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Alfred Zeltmann’s Interview

Manhattan Project Locations:

Al Zeltmann grew up in Brooklyn, New York. After being drafted into the Army during World War II, he was assigned to the Special Engineer Detachment and arrived at Los Alamos in 1944. After the war, he stayed at Los Alamos, and worked as a physical chemist at the Los Alamos laboratory for nearly 40 years. In this interview, he recalls his Manhattan Project work, including on the “RaLa” experiments with Gerhart Friedlander, and describes the relationship between the military and civilians on “The Hill.” He also remembers receiving some unusual instructions from a mail censor after his wife complained he “wasn’t very warm” in his letters.

Date of Interview:
October 12, 2017
Location of the Interview:


Nate Weisenberg: My name is Nate Weisenberg, and I’m here with the Atomic Heritage Foundation. It is Thursday, October 12, 2017, and I am here with Mr. Al Zeltmann at his home in Los Alamos. My first question for you is if you could please say your name and spell it. 

Alfred Zeltmann: Well, my name is Alfred Zeltmann. Z-E-L-T-M-A-N-N. I’ve lived in Los Alamos for about seventy-three years. I came here as a GI in the Special Engineer Detachment, which was formed from various ASTP [Army Specialized Training Program] units during World War II. We were allegedly training to be officers, but at the time they needed technicians for the Manhattan Project. They were also pretty well satisfied with the number of officers they had. So they broke up the Army Specialized Training Program and sent a lot of us to various parts of the Manhattan Project.

Let’s see. I guess you’d like some of my background, where I started from. I was born and raised in a part of Brooklyn, Greenpoint. I was born in 1921, and as a result my family and I lived through the Depression in New York, which was an unfortunate experience for all of us. About a quarter of the men in New York City were unemployed, and my father was one of those for a couple of years.

I was fortunate enough to go to a very good high school, Brooklyn Technical High School, which had programs in chemical, architectural, civil, mechanical engineering, and I got an opportunity upon graduating to go to Cooper Union, which is a private endowment that gives a free education to people. I worked during the day as a machinist, and went to college at night four evenings a week. They’d have three hours of college. I’d walk down from 23rd Street where I worked in Manhattan down to Cooper Union each night, and from 7:00 to 10:00 we had our classes and then I’d go home. At the time, my family lived in Queens rather than Brooklyn, so it’s a long subway ride. I’d get home about 11:00, and then I could have dinner which my mother made.

I was drafted in 1942, and I went to an infantry unit. They realized pretty soon that I wasn’t fit for the infantry. I was sent off the Ohio State University to continue my college program, essentially. When the Army decided to break up its specialized unit there, some us were sent to Oak Ridge and some to Los Alamos and others to Pullman [misspoke: Hanford], Washington.

When I got here it was a very pleasant atmosphere. The civilian scientists who were operating here were very solicitous of the GIs’ welfare, so that they were able to do a lot of good for us. It was a very pleasant experience to live here. It was the Army, but the civilians were living here too. They constructed a lot of housing in short order here for the civilians. The GIs, of course, lived in barracks. The GIs did various things. Some of us who were staff members were able to continue functioning as research assistants, but some of the GIs actually had Ph.Ds., so they were on a pretty good level and actually were carrying out their own research.

I was working on several projects which were critical to the production of the bomb, so in the course of time I met Oppie, [J. Robert] Oppenheimer. Who was concerned about a particular project we were on, so I got to meet him. I never met General [Leslie] Groves, although he presided on several ceremonies here at Los Alamos. It used to be that every time General Groves would show up here they’d have a parade, and he’s award us a special award, a gold arm for our sleeve of the uniform. We used to call it the “golden toilet seat.” But he’d give a speech, and we’d have a parade.

Oppenheimer and Groves were my heroes actually for the Manhattan Project. Groves was important because, even though he was a senior officer – he started out as a Colonel, I guess. Here at Los Alamos, he kept his hands off the scientific work and let Oppenheimer do what he had to do to produce a bomb. He just provided the money and the equipment. And Oppie got along very well with the scientists and everyone, actually. He was a gracious man. I guess he could be stern with his equals at his scientific level, but he was generally pretty sympathetic to the GIs and their needs.

