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Fred Vaslow’s Interview

Fred Vaslow, a physical chemist, began working on the Manhattan Project while a graduate student at the University of Chicago. During his time working on the project, Vaslow worked in several of the secret cities, including Los Alamos alongside J. Robert Oppenheimer. Vaslow shares many insights including the general opinion about the bomb among scientists who had contributed to its creation as well as the spreading denigration of Oppenheimer’s character after the bombs were dropped.

Date of Interview:
August 13, 2013
Location of the Interview:


Cindy Kelly: I am Cindy Kelly, Atomic Heritage Foundation. I am here today with a special Manhattan Project veteran. My first question is for you to say your name and spell it. 

Fred Vaslow: Fred, F – R – E – D, Vaslow, V – A – S – L – O – W.

Kelly: The next question is, when is your birthday?

Vaslow: November 17, 1919.

Kelly: Where were you born?

Vaslow: Chicago.

Kelly: Why don’t you take the story from here? Tell us a little bit about your childhood and education. 

Vaslow: I grew up in Chicago. My father was a photographer. We first lived in the back of the studio, and later on we moved to the South Side of Chicago. We had a two-story house with the studio below, and we lived above. It was quite an ordinary childhood. I went to Marquette Grammar School and Harper High School. Then I went to City Junior College and the University of Chicago. I started graduate school, and then the war came along. 

My boss went off to work on the Manhattan Project. I was still doing graduate work. I got on a project at the University of Chicago that was supposed to make a volatile compound of uranium, which eventually we did, a volatile compound of uranium, which suggested that—if you want a volatile compound of uranium, that means we were out to make a bomb. So we got this volatile compound of uranium, which decomposed if you look at it. It wasn’t a practical thing. 

So they settled down and got this material, UF6, which is used now with K-25 to separate the U-235 from the rest of the uranium. This project ended and then I went out to Ames, Iowa, where there was another part of the Manhattan Project. I don’t know if it was called the, “Manhattan Project.” That was under a Dr. Frank Spedding, who was an expert in rare-earth chemistry. The supposition was that plutonium would have chemistry similar to rare-earth chemistry, which it did not. 

One of the interesting things about the people at Ames is that they developed a very nice method for making very pure uranium billets, which they did. I wasn’t a part of that. At first I was just analyzing uranium. That was the subject of the pure uranium. 

Later on I got to work on the chemistry of plutonium, trace amounts of plutonium. You would radiate something in the cyclotron somewhere and we’d get these samples of what I think was probably uranium with trace amounts of plutonium. We worked on that for a while, and it seemed that nothing very much happened really. The process we were working on didn’t turn out too well. We were hoping the plutonium chemistry would have a volatile fluoride compound. We were making these fluoride compounds and we had these plutonium tracers all over the room, but it didn’t follow what it was supposed to do. 

After about 1945, this project at Ames was slowing down. I then got the opportunity to go to Los Alamos. They needed somebody with my experience. So I drove off from Ames, Iowa and out into this Wild West. I grew up in Chicago and seeing the Wild West was really quite an exciting thrill. The last day of the trip, I had to cross about two or three mountain ranges, and finally ended up at P.O. Box 1663 in Santa Fe, where I got directions to go to Los Alamos. 

I started off for Los Alamos and came to this road, which snaked up the mountainside. There was a vertical fall on one side with a narrow winding road. And by the time I got to the top, I’d blistered my hands having driven through three mountain ranges that day. I had never experienced mountains before in my life. 

I got to Los Alamos and got a very pleasant dorm room, and reported to work the next day. I was given two reports to read, “Los Alamos One” and “Los Alamos Two.” The first said, “We were here to make a bomb,” which I knew already. The second one gave about a half of dozen ways of making an atomic bomb. 

I had little bottles on my desk. One was labeled, “metal shavings.” It looked like maybe like lead or zinc. Other ones were labeled, “Combat unit two” and “Combat unit three.” I had a white badge and everybody who had a degree of something scientific got a white badge, which meant that you were entitled to all of the information that was available.

