception the Bulletin,  published in Chicago, has remained one of the most
perceptive and committed voices addressing nuclear controversy of every kind.
On 21 May 1946 Louis Slotin, a Canadian physicist working at Los Alamos, was
performing an exercise he called 'twisting the dragon's tail'. He had done the operation
many times, while determining experimentally the details of fast critical assembly of the
hemispheres of uranium-235 which had to slam together to produce the desired nuclear
explosion. In this way Slotin had determined experimentally the critical mass for the
Hiroshima bomb. Slotin's exercise involved sliding the two hemispheres gradually
towards one another along a rod, using two screwdrivers, and watching the neutron
detectors display the build-up to criticality. On 21 May he was showing the phenomenon
to a group of a half-dozen colleagues, when the screwdriver slipped. The room was filled
with blue light. Slotin tore the hemispheres apart with his bare hands, and in so doing
probably saved the lives of his colleagues. But he himself was doomed, and knew it. He
died nine days later, his terminal sickness being meticulously charted by otherwise
helpless medical staff. Slotin's Los Alamos colleagues were forbidden for security
reasons to alter their daily routine or reveal anything about the accident, while they
witnessed his lingering death.
The assembly that killed Louis Slotin was earmarked for the second bomb in a pair of
weapons tests which the US Navy was preparing to carry out at Bikini atoll in the
Marshall Islands. The Marshall Islands had been before the Second World War a German
protectorate; this responsibility was taken over by the USA at the end of the war, but the
'protection' thereafter given sounds reminiscent of the 'protection' referred to by
racketeers. Tests 'Able' and 'Baker' were carried out 30 June and 25 July 1946. 'Able' was
an atmospheric nuclear explosion, 'Baker' one deep underwater in Bikini's lagoon. Both
drew bitter protests from many scientists, notably the Federation of Atomic Scientists, a
newly formed federation of local groups of scientists concerned about the implications of
their work; subsequently it became the Federation of American Scientists, and in the
1980s is still deeply involved in and outspoken about nuclear issues. It was said that the
US Navy staged the Bikini tests primarily to show that the Army was not the only branch
of the military with nuclear capability. About 42 000 onlookers arrived in 250 ships and
150 planes - military, media, politicians, diplomats, plus additional thousands of
scientists with a piece of the action. Scientists not thus involved insisted that the tests
would serve little genuine experimental purpose, and that they would appear as mere
sabre-rattling while the UN grappled with the problem of international control of nuclear
technology. To them and many others the whole business looked like a grisly public
relations exercise to show off the USA's latest accomplishment.
Whatever their raison d'etre, the Bikini tests had an aspect which the public did not learn
at the time. In order to clear the necessary room for their activities, the US Navy in
March 1946 unceremoniously evicted 167 Marshall Islanders from Bikini, transporting 79
them to Rongerik, another island many kilometres distant, with much poorer vegetation,
soil and fishing, making expansive promises to the evicted islanders which were
thereafter quietly forgotten. The Navy repeatedly assured the islanders that all would
soon be able to return to their homes. What they did not add was that the 1946 tests
played havoc with the fertile lagoon of Bikini, leaving it full of radioactive mud and
making marine life for more than 150 kilometres unsafe to eat. Not until  1968 were the
first nine islanders permitted to return to Bikini, to an island altered almost beyond
recognition by the nuclear explosions and their after-effects. The mangled ruins of US
weapons sheds and towers loomed out of the overgrowth. The new vegetation was coarse
and unproductive; even the coconut crabs, huge tree-climbing crustaceans looked upon as
a Marshall Island delicacy, had accumulated so much strontium-90 in their shells that the
islanders had to  be forbidden to eat them. Nevertheless by 1980 the islanders themselves
had so much radioactivity in their bodies that they were once again removed from the
islands. US authorities were forced to admit that the atoll might not be safe for human
habitation  for a century or more. The first Bikini tests were called, grandiloquently
'Operation Crossroads'. For the Marshall Islanders they must have looked more like a
dead end.
No sooner had the Hiroshima and Nagasaki bombs brought a stunning conclusion to the
Second World War than the first manifestation of nuclear paranoia became manifest. The
bombs had of course been made through a combined effort of US, British and Canadian
scientists and engineers; but the Manhattan Engineer District  - code name given to the
bomb-development project - had all its major facilities in the USA. By midsummer 1945
the Americans had virtually taken over the project, including its direction and, more
importantly, the information it generated. Only days after the Nagasaki bomb a  bill was
presented to Congress whose ultimate effect, as the Atomic Energy Act of 1946  - the
McMahon Act  -  was to make it illegal for Americans thenceforth to give their erstwhile
allies any further access to information about nuclear energy. Top-level  discussions,
including those between the three heads of government, were contradictory in content
and inconclusive in outcome. Eventually the three wartime partners embarked on separate
programmes. The evanescent hopes for effective international control of nuclear energy
were stillborn. Instead, with the American weapons tests at Bikini, beginning in 1946,
and the first Soviet atomic bomb test in 1949, the nuclear arms race began. It has seemed
ever since to be a race that no one will win.