Actually, the GIs may have been doing just as well as some of the civilians, because a sergeant like myself would be getting a hundred dollars a month as a salary and also getting an allowance because I was married at the time. Civilians at that time would be doing very well to get two hundred dollars a week, and it was a lot easier for us with our rank at two hundred then it was for them.

A lot of us used to go back to work at night because there wasn’t much else to do. If we went to a movie, then we would stop off at the Tech Area and carry out some project. People tended to work a lot more than eight hours a day trying to get things done. I imagine we started out with a scientific staff that couldn’t have been three hundred or so, and it was several thousand by the time the war ended. In fact, I was in the first one hundred fifty GIs to come here. And by the time the war ended there were ten or twelve barracks with maybe fifteen hundred GIs here. Apparently, the Army could supply any number of college students. They didn’t know what to do with them otherwise. They sent them to a project like this.

A lot of us weren’t convinced that this was a place to live having come from big cities, not used to the West, but after a while it grows on you. Life, as I say, was relatively pleasant. You made your own entertainment. We played bridge in the barracks, and I suppose other people played cards and gambled.

There was a battalion of WACs [Women’s Army Corps] here also, so that single GIs met girls here that they married. We used to have colloquia, on I think it was Tuesday evening, in which Oppenheimer would introduce a speaker, and also note what progress had been made on the sticky issues of manufacturing a bomb. Then there would be a speaker who would speak extensively on whatever project was of interest. Up front in these colloquia would sit all the present and future Nobel Laureates. There would be [Edward] Teller. [Richard] Feynman was here, a young fellow just starting his career, and a number of other Nobel Laureates. There was quite an elite group. I can’t imagine some of the people who had to give those colloquia, the younger scientists in front of this very critical audience, but I guess it was a way of maturing.

After the war, they did manufacture some housing for the people that stayed on. There was some difficulty at their end of the war. A lot of the senior scientists wanted to go back to the universities and pursue their careers, so they weren’t sure that they could get enough staff to stay and continue the work. A man named Norris Bradbury took over the leadership of the lab, and he was able to pull things together. They gave us very good salaries to stay here. In fact, I was making a lot more than most Ph.Ds. made immediately after the war. You wouldn’t believe how cheap you could get a good scientist in those days. Three thousand dollars a year was a great salary, and of course things expanded very quickly. But they were able to build the atomic bomb for less than two billion dollars and the reason, people were getting dirt cheap salaries. But most of us would have been happy to work for a lot less just to be involved in the work that we were doing.

A lot of people, after the war, seemed to express doubts about the morality of building an atomic bomb, but while we were here during the war we realized a lot of people were going to die unnecessarily if we didn’t have, a lot of Americans at least. So it was quite logical for us to want to make an atomic bomb in hopes to end the war earlier. I don’t know what else to say. I’ll be glad to answer any questions you might have.

Weisenberg: Picking up on the last point that you just made. When you got here, did you know what you would be working on?

Zeltmann: Oh, yes. There was never any doubt of what we were working on. As a staff member, when you came in you were given a special report. It laid out exactly the size and amount of material that you were going to need for the bomb, and they even projected, I think, pretty much the exact yield of the first atomic bomb. Something like eight megatons – no, not megatons, eight kilotons – of explosive. That was the reason why there were white badges. White badges were the people allowed to attend the colloquia. If you had a red badge or a yellow badge you were excluded. We all had the same kind of clearance, but they just didn’t want to distribute the knowledge too widely. I don’t think it was any secret. I think most of the wives knew what their husbands were doing, and you just didn’t talk publicly about what was going on.

There were incidents where – I don’t know how true they were – they said that packages were delivered “To the atomic bomb project, Post Office Box 1663.” That was one thing that was interesting here. Our mail was censored – what we would do is send our mailed out unopened, not sealed, and the censor would read it, and if he didn’t like what you said he’d send it back to you. And the same way coming in. Your mail would be censored as well. We were allowed to tell our relatives where we were and that we couldn’t reveal any information, but people knew where we were.

An interesting experience I had: I went home to New York after the first atomic bombs had been exploded. I was at the barber shop and telling the barber where I was. He wanted to know how I liked living in a foreign country. Most people didn’t know at the time where New Mexico was, I guess, and thought it was part of some other country. 

