Glasstone's errors in The Effects of Nuclear Weapons, and the strategic implication for deterrence. Realistic effects and credible nuclear weapon capabilities for deterring or stopping aggressive invasions and attacks which could escalate into major conventional or nuclear wars.

Monday, January 08, 2007

Censored information from The Effects of Nuclear Weapons

'On the one hand, a strong point can be made for the fact that civil defense, appropriate civil defense, would save a great many lives; on the other hand, one can also make a strong case that any civil defense, appropriate or otherwise, may increase the danger of a war because people will feel that they don't have to avoid it because they have civil defense.'

- Dr Frank Fremont-Smith, director of the New York Academy of Sciences Interdisciplinary Communications Program, Proceedings of the Second Interdisciplinary Conference on Selected Effects of a General War, DASIAC Special Report 95, July 1969, vol. 2, DASA-2019-2, AD0696959, page 281.

On this blog you will find links to online versions of the 1957 and 1977 editions of The Effects of Nuclear Weapons, by Glasstone and Dolan, U.S. Department of Defense. But you won't find any links to the longest version of the book, the 1962/4 edition, which will be quoted and discussed at length below. Here is the Foreword, written and signed by the U.S. Secretary of Defense Robert S. McNamara and the U.S. Atomic Energy Commission Chairman Glenn T. Seaborg (both appointed by Kennedy), to the 1962/4 edition:

'This book is a revision of The Effects of Nuclear Weapons which was issued in 1957. It was prepared by the Defense Atomic Support Agency of the Department of Defense in coordination with other cognizant government agencies ... Although the complex nature of nuclear weapons effects does not always allow exact evaluation, the conclusions reached herein represent the combined judgement of a number of the most competent scientists working on the problem.

'There is a need for widespread public understanding of the best information available on the effects of nuclear weapons. The purpose of this book is to present as accurately as possible, within the limits of national security, a comprehensive summary of this information.'

The major part which was deleted in the 1977 edition was the final chapter (Chapter 12), Principles of Protection, which on page 631 (1962/4 edition) states:

'At distances between 0.3 and 0.4 mile from ground zero in Hiroshima the average survival rate, for at least 20 days after the nuclear explosion, was less than 20 percent. Yet in two reinforced concrete office buildings, at these distances, almost 90 percent of the nearly 800 occupants survived more than 20 days, although some died later of radiation injury.

'Furthermore, of approximately 3,000 school students who were in the open and unshielded within a mile of ground zero at Hiroshima, about 90 percent were dead or missing after the explosion. But of nearly 5,000 students in the same zone who were shielded in one way or another, only 26 percent were fatalities. ... survival in Hiroshima was possible in buildings at such distances that the overpressure in the open was 15 to 20 pounds per square inch. ... it is evident ... that the area over which protection could be effective in saving lives is roughly eight to ten times as great as that in which the chances of survival are small.'

Page 645 (1962/4 edition) provides definite ideas:

'The major part of the thermal radiation travels in straight lines, so any opaque object interposed between the fireball and the exposed skin will give some protection. This is true even if the object is subsequently destroyed by the blast, since the main thermal radiation pulse is over before the arrival of the blast wave.

'At the first indication of a nuclear explosion, by a sudden increase in the general illumination, a person inside a building should immediately fall prone, and, if possible, crawl behind or beneath a table or desk or to a planned vantage point. Even if this action is not taken soon enough to reduce the thermal radiation exposure greatly, it will minimise the displacement effect of the blast wave and provide a partial shield against splintered glass and other flying debris.

'An individual caught in the open should fall prone to the ground in the same way, while making an effort to shade exposed parts of the body. Getting behind a tree, building, fence, ditch, bank, or any structure which prevents a direct line of sight between the person and the fireball, if possible, will give a major degree of protection. If no substantial object is at hand, the clothed parts of the body should be used to shield parts which are exposed. There will still be some hazard from scattered thermal radiation, especially from high-yield weapons at long ranges, but the decrease in the direct radiation will be substantial.'

A person on the ground whose clothes ignite (which is only a risk under extremely high thermal exposure to dark coloured clothing) can immediately extinguish the clothes by simply rolling over to starve the flames of oxygen.

Page 653 (1962/4 edition) correctly explains:

'Some, although perhaps not all, of the fallout in the Marshall Islands, after the test explosion of March 1, 1954, could be seen as a white powder or dust. This was due, partly at least, to the light color of the calcium oxide or carbonate of which the particles were mainly composed. It is probable that whenever there is sufficient fallout to constitute a hazard, the dust will be visible.'

Page 658 (1962/4 edition) shows how to deal with fallout on food and water:

'If emergency food supplies do become contaminated, or if it is necessary to resort to contaminated sources after emergency supplies are exhausted, many types of food can be treated to remove the radioactive material. Fresh fruit and vegetables can be washed or peeled to remove the outer skin or leaves. Food products of the absorbent typecannot be decontaminated in this manner and should be disposed of by burial. Boiling or cooking of the food has no effect in removing the fallout material. Milk, from cows which survive in a heavily contaminated area, may not be safe to drink because of the radioiodine content and this condition may persist for weeks or months.

'Domestic water supplies from underground sources will usually remain free from radioactive contamination. Water supplies from surface sources may become contaminated if watersheds and open reservoirs are in areas of heavy fallout. However, most of the radioactive fallout material would be removed by regular water treatment which includes coagulation, sedimentation, and filtration. If a surface water supply is not treated in this manner, but merely chlorinated, it may be unfit for consumption for several days after an attack. As a result of dilution and natural decay the contamination will decrease with time.

'If the regular water supply is not usually subjected to any treatment other than chlorination, and an alternative source is not available, consideration should be given in advance planning to the provision of ion-exchange columns or beds for emergency decontamination use. Home water softeners might serve the same purpose on a small scale. The water contained in a residential hot-water heater would serve as an emergency supply, provided it can be removed without admitting contaminated water. Water may also be distilled to make it safe for drinking purposes.
It should be emphasized that mere boiling of water contaminated with fallout is of absolutely no value in removal of the radioactivity.'

Decontamination of streets, buildings and farm land is discussed on page 659 (1962/4 edition):

'Because of its particulate nature, fallout will tend to collect on horizontal surfaces, e.g., roofs, streets, tops of vehicles, and the ground. In the preliminary decontamination, therefore, the main effort should be directed toward cleaning such surfaces. The simplest way of achieving this is by water washing, if an adequate supply of water is available. The addition of a commercial wetting agent (detergent) will make the washing more efficient. The radioactive material is thus transferred to storm sewers where it is less of a hazard [underground drains are well shielded from people]. ... if facilities are to be provided across open country which is contaminated over large areas, bulldozing the top few inches of contaminated soil to the sides will be satisfactory only if a wide strip is cleared. Thus, if the strip is 250 feet in width, the radiation dose rate in the middle will be reduced to one-tenth of the value before clearing. A similar result may be achieved by scraping off the top layer of soil and burying it under fresh soil. Something like a foot of earth cover would be required to decrease the dose rate by a factor of ten.'