Everybody at Los Alamos knew that the bomb test was to be in a couple of days down near Alamogordo, a couple of miles south. Having driven from Ames, I had gas coupons. Gas was rationed there. I had these extra gas coupons, and some people at Los Alamos wanted to go down there, but they lacked gas coupons. So I got to go along down there. We camped out overnight somewhere near Albuquerque. The next morning, these people showed us where to go. So we started south and drove along the Rio Grande and crossed a bridge over into this desert area. 

On the map it was called “Jornada del Muerto,” very appropriately, “Journey of Death.” We found a little ridge that overlooked towards the east. I was looking at Google the other day and as far as I remember I identified where we were. We were perhaps twenty or twenty-five miles east of the site. We were not there officially. We were there unofficially, but nobody was going to stop us. 

So we camped out overnight, and the next morning was cold and rainy. The conditions didn’t seem very good to set the bomb off. We were getting kind of discouraged, but then off in the east we saw this green rocket go off into the sky. A couple of minutes later we saw this red rocket go off into the sky. Then a little bit later, we saw this red glow starting in the east. It seemed like sort of a dome growing and growing and growing. This dome grew every larger and larger. Finally it stopped and we ran for cover, diving behind some rocks. We were on sort of a mountain there. The thunderclap came. It wasn’t particularly impressive. We saw this cloud coming towards us and we got the hell out of there as fast as we could, back to our car. Even though we couldn’t see, we somehow stumbled back to our car and headed back. 

We stopped in Albuquerque at the La Fonda Inn and toasted our victory over this thing, this great happiness. It probably scared the hell out of the security men. Here we were toasting ourselves. 

So we got back to Los Alamos. There was a headline in the Albuquerque newspaper about this ammunition dump that had exploded in New Mexico containing pyrotechnics, poisoned gas, and all kinds of strange explosives. I should say that the Army had scattered cars about. Just in case this cloud drifted over inhabited places, they were ready to evacuate. 

About a week later, I was working at my desk with these little tubes of plutonium. The announcement came over the PA system, “Our first combat unit has been successfully dropped over Japan,” and we cheered. A few days later the people at Los Alamos began to think about the consequences and formed what I think was called the Los Alamos Association of Scientists to try to make sure that this bomb was not going to be used again, but that atomic energy was only going to be used for peaceful and useful purposes. So this was formed. I’d been working on plutonium, then a couple of days later the war ended. 

I want to give my take on this. It’s been very controversial, “Should we have dropped a bomb? Was it a horrible thing to do?” Yes, it was a horrible thing to do. But this was a time of horrors. There was a firebombing of Tokyo, which killed all those people. There were the horrors of Europe with the Nazis, and the horrors of the Japanese in Nanking. There were any number of horrors, so this was another one of these horrors. To me this bomb ended the horrors. History won’t tell us what might have happened. All we know is that this bomb was dropped and a few days later the war ended. I should also emphasize that it wasn’t a horror, dropping the bomb. It was the sheer shock of seeing two cities destroyed in an instant. It wasn’t a horror to them. It was seeing their land destroyed.

I was what you would call a physical chemist, not an analytical chemist. I was doing analytical chemistry with this plutonium and I wanted to do physical chemistry. The war had ended by this time and I changed over to another division, a high explosive division. I was working on a mixture of TNT and some other materials that were used to make these plastic lenses that the bomb was made of. I was working on high explosive plutonium. Off in one corner of the room was this spy, I can’t remember his name. I knew that it was a guy and I couldn’t remember his name. 

About December my draft board let me go. I thought I would go back to Chicago and go back to school. I headed back to Chicago and my research boss was still at Oak Ridge. I stayed in Chicago and took a couple of courses. I listened to a course under Fermi. He was a wonderful speaker. Everything seemed so very clear. Although when I went home and tried to do it myself, I couldn’t figure it out. 