The McMahon Act was not at the time regarded even by British and Canadian scientists -
much less their American colleagues - as a particularly unfortunate step. The scientists, it
is true, realized too late the Act's divisive implications. But it was initially hailed as a
victory for rationality, in that it specifically overrode any military claim to control of
nuclear developments, Instead, the McMahon Act established two civilian bodies to
exercise this responsibility and control: the US Atomic Energy Commission (AEC) and
the Congressional Joint Committee on Atomic Energy (JCAE). The Act gave the AEC
complete control over the funding and direction of post-war nuclear research and80
development, military and otherwise. The JCAE was to be the Congressional watchdog
over the AEC, the channel through which the elected representatives of the public would
monitor and oversee American activities in the nuclear field.
The McMahon Act brought an immediate order into the post-Nagasaki nuclear situation,
within the USA at any rate. On 1 January 1947 the AEC came formally into being. It
qualified for a healthy slice of the Federal budget, and took over all the facilities
established for the Manhattan Project; from that date onwards the American nuclear
effort assumed a new dimension.
The AEC's fundamental responsibility was of course development of more powerful and
efficient nuclear weapons, and provision of the infrastructure to build them in quantity.
Undoubtedly the fiercest controversy in the early years of the AEC centred on whether or
not to pursue development of a new form of nuclear weapon, long referred to simply as
the 'Super'. There is a limit to the amount of fissile material that can be slammed together
efficiently into a prompt critical configuration. Accordingly there is  a limit to the energy
release possible in a pure fission bomb. Since this energy release is equivalent to that of
several hundred thousand tonnes of TNT - several hundred 'kilotons' - it might be thought
sufficient for most purposes; but Soviet and American weapons designers thought
otherwise.
At least some of them did. Robert Oppenheimer, the brilliant wartime director of the Los
Alamos Laboratory, thought the Super was ill-advised, and made no secret of his opinion;
in due course this was made the basis  of one of the shoddiest episodes in American
scientific history, the 'trial' of Oppenheimer in April 1954 which permanently deprived
him of access to the nuclear information he had been instrumental in developing. The
Oppenheimer case underlined an AEC attitude which was to persist long after AEC
interest had diversified into civilian applications of nuclear energy. One of the
extraordinary powers granted by the McMahon Act permitted the AEC to call upon the
services of branches of the Executive  - such as the FBI and the CIA. The AEC spent
millions every year on exhaustive vetting of employees, nominally for reasons of
'national security'; and the AEC's control of access to information established a pattern
that was subsequently difficult to break, even in contexts to all appearances non-military.
The principle of the Super was straightforward. If a fission bomb is surrounded with
material containing nuclei of heavy hydrogen - deuterium, or, better still, tritium
(hydrogen 3, with one proton and two neutrons in its nucleus) - the ferocious energy of
the fission blast speeds up the light nuclei so that they collide and stick together as helium
nuclei. Each 'fusion' of two hydrogen nuclei into a helium nucleus releases a burst of
neutrons and additional nuclear energy once again, mass is converted into energy.
Since there is no immediate upper limit on the amount of 'fusible' material that can be so
triggered, the energy release of a fission-fusion or 'thermonuclear' bomb - more
commonly known as a hydrogen bomb - is effectively unlimited. Further improvements -
if that is the correct word - are also possible. The fusion reaction, like the fission reaction, 81
releases free fast neutrons. Accordingly, a triple-decker bomb can be made: a fission
bomb surrounded by fusible hydrogen surrounded by ordinary uranium - much cheaper
than heavy hydrogen, and unlimited by criticality considerations. The outer layer of
uranium intercepts the barrage of neutrons from within it and undergoes fission, adding
yet more energy to the total  - and, incidentally, adding also a further enormous quantity
of fission products, far more than those from the small fission 'trigger'.
Through the late 1940s and into the early 1950s one overriding concern dominated
nuclear controversy: the accelerating arms race between the USA and the Soviet Union,
and the pursuit of the fusion weapon. Espionage, counter-espionage and the Cold War
climate made nuclear secrecy and nuclear secrets a fountainhead of collective paranoia.
