Posts Tagged ‘United Kingdom’

Visions

More nuclear symbolism

Tuesday, January 22nd, 2013

Two small graphical things I wanted to share that came from feedback on a few recent posts.

The first is an explanation, of sorts, of the United Kingdom Atomic Energy Authority’s very unusual emblem:

UKAEA Coat of Arms

I had ragged on the AEA’s design as being particularly stodgy, but I’ve been corrected. It’s just unduly weighed down by obscure symbolism, as a commentator pointed out. It was, apparently, designed by the Royal College of Arms with the following visual references:

  • The central shield is black denoting the core of a graphite reactor, with inserted rods of silver uranium.
  • The inverted triangle shows gold and scarlet bolts of heat and power.
  • The energy released by splitting the atom is controlled by a pair of red pantheons, which are ferocious heraldic beasts. They are firmly held to the ground by thick golden chains to ensure the energy is firmly controlled.
  • The pantheons have 13 six-pointed stars and two seven-pointed stars, totalling 92. These represent the 92 natural elements found in creation and also the atomic number of uranium.
  • The five spikes on the collars signify the atomic number of boron, which was used to shutdown the early reactors.
  • There are numerous representations of 8 for the atomic number of oxygen, 2 for helium and 1 for hydrogen – suggesting water. The whole gives insights into the four medieval elements of earth, air, fire and water.
  • The sun represents the power of fusion, and the small shield with the black bird (a martlet) is the Coat of Arms of Lord Rutherford. He is recognised as the founder of nuclear physics.
  • The steel helmet signifies the arms of a corporate body.
  • The whole is placed on the earth on which flowers and plants are flourishing normally. [???]
  • The motto “E minimis – maxima” means; ‘from the smallest, the greatest‘.

I thought that was interesting enough to share. Any resemblance between the “pantheons” and mutated horse-dogs is apparently entirely coincidental. And despite the barren, Moon-like appearance of the “earth,” it is apparently “flourishing normally.” Actually, the above image, painted on the doors of the Dounreay Prototype Fast Reactor, is slightly different than the other image of the emblem I had posted, which does have a more flourishing-looking ground cover, as well as a knight’s head.

All of this is a stark contrast from the US Atomic Energy Commission’s emblem, whose symbolism seems to have been, “it’s an atom, stupid.” I hereby promote the AEA’s emblem from “most boring” to “not as boring as I thought,” which leaves the current Department of Energy seal as the “most boring.”

Secondly, I have another cryptic drawing referencing the history of the hydrogen bomb, again by George Gamow. This one has been reproduced here and there, but a friend of mine came across an original version in the Gamow papers at the Library of Congress awhile back, and sent me his photographs of it and its captions. The drawing follows:

H-bomb history drawing, by George Gamow

The attached caption (written, as always, in Gamow’s amusing handwriting and bad English) was as follows:

A drowing made by G. Gamow (with photographic inserts) which was handing [hanging?] in his office in the Los Alamos Scientific Laboratory during the dispute about the political necessity of developing an H-bomb and during the early stages of its developement after President Truman sayd: “Yes, go ahead.”

Top left is Comarade Stalin carrying the A-bomb made in the USSR.

Top right is Dr. Robert Oppenheimer who was objecting against H-bomb project on the basis that it is extremely difficult (actually it took less than two years) and will induce USSR to do the same (actually Russians worked on H-bomb when this discussion was taking place).

The coffin with the Harvard University coat of arms belong to Professor Dr. James B. Connant who said that: “H-bomb will be built only over his dead body.”

On the bench below are Dr’s Stan Ulam, Edward Teller, and George Gamow, demonstrating their proposals for making H-bomb. The simbolism of these deviced cannot be explained because AEC classified them as “SECRET”. 

The “simbolism” is fairly cryptic. The caption dates it around February 1950, so that might make it even harder to make sense of, as we’re talking about fairly early days when it comes to the final H-bomb design, but I’m not sure how reliable I find that dating. (The H-bomb debate was in late 1949-early 1950, though the caption was obviously written at a much later time.)

Looking for some insight into the technical discussions that were happening at this time, I took a gander at Anne Fitzpatrick’s quite detailed thesis on the early history of the H-bomb, “Igniting the Light Elements: The Los ALamos Thermonuclear Weapons Project, 1942-1952,” (Virginia Polytechnic Institute and State University, 1999), which was issued as LA-13577-T. Fitzpatrick’s work is notable as one of the few H-bomb histories that have been written by a non-participant but also with access to classified information. (The whole thing was, of course, screened for security, and she notes in a few places where she was asked to label things merely as “special” to make them more vague.)