My boss said, “Why don’t you come down to Oak Ridge and finish your PhD research there?” Which I did. He said that he was going to go back to Chicago in a couple of months, and he never did. I never went back to Chicago, although I got my degree from Chicago.

I continued doing what you might say was basic science on the separation process on exchange resins. I was working on that. I got my degree in that, finally got my thesis. I thought that, “There are so many interesting problems for a physical chemist in biology. I’ll see if I could get a job in the biology division at Oak Ridge.” I talked to Alexander Hollinger and he gave me a job. He probably regretted it after a while. 

I first started on DNA. At this point in time, nobody knew what DNA was really for. So I took this thymus gland and made this preparation of DNA, sort of a gooey, waxy mess. I didn’t really know what it was, and I radiated it. Hollinger was very fond of radiating things to see what happened. After a while I got interested in some other form of protein action, enzyme action. We got a little process of measuring some of the thermal dynamic properties of this enzyme substrate. I could measure the thermodynamic properties, and I was using the reactor at Oak Ridge. I would get a little reactor sample. I would go to the reactor in the morning with this little lead pig, this little tube. It was like the little tubes they used to use in the department stores to send to the cashier. You put this little tube in the reactor, come back the next day, carry this back and do your work, make this material needed for doing this biological work, which incidentally was pretty much what I would have been doing when I was working on the separation process on exchange. 

I was having trouble with Hollinger, the head of the division. He and I didn’t agree on many things. Europe was in flux, so I wanted to see Europe before it maybe it exploded. My boss, Waldo Koden, had just been to Denmark and talked to this laboratory in Copenhagen, the Karlsberg Laboratory, and he wrote to them and asked if they would be willing to take me, even though I didn’t have a fellowship. They said they would, and I went there on my own for a while. The Karlsberg Lab was really quite a wonderful place. They had Kaj Linderstrom-Lang, who was active in the Danish Resistance. He was really a marvelous person, an excellent scientist, and also an all-around person with coaching and having fun. It was just a wonderful place to work. There were some famous people there. At one point I was sitting right across from a Nobel Prize winner. It was also there that I met my wife. She was the secretary in charge of Americans. She took charge of me. We got married in Copenhagen. After a while I did get a U.S. Public Service Fellowship, which lasted me for two years. I finished my work. One prominent authority described this work as classic, so I guess it was a fairly good piece of work.

I came back to the states and was out of a job for a while. My teacher, George Boyd, said that he could hire me at Oak Ridge. So I came back to Oak Ridge. I again was working on design exchange resins using thermodynamics. I did that for a couple of years and then got tired of it. I had some strange ideas over there. I don’t know if you’re familiar with what the Rorschach Test is? A patient will look at spots and tell a psychiatrist or a psychologist whatever they think they are. When a scientist does the Rorschach, it’s a little different. He looks at a lot of spots and he sees a lot of things. He’ll draw a line here and a line there. I sort of thought it looked like that, Rorschach chemistry. 

I continued though with calorimetry. After a while there were more crazy ideas by Pauling and Bernell, and after a while I thought I might want to work on this. I wrote a suggestion to Pauling and got a mildly optimistic letter back from him. I showed it to my boss and he reluctantly let me do this sort of thing that I wanted. So I spent the next couple of years doing density measure, and later I thought I saw something there. A little later I did some calorimetry. I got my work published and nobody believed it. It’s long been forgotten.

The people at Atomic Energy were closing, squeezing, and firing people. So I got fired and I retired. I got a job at Argonne National Laboratory, writing environmental impact statements. I hated doing these environmental impact statements, but Argonne was a nice place to work. That ended after about six or seven years. I then got a job for a year at Brookhaven doing some work, which I have no idea why they wanted it. It was the most stupid thing I’ve ever done. Living out on Long Island was quite fun and pleasant, although the job I have to say was horrible. This ended after about a year. I retired and came back to Oak Ridge. It’s where I’ve been ever since. That’s about it.