The final page of Chapter 12, page 661 (1962/4 edition), has a Conclusion which states:

'Much of the discussion presented in earlier sections of this chapter have been based, for simplicity, on the effects of a single nuclear weapon. It must not be overlooked that in a nuclear attack some areas may be subjected to several bursts. The basic principles of protection would remain unchanged, but protective action against all the effects of a nuclear weapon - blast, thermal radiation, initial nuclear radiation, and fallout - would become even more important. There is a good possibility that many people would survive a nuclear attack and this possibility would be greatly enhanced by utilizing the principles of protection in preattack preparations and planning in taking evasive action at the time of an attack, and in determining what should be done in the recovery phase of an attack.'

There is also some important censored information in the earlier June 1957 edition of The Effects of Nuclear Weapons, which is available online (see pages 514-517 of the 1957 edition): on page 514-5 three photos of successful Japanese 'blast-shielding walls' at Nagasaki which stopped damage from the nuclear explosion are shown. These walls are about 10 feet tall, and are wider at their base than at their top to avoid overturning by blast. They are made out of either precast reinforced concrete or earth-filled wooden panels. Both types fully protected vital Japanese machinery, such as electrical transformers, at 0.85 mile from ground zero in Nagasaki. Pages 516-7 of the 1957 edition shows photos of unprotected earth-moving equipment (bulldozer and road grader) badly damaged by 30 psi peak overpressure in a Nevada test: the road grader has lost tyres and the bulldozer is overturned with track damage. Another picture is shown of identical equipment completely protected after exactly the same 30 psi peak overpressure nuclear blast, because the bulldozer and road grader in this example are in an open trench (at right angles to the blast motion) which has a depth equal to the height of the equipment. Although some blast wave energy diffracted straight into the trench, the main mechanism for blast damage is wind drag, which is caused by directional dynamic pressure. Unlike the overpressure, the wind pressure does not diffract unless it is forced to do so by being blocked. Hence the blast wind blew straight over the top of the open trench, without causing any displacement or damage to the equipment. All of these photos and information were removed from all future editions of The Effects of Nuclear Weapons.

Some earlier posts related to nuclear effects and civil defence:

The best suggestion about how to shield fallout gamma radiation in the home in an emergency remains the old but valid idea of staying in an inner room, as far from outside walls and the roof as possible, and with as much massive furniture (or any other massive objects) intervening between the fallout contamination outside and the people taking refuge, as possible.

Electromagnetic Pulse (EMP)

It is interesting to quote the scientific section from the April 1962 edition of The Effects of Nuclear Weapons introducing the electromagnetic pulse, pages 502-506 of Chapter X, Radio and Radar Effects (for the 1977 edition chapter on electromagnetic pulse, which is a very different treatment and deals with high altitude burst EMP as well as that from air and surface bursts, click here). Notice that this April 1962 section is the first mention of EMP in the Effects of Nuclear Weapons (it is not mentioned in the 1950 or 1957 editions), and that at the time of publication (April 1962) the main EMP mechanism had not even been discovered (it was discovered after analysis of the results of the Starfish Prime nuclear test on 9 July 1962):

'The Electromagnetic Pulse

'Origin of the Electromagnetic Pulse

'The electromagnetic pulse or "radioflash" which is produced at the time of a nuclear detonation is of considerable interest. It is fairly well known that even small detonations of ordinary chemical explosives can produce electromagnetic signals, so it is not surprising that substantial pulses of this type accompany nuclear explosions.

'There appears to be at least two different mechanisms whereby an electromagnetic pulse may be produced by a nuclear explosion. The first is associated with the creation by radiations from the burst of some kind of asymmetry in the electric charge distribution in the region surrounding the detonation [the 'electric dipole' Nevada test EMP mechanism]; the second is the result of the rapid expansion of the essentially perfectly-conducting plasma of weapon residues in the earth's magnetic field [the magneto-hydrodynamic late-time EMP mechanism discovered after the 1958 Teak test]. The first mechanism, often called the 'Compton-electron model' for reasons which will be seen below, is believed to be the principal means for generation of electromagnetic pulses by detonations on or slightly avove the earth's surface and by those near the 'top' of the sensible atmosphere [this belief was totally wrong, since it completely ignored the magnetic-dipole mechanism, ie, the deflection of Compton electrons by the magnetic field which was discovered after the 9 July 1962 Starfish Prime test]. The other, called the 'field displacement' model [now called magneto-hydrodynamic EMP, or MHD-EMP], might be responsible for electromagnetic signals from underground bursts where the expansion is restrained in a more or less spherically symmetrical manner by the surrounding material, or from those at such great altitudes that the only interaction of the explosion is with the geometric field [wrong, because downward travelling gamma rays will still cause the Compton effect and the mechanism for EMP then will be by the deflection of of the Compton electrons by the earth's magnetic field].

'In the Compton-electron model the photons of the initial gamma radiation leave the exploding weapon with high energies, very soon collide with electrons in the atoms and molecules of the surrounding air, and transfer to them most of their energy. These Compton electrons move rapidly away, on the average, from the center of the burst. Provided some kind of asymmetry exists, this motion is apparently one of the main sources of the electromagnetic pulse. If the explosion were perfectly symmetrical, in a uniform atmosphere, the effects would be equal in all directions; the opposite components would then compensate each other exactly and there would be no electromagnetic signal. However, there are invariably a number of unrelated factors associated with a nuclear explosion which insures the presence of an asymmetry and, hence, of an electromagnetic pulse.

'The most obvious asymmetric situation is that arising from a surface or near-surface (within 350 feet or so) burst, where the presence of the earth itself confines expansion of the weapon residues and radiation emission to the upward hemisphere. At the other extreme, where the explosion takes place high in the atmosphere, there will be very little interaction by upward-moving gamma rays because of the low air density, whereas those going downward will produce Compton electrons within a moderate distance. In both these cases, though their detailed behavior is probably different and their directions are opposite, the effective Compton-electron pulse is essentially vertical. Moreover, no matter where the burst occurs, there is inevitably some asymmetry in the emission and interaction of the photons. For example, the gamma-ray flux from an exploding weapon is itself never fully symmetric because of the presence of auxiliary apparatus, external structure, or the carrying vehicle. It should be noted that, while the 'natural' asymmetries tend to be vertical, the other type may be oriented in any direction.

'The Compton electrons created by the initial gamma radiation thus move away symmetrically, at high velocity, from the exploding weapon. Since the remaining symmetrical components still compensate each other's effects, this motion appears from a distance to be a practically instantaneously accelerated pulse of current in one direction; it is, in other words, something like an 'electric dipole' radiator of classical electrodynamics. The current pulse in the air radiates electromagnetic energy just as it would if it were flowing in a wire transmitting antenna, and this radiation constitutes the first part of the characteristic signal of the explosion.