Fitzpatrick notes that Gamow spent a sabbatical year at Los Alamos in 1949-1950, to help with work on the H-bomb, which matches up with his caption above. While there, he seems to have produced a bevy of H-bomb-themed drawings, of which she reproduces three. One shows the complexity of the energy flow problem in a Super, another portrays the hydride bomb (“Elmer”) as “unattractive and clumsy” in comparison with a lower-yield water penetrating fission bomb (“Elsie”/”L.C.”), and the another portrayed Ulam and Teller themselves as the ultimate Super design:

Gamow's Can't Lose Model for the Super

But back to the original, “simbolic” Gamow image. Ulam’s spittoon almost surely references the fact that you’re using forces at a (relative) distance to compress the secondary, right? Whether one does that by hydrodynamic lensing (Ulam’s original proposal) or radiation implosion (the later Teller-Ulam design) doesn’t seem to be distinguishable. On the other hand, Ulam didn’t propose that until 1951, so this might be something else entirely. Fitzpatrick’s thesis doesn’t spell out any additional Ulam proposals that I saw.

Teller’s is much more cryptic. Looking at Fitzpatrick’s thesis, she says that at this time, Teller was championing a device dubbed “Little Edward.” (Oh myyyy.) This was, she says, “a giant, high-yield multi-crit gun device proposed by Teller that was supposed to produce x-radiation to ignite the D-T mixture in the Super.” Could that be the string of beads with the giant Omega in the middle of it? It sounds like an ungainly device, and indeed, it was eventually dropped as being very wasteful and without much guarantee that it would do anything better than other designs on the table.

And lastly, there’s Gamow’s. According to Fitzpatrick, Gamow’s design was known as the “Cat’s Tail.” She says that it was “a variation on the large fission detonator purported to ignite the Super… Gamow theorized that the Cat’s Tail needed less T[ritium] than had been assumed in the ENIAC Super problems, but could not guarantee this.” Since, as far as I know, Gamow’s designs have never been discussed openly (and were not successful), it’s pretty difficult to try and correlate such an image to an actual bomb design.

Presumably there were no cat-driven hydrogen bombs, though having owned a cat, I can see that one might be seriously tempted to exploit some of their malicious energy in this way. I welcome any and all additional interpretations.

Redactions

The Height of the Bomb

Wednesday, August 8th, 2012

The United States justly gets the lion’s share of credit for making and using the atomic bomb. The Manhattan Project was an international effort, we all know, but the U.S. bore the greatest amount of the labor, the cost, and the ultimately responsibility. When people get mad about the bomb, they get mad at the United States. It makes sense.

The importance of the United Kingdom, in some narratives of the bomb, was mostly in pushing the idea, sending a handful of scientists to help, and signing off on the use of the bomb. (Let’s not even get into Canada, who, according to this narrative, just provided some uranium and a lab that wasn’t allowed to communicate with the rest of the Manhattan Project.)

Several members of the British Mission to Los Alamos: William Penney, Otto Frisch, Rudolf Peierls, and John Cockroft. Photo via Los Alamos.

That handful of scientists, though, included some fairly important people. James Tuck did crucial work relating to the development of the explosive lens in the Trinity and Nagasaki bombs. Klaus Fuchs, aside from being the most significant Soviet spy on the project, helped tremendously with the design of the implosion bomb and the neutron initiators. And so on.

William Penney (later Baron Penney), who later ran the British atomic bomb project, did a whole variety of interesting things. He was crucial in developing means of assessing the effects of the bomb, was the only member of the British delegation to witness the bombing of Japan (he was on an observation plane on the Nagasaki mission), and was one of the first Allied scientists who went into Hiroshima and Nagasaki after the war.

One of the other topics he worked on was the question of what height the bombs should be detonated at for maximum effect.

Illustration of one of the effects of a bomb detonated in the air: a reflection of the blast wave off of the ground, which produces a powerful shock wave known as a Mach stem. From Glasstone and Dolan’s The Effects of Nuclear Weapons (1957 edn.).

This was a non-trivial issue: prior to nuclear weapons, it was pretty common for a bomb to detonate just when it actually physically made contact with its target. With atomic bombs, though, that isn’t ideal. Set one off too high, and much of the blast is going off into outer space and not the target. Too low, and a lot of it is going off straight into the ground. There is no truly “right” height, in the sense that any height will produce different effects that may or may not be desirable, but if the goal is the destruction of civilian buildings, then there are heights that work much better for that than others.

