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National Museum of Nuclear Science & History

Elliot Charney’s Interview

Manhattan Project Locations:

In this interview, Elliot Charney discusses his involvement in developing the barrier material for the gaseous diffusion plant in Oak Ridge, TN. Charney worked with Norris and Adler at Columbia University to develop a barrier that would be suitable for the separation of U-235 from U-238. Charney describes some of the problems that arose during the project and explains the urgency of his work.

Date of Interview:
September 12, 1965
Location of the Interview:


Charney: Where shall I start?

Groueff: Tell me how you got involved in the whole project and your first meeting with all those people and where you came from. Start from the beginning. 

Charney: I had actually just graduated from college and I was prepared to go into the Army or to look for a job. Since I had not been called up yet, I was looking for a job, and I got a letter from [Edward] Adler, who had been my instructor at college.

Groueff: At Columbia?

Charney: No, at City College, saying that if I was interested in the position, I should come to see him. He gave me the number of a room in the physics building at Columbia. It turned out to be a basement room, and I knew nothing about this, of course. It turned out to be a basement room where I found them. 

Groueff: When was that?

Charney: This was in October of 1942. He immediately took me up to see [John] Dunning, and in the course of half an hour’s conversation during which Dunning described something of the work but made no indication of what the purpose was, I was reasonably excited about it and accepted the position.

Groueff: He did not say anything about the war?

Charney: Not at that first meeting. 

Groueff: You were a chemist?

Charney: Well yes, it was a chemist position that obviously had some military and secret purpose. Its ultimate purpose was not at that meeting known to me. The description of the work, that is, the attempt to make barrier for the purpose of gaseous diffusion, this was stalled but not the ultimate purpose. It was not actually until some months later that I became aware of what the overall problem was. At any rate, the basement laboratory—do you have a description of the basement laboratory?

Groueff: No. 

Charney: The basement laboratory was several doors removed from the cyclotron room and consisted of a moderately large basement room, which looked like any other chemical laboratory. We occupied approximately half of it. [Edward] Norris at that time was on a consulting basis; he came in once or twice a week, yes. Adler was suspending substantially full time, although he was still connected with the college, City College, where he had some duties there.

Groueff: How old were you then?

Charney: I guess I was twenty. 

Groueff: Twenty.

Charney: Yes. 

Groueff: So you did not have any experience? 

Charney: No experience. I had just finished college as a graduate chemist. 

Groueff: I see. The reason you were selected was because Adler knew you?

Charney: That is right. I was a student of his at the college. 

Groueff: How many people worked in this basement laboratory? 

Charney: There were probably some twenty people, which were divided, I would guess, about seven or eight on various aspects of running a cyclotron. Three of us on the barrier. 

Groueff: Only three?

Charney: Yes, just Norris, Adler, and myself. I was the only full-time employee. The rest on the gas problem—uranium hexafluoride—and on pumps, which work was already underway on all of those? 

Groueff: All those in the same room?

Charney: No, no, we occupied the entire basement. 

Groueff: In your room, it was just the three of you and some other people? 

Charney: There were three of us and an electronics technician who was building electronic chassis for the cyclotron. 

Groueff: Dr. [Willard] Libby was with you?

Charney: Libby was actually located in another building. I am trying to recall—I guess Libby had a group of possibly—I do not think it could have been more than four or five people and was located in the chemical engineering building. 

Groueff: They must be working on corrosion problems. 

Charney: Yes. 

Groueff: Not directly on the barrier? 

Charney: That is right. 

Groueff: So the making of barrier was Adler, Norris, and you?

Charney: That is right. 

Groueff: Now could you describe Adler and Norris and how they appeared to you when you saw them?

Charney: Norris actually made very little personal impression on me other than that I was quickly aware of his lack of formal training. At the same time, considerable intuition, especially in electric chemical problems, which were involved. Adler, of course, I had known before. Adler was a very, very volatile individual and always remained so. 

Adler and Norris were very well paired; both of them are very empirical people. Their approach would tend to be—I would say it is not a developed logical approach. The thing that looked good at the moment was the thing to be pursued without any real attempt to develop a logical pattern. In fact—Norris, I am not so sure, was aware of this—Adler was very well aware of it himself and depended to some extent on me to carry along the threads of the logic while he went ahead with the ideas, yes. 

Groueff: Imagination?

Charney: Yes. 

Groueff: Is he a very inventive guy? 

Charney: Yes, I think they were both inventive people. Adler was probably more high-strung and more volatile than Norris. 

Groueff: Exuberant, expansive? 