Kelly: That’s pretty good. I don’t think you took a breath with your life story in thirty minutes. That’s marvelous. I don’t think that most people could do that. 

Vaslow: Since retiring we’ve done a lot of traveling. We’ve been to about fifty or sixty different places, including Afghanistan and Mongolia. We’ve been to all of Western Europe and to a lot of places in Asia. We’ve been in Nepal, Bhutan, Japan, and China. I used to garden, but I don’t do much of that anymore. I used to do a little woodwork, but don’t do much of that anymore. That’s my life.

Kelly: That’s good. One question I had was, how far away do you think you were when you were watching the test?

Vaslow: I just checked on that on Google yesterday, and I think I found the road we came in across the Rio Grande. As far as I can estimate from the Google map, we were about twenty to twenty-five miles away. 

Kelly: So it was well outside the safety zone. I guess ten miles away was where most of the observers were in their concrete bunkers. You were another ten miles beyond that. 

Vaslow: The sight from twenty miles away was very, very vivid and scary. 

Kelly: You had a good description of that. It was very vivid. How many of your colleagues decided to switch fields of science away from nuclear physics and into some other field?

Vaslow: I really can’t say. It was pretty much of an individual decision. As far as I know, I was the only one who decided to go into biology, for whatever reasons. Even now, for a physical chemist, there are so many challenges in biology. There are these little abstracts of meeting reports. The last one I’ve seen, about half the papers were of physical chemistry and biological concerns. Back when I started, there wasn’t much of this. Now it’s very common. This was sort of a biological thing. I can’t think there was any moral inspiration, that I wanted to get away, but I think it was more of the idea of seeing these interesting physical chemical problems. 

Kelly: Where you in Chicago when they built the CP-1, the Chicago Pile-1?

Vaslow: Yeah. I was doing graduate work and the draft board was getting close. The University of Chicago offered a physical training course for pre-draftees. A part of this physical training course was jumping over the seats in the West Stands. I didn’t know it was right there right below where I was jumping over seats. There were these workmen coming out with their faces black with carbon. I had no idea what they were doing. Of course they were working on uranium. I knew about U-235. You could conform a bomb with U-235. But at this point, I did not know about plutonium and that they were building a reactor. I did not know about what this reactor was until I got to Ames, Iowa. There I found out about plutonium, nuclear reactors, and the possibility of nuclear energy. Here I was jumping over seats, when right below was the first pile. 

Kelly: A good chain reaction right there.

Vaslow: Yeah, a chain reaction right below there. 

Kelly: As a physical chemist, you were not working with the physicists.

Vaslow: No, most of the time I was doing analytical work in Chicago. I was trying to get some of the chemical compounds of uranium. It was a rather an exotic compound with some exotic chemistry. This ended and I went to Ames, where again, I was doing analytical chemistry on pure uranium for the first part. Later on I ended up doing tracer chemistry of plutonium. 

Kelly: Why was it so important to understand the chemistry of these products?

Vaslow: When you have a fission reaction, you have the splitting up, and also at the same time you have these fission products. You have the new element, plutonium. Then you have these fission products. There’s a horrible mess of chemistry there. It’s highly radioactive. And separating the plutonium from this horrible mess of radioactive elements is a very difficult and complex process. Just about every group leader in the project in the Chicago lab had their own way of separating the plutonium. 

Eventually Groves, who I disliked but enormously respected for what he did, decided that we would use Seaborg’s process for separating the plutonium from the rest of this mess. So everybody on the project was working with Seaborg’s process. Every weekend we’d go to Chicago and attend a meeting with a little step here and a little step there. Eventually they got a suitable process for using Seaborg’s method for extracting plutonium. They got this method going on at Hanford to get it separated out. They’d then send it down to Los Alamos, and I think I’ve already told you about the bomb. 

Kelly: Did you hear of a Joseph Kennedy, who worked with Seaborg?

Vaslow: I think he was head of the chemistry division. I never met him.

Kelly: And there was an Arthur Wahl. 