'When the Compton electrons move away from the explosion they leave behind much slower moving positive ions, which are the other component of the ion pairs. This relative displacement of positive and negative charges produces a radial electric field. In addition, in its passage through the air each Compton electron itself produces a large number of [secondary] electron-ion pairs, perhaps 30,000, mostly toward the end of its path of 10 to 15 feet [in sea level density air]. Under the influence of the radial electric field, the large number of electrons now present will be driven back toward the burst point. This initiates a second pulse of current, but it is rapidly terminated by recombination of electrons with ions and by attachment of the electrons to neutral atoms and molecules in the air, even before the electric field is neutralized. The negative ions produced in the attachment process, and a corresponding number ofpositive ions, remain free a while longer because the ions, being heavier and less mobile than electrons, collide less frequently. This large volume of ionized gas (or 'plasma') undergoes oscillations at characteristic frequencies similar to those observed in experimental plasmas in the laboratory. The oscillations damp out in a short time, as the negative particles (ions and electrons) combine with positive ions, but while they last they produce electromagnetic waves in the radiofrequency range.

'Characteristics of the Compton-Electron Signal

'The effective rise-time of the main part of the initial signal pulse (produced by the Compton electrons) from surface or near-surface bursts is of the order of 10^{-8} second, so that oscillation frequencies as high as 100 megacycles (10^8 cycles) per second [100 MHz] may be expected. However, only a very small part of the total electromagnetic energy radiated is carried at such high frequencies. In addition, the higher frequencies are attenuated much more rapidly than the lower ones in normal propagation through the atmosphere. The frequencies of the plasma oscillations, which continue for several milliseconds and radiate considerably more energy, are much longer. These frequencies are attenuated hardly at all in normal propagation. At the lower end of the spectrum are the extremely low frequencies (in the very low kilocycle region) which might be detected very close to any such excited radiating dipole; they would exist principally in the 'induction' and 'quasi-static' fields and not be radiation at all.

'The slectromagnetic signal, as detected at a range of a hundred miles or so, thus consists of a continuous specutrum with most of its energy distributed about a median frequency (10 to 15 kilocycles per second) which is related inversely to the yield. At much longer distances, of many hundreds or thousands of miles, the form and spectrum of the pulse are determined largely by the characteristics of the medium of propagation, i.e., the 'duct' between the surface of the earth and the D- or E-region of the ionosphere.

'A somewhat similar explosively-excited vertical dipole radiator which is frequently encountered in nature is lightning, and the electromagnetic signal (or static) associated with lightning also has a peak in the region of 10 kilocycles. This must not be taken, however, to mean that there is a detailed similarity in the modes of generation of the electromagnetic signals from lightning discharges and from nuclear explosions. The transmission path largely obliterates the characteristics of the original signal in both cases.

'The Field-Displacement Mechanism [Magneto-Hydrodynamic EMP, or MHD-EMP]

'The second possibility which has been mentioned for the generation of radiofrequency signals by a nuclear explosion is considered to be of particular significance for extremely-high-altitude bursts. Immediately after the detonation has occurred, the hot weapon debris is essentially a highly ionized vapor (or plasma) which is expanding rapidly. A property possessed by all plasmas is a tendency to exclude a magnetic field, such as that of the earth, from its interior. The expanding plasma of weapon residues thus causes a violent distortion of the earth's magnetic field. As a result of the interaction between the geomagnetic field and the charged particles in the expanding plasma and in the very tenuous, largely ionized, surrounding gases, this disturbance propagates away from the burst region as a 'hydromagnetic wave'.

'The hydrodynamic wave retains its identity and characteristics in propagating over very long distances at high altitudes, but at lower levels, where it interacts with the denser atmosphere, it is detected as an ordinary electromagnetic wave or magnetic disturbance. The field-displacement mechanism is believed to be especially important at very high altitudes where the air density is low and the expansion of the debris is not impeded by the atmospheric pressure. It is probable that the same mechanism may operate to produce an electromagnetic signal from an underground burst. The expansion of the debris is here limited to a few yards and the signal is therefore small, but it may be detectable at short ranges.'

More information on EMP at nuclear tests:

Review of Dr Austin M. Brues and Dr Arthur C. Upton (Chairmen), Proceedings of the Second Interdisciplinary Conference on Selected Effects of a General War, DASIAC Special Report 95, July 1969, vol. 2, DASA-2019-2, AD0696959. The abstract of this 423 pages long report states:

'This report is a result of a second conference on the selected effects of a general war held at Princeton, New Jersey, 4-7 October 1967. Specific topics included in this particular conference were the effects of the 1954 hydrogen bomb tests in the Pacific Ocean which resulted in the fallout contamination of Marshall Island natives and of the Japanese fishermen on the Fukuryu Maru (Lucky Dragon); the ecological effects of nuclear tests in the Pacific regions; and the effects of the aircraft accident in Spain, in which nuclear weapons broke up, but did not explode ('Spanish Incident'). The conference was sponsored by the Defense Atomic Support Agency under the auspices of the New York Academy of Sciences. This volume is the second of a 3-volume series on this subject. The other two volumes have similar titles and are numbered DASA 2019-1 and DASA 2019-3.'

Page 38 notes that the 'fallout' controversy stemmed to the 1 March 1954 Castle-Bravo nuclear weapons test when 23 Japanese crew on the No. 5 Fukuryu Maru ('Lucky Dragon No. 5') tuna trawler before dawn when they observed what appeared to be a 'sunrise' in the west-southwest followed by an explosion sound 7-8 minutes later. Because of the known speed of sound, these facts prove that the Japanese tuna trawler was 150 km east-northeast of ground zero, directly on the fallout hotline and near the north of Rongelap Atoll which received the most fallout. Fallout began to arrive on the ship 3-4 hours later when they were drawing in the nets. As a result, the fish and the crew were contaminated on exposed skin.

Beta burns take two weeks to appear and at that time, on 14 March, the trawler returned to Yaizu Harbour, Japan, and the fallout effects from the test began to appear.

On page 40, Dr Merril Eisenbud states that there was no evidence of a wind change that contaminated Rongelap:

'I was then Director of the [U.S. Atomic Energy Commission] Health and Safety Laboratory and was in direct communication with one of our teams stationed in the Marshall Islands. The only wind information I have ever seen came in an official dispatch, at H - 6 hours, which arrived in New York just a few hours before shot time. From my recollection I would say that it would not have required a wind shift to dump the fallout on Rongelap. Unfortunately, the situation has never been documented in a manner that would make it available to many of us who were interested in the exact meteorlogical circumstances.'

On pages 43-44, Dr Eisenbud adds: 'the instrument on Rongerik, which was an automatic instrument [a graph recorder radiation meter] went off scale [500 mR/hour] at H + 7 hours. This was an instrument that was not part of the Task Force. It was being operated by what was basically a CINCPAC-supported civilian organization based with the Task Force but not operating as part of it. When the instrument went off scale, the operating procedure called for the aerial confirmation of this and there was not enough interest in the Task Force to authorize sending a plane over the island to see if, in fact, the instrument was working properly. As I recall it, this was delayed about 36 hours. No information beyond the initial dispatches came into the States for about two days. In other words, there was just a complete breakdown as far as information was concerned, in taking the steps that were necessary in order to evaluate the situation, and to take the necessary palliative measures. ... right up to the last minute, with the fallout lying on the ground, the people just didn't go up to investigate.'