All of which Penney wrote up in a charming December 1944 report on “The Height of Burst of the Gadget.”1

Click for the PDF.

It’s a chilling — and fascinating — document for a few reasons. One is that it goes against any myth that the height of the bomb was set to minimize fallout exposure. This is discussed in great length by Sean Malloy in a recent article in Diplomatic History, which I will be posting a review of fairly soon.2 The entire reasoning for the height of the bomb detonation was about blast and fire effects. Radiation didn’t come into it. Later, when it was questioned as to whether there were fallout issues, the Manhattan Project principals said that they thought the height of the blast would avoid a lot of fallout — which is somewhat true — but this isn’t what caused them to set the height of the blast.

Another interesting bit is that Penney actually wants you to set the bomb off very low — 500 feet or so above the ground — rather than very high. The reason, though, is that Penney is assuming a much smaller bomb than actually was built: his calculation is based on the notion that the bomb will only be about 1 kiloton in yield, whereas previous guesses had been that it would be 10 kilotons or so in yield.

William Penney in the 1950s, looking like a character out of a Le Carré novel

Penney’s document is remarkable in its frankness about the point of the bomb: to destroy civilian houses. He also makes a big distinction between the types of targets available:

There is a significant difference in the blast resisting characteristics of German towns and of Japanese towns. While in Germany a broad distinction may be made between industrial buildings and the remainder, it is true that there is no pronounced contrast in the strength of one building or another, with the exception of the multi-floored reinforced concrete structures which are relatively few in number. In Tokyo or Yokahama, some areas consist entirely of extremely strong steel framed and concrete structures built to resist earthquakes, whereas other much larger areas contain only comparatively flimsy wooden houses with tiled roofs. … Therefore, it may be said that if the gadget is to be used in area attack against a German town, only one height of fusing is required for attack anywhere. Such is not the case for area attack on Tokyo. If the accuracy of delivery can be guaranteed within 500 yards, then the bursting height for attack on wooden houses can be set twice as high as for attack on the business and shopping areas. If this accuracy cannot be guaranteed, then some suitable compromise must be worked out from tactical and statistical arguments.

In other words, all German buildings would be more or less affected in the same way in an atomic bomb blast. Japanese buildings, however, vary between very strong industrial buildings and very flimsy civilian buildings. If the goal is to target civilians, you have much more leeway in the blast height.

Two very interesting things here: One, an atomic attack on Germany is still being explicitly discussed. Two, the “area attack” being discussed is one that contemplates the direct and purposeful targeting of civilians — perhaps even at a detriment to targeting industrial facilities.

Penney then moves on to consider what kind of damage you’re trying to maximize: “complete destruction” versus “severe but not unrepairable damage.” Penney notes that “opinion in England” has gone from favoring “severe” damage to favoring “complete destruction.” Why? Because it turns out that “severe” damage is pretty quick to repair, as the Londoners discovered after the V-1 attacks (“the robot attacks,” as Penney calls them), and because “complete destruction” “implies many casualties, and this in turn has a very serious effect on the efficiency of fire fighting.

Dwell on that for a moment. The more people you kill, the less people who can put out the fires. Lest you think this is perhaps just a moment of remarkable cruelty, Penney actually elaborates on this theme at length later in the report. He makes a distinction here between the “Fire Force” and “fire guards,” which, if I understand it correctly, is the distinction between professional and amateur fire prevention forces:

The explosion of a gadget in either Germany or Japan, causing large amount of [“complete destruction” class] damage will almost certainly result in fires. While the general impression among the Fire Force in England is that the Japanese are likely to prove the most efficient fire guards in the world (because their ordinary lives gives them continual experience), the large number of casualties associated with [this class of] damage may well lead to such confusion in Japan that the critical incubation period of the fires [to become a firestorm] is passed unobserved. Thereafter the fire guards are useless, and only the Fire Force counts. The possibility of eliminating a large fraction of the Fire Force of a Japanese town by getting the fireman into the radioactive contaminated area to fight fires is attractive and realistic. The success of a follow-up attack may be greatly increased in this way. … If a gadget can be followed or accompanied by small [incendiary devices] the probability of a devastating fire, spreading well beyond the limits of the blast damage, will be greatly increased.

Gristly thoughts, no? This is also the only area of the report where radioactivity is mentioned: as a way to kill firefighters, so you can encourage a massive conflagration to develop.

