FDR and the bomb

Franklin D. Roosevelt is one of the most enigmatic figures of the early American atomic bomb program. The four-term US president always features briefly in any story of the Manhattan Project: first, for his creation of the Advisory Committee on Uranium, an exploratory research effort in response to a letter urging government action that was sent by Albert Einstein in August 1939; second, for his approval of a broader expansion of that research into a “pilot” program in late 1941, just before the US entry into World War II, which resulted in more intensive investment into uranium enrichment and reactor design; and third, in mid-1942, Roosevelt approved bringing in the US Army Corps of Engineers to manage a full-scale bomb-production project. This latter action is often subsumed by the attention given the first two, but it is the production program decision that actually resulted in the US getting an atomic bomb by 1945, and is the decision that makes the United States unique among powers in the Second World War, as while several powers had research programs, only the US turned it into a production program. It was the beginning of the Manhattan Project as we tend to characterize it, the kind of program that produces weapons and not just data.

A little history trick I always tell my students: if you see Truman and FDR in the same photograph, that means Truman doesn't know about the atomic bomb. Photo source: History.com

A little history trick I always tell my students: if you see Truman and FDR in the same photograph, that means Truman doesn’t know about the atomic bomb. Photo source: History.com

So Roosevelt looms large, as he ought to. Without Roosevelt’s actions, there would have been no atomic bomb in World War II. And yet… What did FDR really think about the atomic bomb? Did he see it as a true end-the-war weapon? Did he think it was meant to be used in war (as a first-strike weapon) or did he think of it primarily as a deterrent (i.e., against the Germans)? The question isn’t just an idle one, because Roosevelt’s sudden death, on April 12, 1945, left his successor, Harry Truman, with major decisions to make about the future of the war, and Truman, in part, thought he was acting in accordance with FDR’s wishes on this matter. But, as is well known, FDR never told Truman about the atomic bomb work, and never set out his wishes on this matter — so there was a tremendous amount of assumption involved.

I get asked about FDR’s views on a fairly regular basis, and it’s one of those wonderful questions that seems simple but is really quite complex, and quickly gets you into what I think of as “epistemological territory”: How do we know what someone’s views were, in the past? How do we get inside the head of someone dead? Well, you might say, obviously we can’t completely get inside someone’s head (we can barely get inside the heads of people who are alive and in front of us, and a Freudian might argue that we barely have conscious access to our own motivations and thoughts), but we can look at what evidence there is that was written down that might reveal some of their inner thoughts.

But with FDR, this is very tricky: he didn’t write that much down. He didn’t keep a diary or journal. He didn’t send that many letters. He didn’t record phone calls, conversations, write “memos to self,” or any of the other documenting habits that are common to major political figures. He was notoriously secretive and private. He didn’t explain himself. If Truman was comparatively straightforward in his thinking and action, Roosevelt was a grand schemer, trying to out-wit and out-charm the world (sometimes successfully, sometimes not). He could be downright gnomic. At one point, Vannevar Bush (FDR’s top science advisor) asked Roosevelt whether the Secretary of the Navy ought to be included in discussions on the bomb project. He later recalled that FDR “looked at me with one of his strange smiles and said, ‘No, I guess not, not now.’” End of anecdote, no real indication as to what FDR was thinking, other than a “strange smile” that no doubt concealed much.1

What approval of a nuclear weapons program looked like under Roosevelt: "VB OK FDR." Report by Vannevar Bush of June 16, 1942, asking to expand the fission work into an all-out effort.

What approval of a nuclear weapons program looked like under Roosevelt: “VB OK FDR.” Report by Vannevar Bush of June 16, 1942, asking to expand the fission work into an all-out effort.

As this example indicates, we do sometimes have accounts, including contemporary ones, by people who met with Roosevelt and talked with him. But even these can be quite tricky, because FDR did not, again, generally explain his full thinking. So people like Bush were left with half-versions of the story, knowing what FDR said but not what he thought, and while this is, to be sure, a common-enough human experience, with FDR the gap between thought and expression was exceptionally large.