A sea plane was finally sent to check Rongelap two days after the detonation, the delay being due to the problems of fallout at Bikini Atoll (the firing party was trapped by the fallout and had to be evacuated) which took priority over the other inhabitants of the Marshall Islands including thr U.S. weather personnel who were contaminated on Rongerik Atoll to the east of Rongelap Atoll (they avoided beta radiation burns by washing fallout off skin and changing into long sleeved shirts). It was 50 hours after burst when 16 older people were evacuated by sea plane from Rongelap when it was surveyed, and 51 hours when a ship took the remaining 48 people to safety.

Regarding the contamination to the Japanses tuna trawler, Dr Eisenbud personally had to fly to Japan and measure it, as he states on page 48:

'I saw that ship March 22, 22 days later, and by that time it was still reading generally about 110 mR per hour ... we knew what the decay-characteristics were, and if we extrapolated from that ... to H plus four hours, the integrated dose was something better than 100 R. ... By this time the ship had been hosed ...'

Dr Theodore B. Taylor commented on page 51 about the detection of fallout from the 81 kt Dog shot on a 300 ft tall tower during Operation Greenhouse at Eniwetok Atoll in 1951 (a windshift unexpectedly blew fallout over the island where the personnel were living during the tests):

'Apropos of the Dog shot, fallout was clearly audible. There were little beads of steel from the tower that condensed, and one heard this constant tinkle, tinkle of steel from the tower hitting the aluminum roofs and then rolling down the gutters and piling up in little piles on the ground.'

On page 69, the issue is addressed as to why the irradiated Japanese fishermen did not at any time radio back to their home harbour a report of seeing the explosion and being contaminated by fallout (they were in contact with their home port twice daily by radio). The reason is given, with reference to Dr Ralph E. Lapp's book about the affair, The Voyage of the Lucky Dragon, that the crew had spent two months in jail in Indonesia for poaching and feared that the Americans would arrest them for allegedly spying on the nuclear test. In passing, it is interesting that Dr Ralph E. Lapp (who died in 2004) in 1954 first alerted the world's media to the radiation dangers in his many articles for the Bulletin of Atomic Scientists about the seriousness of the Bravo test fallout and its implications for civil defence, but in 2002 he wrote a letter to the Washington Post (Thursday, November 21, 2002; Page A40), Radiation Risk Realities, in which he complained about too much fear of radiation:

Washington Post, Thursday, November 21, 2002, page A40:

'Radiation Risk Realities

'The Nov. 11 front-page story on "dirty bomb" risks, "Hunting a Deadly Soviet Legacy," needed to put the threat in perspective. The release of radioactive cesium into the atmosphere from the Chernobyl plant in 1986 was 1,000 times as great as the release in the "dirty bomb" scenario.

'In assessing radiation risk, it is essential to understand the basic facts about data accumulated during half a century of medical studies. Among a half-million Hiroshima survivors, for example, fewer than 1 percent of the observed cancer deaths were the result of the A-bomb radiation.

'How many Americans know that?


Dr Lapp's issue with the media was that it ignored the facts and exaggerated or suppressed evidence simply to stay on the fashionable bandwaggon of popular hysteria which could motivate people to buy the paper or watch the media TV reports. Facts without hysteria don't sell the media efficiently to the ignorant, unlike exaggeration. The media feels no duty to inform people of facts, just to kill off competitors by exaggerating facts to create a fictional news 'story' which scares people and creates prejudices, bias and bigotry.

Continuing the review of Proceedings of the Second Interdisciplinary Conference on Selected Effects of a General War, DASIAC Special Report 95, July 1969, vol. 2, DASA-2019-2, AD0696959, page 76 has a discussion by Dr Lin Root of the death of the radio operator, Kuboyama Aikichi, of the Japanese fishing trawler about six months after exposure (he died on 23 September 1954).

He died of a hepatitis, a liver infection, due to an infected blood transplant. Dr Root explained: 'Japanese doctors give very small blood transfusions, and Kuboyama needed a great many.'

The blood transfusions killed him with an infection when his white blood cell count has been suppressed, and were of no practical use whatsoever in combating the radiation malaise, for which blood cells created continuously by regenerated bone marrow are required. If anything useful had been done, it would have been to have given a bone marrow transplant, not infected blood.

The bad beta burns to skin on the Japanese fishermen was due to the long exposure as they hauled in nets full of tuna for several hours. The fast decay of the fallout meant that most of the contact beta exposure occurred during that time. With the Marshallese Islanders on Rongelap and Ailinginae Atolls, the beta burns occurred to moist skin with sweat glands including the neck, armpits, elbows, and the top surfaces of feet but not the bottom surfaces of feet (which were in direct contact with the contaminated ground, but were not beta-burned, because of the extra thick deal skin layer on the soles of the feet, which stopped most of the beta particles). In addition, the Marshallese women used coconut oil as a hair dressing, which was sticky and retained fallout, causing exposure of the hair roots and epilation, beginning at about the same time as the beta burns (after a latent period of 14 days or so from time of exposure).

On page 85, Dr Theodore Taylor comments on radiation hysteria by involking the example of President Kennedy's ignorance of natural background radiation and the effects of dosage:

'I think the mystique is right here at home, typified by a comment that President Kennedy made to Jerry Wiesner when they were sitting together in the White House and it was raining out. Kennedy asked Wiesner whether there was fallout in the rain that was falling on the White House lawn, and Wiesner said, "Yes, there still is." This was an intense emotional experience for the President, to see rain with fallout on the outside; nothing connected with anything in any way quantitative at all. As far as he was concerned, that rain that was falling outside was bad.'

(For a very refreshing review of the controversy over safe levels and tolerance doses versus the popular mainstream 'all radiation kills, end of story' hysteria, see Dr Daniel J. Strom's amusing 1996 report The Linear, No-Threshold Dose-Response Model: Both Sides of the Story. Pacific Northwest National Laboratory, Richland, Washington.)

An amusing argument, over whether the unknown risks of natural chemical in cranberries are similar to low level radiation risks, then occurred. Dr Stafford L. Warren responded:

'Not everybody buys cranberries and couldn't care less, but everybody is subjected more or less to the fallout.'

Dr Charles L. Dunham (of the Division of Medical Sciences, National Research Council, U.S. National Academy of Sciences) responded to Dr Warren:

'So is Vitamin A. It's toxic, too.'

On page 138 there is an interesting discussion of why the tree-climbing coconut crabs on Rongelap Atoll concentrated strontium-90, which being similar to calcium was highly diluted by the calcium in the coral (calcium carbonate) soil on Pacific Atolls like Rongelap, Bikini, Eniwetok, Utirik, etc. The tree-climbing coconut crab builds up a concentration of strontium-90 with calcium for forming a new shell when it outgrows the old one. Dr Lauren R. Donaldson explained:

'One distinct difference between the coconut crab and the usual crustacean is that as soon as the crab finishes the molting process and the new shell is formed, the crab eats the old shell and thus these minerals are returned to its body. ... So it preserves the minerals and they go on perpetuating this process year after year. This is a particular situation peculiar to the coconut crab. It's not typical of crustaceans in general.'