My wife, in the earlier days, was not allowed to be on the project, and so she sent a letter. The censor noticed that she was complaining that I wasn’t very warm in my letters, and the censor finally sent me a note – “Tell her what she wants to know!” Which was pretty interesting. I guess they assigned young officers to read the mail to censor them. What else? 

Oh, daily life. The barracks was on the west end of Trinity [Drive] near the hospital, and the Tech Area was about a mile up the road. And we used to walk that back and forth every day. We had to come back to the barracks area for lunch, the same way for dinner. During the summer, it had a tendency to rain about noon every day, and you’d have a fresh uniform on, and you’d get pretty soggy moving up and down that road. 

In the evenings, as I said, if you weren’t going to a colloquium you went to the movies. Pretty cheap, ten, fifteen cents, I guess. We saw all the pictures. They always had a military picture that you might listen to or watch, warn you about venereal diseases or something like that. There was always one short film like that to go with the feature film, I guess. 

One of the favorite meals in the Army was tongue. It wasn’t my favorite, but the chef used to put out these long trays of beef tongue, four rows. During the war, there was a shortage of electricity, and the power would go out just about dinner time. When the power went out, you found out when it came back on that you were sharing your meal with the cockroaches. [Laughter] 

I didn’t like the beef tongue anyway, so you could go up to the PX [Post Exchange], and you could get a steak and a salad for about a buck, a buck and a quarter, and so that was frequently what we did, some of us. Army food wasn’t all that great. I guess it was nourishing, but I could have done without a lot of it. Can you think of anything else? 

Weisenberg: When you were at Ohio State, what did they tell you about where you would be sent next? 

Zeltmann: Nothing. It was very interesting the way they got us all together, and they had a real old train. They probably didn’t use the main lines. They took us down to Oak Ridge on some – the way the Army transported us, there were un-cushioned seats on the train. They were just slats. And there would be three of us in two facing chairs. One facing two others. We got down into Oak Ridge, and they transported us in a bus with all its windows shielded, and they moved us into Oak Ridge into a barracks. 

I was there for about a month until they assigned us to Los Alamos. Then we came out on a very slow train from Oak Ridge. Instead of taking us directly, they took us up to Chicago because the brakes on the train were worn out, and they had to fix them somewhat. Then we got from Chicago down to Lamy, and at Lamy they picked us up and delivered us to Palace Avenue down there in Santa Fe. Then we got another bus up here to Los Alamos. 

The train from Chicago to Los Angeles was a California Limited or something like that, and it was frequently twenty-four hours late going through Santa Fe. Santa Fe is one of those capitals that doesn’t have a railroad going through it, a passenger railroad, so the closest place was a place called Lamy. I guess it’s about fifteen miles from Santa Fe. They dumped us there. Just a station and a restaurant, I guess. We were wondering what we were getting into when we were dumped down there in Lamy. I don’t think Lamy has improved much over the years, so we were very uncertain. 

Actually, they shipped us out here with about thirty GIs at a time. At the time, they assembled us in front of a big assembly building, which was in the center of downtown Los Alamos where there are a couple of bank buildings now. At the time, I guess they hadn’t finished the first barracks building. We lived in sixteen-by-sixteen square shacks, tapered roofs, and standard Army type of building you probably seen in M*A*S*H

There wasn’t, as I say, much entertainment. You could go to the PX and get a hamburger. Right now, downtown, there’s a post office building. Right where that post office building is there used to be a general store, and as you go further down there was a PX where everybody went for – they did have a jukebox, so sometimes some of the GIs and WACs would be dancing. You could eat. And then there was a gas station and a barber shop, and that was the extent of the center of town.

Across the street from the general store was a military commissary where civilians got all their food. Obviously, everything else was military. It was either the – I forget what they call them – assembly buildings they used as a church on Sunday. We used it for the colloquia. And all of these square sixteen by sixteen square buildings along the main street; that was all that was there. They did eventually build some civilian housing to the north of Trinity.

Weisenberg: Who were some of the people that you worked with?

Zeltmann: Well, I worked with some people who were relatively famous here. Rod Spence was the group leader. He and several others like Gene Robinson were working on the half-life of tritium. There wasn’t much tritium around in the early days, but they – it’s a rapidly decaying radioactive hydrogen which is used in bombs. But my group leader was a man named Gerhart Friedlander, who is a very famous radiochemist. Friedlander and [Joseph W.] Kennedy wrote the primary book for radioactivity [Nuclear and Radiochemistry]. In fact, two of my friends and I took the course that Friedlander gave up here for radiochemists, and we prepared the original notes for this book that became famous. Joseph Leary and Gordon Knobeloch. 