Whatever the effect of the McMahon Act within the USA, the erstwhile partners of the
USA took it as an act of betrayal. The fury and resentment it engendered still linger in the
upper echelons of the UK and Canadian nuclear communities. Even the official US
announcement of the Hiroshima bomb was regarded in the UK as taking too much of the
credit (if such it was) for the USA; on 6 August 1945 the UK Prime Minister issued a
stiff statement pointing out the key roles played by the UK and Canadian contributors to
the Manhattan project. However, once the initial grievance had been at least suppressed,
the UK and Canadian governments reacted quite differently. The Canadians decided that
Canada neither wanted nor could build nuclear weapons. The UK scientists who had been
engaged at the Montreal laboratory of the wartime project were recalled to the UK -
indeed the Canadians felt somewhat as though, having constructed substantial
installations, they were being left holding an expensive and useless bag. We shall return
to the Canadian effort shortly.
In the UK, the McMahon Act rankled deeply, and it was never seriously doubted that the
UK must thereupon embark on her own nuclear-weapons programme. The UK public  -
and that includes almost all of Parliament  - knew, it must be said, virtually nothing of
this. Only a passing reference on 12 May 1948, in a House of Commons answer by the
Minister of Defence, gave any indication of the furious activity then under way:
'Research and development continue to receive the highest priority in the defence field,
and all types of weapons, including atomic weapons, are being developed.' That was all;
the Minister would not elaborate, since it was 'not in the public interest' to do so. The
organization given the task of developing UK nuclear weapons was the Division of
Atomic Energy Production, Ministry of Supply, eventually to become the United
Kingdom Atomic Energy Authority (UKAEA).
In only two and a half years the Production Division had completed the Springfields
uranium and fuel fabrication plant; the first Windscale pile loaded with Springfields fuel
went critical in July 1950. At this time the construction of the reprocessing plant had not
even begun; the first irradiated fuel entered the reprocessing plant in late February 1952.
On 3 October 1952 the first UK nuclear bomb vaporized the frigate Plym in the waters of
the Monte Bello Islands just off the northwestern coast of Australia
Several nations besides the UK, the USA and Canada had an early foothold in nuclear
matters. Germany, Poland, Hungary and  other eastern European countries were the 82
origins of many of the scientists who took their abilities to the UK and the USA after the
advent of the Nazis - and, to be sure, of some who did not. French scientists participated
in the wartime deliberations that led to the Manhattan project. Norway had the Vemork
heavy water production plant  - until it was blown up by Norwegian partisans in 1943.
The Soviet Union was keenly interested in nuclear matters well before the Second World
War.
Of these nations the first to embark on a serious nuclear research and development
programme was the Soviet Union. Like every other nation then and since, the Soviet
Union regarded nuclear matters as government matters, not to be left to industry or
academia. In 1943, even as invading Germany was well inside Soviet borders, the Soviet
government set up a nuclear weapons research institute in Moscow, directed by Igor
Kurchatov, and later to bear his name. The Soviet nuclear programme was fully as
intense as that of the Americans,  leading to a fission bomb in August 1949, and a
thermonuclear bomb four years later to the month.
In 1950,  when President Truman gave the go-ahead for US development of the Super,
another huge AEC facility was established: the Savannah River complex in South
Carolina, with more plutonium production reactors (this time moderated by heavy water),
a full-fledged reprocessing plant, waste storage, the lot. But the Super remained elusive.
The Americans are commonly credited with having detonated the first thermonuclear
explosion on Enewetak in the Marshall Islands, on 1 November 1952, but it was in no
sense an 'H-bomb'. It was an explosion of a large-scale experimental installation, nearly
60 tonnes of delicate equipment; it could no more be dropped on an enemy than could an
entire factory. The Soviet thermonuclear explosion of 12 August 1953 was a true
H-bomb, portable and droppable. At least a sizeable part of the AEC had other things on
their minds when on 8 December 1953 President Eisenhower delivered a major  address
to the UN proposing a programme of 'Atoms for Peace'.
On 1 March 1954, in the long-suffering Bikini atoll in the Marshall Islands, the US
detonated its first  H-bomb, designated Castle Bravo. They expected an explosion
equivalent to 7 million tonnes - megatons  - of TNT. They got one equivalent to 15
megatons. An American destroyer found itself in the path of the radioactive dust; its crew
responded by carrying out radiation drill, battening hatches, stationing all hands below
decks and waiting until fixed hoses had cleansed the contamination off the exterior
surfaces of the ship. But no one had told 236 inhabitants of Rongelaap, Rongerik, and
Uterik in the Marshall Islands, and twenty-three Japanese crew members of a fishing
vessel called the Fukuryu Maru, anything about radiation drill.