Vaslow: Yeah, Art Wahl was there. 

Kelly: I think he was a group leader, and the division was Joe Kennedy’s. 

Vaslow: I can’t remember the name of the fellow that I was working for, but he was head of analytical chemistry there.

Kelly: What was it like? You knew there was a war going on. All of your buddies were off in Europe. How did you get deferred? How did you escape going into the Army?

Vaslow: When I got into this project in Chicago, they sent a letter to my draft board that I was necessary for the war work. Then I got to Los Alamos, and I got this 1A notice. I gave it to my boss, who gave it to the Colonel who was in charge. And the Colonel sent the letter to my draft board, “I may be reached at P.O. Box 1663. You will keep this information confidential.” And that was that. They kept sending letters to my draft board that I was essential. I wasn’t of course, but that idea kept me out of the Army. 

Kelly: You probably were essential. 

Vaslow: No, not for the work I did. There were a lot of top scientists at Los Alamos. I was a bottom scientist. 

Kelly: It’s the bottom of the pyramid that holds everything up, right?

Vaslow: I guess so.

Kelly: You mentioned a possible spy, or someone that you ran into?

Vaslow: Yeah, in this high explosives laboratory where I was working. I can’t remember his name.

Kelly: David Greenglass?

Vaslow: Yeah, he was at one end of the lab and I was at the other. Somebody at one end was whacking away with a wooden hammer on this big hunk of TNT. It had its moments. 

Kelly: Did you ever feel that you were in danger?

Vaslow: Not really. The worst experience I had I suppose was at Ames. We had a fluorine gas generator. It was making hydrogen on one side and fluorine on the other. It was in a heavy metal container. But every once in a while the fluorine and hydrogen would mix and there would be a fierce bang and stuff would spray. One time I was working on this thing, and this fierce bang occurred. My co-workers grabbed me and pushed me under this ice cold shower. This was a cold day in January. And I regard this as the worst experience I had during the war. 

Kelly: Which was worse?

Vaslow: It was whatever the fluoride compound was inside that maybe sprayed a little. The container didn’t break. So maybe small amounts may or may not have sprayed on me. But they weren’t taking any chances, and shoved me under this ice cold shower. 

Kelly: Was the shower right in the hallway?

Vaslow: There was a shower right above the workspace. It was right there. I think in general the people were worried about the health of their people. They were constantly checking. 

There was another little incident when I changed over from working with plutonium to high explosives. They had what is called a piss test. You’re told to stay away from work for a day. I drove around Los Alamos and out into the countryside. At one point I was driving through a canyon. There was a herd of cattle ahead of me, and the cowboys just let me drive behind them herding the cattle. So I was a cowboy for about a half hour or so. Then the cowboy rode up to me and gave me a message to carry to the ranch down at the end of the road. It was exciting to participate in a sort of round-up. 

I got back to Los Alamos and they put me in the hospital. They gave me a gallon jug to fill up overnight. They tested for plutonium, and I guess I had a few counts. It was nothing dramatic or anything. It’s not a terribly dangerous material to work with. The chemistry is such that it’s not readily absorbed into the body. So even though it has a horrible reputation, it’s not terribly dangerous to work with. I had only a few counts. It was nothing serious. And very, very few people, if any, have ever died of plutonium poisoning. 

Kelly: There is some controversy over an experiment. 

Vaslow: I know of the experiment.

Kelly: Tell us about that? Tell us about the experiment?

Vaslow: They injected what they thought were terminal patients. Originally they thought nothing would harm them. I realized later on that they decided it was some controversy, but I’m not at all sure what the controversy was. The original thought was that no harm came to these terminal patients. But I don’t know if there are any more interesting results on that. 

Kelly: There was somebody named Edward Cabe, a truck driver, who had a broken leg from an accident. He was injected. 

Vaslow: But I thought they were only very terminally ill patients. If this was done at wartime where there were any number of people at risk for plutonium, if it was done to check that, then possibly there was a moral reason for doing that. If it was done after the war when there was no urgent reason, then it was immoral. It’s just that simple. 