Charney: Yes very exuberant. 

Groueff: Emotional? 

Charney: Very emotional. 

Groueff: He would talk and express all his feelings and thoughts? 

Charney: Oh, yes. 

Groueff: He was not the silent type? 

Charney: No, by no means. 

Groueff: And Norris? 

Charney: Norris was certainly a much quieter individual. I have seen Adler not recently, but certainly in the interim in the last twenty years. I have not seen Norris. At that time Norris was quiet but with a reasonably strong personality. In fact, he was a very determined, quietly determined individual. For example, if he came to the laboratory and discovered that some idea that he had dropped the week before had not been taken up, he would quietly and unobtrusively proceed to do it himself. 

Groueff: Did they get along?

Charney: By and large, they got along very well. Now, there were at various times undercurrents of difficulties between them. Later on when things got very difficult as the processes became more and more developed and Kellex became involved, there were difficulties between them, but I think they always had a very healthy respect for each other. 

Groueff: And Norris quit when he became more and more involved in administration and being executive? He told me he was not fitted for that. 

Charney: It was probably a little bit more than just that. At that time, the people from Ohio State were brought in. 

Groueff: [Ed] Mack?

Charney: Mack, yes, and if I was to interpret what went on—obviously I cannot speak for them—I think that Norris really felt that to some extent, I would hesitate to say, that he was being pushed out.

Groueff: I see, putting somebody above him. 

Charney: Right. I think he sort of felt that he was not going to have the free hand that he would like to have to pursue what he wanted to. 

Groueff: Who was the boss of this particular group in 1942 or 1943? The two of them, and they reported to Dunning?

Charney: To Dunning. I never was completely clear, in fact, as to the way in which the administrative set up was between [Harold] Urey and Dunning. That has probably been formalized somewhere – you may know more about that than I do. 

Groueff: It was not a very good relationship. I think the real day-by-day work was controlled and done by Dunning, but it was under the general supervision of Urey.

Charney: This was more or less the way it seemed without my ever having seen—

Groueff: Urey would not come to your lab to work with you? 

Charney: Not to work with us, but, well—

Groueff: To inquire?

Charney: He would come to inquire, and it was rather interesting actually. Urey would wander down to the laboratories; I imagine he did even more of that possibly with Libby and possibly with the cyclotron people. He did wander down, and I can recall one fairly amusing incident that you may like to know.

Groueff: That is what I am looking for.

Charney: On an occasion that he would wander down—actually by that time, we had moved from the basement to another floor in the same building. We had a small laboratory, but all to ourselves. It was not much bigger than this room, I guess, possibly a little bit wider, and there were limited seating facilities so we had a few stools and we would sit up on stools. 

At any rate, I can remember at least this one occasion when we were sitting around discussing various aspects of the barrier problem, and Urey, as he frequently did, would try to inject some new idea. 

On this particular occasion, he proposed about three or four different things. To each one of them, Norris and I were sitting and talking to him, and as each one came up either Norris or I would say, “Well, this was something we had just tried.” 

Finally, after about the fourth one, he looked at us and said, “The trouble with you is that you have every bright idea before I do!” [Laughter]

Groueff: So relations with him were good? 

Charney: Yes, very good. 

Groueff: Friendly?

Charney: Yes, very friendly. 

Groueff: Dunning would come every day?

Charney: No, Dunning rarely appeared in our laboratory. Now Dunning was very much involved with the cascade problems and with pumps. He spent a good deal of time on that. 

Groueff: Personally not much for the barrier?

Charney: Almost nothing with the barrier.

Groueff: Adler was the man from Columbia in charge because Norris, being a little bit outside—

Charney: That is right. 

Groueff: Now the fact that Norris did not have formal education—did that make it difficult to discuss? For instance, he would not understand your formulae? 

Charney: No, he had sufficient experience in the technical problems and I think he had taken the trouble to self-educate himself, at least in the electric chemical problems. There was no problem in discussing these things with him, and when it came to other things, Adler would explain. He was quick. 

Groueff: He was the one who brought the idea for the first barrier, which is called the Norris-Adler, but Adler and you developed the scientific base. 

Charney: That is right. 

Groueff: The idea came from some electro-mesh or something like that?

Charney: That is right. 

Groueff: He was using for painting screens?

Charney: Right. 

Groueff: This story about the printing and going to Chiclets, was that later or was that at the beginning?

Charney: No, that was later. 

Groueff: Later, so it was not the first thing you tried? 

Charney: No, it was a later development, yes. 