Dr Donaldson on page 191 presented a diagram of the distribution of beta and gamma emitting radionuclides at Rongelap Atoll in 1966 (which had been contaminated mainly by Bravo in 1954 and very slightly by Zuni in 1956), showing that Mn-54, Fe-55, Co-57, Co-60, Zn-65, Sr-90, Zr-95, Ru-106, Sb-125, Cs-137, Ce-144, and Eu-155 were present in the soil, Sr-90, Ru-106, Ce-144 and Eu-155 were in the lagoon bottom sediment, land plants took up Mn-54, Zn-65, Sr-90, and Cs-137, land crabs and rats took up Sr-90 and Cs-137, and humans took up Zn-65, Sr-90 and Cs-137. The Zn-65 in humans came from eating fish and birds, while the Sr-90 and Cs-137 came from eating land crabs and vegetation, particularly coconuts.

Lagoon algae contained Co-60, Ru-106, Ce-144, and Eu-155, while plankton contained Mn-54, Co-57, Co-60, Zn-65, Zr-95, Ru-106 and Ce-144. Lagoon fish eating the algae and plankton concentrated Mn-54, Co-60 and Zn-65, while marine invertebrates contained Mn-54, Co-57, Co-60, Zn-65, Sr-90, Ce-144 and Eu-155. Both lagoon fish and invertebrates were food for the birds, which were found to concentrate Mn-54, Co-60 and Zn-65.

Dr Lauren R. Donaldson showed a film, Return to Bikini, about the 1966 annual survey of Bikini radioactivity and environmental effects. The film discussion is on pages 230-1, and is quite remarkable.

Dr Charles L. Dunham: 'Lauren, this isn't the way I heard the story. There was a movie I saw a few years ago that was announced to the public by Ian Fleming with a 4-page spread in the London Times which showed little fish that had become disorientated, losing their way, trying to climb trees, which showed sea turtles who tried to find where to lay their eggs. They laid great quantities of eggs which were sterile and then couldn't find their way back to the sea. It showed piles and piles of tern eggs, which were also sterile, and very few terns. Now, which is the true story, sir?'

Dr Lauren R. Donaldson: 'Dr Dunham, during the period from 1946 to 1964 we were at Bikini and Eniwetok for several months most years. We made a total of 23 separate expeditions. No matter how hard we looked we could not find a mudskipper "trying to climb trees." In fact, there are no records of mudskippers at either atoll nor are there any mangrove swamps, the preferred habitat for mudskippers.'

Dr Charles L. Dunham: 'This was supposed to be an authentic movie of the aftermath of the atomic bomb in Bikini. Maybe you selected different parts of the atoll.'

Dr Lauren R. Donaldson: 'I think one would have to do more than select a different part of the atoll, in this particular case. I think even John Wolfe with his great accomplishments in environmental control couldn't build a mangrove swamp out in Bikini without an outflow of fresh water. This sort of completely falsified popular release is nothing but disgusting.'

Dr Theodore B. Taylor: 'Who made that particular movie, do you remember?'

Dr Charles L. Dunham: 'It was an Italian movie. It had a lot of other stuff in it. There were beautiful pictures, though. I must admit there were beautiful pictures of wildlife. As Lauren says, undoubtedly the ones of these mudskippers, as they call them, were taken in the mangrove swamps somewhere and there were lovely pictures of giant sea turtles laying eggs. Again they're apparently authentic pictures.'

Dr Frank Fremont-Smith: 'Maybe it was the photographer that was disorientated; thought he was in Bikini but wasn't.'

Dr Charles L. Dunham: 'That could be quite possible.'

On page 280, Dr Theodore B. Taylor discusses Dr Stonier's 1963 book, Nuclear Disaster:

'I think it's a fair statement to say that the book is essentially an anti-civil defense book; that the purpose of it is to decrease confidence in civil defense measures. The reason I'm saying that so emphatically is that there was a panel formed by the American Nuclear Society about two years ago to discuss civil defense. Eugene Wigner and I were on the side of civil defense and Stonier and someone in the Harvard Law School, whose name I've forgotten, were opposed to it. We had a very informative and worthwhile debate. He said that what he really has in mind in his writing now is to display the futility of civil defense. I think that's important because I think he would be the first to agree that he feels very strongly about this and gets emotionally involved in illustrating his point, namely, that the disaster, no matter what we do, will be so complete that we should not do anything which will indicate that people could get away with a nuclear war. I think that's his thesis. ... I think his thesis is that if we fail to prevent nuclear war, all is lost.'

On page 298, Dr Theodore B. Taylor stated his own pro-civil defense position:

'I must just say that as far as I'm concerned I have had some doubts about whether we should have had a civil defense program in the past. I have no doubt whatsoever now, for this reason, that I've seen ways in which the deterrent forces can fail to hold things off, so that no matter what our national leaders do, criminal organizations, what have you, groups of people over which we have no control whatsoever, can threaten other groups of people.'


At 7:21 am, Blogger nige said...

The Bravo test story of the nine people trapped by fallout in the firing bunker at Enyu Island, south west Bikini Atoll, 1 March 1954:

We Were Trapped by Radioactive Fallout

Saturday Evening Post, July 1957

by Dr. John C. Clark
as told to Robert Cahn

Here, revealed for the first time, is how nine scientists were caught 20 miles from ground zero when the biggest H-bomb of all time went off. This is their chilling story.

. . . by Dr. John C. Clark as told by Robert Cahn

When we locked open the main firing switch in the control room before leaving to arm the H-bomb that February day at Bikini in 1954, I had no feeling that this one would be any different from the more than forty other nuclear test shots in which I had participated. Since it was a thermonuclear bomb of a relatively large predicted yield which we were testing, we had tried to figure out in advance all the possibilities of danger and to make allowances for all eventualities. But this is not easy when one is concerned with a device which produces an explosive force roughly equivalent to 15,000,000 tons of TNT --- 1000 times more powerful than the Hiroshima atom bomb.

The energy released by the thermonuclear blast -- which we call the "yield" -- could not be pre-determined with absolute accuracy. Nor could we tell beforehand exactly how extensive the air-wave and tidal-wave effects would be or the precise amount and distribution of the "fallout"-- the radioactive particles from the nuclear cloud which drop back to earth. In the business of testing nuclear devices there are always a few unknowns.

The temperature was in the high eighties, the sky was clear and there was just a slight breeze blowing as we got into the helicopters for the flight to the shot island approximately twenty miles northwest, at the other end of Bikini atoll. It was a perfect day for the end of February--far different from the weather at some places Stateside. All our extensive preparations for this first shot in Operation Castle had come off on schedule and we contemplated no trouble ahead. Little did we realize that within eighteen hours we would become unsolicited human guinea pigs during the strangest and most hazardous effects ever experienced from an American nuclear test.