Oh, Rene Prestwood was a radiochemist who was very good at working with radioactive polonium. Polonium is a radioactive element which tends to get all over your lab. Recoil from the alpha particles drives the other radioactive material all around, so he was very good at working without getting it all over the building. 

Let’s see, I had a group leader later on named Joe Lemons, who was not famous, but he was one of the people I worked with. Oh, Eric Jette, who was a professor of metallurgy at Columbia before the war, was an assistant division leader. Fortunately, I had gone to Cooper Union and I had one of Eric Jette’s students – graduate student [who] was a professor there. That gave me sort of an in with Jette. I think it made my life a lot more pleasant to have some attachment to the division leader. 

Robert [misspoke: Joseph W.] Kennedy was, I think, co-discoverer of element 94 with [Glenn] Seaborg who was in California. After the war, he went off to Washington University in St. Louis and became the head of the chemistry department there. I’ve never said, but my Ph.D. is as a radiochemist, a physical chemist, but specializing in radiochemistry.

 It was rather interesting that for a while after the war everybody wanted to be a radiochemist. Nowadays, my wife tells me there’s about only one school anywhere that is teaching radiochemistry anymore. I guess it’s kind of a difficult regime to set up in a university. I suppose they do radiochemistry all over the country, but not very concentrated. They still do a lot out at Berkeley on radiochemistry.

Weisenberg: What was your first assignment when you got to Los Alamos?

Zeltmann: You worked on a process called Szilard-Chalmers, which was a way of detecting small amounts of neutrons. Since, at the time, really good neutron counters were not available, and they were only able to work with large numbers of neutrons. It was important to prepare initiators for the bomb that had a low neutron count, or none actually. If you tried to assemble a bomb with something that had neutrons in it, the thing would obviously start fissioning before you wanted it to. It was important to get the neutron backgrounds down on these initiators. I was working on a method of detecting neutrons in small quantities in order to refine the process of production so that we had no neutrons in the polonium to start with. 

I later on worked with a project called RaLa, which was a way of detecting or determining the critical mass that you would need for an atomic bomb. There were a number of competing methods attempting to determine what the critical size was, but ours was the most successful. It was called the RaLa project because it was radiolanthanum. 

If you have radioactive barium which results from fission, that barium decays and produces lanthanum-140, which is radioactive and is a very intense gamma source. You could put this gamma source inside of a big sphere and detect gammas coming out. If you observed the attenuation of those gammas as you imploded the sphere of uranium, you could determine how much compression you have. And once you knew that you could decide what the size of the bomb had to be. 

For that, [John] von Neumann, who was a very famous physicist here, had been able to interpret these experiments. Upon determining the compression, you could then determine what the critical mass had to be. That was a very important part of the project because, obviously, you wanted to use as little fissionable material for obvious reasons to make a bomb. Initial projections were for much larger spheres of uranium that you would need, and in fact, impossible amounts. As the calculations were refined they found out they could do with a lot less, and that was what I was working on for about nine months. 

After they solved the problem of the neutron background on the polonium, then I went over to this other project. That’s where I worked with Friedlander who is so very famous. There’s a very classical picture around that shows a WAC and a male scientist hauling a very heavy pot of metal around. Norma Gross was the WAC. She was a lieutenant and a WAC, and her husband was up here in Los Alamos. She got pregnant, so she had to be retired, but the man in the picture is the very famous Gerhart Friedlander. He was a very fine gentleman. He and his wife were very solicitous of the GIs’ wellbeing. It was true of most of the civilian scientists. They looked out for us. I can’t think of much more. 

Weisenberg: It sounds as if people got along pretty well. 

Zeltmann: Yes, they did. The male scientists here – they were mostly male. There were a few women scientists and, as I say, the WACs – there were some Ph.D. WACs here too. The male scientists worked horrendous hours. Some of them just tried to make a twenty-four-hour day out of it, and some of the GIs took advantage of scientists’ wives. It was just human, but that’s the way it was. 