Kelly: As a chemist who studied plutonium, you would not expect the plutonium to be ingested or affect the body. How does that work?

Vaslow: At that time, there wasn’t that much known about plutonium chemistry. During the war, there would have been urgency to find out in the best possible way of what these people were exposed to. Were they really exposed to something terrible, say, like some of the natural poisons are the most poisonous things known? The question was, is this plutonium so horribly poisonous? They wanted to find out. 

But if it was done after the war, this was utterly immoral. If it was after the urgency, there was no urgency for people to have done that. I think it was done after the war, which does put it in the utterly immoral category.

Kelly: So that raises another question that everybody gets to answer. How do you feel about dropping the atomic bomb in Japan? 

Vaslow: I think I discussed it a little earlier. It was a time of horrors. There was the firebombing of Tokyo, the Nazi extermination camps, and the Japanese treatment of people in Nanking. So here we have another horror. Was this spectacularly worse than any other horror? I don’t know. I can’t make a decision. What I would say is that we dropped two bombs and a couple of days later the horrors ended. And for that I was thankful. I know it was a horrible thing to do, but could the war have ended without it? We don’t know. History doesn’t tell us what might have happened. So here we have the horrors ending and the war ending just a couple of days after. As I said, I am thankful for that.

Kelly: Well said. 

Vaslow: Perhaps another thing is Oppenheimer. There were statements that Oppenheimer was a spy and not a patriot, which infuriates me. Getting there so late, I was more of an observer than a participant. I could see how these people adored Oppenheimer. He was this fearless leader. He knew everything, and inspired these people to work. Would all of these top scientists have gone there without Oppenheimer? The bomb probably would have eventually been made, but perhaps much, much later. Maybe it would have been a good thing if it hadn’t been Oppenheimer, so then we wouldn’t have dropped the bomb. But it was Oppenheimer, this fearless leader, who carried this thing through. I heard him talk once or twice. He’s a marvelous speaker. It infuriates me when people denigrate Oppenheimer. 

Kelly: I think we talked on the phone about you sitting in on some of the colloquia? Did you attend any of the colloquia?

Vaslow: Oh yeah. As a white badge, I could attend colloquia. There was one colloquium on the super gadget. It could have been Teller who was talking. The idea they had back then, during the war, would not have worked. 

My white badge entitled me to all of the information that was available at Los Alamos. It was kind of funny that the GIs who had white badges, the scientists, could attend these colloquium. Their superior officers who did not were not supposed to know what was going on.

Kelly: In going to these colloquia, did you see how people from different disciplines would contribute to problem solving? 

Vaslow: I can’t really remember much of what the subjects were. I know that I went to a couple of colloquiums, including Oppenheimer speaking and maybe it was Teller who spoke on the super gadget. I got there just weeks before the end of the war. After the war ended they were giving various courses in physics. So I attended some of the courses. I remember Hans Bethe giving a wonderful lecture, along with a few of these Nobel Prize physicists’ lectures, which I could attend. Of course I didn’t understand too much of it, but they were wonderful lectures.

Kelly: Was that a part of the Los Alamos University?

Vaslow: I don’t know. I don’t think it was called a university at that time. I think it was just various courses in various subjects.

Kelly: I think an informal thing that Oppenheimer started, but obviously didn’t last, lasted about a year, a year and a half. It gave people a chance to hear these brilliant minds lecture before everybody dissipated. 

Vaslow: Yeah. Of course soon after the war ended everybody started back to their universities. I did too. 

Kelly: Interesting. Did you like Chicago? I guess you were born there.

Vaslow: I didn’t particularly care for it when I was growing up. But later on when I was working at Argonne and we were living in a suburb about twenty or thirty miles west, I did kind of get to like Chicago. And I kind of like it now. It’s an interesting city. I compare it to New York, but it was easier to get around. I liked Chicago more when I came back after the war. 

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