Groueff: At the beginning, you worked on the first Norris idea? 

Charney: That is right, the first Norris idea. Now the printing idea actually came fairly soon, I could not possibly recall the dates anymore, but it was not very long before that idea came, and originally whatever we did was done by hand right in the laboratory. It was not until considerably later that when we started to think about production of large quantities of this material that the business of printing at the Chiclet Company happened. 

Groueff: I am going to talk to [Leonard] Shazkin because he used to go with Adler, I understand. 

Charney: Shazkin was a printing engineer. 

Groueff: That is s very unusual process, to use printing and physics and chemistry? 

Charney: Shazkin was a printing engineer, and that is how he got into this originally. 

Groueff: Who gave the idea?

Charney: I do not really recall. I suspect that was probably Adler’s, but that has been worked out actually fairly carefully—unfortunately, I think in secret patents, which the government holds. I would hesitate to discuss—

Groueff: The idea came from your group?

Charney: Oh, yes. 

Groueff: It was not something that you were asked to do, but somebody brought the idea— 

Charney: No, no, the idea came from within the subgroup. 

Groueff: It was one of several ideas that you tried, most of them unsuccessfully?

Charney: Right. 

Groueff: And for several months? 

Charney: That is right. 

Groueff: You would try one and another and usually it would not work. 

Charney: That is right, or it would work partially. 

Groueff: Partially, it would have some of the requirements, but not the others. But was it all in the general frame of the same principle that Norris brought?

Charney: The original principle was eventually abandoned. 

Groueff: Abandoned?

Charney: Yes. The original principle was abandoned, but one of the very first things that I tried, probably within weeks after I was there, was the principle that eventually gave Adler and Norris the barrier. 

Groueff: The thing that he brought from his painting equipment was not yours?

Charney: That is right. 

Groueff: But it gave you some good start. 

Charney: It gave us the good start, and it gave us a whole set of ideas. In fact, without it we would not have gone to the next—

Groueff: It opens your eyes to some new things.

Charney: Exactly. 

Groueff: One of the developments that you tried was this printing? 

Charney: That is right. 

Groueff: Because that is the kind of colorful thing that I am collecting, the chewing gum [story], and I understand Adler was taking his plates by taxi there and would wait until they would print them. They had no idea what they were doing.

Charney: Absolutely no idea. 

Groueff: You said that Charles Yates did some work with Adler?

Charney: I should give you a little bit of Yates’ background because I think that is also fascinating. Yates also has no formal training. He was born in Canada, Canadian I guess, and after a fairly colorful career as a young boy, which included such things as rolling railroad car wheels and things of this kind, somehow finally wound up with the Anaconda Copper Company in Perth Amboy, New Jersey.

Actually, I guess that is international smelting and refining, which I think essentially Anaconda, where he—I would hesitate to say developed, although in the sense that the process, I think, would never have been successful—he certainly made improvements in a process for making copper foil by electro-deposition, continuously forming copper foil by electroplating. 

Now, I do not think I can say very much as to why he came into the project without possibly violating security, because I would have to tell you something about technical details. Suffice it to say that he came into the project on loan essentially from Anaconda people and got involved in the printing process with Shazkin and Adler. 

Now, during the course of this, he developed—actually it was his idea to develop a form of barrier, which combined essentially the Norris-Adler idea, but in an extremely beautiful and strong structural form, and in fact in an extremely efficient form for gaseous diffusion. This came fairly late; decisions were already being made as to what to use in the gaseous diffusion plant. But Yates and I and Shazkin spent a moderate amount of time trying to develop this process. Actually, we were working night and day at that time. 

Groueff: When was that?

Charney: That would be 1944. 

Groueff: That was the later part – Houdaille was already producing the barrier? 

Charney: It was already beginning to produce barrier.

Groueff: So this new thing was too late to be put into the K-25?

Charney: It was too late to be put into the early part of K-25. Let me put it this way, we started on this before barrier production started, but it was apparent that it was going to be virtually impossible to finish the development before barrier production started. Nevertheless, we made a tremendous push on it in the hope that it would prove to be so efficient that it would actually be worthwhile changing over in midstream, because it was a better barrier than the one they were going to put into the plant. We literally worked night and day, sleeping on cots for two or three hours. 

Groueff: At Columbia?