Separately, there is another, related issue that complicates our understanding: people who met with FDR would often use tales of his agreement as a form of authority. Vannevar Bush did this repeatedly, and this is no doubt a pretty standard mode of operation regarding advisors and presidents. Bush would go to FDR with an idea, convince FDR to sign off on Bush’s idea, and then claim it was FDR’s idea, because while people might feel free to disagree with Bush, they couldn’t really disagree with FDR. One of the most famous examples of this is Bush’s report on postwar American science policy, Science—The Endless Frontier, which is constructed to look like it is a reply to a letter by FDR for guidance, but was entirely engineered by Bush as a means of pushing his own agenda, with FDR being a complicit as opposed to a driving force.2

So what do we know? The number of documents that give insight into FDR’s personal thoughts about the atomic bomb — what it was, what it could be used for, what his plans were — are very slim. Some of this is a function of timing: FDR died right around when they were getting concrete estimates for when the atomic bomb would be ready to use, and had he lived until, say, May 1945, he might have been faced with more direct questions about his plans for it. (The first Target Committee meeting was on April 27, and the Interim Committee was created in early May, just to give an indication of how things rapidly started to come together right after FDR died.) So he wasn’t part of the conversations that directly led to the use of the atomic bombs on Japanese cities.

But there are a few other documents that are useful in assessing FDR’s views. It seems fairly clear that FDR’s approval of the Uranium Committee in 1939 was initially because he was interested in the deterrent quality of the bomb. Alexander Sachs, who had the meeting with Roosevelt, related that FDR had confirmed that the goal was “to see that the Nazis don’t blow us up.”3 Again, this wasn’t yet a bomb-making program, it was just a “see if bombs are worth worrying about” program, but that’s still a little insight: it shows, perhaps, that the initial, explicit attraction was not in making a new wonder-weapon, but deterring against another one.

Roosevelt, Truman, and FDR's previous VP, Henry Wallace. Truman is the only one here who doesn't know about the bomb program. Image source: Truman Library via Wikimedia Commons

Roosevelt, Truman, and FDR’s previous VP, Henry Wallace. Truman is the only one here who doesn’t know about the bomb program. Image source: Truman Library via Wikimedia Commons

Between 1939 and 1941 there are big gaps in anything that would indicate FDR’s views on the bomb. This is not surprising, because this was a period of relative lack of movement in the US fission program, which was not yet a bomb program. FDR was occasionally involved in discussions about the program, but there was no “bomb” yet to worry about one way or the other. In late 1941, FDR approved accelerating and expanding the research, at the urging of Bush, James Conant, Ernest Lawrence, and Arthur Compton, and in mid-1942 he approved of a full bomb production program, as previously noted. None of these documents indicate intent for use, however. The June 1942 report by Vannevar Bush and James Conant, whose approval by Roosevelt is indicated only by a scrawled “VB OK FDR” on its cover letter, indicates that a weapon made with 5-10 kilograms of U-235 or Pu-239 (then just called “Element 94”) would have an explosive power of “several thousand tons of TNT.” It goes into great detail on the types of plants to be constructed and the organization of the research. It predicts a “bomb” would be ready by early 1944. But at no point does it indicate what the point of such a weapon was: as a deterrent, as a first-strike weapon, as a demonstration device, etc. There is only point, towards the end, which suggests that a committee be eventually formed to consider “the military uses of the material,” but even this is primarily concerned with research and development for the plants. This is not to say that Bush, Conant, et al. did not have their views on whether it would be a weapon to use or not — but the report does not indicate any such views, and so FDR’s endorsement of it doesn’t tell us much.4

Bush met with Roosevelt many times during the war, and sometimes would write down, afterwards, what they talked about. Clearly this is FDR-as-filtered-through-Bush, but we’ll take what we can get. In late June 1943, Bush wrote to Conant with an account of a recent meeting he had with FDR on “S-1,” their code for the bomb work. In it, Bush related that FDR was curious about the progress of the work and the schedule for having a bomb. Bush told him things were going well but still tentative, and that the date of a bomb had been pushed back to early January 1945, but that this could shift in either direction. FDR also wanted to know how the Germans were doing. Bush explained that they didn’t really know, that they were trying to find ways to slow down any German work, and that they were still worried about being behind the Germans. (They would eventually come to understand they had surpassed them.) Then there is this really interesting passage which is worth quoting from the original:

He [FDR] then himself discussed what the enemy attitude of mind would be if they felt they had this coming along, and were inclined to remain on the defensive until it could eventuate. We then spoke briefly of the possible use against Japan, or the Japanese fleet, and I brought out, or I tried to, that because at this point I do not think I was really successful in getting the idea across, that our point of view or our emphasis on the program would shift if we had in mind use against Japan as compared with use against Germany.5

After which the conversation then shifted to other matters. Such a tantalizing snippet of discussion, but not as fleshed out as one might want! What did Bush and FDR understand the difference to be between the Japanese versus the Germans? Who initially brought up the possibility of use against the Japanese? What did FDR think about the German “attitude of mind”? This snippet hints at exactly the topics one might care about but doesn’t actually reveal anything about FDR’s views on them! Impressively frustrating!

Most of FDR’s interactions with Bush, Groves, and others during this period concerned diplomatic issues, specifically cooperation with the British (a rather long, drawn-out saga), and even a meeting with Niels Bohr (from which FDR mostly took away a fear that Bohr might alert the Soviets, or others, to the US work). FDR helped, for example, in helping to shut down unionization activities at the Berkeley Radiation Laboratory, and was kept abreast of efforts made to monopolize global uranium ore resources. He was not “checked out” in any respect; he was dramatically more concerned with the ins-and-outs of the fission work than, say, Truman would later be. But again, very little of this left any record about what he thought they were going to do with the bomb.6

Atomic diplomacy: Roosevelt and Churchill at Quebec, in September 1944. Source: NARA via Wikimedia Commons

Atomic diplomacy: Roosevelt and Churchill at Quebec, in September 1944. Source: NARA via Wikimedia Commons

Two of the only documents that reveal any FDR-specific thoughts about the use of the bomb were agreements he made with Winston Churchill. In August 1943, Churchill and Roosevelt met in Quebec, Canada, and hammered out the secret “Quebec Agreement.” It said, among other matters, that the US and UK would pool their efforts at both making the bomb and securing global uranium reserves, that they would never nuke each other, that they would never nuke anyone else without mutual agreement, and they would not reveal the secrets of the bombs without mutual agreement. So this at least provides a framework for using the bomb, but it is a limited one — FDR was willing to deliberately tie the US’s hands with regards to dropping of the atomic bomb to the approval of a foreign power, quite an amazing concession!7

Another meeting between Roosevelt and Churchill, in Hyde Park, New York, produced yet another fascinating agreement. The Hyde Park Aide-Mémoire of September 1944 contained the following clause:

The suggestion that the world should be informed regarding tube alloys, with a view to an international agreement regarding its control and use, is not accepted. The matter should continue to be regarded as of the utmost secrecy; but when a “bomb” is finally available, it might perhaps, after mature consideration, be used against the Japanese, who should be warned that this bombardment will be repeated until they surrender.

Here they were explicitly rejecting the appeal by Niels Bohr (which he was able to make personally to both FDR and Churchill, on separate occasions) to alert the world about the atomic bomb. But it is of interest that they were, at this point, specifically thinking about using the bomb against the Japanese (not Germany), but that they thought it would require “mature consideration” before use, and that they were putting “bomb” in scare-quotes. This is one of the few indications we have of FDR’s awareness and acceptance of the idea that the bomb might be used as a first-strike weapon, and against the Japanese in particular.

Lastly, there is one other significant FDR-specific datapoint, which I have written about at length before. In late December 1944, with Yalta looming, Roosevelt and Groves met in the Oval Office (along with Henry Stimson, the Secretary of War). In Groves’ much later recollection (so we can make of that what we will), Roosevelt asked if the atomic bomb might be ready to use against Germany very soon. Groves explained that for a variety of reasons, the most important one being that their schedule had pushed the bomb back to the summer of 1945, this would not be possible. It is an interesting piece, one that simultaneously reveals Roosevelt’s potential willingness to use the atomic bomb as a first-strike weapon, his willingness to use it against Germany specifically, and the fact that FDR was sufficiently out of the loop on planning discussions to not know that this would both be impossible and very difficult. In other words, it reveals that FDR wasn’t aware that by that point, it was expected that the bomb could only be used against Japan, and that is a rather large thing for him not to know — further evidence, perhaps, that he was not completely abreast of these kinds of discussions. At the meeting, Groves gave FDR a report that predicted a weapon ready for use in early August 1945, and specified that it was time to begin military planning, which Groves annotated as having been “approved” by the Secretary of War and the President. But there doesn’t seem to have been any specifics of targets, or even targeting philosophy, agreed upon at this point.8