Fire damage in Hiroshima shown in red

In reality, a massive firestorm did erupt in Hiroshima and Nagasaki, and was responsible for the majority of the deaths in each. Making the bombs go off at just the right height for maximizing this sort of damage was a high priority — it even required the development of new kinds of bomb fuses just for this purpose.3

The bomb that went off above Hiroshima, 67 years ago this week, was set off at 600 meters above the ground. The Nagasaki bomb was detonated at 500 meters. Both of those heights were chosen to maximize damage — especially for the “flimsy” wooden houses of Japanese civilians. 

It’s easy to demonize the people who made these kind of decisions — especially when they describe the pre-irradiation of firefighters as “attractive.” But this is the logic of total war, when you’ve given up on the idea of a morality of war fighting and decide that the ends — and not the means — are all that matter. 

Whether one thinks the bombing of Hiroshima and Nagasaki were justified or not, it must be remembered that along with whatever else they were they were massacres of civilians. It was not an incidental or accidental side-effect: it was what they were planned to be. When the scientists at Los Alamos made plans for how to use the atomic bomb, they optimized them for the burning of civilians. This should not be forgotten or glossed over, even if one thinks it was still the right thing to do.

Notes
  1. Source: William G. Penney, “The Height of Burst of the Gadget,” (13 December 1944), copy in the Nuclear Testing Archive, Las Vegas, NV, document NV0315458. []
  2. Sean L. Malloy, “‘A Very Pleasant Way to Die’: Radiation Effects and the Decision to Use the Atomic Bomb against Japan,” Diplomatic History 36, no. 3 (June 2012), 515-545. []
  3. The Little Boy and Fat Man bombs had two sets of altitude-detecting fuses. One, known as the “Archie,” was based on a small directional antennae that had been originally developed so that airplanes could tell if another airplane was behind them. The other was a barometric switch that relied on the changes in atmospheric pressure at different altitudes. They also had a backup timer system that would go off if the other two failed. The technical specifications of both of these fuses are long since declassified, and even patented! See the “Folded Dipole” and “Pressure Sensitive Switch” patents on my page of atomic patents. []
Meditations

More on Centrifuge History

Monday, June 25th, 2012

I wrote about centrifuges a few weeks ago, and have learned some new, interesting things since then. John Krige, a professor at the History, Technology, and Society program at Georgia Tech, has two quite provocative articles  published about interactions between the US and the UK regarding centrifuges in the mid-to-late 1960s. They are worth your attention.

European centrifuges (URENCO)

Krige’s first article is “Hybrid knowledge: the transnational co-production of the gas centrifuge for uranium enrichment in the 1960s,” just published online (and forthcoming in print, I believe) in the British Journal for the History of Science (BJHS).1 As the title may tip you off, this is an article for a primarily history of science/science studies crowd, and speaks in that idiom. Don’t let the jargon scare you off, though: as far as the genre goes, it’s readable and the underlying point is an important one. It concerns the interchanges of centrifuge information between the US and the UK in the early 1960s, which were done under the 1955 US/UK Agreement for Co-operation on the Civil Uses of Atomic Energy, and their consequences when the UK, Netherlands, and Germany decided to go into a cooperative, profitable effort to produce a commercial centrifuge enrichment plant in 1967. (What eventually became URENCO, I believe.)

The US thought this was a somewhat dodgy enterprise — they really didn’t think centrifuges would be as profitable as gaseous diffusion, their chosen enrichment method, but the UK disagreed — but were happy to support it, so long as the UK didn’t give away any “restricted data” that had been produced by the US. And there’s the rub: the UK and US had been exchanging information for a long time, and the UK really thought that it had produced a completely indigenous design (taking off from Gernot Zippe’s unclassified contributions) without any significant US “data” in it. The US disagreed and threatened to cut off all future US-UK exchanges if the latter didn’t let them verify to their satisfaction that there wasn’t any US data in the design. The UK, for its part, thought that it had a really superior centrifuge design compared to the US, and were worried that if the US claimed parts of it were “theirs,” it would completely muddy up their attempts to get clear of the US monopoly on the enrichment of uranium.

In the end, the US decided the UK design was kosher enough, and all was well with them. But it’s a fascinating (and to me, totally unknown) episode in the US-UK “special (nuclear) relationship,” one which really highlights some fundamentally interesting aspects of both US and UK atomic policy, and the fundamentally transnational (as Krige puts it) nature of modern centrifuge development (an Austrian working in the USSR develops technology that he then further works on in the US and the UK which is then turned into a company with the UK, Germany, and Netherlands, etc.). It also gets into some good history of science questions about how one identifies the source of any given piece of design or machinery — and how difficult that can be.