Charney: Well, mostly at Columbia, yes. We were able to get sufficiently good initial material to convince the Kellex people to try to do something effective about it. Unfortunately, what they were able to do was not effective, I think through no real fault of theirs. I guess Yates and I and Shazkin tried to convince them to let us set up at Columbia at the Kellex laboratories, which by now had been moved to the Nash building, to set up a small program there to develop this. Kellex people did not see eye to eye with this. I think they were impressed with the barrier, but they felt that in order to be successful it had to be done on an industrial scale by an industrial group. 

If I remember, [Percival] Keith called [Colonel Kenneth] Nichols to support him on this. But at any rate, what they did was to try to get the Chrysler Corporation to take this up as a development program. Chrysler refused to have anything to do with it. They were busy with other aspects. 

Groueff: They were making diffusers?

Charney: Yes, and they felt that they could not sink any technical help to it. They were probably a lot wiser than the company that actually did take it up, which was the AC Campbell Company in Boston. Campbell really did not have the technical facilities to take this up; they did have some experience in electrochemistry. They were the largest manufacturer – or certainly the largest manufacturer on the East coast—of plated automobile parts. I went up to Boston to take charge of that program as a Kellex representative. But they were totally inadequate either in the training or in motivation to try to take on this program. It really never got off the ground. 

Groueff: It was never produced. 

Charney: It was never produced. I think the final barrier was better than the one that we were making at the time, but I am also convinced that if we had put some effort into the development, it would have actually been better than the final barrier. 

Groueff: So you used the final one, which was the combination that everybody contributed a little bit to. I know that Clarence Johnson, and [Frazier] Groff from Bakelite. 

Charney: I never knew Groff and I do not really know what his contribution was.

Groueff: I think he mixed the barrier, which was solid and good in the laboratory. He found a way of producing it in large scale and plating it.

Charney: I was aware of course, but I never met him and I never really knew him. 

Groueff: This man, Yates, was he a young man? 

Charney: Yates, by my definition now, he was a young man.

Groueff: He was not a kid. 

Charney: No, he was not a kid by any means. Incidentally, after the war – you just may be interested – after the war he went back to Anaconda, continued for a little while with their copper foil manufacturing, and then took over. He became essentially engineer in charge of mechanization of their Perth Amboy plant. Again, this is all without formal training. 

Now he subsequently left Anaconda, and has gone into competition with them in making copper foil. He is now the largest manufacturer of electriclitically-deposited copper foil in the world. 

Groueff: Under what name?

Charney: Under the name Circuit Foil Corporation. 

Groueff: Okay, where is it located?

Charney: It is located in New Jersey. He lives in Beverly, the main plant is near Beverly, New Jersey, and it is in a town near Beverly, New Jersey. Yes, it is quite a large operation now, they have a plant in Luxembourg, which has now been in operation for over a year and is doing very well. 

Groueff: He never went to college?

Charney: He never went to college. 

Groueff: Even high school?

Charney: He had some high school training, and I do not really recall whether he ever finished high school. He is a remarkable man and he made considerable contributions to the development of that printing process. 

Groueff: Was the printing processes used?

Charney: The experience of it was certainly used, and actually some of the barrier that went into the K-25 plant did use it, but I was never clear on exactly what went into it. 

Groueff: Did they use different kinds of barrier in K-25 or was it just one type of barrier?

Charney: Well, it was one type. Let me put it this way. The effective part of the barrier was one type for all. But parts of these various processes were used for structural support rather than for the gaseous diffusion itself. 

Groueff: Because sizes were different in the cascade, you had to use different—

Charney: Right. Also, it turned out that by working on several manufacturing processes at the same time, they were able to prepare enough to finish the plant faster than they would have if trying to make it all in one way. 

Groueff: There was not one standard barrier, but there were differently made?

Charney: At least two different kinds. 

Groueff: I see. So it was not for nothing, his printing?

Charney: No, it was very useful. 

Groueff: In what way was Yates colorful? Was he an interesting or amusing man?

Charney: Very original, and the most amazing thing about Yates is his enormous engineering ability. This is a man that can virtually build and design machines by hand without ever having any formal training. 

Groueff: Where did he learn that?

Charney: I do not know where his original training in this came. Certainly, he must have picked up a lot of it during his experience at Anaconda, but whether he had considerable experience before that or not, I do not really know. This is a man who knows how to put the right size bearing, for example, on a machine without ever having been told that this is the right size bearing. 

Groueff: He did everything by intuition and was good with his hands. 

Charney: Extremely good with his hands. He literally built enormous manufacturing machines with his own hands, with some help. 

Groueff: He was very good in the laboratory? 