Uterik, Rongerik and Rongelaap are about 160 kilometres east of Bikini. But wind, in a
direction not anticipated by the weapons testers, carried the bomb debris all the way to
the other three islands. On 11 March the AEC issued a press statement:
'During the course of a routine atomic test in the Marshall Islands twenty-eight United
States personnel and 236 residents were transported from neighbouring atolls to83
Kwajalein island according to plan as a precautionary measure. These individuals were
unexpectedly exposed to some radioactivity. There were no burns. All were reported well.
After the completion of the atomic tests, the natives will be returned to their homes.'
Roger Rapoport, a perceptive American reporter, has noted drily (see Bibliography), that
the evacuations were indeed according to 'plan', but that the plan was not devised until
after the accident occurred:
The victims sustained beta burns, spotty epilations of the head, skin lesions, pigment
changes and scarring. And many of the natives did not feel well at all. They suffered from
anorexia (appetite depression), nausea, vomiting and transient depression of the formed
elements in their blood. Over the next sixteen years twenty-one of the natives on
Rongelaap island would develop thyroid abnormalities and thyroidectomies would be
conducted on eighteen of them, All but two of the nineteen children who were less than
ten years old when the accident happened developed thyroid abnormalities; and two of
them were dwarfed for life.
For three years after Castle Bravo, Rongelaap remained too radioactive for the islanders
to return.
The intervention of the US Navy helicopter service to Kwajalein undoubtedly served a
double purpose so far as the stricken Marshall Islanders were concerned. It brought them
much needed medical attention; it also ensured that this attention was not accompanied
by other attention potentially more embarrassing to the weapons testers. The US Navy
did not know, however, that its patrol aircraft had overlooked a Japanese fishing boat, the
Fukuryu Maru.  The  Fukuryu Maru  was trawling for tuna east of Bikini on 1 March,
beyond the perimeter of the delineated test zone, when it suddenly seemed to the
fishermen as though the sun were rising in the west. Within a few hours the boat was
dusted with white ash, sifting down on to the decks, and over the hair and clothing of the
crew. By evening two of the crew were vomiting, and overcome by dizziness. By 3
March others were suffering similar symptoms, with aching eyes and itching skin. There
was clearly something wrong. The fishing boat turned and made for its home port of
Yaizu. It arrived a fortnight later, with all hands suffering from radiation sickness, and
the boat still contaminated with radioa ctivity. Six months later some of the crew were
still in hospital. On 23 September 1954 the radio operator, Aiticki Kuboyama, died.
The fate of the  Fukuryu Maru made headlines all over the world. The irony of its name  -
translated, it means Lucky Dragon  - gave  an additional twist to the grim saga. The
Japanese had been the first victims of the atomic bomb; now it could be said that a
Japanese was the first to die from the effect of a hydrogen bomb. The traumatic jolt of the
Fukuryu Marti incident reinforced the profound psychological revulsion with which the
Japanese regarded nuclear energy. Some four decades after the Hiroshima and Nagasaki
bombs, and three decades after the Fukuryu Maru, the Japanese distrust of nuclear energy
remains as deep-seated as ever.84
The radioactive return of the Fukuryu Maru  alerted the world, with stunning impact, to
the phenomenon of 'radioactive fall-out'. Only a month later, in April 1954, India called
for a standstill on nuclear weapons tests; needless to say the call drew little response. In
1955, the UN General Assembly adopted a resolution establishing a scientific committee
to inquire into the effects of radiation and nuclear tests, the UN Scientific Committee on
the Effects of Atomic Radiation (UNSCEAR). But the jockeying between the
nuclear-weapons testing powers continued unabated, as did the tests and the fall-out, and
the efforts of scientists and the public to bring some sense into the proceedings. Bertrand
Russell drafted an appeal, co-signed by Albert Einstein two  days before his death, which
became known as the Russell - Einstein Manifesto. It called upon scientists of all nations
to unite to seek a way out of the impasse to which nuclear discoveries had brought
mankind. Professor Joseph Rotblat, who had left Los Alamos when it became clear that
Nazi Germany could not manufacture nuclear weapons, undertook the organization of
such an unofficial scientific conference. An American millionaire agreed to play host to
the first gathering, at his birthplace in Pugwash, Nova Scotia. The Pugwash movement
grew from this first meeting into one of the most effective and influential international
avenues of contact between leading scientists of the USA, the Soviet Union, and other
countries, its central objective was  - and remains - to devise ways to control nuclear
developments, to reduce the unparalleled threats they entail.