After clearing the coconut palms through which our landing strip had been cut, I looked down at our sturdy control blockhouse. It certainly seemed out of place among the palms and pandanuses on our tiny tear-drop-shaped island. Coral sand covered most of the roof--sand which the radiation experts said would help protect anybody inside the building from stray fallout radiation.

The structure had also been sealed to withstand up to at least a five-foot tidal wave and built of reinforced concrete to resist the overpressure and underpressure effects expected from the blast. It certainly looked secure enough even to satisfy those who had argued that we would be safer if the firing were controlled from a greater distance. But inasmuch as our control island, Enyu, was the most distant spot on the atoll from ground zero, to go farther would have necessitated firing from a ship. And we wanted to avoid the more complicated ship-controlled firing if at all possible.

It was now shortly after noon and as our Marine helicopter pilot headed north over the atoll, I could see the last few supply ships pulling away from Enyu. The operational plan called for all ships to be safely out to sea by the time we armed the gadget. We hoped to have the arming completed and be back at the control island in time for the helicopters to return to their mother ships before dark.
As we headed across the lagoon to the first of our instrument stations, the string of islands and reefs which comprise Bikini atoll looked like so many beads on a necklace. The largest islands are one to two miles long and at their widest are less than 800 yards across. Others are no more than reefs or sandspits. In a few minutes we dropped down onto one of the small islands. While Herb Grier, an electrical engineer from Boston, checked on some of the recording instruments, I locked open a part of the circuitry in a blast-proof bunker. The Commander of the firing party must lock open all the switches in the firing circuits with padlocks and keep the only key. It's not that we don't trust others. But in the business of arming a thermonuclear bomb, you must be absolutcly certain that no circuits are closed at the time of arming.

About two o'clock, after making a few more stops to check on instruments and to lock open switches, we arrived at the shot site. With me were Grier and Barney O'Keefe, both of the Boston firm of Edgerton, Germeshausen and Grier, electrical contractors to the Atomic Energy Commission. Already there, having flown up in another helicopter, was Dr. Gaelen Felt, one of the top young scientists from Los Alamos.

Felt, Grier and O'Keefe had specific duties concerned with the numerous optical and electronic experiments which are always co-ordinated in the test of a nuclear device. My job was to check on everything at the shot site, and then, when all was in order, to arm the bomb.

We were almost finished with the checking when Gaelen discovered helium, used in optical experiments, leaking from one of the key setups. Some rapid calculations disclosed that by shot time the next morning there would not be sufficient pressure left in the tanks to carry out the experiment. I radioed the information to Dr. Alvin C. Graves, scientific deputy to the task-force commander, who was aboard the command ship. Without this experiment, the test would not be held.

We soon discovered that we could not fix the leaks in the short time left. But we came up with another solution to the problem. If we delayed the arming procedure for seven hours and opened the valves at the last possible moment, there would still be enough helium for the experiment. We did not desire to return after dark because our island landing mat had no lights. However, it was either set back the arming or postpone the test and Doctor Graves gave us the go-ahead for our emergency plan.

We sat around until dark taking it easy while the whirly-bird pilots went off to a nearby construction site and scrounged some food that had been left there by the workmen. The temperature, which varies less than ten degrees night and day, was still in the eighties. Shortly before eleven P.M. we opened the valves of the helium tanks. I then requested permission from the command ship to arm the bomb. Before the final connections are made, a check must be made to determine that no other personnel are in or near the shot island. We are pretty darn sure the bomb won't go off when we arm it, but with the complex circuitry involved there is always the one chance in a million that something might go wrong.
Barney and Herb accompanied me to the artificial sandpit which was ground zero, This "island" had been dredged up out of the coral sand so that it could be in the most advantageous position for the shot. As a safety precaution, we always have someone else along to check every action of the person arming the device just to make doubly certain that each step is done correctly. Much of the work in an atomic test can be done by automation, but for all the experimental bomb tests so far we have done the arming by hand.

All went according to plan, however, and I made the final connections which armed thc bomb. We quickly got into the helicopters and headed back, retracing our path to close the switches I had locked open earlier in the day. The pilots could easily follow the white-coral shoreline and we got back to Enyu about midnight. The men who had been checking things at the control point took our places in the helicopters, which then scooted off to join their ships, already headed away from the shot site.

There were nine of us remaining in the blockhouse. In addition to Doctor Felt, O'Keefe, Grier and myself, there were Dr. Harold Stewart, a scientist from the Naval Research Laboratory; Lt. Douglas Cochrane, a radio expert; John L. Sanderson, of Holmes & Narver, Los Angeles contractors who did the construction work and two radio technicians, Airman First Class Gerald Scarpino and Master Sergeant Alton Greene.

We made our last-minute checkouts of circuits and then waited for the final weather reports from the command ship. Around three A.M.-- zero hour was scheduled for shortly before daybreak--the scientific director radioed, "We have just had the weather briefing and we agreed to continue. So go ahead and start the count-down."

Herb Grier, who was making the time announcements, waited for the tone from WWV, thc world-wide standard-time station. "It is now minus two hours," announced Grier at the beep of the signal. Almost 100 miles away, on small islands in the atolls of Rongelap, Rongerik and Utirik, technicians from an American military weather group checked their watches and recording devices. At other points on the ocean, personnel on ship instrumentation stations synchronized their time settings. And in the air, pilots and navigators coordinated with our announcement to make certain they would be at their correct position at shot time. Other aircraft had already completed search flights in the area and had seen no stray ships. Apparently, as we found out later, they somehow failed to spot the little Japanese trawler Fukuryu Maru--the Fortunate Dragon--fishing about seventy miles off our shot island.

At minus one hour we started our final preparations. I told John Sanderson to button up the generators in a nearby concrete bunker and to secure the control building. After closing the doors to the structure housing the generators, Sanderson climbed a ladder outside our blockhouse to put metal plates and gaskets over the air-conditioning vents. He then entered the blockhouse and sealed the submarine hatch which had been installed as our only door and which was completely watertight and blastproof.

At H hour minus fifteen minutes I told Grier to push the button on the automatic sequence timer. Contrary to popular belief, we don't push a button to set off the bomb. Everything is done electrically by the sequence timer, although up until the last second I can pull a switch to stop the bomb from going off. Also there are "no-go" devices built into the circuitry which automatically prevent the detonation-- should any of the primary experiments not be ready to function properly. There are hundreds of experiments conducted during most nuclear detonations, but we usually limit those which can lock out a detonation to four or five. However, some of these four or five circuits are closed so late that even at the last second we are not sure that a no-go device won't halt the test.
Those last few seconds in the control room are always quite tense. We keep watching the control panel, where lights flash from red to green to show when experiments and circuits are ready to operate. Some remote-controlled cameras near the bomb are not turned on until between minus three quarters of a second and minus a half second. We would rather not have to rely on such delicate timing, but these ultra-high-speed cameras work at a rate of over l,000,000 frames a second and require split-second control.