Charney: Oh, yes. He was not so much engaged in the laboratory operations as in the semi-production. You see, these barriers went through pilot plant operations and the Norris-Adler barrier was produced in significant quantities. In fact, some of the material that was produced in the power plant I know was shipped to Oak Ridge.

Groueff: To be used?

Charney: Yes. 

Groueff: This pilot plant was the Nash Building, and what is the name? Schermerhorn?

Charney: Schermerhorn at Columbia was where the pilot plant was put up. Yates had a lot to do with that. 

Groueff: Another thing I would like to know, when I talked to [Foster C.] Nix, he said that there was one development Columbia/Norris/Adler that was completely independent of his, and his was completely independent at the beginning.

Charney: At the beginning, that is certainly true. 

Groueff: Then Clarence Johnson was working, different people were working. Now, he agreed that the final product is a combination. Of course, each one of those men thinks that his part was the essential part and would say, “It was my barrier.” Norris and Adler say that it is the Norris/Adler barrier reinforced by Clarence Johnson and Kellex people, because in their barrier they used some of their [Norris and Adler’s] experiments. 

Anyhow, I think it is human, but one thing that he disagrees completely with in the book “The New World” is that the book gives certain credit for Columbia to Dr. [Francis C.] Slack. According to Nix, that is completely wrong and that Slack from the very early days worked unsuccessfully on that barrier, which was completely different, never used, and then he was moved to another aspect. He thinks that it is wrong to say that the Columbia barrier was Norris-Adler and Slack. 

Charney: I see. I do not know that my recollection of this date is clear enough to say who is right. It is certainly not true, however, that Slack worked on something completely different. Slack was for a time in charge of the overall barrier development at Columbia and as such in charge of Norris-Adler development as well.

At that time, there were indeed, in addition to the Norris-Adler barrier, one or two other things that were being carried on that were ultimately abandoned.  And to the extent that Slack did not himself, I would guess, contribute ideas to the Norris-Adler development, Nix is probably correct. But Slack was a very effective individual and helped carry that development along.

Groueff: He was in charge of a different group, and it happened that your group succeeded?

Charney: Right. 

Groueff: I would say he was like coordinator? 

Charney: Yes, now he was like a coordinator but it would be wrong to give the impression that he was strictly administrative. I mean, he did indeed have daily contact with the technical people who were working in the laboratory. He himself was not in the laboratory working on the barrier. To that extent Nix may be correct in that; on the other hand, he certainly—

Groueff: But he was involved?

Charney: He was involved definitely, and he, as I say, was a very effective individual, and so to that extent I would say he contributed. It is possibly a little bit of the way you look at things. If you look at it as though Slack, since he was not there in the laboratory making the barrier by hand – to that extent, Nix is probably right. 

Groueff: How would a normal workday be with Norris/Adler and you in this lab? 

Charney: From the end of 1942 to the summer of 1944, when we managed to get ourselves a little break, Adler and myself probably worked close to eighty hours a week. 

Groueff: That is a lot, ten hours a day, more.

Charney: Actually, wound up to about twelve hours a day. We rarely worked on Sunday. I would normally get to the laboratory in the morning at some variable hour between 7:30 and 9:30 and worked until midnight every day, six days a week. 

Groueff: And Adler too?

Charney: Adler worked a little bit less than that there, but he was probably working that hard; he was teaching school at the same time, so he did not put in as many hours at the laboratory. He was probably working that many hours a week. 

Groueff: Did you wear laboratory coats?

Charney: No. 

Groueff: Just shirts?

Charney: Generally, but that is partly a personal preference. Various people worked differently. I usually worked without a laboratory coat. Adler was actually a very sloppy worker. 

Groueff: In what way?

Charney: In the sense that he had this desire to jump into anything, he had no patience with cleaning up. 

Groueff: He was not a meticulous person. 

Charney: No. The tables were covered with the debris of the last few days work.

Groueff: Not at all meticulous?

Charney: Not at all meticulous. Norris was much more meticulous, although he too had little patience with cleaning up, but at least he did not feel that he could work in the space that was already cluttered with the debris. Adler would work anywhere, he would pile things one on top of another, and it was just incredible. I felt obligated to make a little bit of order out of things, and so the only order that was in the laboratory was me.

Groueff: So Adler and Norris were not so much methodical researchers, they were men of intuition and impulse?

Charney: Yes. 

Groueff: And great enthusiasm?

Charney: Oh yes, Adler certainly that could be true of, and to some extent of Norris – although Norris was a much calmer individual.

Groueff: It was rather noisy in there?

Charney: Yes.

Groueff: With Adler?

Charney: Yes. 