What can we make of all this? Frequently I have seen people take the position that Truman himself took: assuming that Roosevelt would have used the bomb in the way that Truman did, because what else might he have been planning? I would only caution that there were more “options” on the table even for Truman than we tend to talk about, which is just another way to say that dropping two atomic bombs in rapid succession on cities is not the only way to use an atomic bomb even militarily. That is, even if one thinks it was inevitable that the bombs would be used in a military fashion (which I think is probably true), it is unclear what position FDR might have taken on the question of specific targets (e.g., the Kyoto question), the question of timing (e.g., before or after the Soviet invasion; how many days between each strike?), and diplomatic matters (e.g., would Roosevelt be more open to modifying the Potsdam Declaration terms than Truman was?). So there is room for considerable variability in the “what if Roosevelt hadn’t died when he did?” question, especially given that Roosevelt, unlike Truman, had been following the bomb work from the start, and was as a result much less reliant on his advisors’ views than Truman was (he frequently bucked Bush, for example, when it came to matters relating to the British).

Would Roosevelt have dropped the bomb on Japan, had he not died? I suspect the answer is yes. One can see, in these brief data points, a mind warming up to the idea of the atomic bomb as not just a deterrent, but a weapon, one that might be deployed as a first-strike attack. In some ways, FDR’s query to Groves about Germany is the most interesting piece: this was a step further than anyone else at the time was really making, since Germany’s defeat seemed inevitable at that point. But, again, the strict answer is, of course, that we can’t really know for sure. Perhaps if FDR had confided his inner thoughts on the bomb to more people, perhaps if he had written them down, perhaps if he had been more involved in the early targeting questions, then we would be able to say something with more confidence. Unless some new source emerges, I suspect Roosevelt’s thoughts on the bomb will always have something of an enigma to them. It is not too far-fetched to suggest that this may have always been his intention.

Notes
  1. Vannevar Bush, Pieces of the action (New York: Morrow, 1970), 134.
  2. See Daniel J. Kevles, “The National Science Foundation and the Debate over Postwar Research Policy, 1942-1945: A Political Interpretation of Science–The Endless Frontier,” Isis 68, no. 1 (1977), 4-26. Another example of this behavior, from my own research, is when Bush wanted to seize patent rights relating to atomic research during the war — this was an idea cooked up by Bush, approved by FDR, and then presented as an idea of FDR’s, to give it more political, legal, and moral heft. See Alex Wellerstein, “Patenting the Bomb: Nuclear Weapons, Intellectual Property, and Technological Control,” Isis 99, no. 1 (2008), 57-87, esp. 65-66.
  3. Quoted in Richard Rhodes, The Making of the Atomic Bomb (Simon and Schuster, 1986), on 314.
  4. Vannevar Bush and James Conant, “Atomic Fission Bombs,” (17 June 1942), with attached cover letter initialed by Roosevelt, copy in Harrison-Bundy Files Relating to the Development of the Atomic Bomb, 1942-1946, microfilm publication M1108 (Washington, D.C.: National Archives and Records Administration, 1980), Folder 58: “Vannevar Bush Report – March 1942,” Roll 4, Target 4.
  5. Vannevar Bush to James Conant, “Memorandum of Conference with the President,” (24 June 1943), copy 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 5, Folder 10, “S-1 British Relations Prior to the Interim Committee [Fldr.] No. 2 [1943, some 1944, 1945].”
  6. For a very nice discussion of Roosevelt’s wartime “atomic diplomacy,” see Campbell Craig and Sergey Radchenko, The atomic bomb and the origins of the Cold War (Yale University Press, 2008), chapter 1, “Franklin Delano Roosevelt and Atomic Wartime Diplomacy,” 1-33. On the UK-US atomic alliances, see Barton Bernstein, “The uneasy alliance: Roosevelt, Churchill, and the atomic bomb, 1940-1945,” Western Political Quarterly 29, no. 2 (1976), 202-230
  7. And just to follow up on that: the US did, in the summer of 1945, request formal UK approval for the dropping of the atomic bomb, and for the release of the Smyth Report and other publicity. The UK readily gave assent to using the weapon against the Japanese, but they did question the wisdom of releasing the Smyth Report. They eventually consented to that as well, after stating their reservations.
  8. Just as an aside: the meeting, by Stimson’s diary account, was only 15 minutes long, and most of it pertained to questions of diplomacy (specifically potential British violations of the Quebec Agreement with respect to French patent arrangements). Stimson’s diary entry mentions nothing about targeting question, German, Japanese, or otherwise. So either the discussion of Germany and Japan did not make much impression on him, or he did not think it prudent to write it down. See Henry Stimson diary entry for December 30, 1944, Yale University. Groves own contemporary record of the meeting also neglects to mention anything relating to targets, and instead is entirely focused on diplomatic questions. Leslie Groves, Memorandum on Meeting with President (30 December 1944), Correspondence (“Top Secret”) of the Manhattan Engineer District, 1942-1946, microfilm publication M1109 (Washington, D.C.: National Archives and Records Administration, 1980), Roll 3, Target 7, Folder 24, “Memorandums to (Gen.) L. R. Groves Covering Two Meetings with the President (Dec. 30, 1944, and Apr. 25, 1945).”