The purpose of nuclear detonations is always to obtain experimental data, and it would be a waste of money and months of scientific effort if the bomb went off and the recording equipment was not in complete readiness.
After the sequence timer had been started, we all gathered in the control room for a final briefing. I requested that all who were not needed in the control room should stand in the hall. I told them that although we expected no difficulty, there would he a ground shock shortly after the bomb went off. This would be followed by the air shock wave, which, at twenty miles' distance, would probably do no great damage. Finally, there was the possibility of a tidal wave sweeping over the building. If it came, it was due at about H plus seven minutes. I told them I had agreed with Doctor Graves that, inasmuch as we had no observation windows, we would wait until H plus fifteen minutes before "unbuttoning" the building, to make absolutely sure we were not under water.

At H minus ten minutes, Grier, O'Keefe and Lieutenant Cochrane manned posts at the control panel. Hal Stewart was in a nearby room where he had his spectrographic instruments, and I stayed in the center of the control room.
"At the next tone it will be H minus one minute," announced Grier a few minutes later.

"Thirty seconds," announced Grier. "Fifteen...." All exccpt two of the lights were green. "Ten . . . nine . . . eight . . . seven ... six ... five...." All was absolutely quiet except for the soft whining of the sequence timer. "Four . . . three . . . two . . . one . . . Zero."

I looked at the panel; all the lights were green, we knew the bomb should have detonated.
"How did it go Al?" I called on the radio to Doctor Graves, forty miles away on the command ship.

"It's a good one," he answered.

Inside our blockhouse we still had no physical evidence that anything had happened, but we braced ourselves against a possible sharp ground shock.

It came--but not as expected. Less than twenty seconds after Zero the entire building started slowly rocking in an indescribable way. I grabbed the side of the control panel for support. Some of the men just sat down on the floor. I had been in earthquakes before, but never anything like this. It lasted only a few seconds, but just as we were breathing easier, another ground shock hit us, with the same undulating motion. Then, a minute later, came the air blast. First the overpressure, then the sucking out by the underpressure. The concrete building creaked, but stayed firm. A few yards away, as we found out later, frame buildings had been blown down by the hurricane winds from the blast.

Immediately after the air blast. Felt noticed some water coming in through the conduits behind the control panel. And about the same time water in the lavatory started shooting up to the ceiling. I radioed the information to Doctor Graves who was as perplexed as we were. Water effects were not expected for six more minutes. We later found out that this water had been forced up from the lagoon by the overpressure created from the air blast, and had come in through pipes and conduits.

For the next few minutes nothing happened. We waited for any possible tidal wave effect.
H plus seven minutes went by. Nothing happened. H plus ten minutes. Finally, at H plus fourteen. I radioed Doctor Graves and told him we would open the door. Cautiously, Sanderson moved the steel plate to make sure we were not under water. When nothing happened, he opened the door. Everything was calm outside.

While I stayed inside to man the radio, the others went out to look at the mushroom." In a couple of minutes, Grier came back to relieve me at the radio and I went outside, taking along a Geiger counter. The shot cloud had spread out and was pure white. It was an awesome sight. I casually placed the radiation counter on top of a fence outside the door and turned away to talk to Gaelen Felt, who was pointing out that the blast had torn the doors open on his instrument trailers nearby. All of a sudden I noted that the radiation meter was already reading eight mill roentgen [per hour]. That meant we were receiving radiation at the rate of 8/1000 of a roentgen per hour, far less than would be received from an ordinary chest X ray.

While we watched, the counter went up to twenty mill roentgen [per hour], then to forty. While this was not yet a dangerous amount of radioactivity, there should not have been any radiation at the distance we were from the bomb blast. It could mean only one thing: we were already getting fallout. We could hardly believe it. The wind was supposed to take the fallout in almost an opposite direction. But our Geiger counters were registering radioactivity, and counters are usually accurate.

After the counter reached fifty mill roentgen [per hour], I had to turn the knob to change scales. The pointer kept climbing. I called for everyone to get inside. It still was far below dangerous radiation levels, but we had no idea how fast and how much it might increase. A dose of 75 to 125 roentgen received in a short interval may produce nausea and other symptoms of radiation sickness. About 450 roentgen might be fatal.

By the time we were back in the blockhouse, the reading near the door was one roentgen [ per hour], and in the control room it was about twenty mill roentgen [per hour]. I radioed Doctor Graves, who checked with the weather boys. No one could understand why we should be getting fallout, but were. Of course it was a known fact that winds at higher altitudes sometimes blow in opposite directions and could shear the bomb cloud as it passed through diferent levels. But no such opposing winds had been predicted.
A few minutes later I again called Doctor Graves on the radio.

"The radiation is building up pretty fast, Al," I reported. "Inside by the door it now reads ten r [per hour]. The level here in the Control room is fifty milli-r [per hour]."

We then discussed the possibility of sending in helicopters to take us to the ships. But Doctor Graves rightly decided that much as he would like to get us off the island, at the rate the radiation was building up outside, it was too risky for all concerned to attempt a helicopter rescue.

We agreed it was safer now to be inside our sand-covered blockhouse than to be outside in the intense, direct radiation from the fallout even for the short time a rescue operation might take. Of course we had no idea how much the radiation might build up inside the blockhouse. But it became increasingly clear that we had no choice. We were trapped.
In a few minutes the radiation level in the control room reached 100 mill roentgen [per hour]. This was above a safe level in which to stay for any great length of time. At this point we did not know how long we would have to stay in the building, so we decided to see if there might be a safer place to which we could retreat.

Felt and O'Keefe first checked Stewart's room near the door. They found the radiation level there many times higher than in the control room. They then went to the radio room across the hall from the control room. Here also the level was too high for safety. There were only three rooms left - a communications room, my small office and a data-processing room. I breathed a sigh of relief when Felt told me that the level in this data room was only ten mill roentgen [per hour]. Fortunately, considerably more sand had been piled on top of the part of the building covering the fifteen-by-twenty-foot data-processing room, and the sand was shielding us from the radiation.

I advised the command ship of our situation. I told them that we had found a room in the blockhouse which seemed perfectly safe unless the fallout level outside got much higher. At the rate of ten milliroentgen per hour we could remain for days without harmful effects. I did advise them, however, that we would man the radio in the control room only every fifteen minutes.

I told the men to make themselves as comfortable as they could in the data room. There were a few Army cots in the building and these were moved into this room. It was now about H plus one hour and I was most concerned as to what was happening to the radiation level outside. I took the radiation meter, opened the door and gingerly placed it outside at arm's length for a quick reading. It read forty roentgen [per hour]. I quickly closed the door.

Shortly after we had gone into the data room, Hal Stewart asked permission to get his spectroscopic plates and film out of his room. If he did not get them at once, all his test results would be ruined. We figured out that he could stay for eight minutes without getting too much radiation, so I said go ahead. He rushed into the room, wrapped the plates and film in a black cloth, and got back in just under seven minutes.

We were not exactly a happy bunch as we sat around in that small back room. We had been forced to turn off the air conditioner because it brought in fallout particles from outside. The entire building soon got hot and sticky. Only a few yards away in the construction camp were steaks we had planned on having breakfast. Instead, we were munching C rations.