US centrifuges (Piketon)

The second paper by John is “The Proliferation Risks of Gas Centrifuge Enrichment at the Dawn of the NPT: Shedding Light on the Negotiating History,” just published online (and imminently forthcoming in print) in The Nonproliferation Review.2 This essay was a winner of an annual prize by the journal (one of two) and John gave a presentation on it last Thursday at GWU (which you can watch online — John is the first of the two speakers/winners, after the introduction by Stephen Schwartz).

In this paper, John tackles the question of the apparent ambiguity in the 1968 Nuclear Non-Proliferation Treaty (NPT) about whether centrifuge-style enrichment activities (like that currently pursued by Iran) were considered a protected form of “peaceful use” to be allowed and encouraged. It has been speculated that at the time of the treaty’s writing, the risks posed by centrifuge enrichment — which is a lot smaller scale than gaseous diffusion plants, and thus easier to hide or protect — weren’t considered by the NPT drafters, and thus represent an unanticipated “loophole” in the treaty terms.

What John has found is that while centrifuges were not discussed in the official record, they were discussed extensively on the backchannel by the US and the UK. In particular, the UK was extremely worried about the proliferation potential for the gas centrifuge. They, after all, were pursuing the technology themselves, and knew it could be a potent game-changer in breaking the gaseous diffusion monopoly. They wondered if it would not be the angle pursued by a future proliferating state, and conveyed as much to the US.

The US was itself comparatively unworried. It thought that it (and its European allies) could control the spread of centrifuge technology through classification and export controls, and still were dubious that the centrifuge would play a bit role in world affairs anytime soon. I pushed John on this at the talk (you can hear me asking a rambling question about this at the 1:41:24 mark in the video linked above), and he elaborated in a way that I thought was more compelling: the US was weary about getting the treaty signed (they had finally gotten the Soviets on board, and the NPT treaty process was over a decade old at that point), and were worried that any attempt to modify the treaty at that point would bog it down for years to come. Furthermore, the UK was engaging in said partnership with the Dutch and the West Germans, and the US really wanted to make sure the Germans were still on board with the NPT.

(The West Germans were really not too pleased with the NPT and it was a huge hassle to get them to ratify it; like many nations, they appropriately saw it as an infringement on their national sovereignty and their future security options. Of course today the Germans are big supporters of the NPT — it’s interesting how these things switch around, depending on where you are sitting at the time.)

The UK didn’t push the matter, because it didn’t want to rankle the treaty process, either, and because it too wanted to profit off of the centrifuge. So both the US and UK let the matter slide. (I think John’s work highlights something that I’ve been thinking for a short while now: there’s a lot of potential for a “deep” history of the NPT, one that goes beyond the open record.)

Iranian centrifuges (Natanz)

Whether this affects one’s interpretations of the NPT today — John thinks that there is basically no real legal argument against Iran being able to develop centrifuges, and certainly no argument that the early NPT drafters had left an unanticipated “loophole” in place that anyone is taking advantage of — seems to me, someone not at all versed in international law, to be unclear. (Do off-the-record conversations between two parties count towards later interpretations of a treaty’s intent?) But either way, it’s a fascinating story. The apparent US lack of concern about specifically centrifuge proliferation has come back to haunt it, these decades later.

Notes
  1. John Krige, “Hybrid knowledge: the transnational co-production of the gas centrifuge for uranium enrichment in the 1960s,” BJHS (online May 2012). []
  2. John Krige, “The Proliferation Risks of Gas Centrifuge Enrichment at the Dawn of the NPT: Shedding Light on the Negotiating History,” The Nonproliferation Review 19, no. 2 (July 2012), 219-227. []
Redactions

Conant on the Role of the British in the Manhattan Project

Wednesday, March 21st, 2012

The Manhattan Project was a joint effort to build the atomic bomb between the United States, the United Kingdom, and Canada. In practice, most of the labor, expense, and manpower came from the United States, and the degree to which the UK and Canada should be equal partners with the US in the bomb project was a controversial subject.

The British were instrumental in prodding the US into serious action with the MAUD report, and the Canadians had uranium. But should that be it? This was the question in late 1942, when the US program was undergoing a massive transformation. Prior to 1942, the American effort was primarily a research program, trying to answer the question of whether atomic bombs could be built in a reasonable amount of time. From late 1942 onward, the effort shifted to a production program, an all-out effort to try and produce an actual bomb for use in the war. Would the British be let in on this later phase? Did the United States need the British?