Groueff: How did he look physically?

Charney: Well at that time he was still quite a young man; he had no moustache. Great shock of wavy hair, which I guess his wife made him cut occasionally. 

Groueff: Usually on the long side?

Charney: Usually on the long side. He was careless about his personal appearance. 

Groueff: No attention to the way he was dressed?

Charney: No. I do not know what else I can tell you about his personality. 

Groueff: Did he smoke?

Charney: Yes, he smoked quite a bit. I smoked quite a bit at that time. I no longer smoke. 

Groueff: Did you take meals around the lab?

Charney: It was very variable. We would occasionally send out for a sandwich and eat in the laboratory. Sometimes we would go out and eat at a nearby restaurant. 

Groueff: Norris was a much older man than you and Adler? 

Charney: Yes. 

Groueff: What was the relationship with him? 

Charney: Very informal. Partly this was his own doing. For example, he never, as he could easily have done, he never treated me as hired help, but more as a colleague. 

Groueff: You called him Mr. Norris?

Charney: No, usually Ed. 

Groueff: Ed? Two men are Ed? 

Charney: Yeah. At the beginning, I called him Mr. Norris, but that quickly wore off. 

Groueff: It was informal? Friendly? 

Charney: It was informal and friendly, and even as I recall a period later when there were strains between Norris and Adler, it always remained on a very respectful basis. 

Groueff: Didn’t he feel uneasy sometimes to be the only man without a degree among so many scientists?

Charney: Yes he did, and that was apparent. I think this is probably one of the reasons that he never really felt that he wanted to be engaged full time. He essentially lived in Connecticut, he never moved to the Columbia area. 

Groueff: Did he feel with all of you, that this was his home?

Charney: Yes. I had a very distinct feeling, and I guess both Adler and I tried to make him feel more confident and kind of shield him from what might have been an uneasy situation. 

Groueff: It gives anybody a slight complex to be an academic in the center of the academic world and to be the only on without a degree. 

Charney: Yes. This is one thing we were certainly aware of, and he actually vocalized it a little bit. 

Groueff: With resentment?

Charney: No, not with resentment, but with diffidence, which we felt was unnecessary because he was good. He had ideas and he was good. 

Groueff: His main qualities were inventive mind? 

Charney: Inventive mind, yes. 

Groueff: Each time you had a problem, he was likely to look—

Charney: Yes, his lack of training certainly showed when the problems became one of refinements that involved improvements in the chemistry or in the technique. In fact, again, later on when he left—again, this may have been part of his reason for leaving—by that time the project had grown considerably, [Edward] Mack was now in charge of a very large group of people who were working on different aspects. I had a laboratory of eight people working for me on only one aspect of the whole barrier.

Groueff: You were about twenty-two?

Charney: Yeah. The various aspects had been split up.

Groueff: Also, Currie came?

Charney: Lauchlin Currie came. 

Groueff: And Hugh Taylor. 

Charney: Yes, several Taylors actually, but Hugh Taylor. It became a very large project. It was rather interesting. The way this was done was that the laboratory was split up into all these various sections, each of which essentially was developing one aspect of the Norris-Adler barrier process, but in each of which carried along essentially a sub-pilot plant manufacturing process as it went from one laboratory to another. 

In other words, we were actually manufacturing in these sections, on a sub-pilot plant basis, finished barrier, so that each of the various sections would not only carry through the first step in the process. There would be a number of things prepared, partly for research on that step of the process and partly for a standard material to be carried through the rest of the process with which other sections would be designing and performing new things. For example, a set of the initial project, perhaps forty pieces or so, would leave the first section. Now possibly five or ten of those pieces would have been treated in some different way or something as part of the development of the first step. The next section would take all forty, treat all but five or six of those that had not been given a different treatment by some procedures themselves.

At the end, they would come out perhaps forty pieces with possibly four or five different treatments, including one which was carried through as a standard all the time. 

Groueff: At the end, you could compare the advantages of different barriers?

Charney: Right, that was one part of the arrangement. In addition to this, there were a number of side developments going on. There was the printing development, which was going on at a pilot plant stage essentially. That was being done at the Chiclet Company. It was distinctly separate because the part of the process that involved printing in this other development that I was describing to you, the section development, was at a sub-power plant stage and was being done in one of these sections. The major printing development, at least at a pilot plant stage, was carried out by Shazkin, Adler, and Yates, partly at the Chiclet Company. 

Then at the same time, a number of people including Adler were carrying out privately in little laboratories just completely new ideas, things that might work either with the barrier that was being considered or some other barrier.