There was a laundromat of a sort over on Trinity as part of a – there were civilian houses all up and down Trinity and over towards the Omega Canyon. There was a laundromat where the ladies gathered and socialized. The civilians mainly socialized within their own homes. Of course, most of the GIs were excluded from that. Oppenheimer was famous for his martinis and his private parties. That would have been great to attend, I guess. 

Weisenberg: You weren’t ever invited to one of those? 

Zeltmann: No. No. I wasn’t on that level at all. We all had our lives to lead, and the civilians were busy leading their lives. They had their families here, and apparently, they developed a pretty good school system for the civilians. But considering the way we lived in the barracks, you can see that there wouldn’t have been all that socialization between the military – at least the Special Engineer Detachment. Occasionally we’d be invited, say, to Thanksgiving dinner or something with a civilian family, that sort of thing. But in general, there wasn’t all that much mixture between GIs on my level. The officers might have had more purview to mix with the civilians. 

Weisenberg: You were a sergeant. Is that right? 

Zeltmann: Yeah. Tech[nician] 3 [Third Grade] and one stripe underneath. They were pretty generous with – certainly from the early times – with rankings for GIs. Normally it would take you a lot longer, I guess, to get to be a T-3 in the Army. They liked to roll out those stripes for people reenlisting, that sort of thing. 

Every once in a while, we’d get a commanding officer who wanted to make us more military. It was very hard to get technical people to be willing to perform the military aspects. They would attempt to take us out and drill us for – march up and down and that sort of thing. But for the most part they managed to put officers here who just restrained themselves. We didn’t have to do much of a military sort. As I say, occasionally a colonel would come in here and want to have inspections in the barracks and that sort of thing. It was usually a disaster. We were relatively un-military, I’d say. 

My wife was finally allowed to come to Los Alamos because my group leader needed a secretary, and she was a good secretary, so he managed to make sure that she got here. We were able to live then, towards the end of the war, in a civilian dormitory. We had one dormitory room. Prior to that my wife lived in Albuquerque. Some wives lived in Santa Fe, but not many. 

Weisenberg: She moved from New York to Albuquerque. 

Zeltmann: Yes. She was an English girl whose parents immigrated to the United States, and I met her in Brooklyn. Of course, we were engaged when I was drafted. We decided that she wouldn’t come with me where I was stationed in Kansas, but it only took about two months to realize we couldn’t live without each other, so we got married in Kansas. I was in the 94th Division, Infantry Division, as part of the Combat Engineers. In the course of getting my Ph.D., my first wife wasn’t interested in hanging around while I got my Ph.D., so we got divorced after about seven years. 

Weisenberg: What was your first wife’s name? 

Zeltmann: Audrey. She died ten years or so ago. We were friends afterward. It was a relatively friendly divorce. 

Weisenberg: Shifting gears a little bit, did you witness the Trinity Test, or were you aware what was happening at Alamogordo? 

Zeltmann: Yes. And that was one of the mistakes I made. I didn’t go. It would have been relatively easy to arrange to go. 

Actually, I was in Albuquerque when the people were coming back from Alamogordo that morning after the bomb test, and we were all in a restaurant, and you could hear people talking about the results. Actually, some people went up on the mountain and could see the burst of light from the shot, I guess, down that way. 

A few people had their own personal cars up here. Occasionally the GIs could borrow a car and go down to Albuquerque. Actually, there was a bus that went down too you could take. It had a schedule of its own. During the war the roads weren’t all that great, and the WACs would have to go down to meet a plane or to send some correspondence off. They used to get down to Albuquerque in a very short time. In those days, you had to go – there was no direct route to Pojoaque – you had to go down to Española – it was an eight-mile triangle that you have to go through rather than just go straight to Pojoaque. 

The road to Albuquerque used to flood occasionally and there were places where the railroad crossed the road, so the road dipped, and those would flood. You couldn’t get through. That was true for, oh, well into the 50s before they fixed that up. I guess they diverted the railroad. 

Weisenberg: Do you remember where you were when you heard about the bombing of Hiroshima? 

