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Alfred Nier’s Interview – Part 2

Manhattan Project Locations:

Dr. Alfred Nier was an American physicist well-known for his work on spectrometry. Nier designed the mass spectrometers used for Manhattan Project experiments and his instruments were sent to all of the major Project sites. With his mass spectrometer, Nier helped prove that that U-235 was fissile, not the more abundant isotope U-238. Nier worked for the Kellex Corporation to design and construct the apparatuses used to monitor the separation of Uranium-235 and Uranium-238, as well as leak detectors for the K-25 gaseous diffusion plant. In this interview, Nier discusses his early involvement in the Manhattan Project in New York and the transport of uranium between Project sites. He also discusses his experiences working at both the Nash Garage Building in New York City, and the K-25 Plant at Oak Ridge, Tennessee.

Date of Interview:
November 30, 1964
Location of the Interview:


Alfred Nier: By the summer of 1943, the question came up, what I should do next? And I had a chance to – [J. Robert] Oppenheimer had gotten a hold of me and suggested I might come out to Los Alamos.

Stephane Groueff: And you knew him?

Nier: I knew him, yes. I had met him before, too. I knew him. And John Williams, my colleague here on the staff, was already out there, and played an important part in the project out there. And they wanted me to come there. And Chicago people again suggested maybe I should come down there. I didn’t know what to do.

I finally decided that perhaps the most good I could do is continue this instrument development because these problems that Kellex would have in the plant were tremendous problems, the analytical problems of keeping track of everything. And this is the kind of thing that Keith refers to, these enormous engineering problems.

Groueff: Without precedent.

Nier: Without precedent, really. While it wasn’t much science for me, and perhaps scientifically, I had fared better. But this was a real challenge to work, on these large-scale—

Groueff: You knew about their difficulties?

Nier: Oh, yes, I could see it. Because Dunning and I were very close friends, and I knew about this whole program through Dunning, of course, and Benedict, too.

Groueff: Where did you see them? You were going to New York?

Nier: Oh, I went to New York very frequently because Urey was still there, you see, and I had to report to him. And I went down to see how our instruments were doing there.

Groueff: With Dunning?

Nier: With Dunning.

Groueff: And Benedict.

Nier: Benedict and so on.

Groueff: So you knew about the tremendous difficulties?

Nier: Yes.

Groueff: Now who called you first there, Benedict?

Nier: I think it was Benedict largely who—

Groueff: Suggested.

Nier: —suggested this, probably. And Dunning, of course, thought – Dunning was very much interested in the gaseous diffusion plant because after all, it was he and his colleagues who had worked out the first barriers in the laboratory. We had shown, our measurements – yes, I should’ve mentioned that, too. Our measurements here proved that this method would work. See, the first samples of Dunning’s measurements, which they’d done with their little, I’ve forgotten, six stages or what it was, or three stages, we were able to demonstrate that this was working. So they would send us the samples, and we would telegraph in code the answers back to them. And usually, Gene Booth, I dealt with at that time. Have you met Booth, by the way?

Groueff: No, not yet.

Nier: He’s a wonderful fellow and you must meet him.

Groueff: Because Dunning said that he was his principal assistant.

Nier: Oh, he was one of the smartest people I’ve ever known.

Groueff:  Is he still there in Columbia?

Nier: No, he’s around. He’s with some laser company or something in the New York area. He’s someplace in the New York area now.

Groueff: And you were sending him telegrams?

Nier: Yeah, then they would send us the samples and then we would send back—

Groueff: Samples of barrier?

Nier: No, no, of the separated uranium.

Groueff: Separated uranium.

Nier: Yeah. And this, we demonstrated then clearly that they were succeeding in their separations. And this is what then gave Dunning then the background information he needed to extrapolate this onto the K-25 plant.

So we were the only ones who had, initially, the facilities here for helping them. And then, of course, when Ingraham went down to New York in Dunning’s own laboratory, they then carried on this work there, you see. But the original samples that were – of the separation – were done here, where we told them that they had succeeded in the barrier in the gaseous diffusion process.

Groueff: How did you communicate with him? By telegram?

Nier: Yeah, by telegram usually.

Groueff: Coded?

Nier: Yes, they used code in all of it. Although it wouldn’t mean anything to anyone anyhow. It was all numbered samples so you’d say “-half percent,” “six over seven,” or something like that.

Groueff: And the samples arrived how?

Nier: Express.

Groueff: In the mail?

Nier: In the mail. Well, Railway Express.

Groueff: In containers?

Nier: These came in copper tubes. Usually, it would be a piece of copper, refrigerator tubing, three-eighths of an inch in diameter. One end was squeezed shut and soldered shut and the other end had a flare-fitting on it, the kind of standard fitting you have in refrigerator parts. And these tubes were usually a foot long, something like that.

Groueff: So it worked, at Columbia?

Nier: Yes, at Columbia, they had this little pilot plant.

Groueff: In the Nash Building?

Nier: No, this was in the Pupin Laboratory, in the Physics Building. And then, of course, later on, they continued on the Nash Building. But this is still the work that was—

Groueff: Their barrier never worked too well. Why didn’t they develop it then? Or it couldn’t be made in several acres?

Nier: That may have been. You see, at first, they were just interested in demonstrating the principle that this would work. And that, they succeeded in. In the laboratory, I guess it was in the basement of the Pupin Laboratories where this work was going on.