Charney: Despite what I have written in that book there are many details that I can’t recall. Let’s see, what was I—

Groueff: You were saying that one of the complicated problems was to see whether the barrier works. 

Charney: Yes, right. Now the problem is: the measurement of the isotope separation, even with the mass was very small, and the difference in isotopic masses were very small. U-235 hexafluoride and 38 hexafluoride, there’s only a small difference in mass. So even with the mass spectrometers available to us at the time, the measurement of the efficiency of Barium was not an easy one. 

Furthermore, there were other characteristics of the barrier that had to do with its resistance to corrosion, with its porosity, how much gas you could put through it, with its ability to withstand pressure surges, with its capability of absorbing gasses onto the surface. 

So each of those were separate problems on which research was carried on in the same group. There were separate sections involved with each of these things and in fact part of this little laboratory-size manufacturing process was involved just in making material for these groups that were doing research on methods of characterizing the barrier. 

So then all this was being carried on at the same time. You couldn’t pull something off the shelf and say, “Well now at least we have some way of characterizing the barrier.” You go ahead and make it. You had to. At the same time you were making barriers, we had to be developing methods of characterizing it. So this was going on as well. 

Groueff: Did you find some methods that you can say for sure that the barrier is good?

Charney: Much of this is available in the technical literature actually. This is not classified material. There are now improved techniques in measuring absorbed gasses on surfaces and methods of measuring the porosity of porous materials. Of course all the time the mass spectrometers were being improved to be more and more sensitive so that measurements—

Groueff: Dr. [Alfred] Nier?

Charney: Yes. Nier was improving the mass spectrometers to be able to make measurements of small mass differences with greater and greater accuracy. So that smaller and smaller quantities of gas could be used for making measurements, for example. And then there was the whole pump development.

Groueff: Now the way I heard the story the Columbia, one group was working very hard under  [Eugene] Booth. 

Charney: Booth, that’s right. 

Groueff: And they had a pump that looked quite good, but finally the pump couldn’t be used with the hexafluoride and the big problem was the seal problem. 

Charney: That’s right. 

Groueff: And then a group in Kellex under [George] Watts and [Judson S.] Swearingen

Charney: Swearingen—

Groueff: Then discovered the seal. Watts and [Owen C.] Brewster and Swearingen built it and sent it to be built by Allis-Chalmers.

Charney: That’s right. 

Groueff: So the pump of Columbia was not used?

Charney: Not the pump. Actually, some of the Swearingen seal and some of the techniques that were used in that pump were techniques that were used on the Columbia pump. 

Groueff: I see. 

Charney: There again was a sort of a combination. 

Groueff: Bush advised also Swearingen all the time on scientific aspects and things. 

Charney: Yeah. So there again, while the two pumps as such were never combined, the seal itself was Swearingen’s seal. 

Groueff: Yeah.

Charney: But, it made use of a principle that was used in the Columbia pumps, and in fact there were three different pump developments at Columbia. I don’t really recall anymore whether Henry [A.] Boorse [Jr.] was in charge of all three or of the one major one. Clark Williams, does that name come up?

Groueff: Clark Williams? No. 

Charney: No, I don’t really know whether. I just don’t remember.

Groueff: I may go and see Boorse.

Charney: At any rate there was again a combination of ideas. Again, in connection with the pumps and with the characterization of barrier there was this problem of pressure surges in the plant. Did Arthur Squires or Manson Benedict describe any of this work?

Groueff: Of which work is that?

Charney: The work of designing the cascade. In designing a large cascade, there is the problem of each element affecting the subsequent element. 

Groueff: Yes. 

Charney: And there was very serious concern given to the possibility of a pressure surge in the plant, a small pressure surge starting somewhere in the plant, would build up to enormous pressure somewhere and just blow it apart.

Groueff: Yes, they told me the British were very confident that it wouldn’t work and they had to do some mathematical—

Charney: Yes. There was enormous mathematical development that was involved with the servo control. You must realize that at this time servomechanisms were really very new. Quite a bit of development of servomechanisms were involved with the control of the plant. 

Groueff: How did that work?

Charney: Suppose you were pumping gas and for some reason you get a mild stoppage or the pump doesn’t work properly. If pressure builds up either in the back or the head of the pump, the next stage in the process is going to see that pressure surge. You now have a mechanism which is designed to open or close a valve to relieve that pressure surge. Suppose it does that. You may have relieved the pressure surge, but now that valve is closed a little bit. 