A little over an hour after shot time, Doctor Graves radioed that the command ship was also starting to pick up radiation. They would have to move farther away and we might lose radio contact. And about that time our generator began failing and the lights gradually went out, leaving us in darkness, and with only battery-powered radio equipment.

We kept checking the Geiger counter with our flashlights. After the first hour, it was still at ten mill roentgen [per hour]. If the wind didn't change and cause more fallout we probably were safe, because the radiation outside the blockhouse would decay with the passing of time. But we aready had had one unpredicted wind shift. Now we really didn't know what to expect.

The minutes ticked on. We could hear the command ship, but they could not pick up our signal. However, about three in the afternoon they started coming back, and once again I contacted Doctor Graves. Our radiation level had not increased and we figured the best thing do was to remain inside until late in the afternoon to let the outside radiation level fall. We worked out a plan for a rescue operation to take place at about 5 30 P.M.
Late in the afternoon we checked the outside radiation and found it to be about twenty roentgen per hour. To keep the "hot" dust off our bodies, we wrapped ourselves completely in bed sheets, cutting holes only for our eyes. Three helicopters were sent from the command ship. As we heard them overhead we left the blockhouse, got into our jeeps and drove the half mile to the landing mat. The pilots hovered as we left the building and set down when we arrived at the mat, The whole operation took less than five minutes. As soon as we were in the helicopters we took off the sheets and a radiological safety officer checked us. Within twenty minutes we were back on ship, where we showered and were given a thorough radiation check. None of us had received any harmful amount of radiation.

The next day we found out how really fortunate we had been. It was estimated that fallout radiation outside our blockhouse was several hundred roentgen. Had we been forced to stay outside the entire day without protective cover, it would have been fatal to all of us.
The twenty-three Japanese fishermen in the Fortunate Dragon, which was seventy miles further away from the shot than we were, received burns. Twenty-eight Amercan personnel manning weather stations, and 236 natives on Rongelap, Rongerik and Utirik also received radiation during the unforeseen fallout.

However disconcerting it may have been to us at the moment, our experience proved to be a windfall for the Civil Defense people. They had long hoped for something more than theoretical data on what might happen under extreme radiation conditions if people had the proper safeguards. Now, for the first time, humans had been in an area of lethal radiation and had been unharmed because of adequate protective covering. Civil Defense had representatives at the test site during the operation and by making a study of our experience they were able more reliably to predict how Americans might protect themselves during a radiation disaster. It has now been figured, according to Civil Defense, that shelter in an old-fashioned cyclone cellar with a covering of earth three feet thick would reduce the radiation level to about 1/5000 of that outside.

When we finished measuring the yield of the bomb, it was found to have been almost twice that which had been predicted, a margin of error not incompatible with a totally new weapon and certainly welcome to the scientists. It had been so powerful that at one of the concrete bunkers one and a half miles from ground zero a twenty-ton door had been blown right through the building against the back wall fifteen feet away. And on our control island twenty miles away all the wooden buildings had been completely demolished.

[For technical report on the damage to these structures, see Wayne J. Christensen, “Blast Effects on Miscellaneous Structures, Operation Castle, Project 3.5,” U.S. Armed Forces Special Weapons Project, weapon test report WT-901, 1955. The two massive concrete instrument bunkers at 2500 yards survived 130 psi peak overpressure from the Bravo test but were damaged in detail. The door referred to is the shutter door on Station 1341 at “Able” (codename) Island, 7500 feet from ground zero for Bravo shot, hit by 130 psi peak overpressure. The report states that light wooden buildings severely damaged when hit by 1.4 psi peak overpressure and a total positive blast duration of 13.4 seconds, at 14.5 miles from ground zero of the Bravo detonation.]

Two days later when we returned to our control island, the radiation level was still much too high for personnel to remain any length of time. Bulldozers were brought in to scrape off the top soil containing most of the radiation and push it into the ocean. This reduced the radiation level around the blockhouse enough so that we could use it again for part of the test work. But for the remainder of the tests on that atoll we made a change in plans--the firing operations were conducted from the command ship. Being guinea pigs once was more than enough for us.

The End.

About the author:

Dr. John C. Clark is a scientist who has specialized in weapons of war since he directed research in "detonation phenomena" at Aberdeen Proving Grounds in World War II. In the past ten years he has often been Firing Party Commander and Test Director for nuclear tests in Nevada and the Pacific. On two occasions when malfunctions in recording devices stopped tests at the last moment, Doctor Clark personally disarmed the bombs. He left the Los Alamos Scientific Laboratory staff last March to join the Astronautics Division of General Dynamics Corporation's Convair Plant in San Diego.

There is another account of this incident by Bernard J. O'Keefe in his 1983 book "Nuclear Hostages" (252 pages, Houghton Mifflin, Boston). O'Keefe was also in the firing bunker at the time of the Bravo test, and recalls different figures for the fallout radiation buildup, from memory I believe he claimed it reached 65 R/hr outside the shelter door at 1 hour after burst. He also provides more details of the electrical failure, explaining that he analysed the electrical supply on an oscilloscope as it began to fail and one of the three AC phases was blown. This reduced the voltage available and as a result of overload the remaining phases broke down. Unlike Dr Clarke's 1957 account above, O'Keefe gives details of the electromagnetic pulse at shot time on the control panel, blowing meters and indicator lights after travelling back to the bunker via underwater cables to the bomb about 20 miles away. The EMP current pulse from Bravo coupled from the explosion via the cable to Enyu Island probably resulted in the damage to the generator system.

At 8:07 am, Blogger nige said...

Update regarding the quotation in this post of Glasstone's 1962/4 "Effects of Nuclear Weapons" statement that something like a foot of earth cover over fallout will reduce the dose rate by a factor of 10:

Actually, because most radiation from fallout comes directly from a wide surrounding area, the protection afforded is much better than a factor of 10: the gamma rays from a smooth uniformly contaminated terrain come from an average distance of 15 metres from the observer/geiger counter centred at ~1 metre height.

These direct gamma rays are therefore travelling through not the 1 foot vertical earth cover (the contribution from fallout below your feet is negligible) but are travelling at an angle of only 3.8 degrees from the horizontal (not 90 degrees as the 1 foot or factor of 10 shielding suggests), and hence travel through a larger slant distance of earth, about 5 metres thickness of earth for the fallout 15 metres away.

Obviously this increases the amount of earth-scattered radiation reaching the observer, so when you put an earth layer over fallout, the distance of mean fallout contribution (i.e., the radius beyond which the fallout gives 50% of the total dose) is no longer 15 metres, but is reduced greatly.

However, the shielding is still much better than Glasstone's factor of 10 protection suggests.

James Sartor gives data on page 96 of The Control of Exposure of the Public to Ionizing Radiation in the Event of Accident or Attack, Proceedings of a Symposium Sponsored by the National Council on Radiation Protection and Measurements (NCRP), April 27-29, 1981, Held at the International Conference Center, Reston, Virginia which show that 1 foot of earth cover over fallout gives a protection factor of 50, while 6 inches of earth cover gives a protection factor of 6.7.


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