By 1956 the AEC was willing to concede that if an animal - say a cow  - eats grass
sprinkled with strontium-90, chemically similar to calcium, not only its bones but also its
milk contains the radioisotope. The AEC belatedly agreed that milk was much the most
significant source of strontium-90 in the human diet. In 1957 the AEC Biological and
Medical Advisory Committee concluded, contrary to earlier AEC assertions, that fall-out
from nuclear tests to the end of 1956, far from being devoid of genetic significance,
already seemed likely to produce between 2500 and 13 000 major genetic defects per
year in the global population. Meanwhile scientists outside the AEC were pinpointing
troublesome radioisotopes which the AEC had either failed to take seriously or ignored
completely  - radioisotopes like carbon-14 and iodine-131. AEC fall-out surveys, it
became evident, usually missed iodine-131 completely, because of its short eight-day
half-life, despite the fact that iodine-131 would be concentrated, like all iodine isotopes,
in the human thyroid, and might therefore do damage (especially to children) far out of
proportion to its concentration in the external surroundings.
In 1957, largely as a result of pressure from the public and the scientific community
outside the AEC, the US Public Health Service instituted a fall-out monitoring system,
which soon expanded into a widespread network taking frequent samples; before long
these fall-out monitors had identified strontium-89 and 0, iodine -131 and other hazardous
radioisotopes in quantities copious enough to be far from reassuring. Ralph Lapp's classic
study  The Voyage of the Lucky Dragon  demonstrated that the AEC was anything but
scrupulous in its stewardship of the public welfare.
From the mid-1950s onwards, as a result of the fall-out issue, the world's public began to
pay much closer and more critical attention to the activities of the nuclear authorities. 85
Public concern increasingly encompassed not only nuclear weapons but also the
mounting official enthusiasm for civil nuclear power.
President Eisenhower's proposal of 'Atoms for Peace' presaged yet a further
transformation in the American nuclear scene. A new Atomic Energy Act in 1954 made it
possible for private contractors to build reactors and to possess fissile material under
licence from the AEC, and declassified a variety of useful information. However the
short-term prospects for nuclear electric power generation did not look very enticing to
US industry. The technology was certainly promising, and reasonably hard-headed
estimates of probable generating costs would have been persuasive, but for the prevailing
low costs of oil and - even more competitive - the surging abundance of indigenous
natural gas and coal.
There was little doubt that power reactors of several designs could be built, and that they
would indeed generate electricity at a cost which was not unreasonable. But only the
most sanguine anticipated that power reactors could compete economically in the USA
with fossil-fuel generating units before the mid-1960s. On the other hand, it was clear
that if this new technology were to establish itself it could not be expected to be
economically viable from birth. The AEC accordingly began to draw up plans for a
Cooperative Power Reactor Development Project, and US industry began to show
tentative signs of interest. The US superiority in nuclear experience and resources gave
them an embarrassment of choices when it came to civil applications, but that same
wealth of resources also made the economic context unpropitious. The UK situation was
precisely the reverse. Their straitened circumstances meant that they had to focus their
efforts within a very narrow range of technology. But the context of postwar European
economics, with limited supplies of other fuels available, at moderately stiff prices,
meant that power production by nuclear means looked appetizing. By the late 1940s the
British Atomic Energy Resea rch Establishment at Harwell was attacking with gusto the
design problems posed by power reactors.
In August 1952 the military Chiefs of Staff issued a call for greatly increased production
of weapons-plutonium. A power reactor producing plutonium as a byproduct would for
the nonce have to be regarded as a plutonium reactor producing power as a by-product.
Designs for such a dual-purpose reactor had already been undertaken, labelled 'Pippa'
('pressurized pile producing power and plutonium'). Apart from the transposition of the
last two items, 'Pippa' was, in March 1953, given the go-ahead. We know it now as the
first Calder Hall reactor. In some respects its design was Hobson's choice  - neither
sufficient enriched uranium nor sufficient heavy water could be guaranteed for otherwise
more desirable designs, and the fast breeder did not come into the category of production
reactor for short term purposes. But a long and thoughtful study of the economic status of
a natural uranium power reactor was already extant, prepared by R.V. Moore of Harwell
in the early autumn of 1950, comparing the performance of a 90-MWe nuclear station
with that of a similar coal-fired station. It identified the essential basis of this economic
comparison, which was to become a perennial: coal involves low capital costs and high
running costs, whereas nuclear power involves high capital costs and low running costs.
Moore's analysis showed that the crossover point, at which nuclear electricity from 86
natural uranium became cheaper per unit than coal-fired, was well within attainable
nuclear criteria.