Now, there’s a correction made, and that sort of thing goes on up the line. But now there’s been a correction made in this original valve and unless it can find its way back without disturbing the pressure in the system it’s now in a new position. 

Groueff: I see. 

Charney: And when the next pressure surge comes along it’s going to possibly do the same thing again. Now, it can get itself into a situation where it will propagate a very serious pressure disturbance up and down the plant, first of all destroying the separation because that depends on having accurately controlled pressures on both sides of the barrier. And in a really bad situation, creating so much pressure as to actually blow out a part of the plant, which will release uranium hexafluoride all over the place and do serious damage. 

So the problem came in designing not only from a technical point of view but from a mathematical point of view, designing the plant in such a way as to minimize the possibility of this happening. A so-called minimization problem. And a great deal of time and effort went into it and it is to the credit of these people that when the plant was built by a mathematical design which had essentially not been tested, the thing worked. Now there was a pilot plant. A gaseous diffusion plant at the Nash building.

Groueff: Through the whole campaign?

Charney: Only a few stages. But you see, that that kind of problem couldn’t be—

Groueff: Because the effect, like a snowball.

Charney: Right. So that pilot plant was used for other things, measuring the efficiency of pumps, of barriers. 

Groueff: Not for the cascade?

Charney: Not for the cascade. 

Groueff: Now on the cascade I’m also a little confused. There were two separate works, or there was in interchange of ideas? Because between the Columbia cascade group was Dunning, and Booth.

Charney: Yes. 

Groueff: And I don’t know who, [Karl P.] Cohen.

Charney: Cohen. 

Groueff: And then there was Manson Benedict with Kellex group. Now when you listen to Keith or Benedict or Kellex, the one used at K-25 was definitely the cascade design, and thought of and built by Benedict. Then the Columbia people would call it the Dunning-Booth Cascade and present it as if it was designed there.

Charney: Well, I think I can tell you a little bit about that. There again, I wasn’t close to that development but because of this book and partly because I knew all of these people reasonably well. As narrowly as I could tell, this is a very interesting thing. The original principle of that cascade is in Dunning’s diary, written well before. 

Groueff: Yes. He mentioned that.

Charney: Did Dunning mention this diary?

Groueff: Yeah, before the war. 

Charney: Well not before the war. 

Groueff: In ‘39 or ’40. Something like that. 

Charney: About ‘39 or ‘40 yes. And I had access to that diary.

Groueff: You saw it?

Charney: I saw that diary, and the principle is all there, including the variations which finally became part of the thinking of the design of the cascade. In fact, the final cascade is virtually in Dunning’s diary. Now that’s the principle. Dunning and that group worked very hard on the Cascade subsequently as did Benedict, and Squires and Daniels.

Groueff: I didn’t see him. 

Charney: And Cohen, Cohen made very major contributions to this problem of pressure surges. At any rate, I would say that any evaluation that Benedict gave you was essentially correct. Keith was a very jealous, I don’t blame him. He was in charge of a big industrial complex and he was very jealous of having it given major credit for things. In fact, those people worked very closely together and if Benedict has given you an evaluation of what went on, I think Benedict is modest, not only is he modest, he’s an extremely careful, honest and very honorable individual. 

Groueff: Yes, he really seemed to be one of the top scientists in his field. 

Charney: Yes. I think so, and I think he’s a tremendous person, both as an individual, and as a scientist and if he’s given you some evaluation of how that fell into—

Groueff: He didn’t talk too much because he’s not a very talkative man, but he gave me a description of what he was doing, because most of it is classified. But I don’t know how the comparison of his work and Columbia Dunning-Booth work. Was one supplementing the other?

Charney: As far as I was able to detect, it was one supplementing the other. Now I wasn’t directly involved in that work and so I can’t really tell you. But as narrowly as I could tell, it was one supplement the other. 

Groueff: But it was more or less theoretical work because they didn’t have the components and they did it without the gas.

Charney: Well Booth and Dunning of course eventually had the small cascade. They also started out with single stages and then two stages and these developments were kept going. Once they had a single stage going that was kept up, a double stage was built alongside of it, and a multiple stage. I don’t really remember how many, but quite a few. But honestly nothing like the gaseous diffusion plant. 

Groueff: Too bad it’s classified, because when I go to Oak Ridge I would love to see it, but nobody’s allowed inside. 

Charney: Yeah. 

Copyright 1965 Stephane Groueff. From the Stephane Groueff Collection, Howard Gotlieb Archival Research Center at Boston University. Exclusive rights granted to the Atomic Heritage Foundation.