Zeltmann: Well, we knew it was about to be exploded. It was probably just a working day. We were in a lab. Nothing remarkable, particularly. It was another day. I guess there was a general feeling of elation. It wasn’t all that certain that a particular type of bomb was going to go off. The Thin Man [misspoke: Little Boy] was almost guaranteed to work, but it was never all that certain at the time. They hadn’t had any experience except the one shot down at Trinity. As I say, after the fact, there were a lot of people having their doubts about whether it should have been used or not, but I think the general feeling of most of the civilians was it was a good thing. Certainly, the GIs thought it was. We were hearing terrible tales of life in the Far East. I don’t think any of us would have liked to have gone to Tokyo.

Weisenberg: Did you know anyone who later turned out to be a spy, or was involved in espionage? 

Zeltmann: Yes. I didn’t know them personally, but we had U-shaped barracks, and the center of that U were the showers and the bathrooms and what have you. I was on one side of the barracks and [David] Greenglass was on the other side. I didn’t know him. One of the reasons – he was a machinist and probably a red badge or yellow or something like that, but I knew people – I had good friends who were close to him in that barracks. 

When I think back to that business of them executing the Rosenbergs, that is worse than exploding the atomic bomb over the Japanese. I think at that time the Russians were our friends, presumably, our allies. True, they were spies. But what was further wrong, it seemed to me, was they used his wife to attempt to get him to be more responsive, and they executed her because she wouldn’t be used. I thought that was awful. 

I used to see this fellow [Klaus] Fuchs, who was the English spy. And politically what [Lewis] Strauss did to Oppenheimer was just gross.

We had a fairly large group of English scientists here during the war. It’s rather interesting. People like Fermi and Teller and so many others, even Einstein, were not Americans, who provided a lot of the top scientists. 

Edward Teller had a very deep voice and if you were in a restaurant – one time even postwar, I remember I could hear his voice and know immediately it was Edward Teller. He was a great scientist, but his ego allowed him to really betray Oppenheimer. Well, there was jealousy there. Oppenheimer wasn’t ready to make the super bomb and Teller was, and it was always a question of who was a better scientist. At that level, it’s hard to compare them. They’re all geniuses on a different level, on different areas. But Oppie was just personally popular so that he was able to wring the best out of his whole scientific group. 

There was another famous fellow here, George Kistiakowsky, who was a famous professor from Harvard. I took a course from him in thermodynamics. One of the things they are always presenting is the fact that perpetual motion machines and infinite sources of energy just can’t exist because of the second law of thermodynamics. I remember one of the test questions, and when I was young I was willing to give a patent to this guy who had this perpetual motion machine, but it didn’t help my grade in thermodynamics.  

There was a post group of Provisional Engineers and they, with the military, kept security. They were from Kansas. It was the only cavalry still left in the Army, I guess. They didn’t exercise their horses enough, so the civilians were able to go down on a Sunday and get a horse to ride around. We’d get some exercise for the horses, which was fortunate for people who liked to ride horses. We had a couple of people killed in the time I was here. A fellow [Horace Russell] in our group was from Kentucky and had a big bay horse which he rode. Apparently, the thing got frightened. The horse raced down the canyon, and this fellow got knocked off and died from a concussion, I guess. There were a couple of other accidents they had.

I got a lot of radiation from this radiolanthanum. There were a group of us who got many, many times the dosage that – within thousands of times the radiation they’d allow people to get today. The Army Surgeon General came by and asked how much radiation we were getting. We told him. And he said, “Well, soldier, this is war.” 

Which it was, but nowadays the amount of radiation that people are allowed to get is just trivial and probably not as bad as cosmic radiation. Things have changed a lot. Of course, before the war the women were painting watch dials with radium and licking the brushes. I guess they didn’t have very long lives.

Weisenberg: Have your thoughts or reflections on working on the Manhattan Project – have they changed at all over time? 

Zeltmann: I don’t think they’ve changed very much. As a GI who didn’t want to go to Japan, I certainly thought it was a great idea to drop the bomb. People were very unyielding. There was a lot of talk about how they should demonstrate the weapon. Well, first of all, that was impractical because there wasn’t that much fissionable material ready at the time. I think they only had one more bomb on the way at the time of the surrender, and I’m not sure it would have made a difference. 

You always debate the morality of killing people, and people wonder whether we would have used it on the Germans, as we were willing to use it on the Japanese. That’s an interesting point. We always have these biases. I’ve generally been pretty well biased against the Japanese because I was drafted out of college and had to give up three years of my life to the Army. I profited by it in the long run, but it wasn’t anybody’s intention to make my life better. 