The blue flash

This last weekend was the 70th anniversary of Louis Slotin’s criticality accident. One slip of a screwdriver; a blue flash and wave of heat; and Slotin had a little over a week to live. It’s a dramatic story, one that has been told before. I tried to give it a little bit of a fresh look in my latest piece for the New Yorker’s Elements Blog: “The Demon Core and the Strange Death of Louis Slotin.”1

Demon Core New Yorker Screenshot

In researching the piece, I looked over a lot of technical literature on the accident, as well as numerous accounts from others who were in the room at the time. A few things stuck out to me that didn’t make it into the piece. One was that it was remarkably non-secret for the time. Los Alamos put out a press release almost immediately after it happened (by May 25th, five days before Slotin’s death, it was in national newspapers), and followed it up with more after Slotin’s death. For mid-1946, when the Atomic Energy Act had not yet been signed and the future of the American nuclear infrastructure was still very much in question, it was remarkably transparent. The press release was where I saw the phrase “three-dimensional sunburn” for the first time.

I also went over the account of Slotin’s case that was published in The Annals of Internal Medicine in 1952.2 Slotin isn’t named, but he’s clearly “Case 3.” Harry Daghlian, who also died from an accident with the same core, is “Case 1,” and Alvin Graves, who was the nearest person to Slotin during his accident, and later became a director of US nuclear weapons testing, is “Case 2.” The article is long and technical, and ends with some of the most disturbing photographs I have ever seen of the Daghlian and Slotin accidents. There is a photo of Daghlian’s hand that has been reproduced many places (including in Rachel Fermi’s Picturing the Bomb), but I’d only previously seen it in black and white. It is much worse in color — the contrast between the white blistered skin and the pink-red stuff under the cut-away area is dramatic and disturbing. There are others in the same series that are just as bad if not worse: blackened, gangrenous fingers. Slotin’s photos in that article are comparatively tame but still pretty unsettling. Blisters. Cyanotic tissue. A photograph of his left hand — the one that was closest to the reacting core — on the ninth day of treatment (his last day alive) looks almost corpselike, or even claw-like. It is unsettling. I will not post it here.

An anonymous e-mail tipped me off that there were more photographs, and more documents, at a collection at the New York Public Library. These were part of a collection deposited by Paul Mullin, who authored the Louis Slotin Sonata, a very interesting, very curious play about Slotin from the late 1990s. I haven’t seen the play, though I had seen mentions of it for awhile. Mullin’s materials were fascinating and very useful. There were two boxes. The first was mostly notes relating to the creation of the play. It is always interesting to see how another researcher takes notes, much less one whose end-product (a play) is very different from the sort of thing I do. It does not take much glancing at his notes to see that Mullin got as deep into this topic as anyone has. The second box contained research materials: four folders of documents obtained from Los Alamos under the Freedom of Information Act, and a folder of photographs.