Not really, thought James B. Conant, President of Harvard, chairman of the National Defense Research Committee1, and close friend of Vannevar Bush (director of the Office of Scientific Research and Development, which was the civilian side of the Manhattan Project). This week’s document is a letter from Conant to Bush from December 1942, outlining the many reasons he thought that the US should essentially abandon the British at that point in the work:2

Click image to view full PDF.

Conant implored Bush to clarify the matter of UK participation before the full-scale bomb project, run by the U.S. Army Corps of Engineers, got under way, “for it will be clearly difficult to continue to have complete scientific interchange on the one hand and restricted development interchange on the other unless the arrangement is carefully spelled out, for the line between research and development is nebulous, and the same people are often involved in both.”

For Conant, the decision had to be completely pragmatically. The was “presumably one one reason” to share secret military information between Allied nations, “namely, to further the prosecution of the war in which both are engaged.” The question was, would sharing all information with the British do this? He thought not. The British were not producing fissile material, for example, so “our passing our knowledge to them [in that subject] will not assist the British in any way in the present war effort.” So under this scheme, the British would only get to participate in the parts that they themselves were working on which would actually get them closer to making an atomic bomb during World War II. Which is to say, bomb design, reactors, and plutonium would be left out of the story for the British. (“If there be any national rights in this whole area ’49’ [code for plutonium] may be said to be a strictly U.S. invention.”)

Would there be complications? Conant acknowledged that if they cut the UK out at this point, Canada might deny them heavy water. That would be annoying, but not a deal-breaker. They might also deny them uranium ore, which would be a somewhat more dicey procedure until the US was sure of its access to domestic supplies. (They had a considerable amount of high-value ore from the Belgian Congo, but this was insufficient for the entire project.) The British, of course, would “certainly be displeased,” but Conant concludes that “there would be no unfairness to the British in this procedure.”

What would be the advantage to the US in doing this? Conant says simply that it would help with secrecy:

The advantages of restricting all further information to the United States is obvious. Secrecy could be more easily controlled. We are not just reaching the point where the advances are military secrets of the first order of importance.

Conant and Bush were also worried that the British interest in participating in the bomb project had nothing to do with the current war, but with an eye towards scientific and commercial prestige in the postwar period. Conant does not mention this here, though.

There would be many more salvos on this front as Conant and Bush frantically tried to persuade Roosevelt not to let the British into the full, new Manhattan Project. At one point, Bush thought he had convinced FDR of the soundness of this measure.

But however persuasive Vannevar Bush could be, he couldn’t match up to Winston Churchill. By mid-1943, Churchill had convinced Roosevelt that full cooperation was the only true path, and the Quebec Agreement was (secretly) entered into. Not only would the British get access to American research, and send a delegation of scientists to Los Alamos, but they would get to have equal say on whether the bombs themselves were used, and whether the US could share the information with any other countries. In practice, though, the British were nearly completely kept out of Hanford (James Chadwick visited it once), though they learned much about plutonium through their work at Los Alamos. The Canadians founded labs at Montreal and Chalk River, but were more or less excluded from American information by General Groves.

Conant would eventually embrace the Quebec Agreement as well. But his initial reason for wanting to keep the British out — because of the difficulty of controlling secrecy — proved exactly correct. It was, after all, Klaus Fuchs, a member of the British delegation to Los Alamos, who proved to be the most significant of the wartime atomic spies. Of course, he was wrong the British had nothing to contribute: the British delegation (including Fuchs) made major contributions towards the practical realization of the bomb while at Los Alamos. So maybe it all evens out.

Notes
  1. Note that at this point, Office of Scientific Research and Development had taken over most of the responsibilities of the original NDRC. The NDRC became the “NDRC of the OSRD” at this point, which meant that it was merely an advisory body of the OSRD. []
  2. Citation: James B. Conant to Vannevar Bush, “US-British Relations on S-1 Project” (14 December 1942), in Bush-Conant File Relating the Development of the Atomic Bomb, 1940-1945, Records of the Office of Scientific Research and Development, RG 227, microfilm publication M1392, National Archives and Records Administration, Washington, D.C., n.d. (ca. 1990), Roll 2, Target 4, Folder 9, “S-1 British Relations Prior to Interim Committee, [Fldr.] No. 1 [1942].” []