Weisenberg: You stayed in Los Alamos after the war. 

Zeltmann: Yes. I went – I had a senior year at college to do, but mostly took graduate courses. Then I went down to UNM to get a Ph.D. I got my Ph.D. with a man named Milton Kahn, who was working for Emilio Segrè during the war. His wife [Ann Kahn] actually had a lab down the hall from mine, and he was already a radiochemist. It was very convenient. But the problem going to school at that time in New Mexico was that the chemistry department didn’t have many courses to offer on the graduate level, so I had to take a lot of my courses in physics and mathematics.

We were pretty cavalier about radioactivity shortly after the war. We were trying to measure something called the half thickness of these lanthanum gammas in air, several hundred meters, I guess. What we did was get a meteorological balloon, and we put a very large source of radioactivity under that balloon. We had the security guards on either side of the canyon ready to shoot it down if it got away.

Unfortunately, a rain squall came along and plummeted that balloon right down in among all those scientists, and it was a really big radioactive source, so we all scattered. But the danger was just fantastic. We were lucky. We had sealed off the compartment, the platinum container actually, and when it hit the ground it didn’t spill any radioactivity out through the squeezed opening. But it was really terribly dangerous.

Yeah, that was one thing we did that was – in those days, early on, we weren’t afraid of the radiation the way people are today. Actually, it was just down this canyon from – it goes into the main road. When you go down that canyon, you’ll see some buildings off to the left, and that’s the end of Bayo Canyon. Which is very famous in Los Alamos lore because that’s where we used to prepare these very intense radioactive sources.

What would happen was every two weeks, a shipment of radioactive barium, which they had prepared at Oak Ridge, would be sent to Los Alamos in one of these massive lead picks. We would let the radioactive lanthanum grow in to the barium, and then the process was separating the radiolanthanum from the barium. This is what we used to put inside these massive, five thousand-pound shots of lenses of explosive which we were using to determine the critical mass.

But as I say, it was real close to – of course, none of these houses were in this area at that time. It wasn’t until much later that they opened up. When was it? 1960 or so, they finally started selling the old houses that the AEC [Atomic Energy Commission] owned and allowing us to buy lots to build our own houses. Incidentally, I built this house myself. I did about seventy percent of the work that’s involved in it.

Weisenberg: Was there a story about a burro and a guy named John Rodriguez?

Zeltmann: Oh yes. I did that. Yes. John was a chemist who was working with beryllium and unfortunately, he was one of the first casualties of Los Alamos. He got beryllium poisoning, but I don’t know whether he got it here or whether he got it at –

Joy Drake: I think it was here.

Zeltmann: Yeah. Beryllium was another bad element to work with. In any case, there are reasons for wanting to use low atomic weight materials in the bomb, and you work with beryllium. But the story about the burro was he had a stable. He had some horses, and he had a burro. But the horses weren’t very good at doing their business in the stable, and the burro trained the horses to go outside. Yeah, that was certainly true.

This fellow was named John Rodriguez. He was a bright young fellow. It was just unfortunate. I think he had worked on beryllium at Brown University. He probably worked on beryllium there, and he used his talents here. Yeah, it was a really sad – because his wife and his brother were heard to be figuring out what they were going to be doing with the fifteen thousand dollars that the government had generously awarded them because of his death.

 There were a lot of impromptu arrangements like having a stable for a few horses. This was down in the Omega Canyon, where they actually had a couple of reactors over time. They had a fast reactor down there. And they had one where, when I was doing my Ph.D., I did it with radioactive iodine. It has an eight-day half-life, and I was studying how the iodine exchanges with the thyroid gland. And to get this radioactive iodine, you put tellurium into a pile, a reactor, and irradiate it with neutrons. The neutrons on tellurium produce radioactive iodine, and I used this radioactive iodine to study rates of chemical reaction. It’s called exchange reaction. 

They also had something called a water boiler, which was just a solution of uranium nitrate originally. You get enough uranium nitrate with tampers around and you have a controlled nuclear fission, and they called it a water boiler. During the war, they decided that they didn’t want to use the nitrate because nitrate tends to decompose. They brought that solution up to my lab, and they reprocessed it into sulfate or perchlorate. I don’t know which, but here again is a situation where in a relatively open lab amongst a lot of chemists they processed fission elements. It certainly has changed. 

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