The hands of Louis Slotin, shortly after admission to the Los Alamos hospital. Source: Los Alamos National Laboratory, via the New York Public Library (Paul Mullin papers on the Louis Slotin Sonata).

The hands of Louis Slotin, shortly after admission to the Los Alamos hospital. Source: Los Alamos National Laboratory, via the New York Public Library (Paul Mullin papers on the Louis Slotin Sonata).

The photographs were, well, terrible. They included the ones from the Annals of Internal Medicine article, but also many more. Some showed Slotin naked, posing with his injuries. The look on his face was tolerant. There were a few more of his hand injuries, and then the time skips: internal organs, removed for autopsy. Heart, lungs, intestines, each arranged cleanly and clinically. But it’s jarring to see photographs of him on the bed, unwell but alive, and then in the next frame, his heart, neatly prepared. The photo above, of just his hands, is one of the tamest of the bunch, though in some sense, one of the saddest (there is a helplessness, almost like begging, in the position). I didn’t make copies of the really awful ones. History is often very voyeuristic — I joke with students that I read dead people’s mail for a living — but, as I commiserated with Mullin over Twitter, at some point you start to almost feel complicit, as silly as that notion is.

The documents were invaluable. They mostly covered the period immediately after the accident — people checking in on Slotin’s health, the complicated legal aspects of dealing with the death of a scientist (and with his distraught family), the questions of what to do next. An inordinate amount of paperwork was generated in dealing with the disposition of Slotin’s automobile (a 1942 Dodge Custom Convertible Coupe). The Army’s interactions with Slotin’s family appeared sympathetic and generous. There appears to have been no cloak-and-dagger regarding the entire affair. Slotin was, after all, a friend to many of those at Los Alamos, and a key member of their “pit crew.”

One of the accounts that I found most fascinating was that of the security guard, Patrick Cleary, who was in the room when the accident happened. Cleary was there because you don’t just keep a significant proportion of the nation’s fissile material stockpile unguarded. He seems to have understood little about what risks his job entailed, though:

When the accident occurred, I saw the blue glow and felt a heat wave. I knew something was wrong, but didn’t know exactly what it was, when I saw the blue glow and somebody yelled. … Our instructions are also to keep in sight of all active material that is around, except in the case of a critical assembly, but [I] am not sure about that. I did not actually know what the material or sphere was at the time, or anything about it.3

When Cleary saw the flash and heard yelling, he literally took off for the hills, running. He was called back, as the scientists tried to reconstruct where people were standing for the purposes of dosage calculation. Cleary, in fact, was the last person to leave, because security guards can’t walk off the job — he had to wait until a replacement came.

Close-in shot on the Slotin accident re-creation. The beryllium tamper is on top; the plutonium core is the smaller sphere in the center. Notice in this particular shot, they have a "shim" on the right. Slotin removed the shim right before his fatal slip.

Close-in shot on the Slotin accident re-creation. The beryllium tamper/reflector (they called it a tamper) is on top; the plutonium core is the smaller sphere in the center. Notice in this particular shot, they have a “shim” on the right. Slotin removed the shim right before his fatal slip. The scientist re-creating the photograph is physicist Chris Wright. I wonder if they took extra precautions in making this particular set of photos?

For a long time I had been wondering what happened to the so-called “demon core,” which was also known as “Rufus,” something that strikes me as just too strange to be anything but true. It has been reported many times that it was used at Operation Crossroads, at the Able shot. I found some documentation that suggested this was very unlikely. For example, shortly after the accident (Slotin was still alive), lab directory Norris Bradbury wrote to a few other scientists at Los Alamos about how the accident had affected the forthcoming Crossroads tests. He notes that the sphere in question was getting “its final check” during the accident — so it was definitely slated for Crossroads. But he continues:

Obviously Slotin will not come to Bikini. [Raemer] Schreiber will come although the date of special shipment was postponed one week to allow us to pull ourselves together. Only two shipments will be made at this time as I see no courier for the third. The sphere in question is OK although still a little hot but not too hot to handle. We will save it for the last in any event if it is needed at all.4

Which seemed pretty suggestive to me that they weren’t going to use it: only two shipments were going to be made early on, and “the sphere in question” was not one of them. It would be saved for the “last event.” Which in this case was the “Charlie” shot — which was cancelled.

I wanted some more confirmation, though, because a plan isn’t always a reality. I e-mailed John Coster-Mullen, who I knew had done a lot of research into the Slotin and Daghlian accidents. (John is the one that provided me with these wonderful high-resolution photographs of the Slotin re-enactment, and some of the documents in his appendices to Atom Bombs were very useful for this research.) John suggested I get in touch with Glenn McDuff, a retired scientist at Los Alamos who was also one of the consultants on Manhattan (he drew the equations on the chalkboards, among other things). This turned out to be a great tip: Glenn has been working on an article about the fate of the first eight cores. There is much still to be declassified, but he was able to share with me the fate of the core in question: it had not been used at Crossroads, it had been melted down and the material re-used in another core. Glenn says there was no particular reason it was melted down. It was old, as far as cores went, and they were constantly fiddling with them in those days — the days in which they still gave bomb cores individual nicknames, because there were so few of them.

For nuke nerds, this is the big “reveal” of my New Yorker piece, the one thing that even someone very steeped in Los Alamos history probably doesn’t know. (For non-nuke nerds, I doubt it registers as much!) And even though it is a bit anticlimactic, I actually prefer it to the version that the core was detonated shortly after the accident. The part about them immediately re-using the core in a weapon just always seemed a little suspicious to me — it almost implied that they had done it due to superstition, and that didn’t really jibe with my sense of how these scientists viewed the accident or these weapons. And even the anticlimax has a bit of a literary touch to it: the “demon core” wasn’t expended in a flash, it was melted down and reintegrated with the stockpile. Who knows whether bits of its plutonium ended up in other weapons over the years, whether any of that core is still with us in the current arsenal? There’s perhaps something even a bit more “demonic” about this version of the story.

Notes
  1. A few small errata to the piece, based on a few questions I got: 1. Should the beryllium hemisphere be called a tamper or a reflector? In most contexts today we would call it a neutron reflector, because that’s the property that you use beryllium for in a bomb (a tamper’s job, generally, is to hold the core together as long as possible while it reacts, and so heavy, dense metals like uranium are used). But in this case, the scientists at the time referred to it universally as a “beryllium tamper” so the editor and I just decided to keep things simple and call it that, rather than call it a “reflector” and then clarify that it was the same thing as the “tamper” that was cited in the quotes. (This is the kind of linguistic hair-splitting that goes into these pieces — a balance between the historical language, the present-day language, the technical aspects, etc. We try to come to sensible decisions.) 2. At one point, it refers to the “pits” at Hiroshima and Nagasaki. This is just meant in a colloquial way here to refer to their fissile material cores. The Hiroshima bomb of course was a different design, made of two different pieces, called the Projectile and the Target in the documents at the time. It seemed unnecessary to introduce all that complexity to make a point that they didn’t give it any kind of colorful moniker. 3. There was one legitimate typo in the piece as published, which was my fault. It misstated the amount of time between the Daghlian and Slotin accidents (three months instead of nine). I’m not sure how that got in there — I actually re-looked up the date differences at the time I wrote it, and know the months cold. One of those strange disconnects between the head and the fingers, I suppose, and somehow I missed it in re-reading the drafts. Very frustrating! It’s the little things you aren’t worried about getting wrong that can get you, in the end. It has been fixed.
  2. Louis H. Hempelmann, Hermann Lisco, and Joseph G. Hoffmann, “The Acute Radiation Syndrome: A Study of Nine Cases and a Review of the Problem,” Annals of Internal Medicine 36, no. 2 (February 1952), Part 1, 279-510.
  3. Patrick Cleary, account of the Slotin accident (29 May 1946). Copy in the Paul Mullin, “Production materials for the Louis Slotin Sonata, 1946-2006,” New York Public Library.
  4. Norris Bradbury to Marshall Holloway and Roger Warner (undated, ca. 24-29 May 1946). Copy in the Paul Mullin, “Production materials for the Louis Slotin Sonata, 1946-2006,” New York Public Library.