Groueff: So they called you from Kellex and you accepted?

Nier: Yes. I didn’t need to do the measurement work anymore. We had developed instruments for these various projects, so I was free. And it looked like the Kellex was the logical group to go to work with.

I should add one more thing in this – that in the Summer of 1942, I had built quite a few of these instruments by that time, the uranium instruments, the leak detector. Well, I think leak detector had started, at least. I don’t know if the hydrogen instruments had been started then yet or not. But at least it looked like a logical time. And so I gave up the work here and moved to Columbia, actually. And my wife moved with me, it was just the two of us then. And we lived there for a week.

Groueff: In New York?

Nier: In New York, down a few blocks from Pupin on 120th Street, somewhere around there. But it seemed to me at that time it was premature. I had these wonderful shop facilities here where I could build things, and down there, they didn’t really have the facilities at that time. So it didn’t make much sense to work right there when so much work needed to be done. So I decided it was better to come home for another year. So we turned around and came back here and I stayed here then until July of—

Groueff: ’43.

Nier: ’43, yes.

Groueff: And then when and how did you move to New York? The whole family?

Nier: Well, it was just my wife and I, so this was easy.

Groueff: You took the train?

Nier: We took the train. There are interesting sidelights on this and how you find a place to live. We took the train from here to Chicago and then this was on a Tuesday. We bought the Sunday New York Times in Chicago and looked at the want ads to see what apartments were available. And of course, at that time, there was a kind of a depression in New York because of the war. New industries had not located, they were afraid it might be bombed and they weren’t locating things there. I remember the taxi drivers complained about how bad business was in those days.

But we looked over things and we found an apartment up on 231st Street and Henry Hudson Parkway, which is just a few blocks from where Dunning lived. Just a coincidence that we were almost neighbors. But my wife went up there then the next day and looked at it and I went up that evening. I said, “This is too far, this is too far,” but it ended up we lived there anyhow. And it was very convenient for the Nash Building, where I ended up.

Groueff: How did you commute? You had your car?

Nier: No, subway.

Groueff: Subway.

Nier: Yes.

Groueff: Every day.

Nier: Every day, every day.

Groueff: And you worked at that time? Where was your office?

Nier: In the Nash Building. See, Kellex had two or three floors.

Groueff: They were in the Woolworth, no?

Nier: Yes, that’s where their offices were, in the Woolworth. But they had laboratories set up over in the Kellogg plant in Jersey City. And then, most of the work, however, was being done in the Nash Building.

Groueff: And your offices were at the Nash Building?

Nier: In the Nash Building.

Groueff: These weren’t Woolworth?

Nier: No. At first, until the Nash Building, until we could get into it. I was the first inhabitant of the project in the Nash Building. And until the building was ready, I had an office in the Woolworth Building. And I spent most of my time then just in the library and reading and planning and seeing what we could do.

An interesting sidelight on this, also, is that I had a feeling that mass spectrometers were too complicated for this work. I had general responsibility of finding means for making measurements of all kinds that might come up in the plant. And so I spent a great deal of my efforts trying to avoid using mass spectrometers. And always, there would be some difficulty that—while you can find other methods that are good for some things, so much was unknown here that one couldn’t be sure that if you find some other method, that it wouldn’t be nullified by some new gas they might use in the refrigerant in the plant. The plant was being designed then and no one would tell you – could tell you—

Groueff: They didn’t know themselves.

Nier: They didn’t know themselves, you see. And so finally, somebody told me – I tried so hard not to use mass spectrometers because I felt that they were so complicated and this would be so difficult that there must be simpler ways of doing it. And somebody down there finally told me, they said, “Well, we hired you because you’re supposed to know something about mass spectrometers. Why don’t you go ahead and build them?” So this is essentially what I was told. I’ve forgotten who it was, probably Mr. [Albert L.] Baker or someone like that.

But we then carried out the development on mass spectrometers and also, other analytical methods, which might be applicable to problems in the plant. So we came up with a number of different instruments.

Groueff: In the Nash Building?

Nier: In the Nash Building, yes.

Groueff: Who were the people you worked directly with? Watts was your—

Nier: George Watts was the head of the Instrument Department. There was a man by the name of Tom Abbott, who was a kind of assistant to the head and later, become the head of it – I think when Watts left at the end of the war. And Abbott and I worked together as kind of a team. Abbott had been a manager of one of the General Electric plants and had come to Kellex. A very intelligent person, who had considerable managerial ability and had the ability to communicate with scientists, which a lot of the managerial people didn’t have. And he and I worked with the General Electric people who put into production the instruments we were developing.

So Tom Abbott and I regularly took the train up to Schenectady from New York. We would either take the evening train or the overnight train. We made many, many dozens of trips during that two years.

Groueff: To General Electric?

Nier: To General Electric, where he would take care of the administrative phases of this and I talked to the technical people. Sometimes we were together – usually, together – because one of Abbott’s jobs was to see to it that they produced and stayed on schedule. My job was to see to it that they got the information, and sometimes I would take along with me some of my young assistants.

You might be interested in the kinds of instruments we worked on. We carried on the developing of the leak detector. The leak detectors we had built up until that point, the ones I’d built here, were not completely practical in that the main part was of glass, and here you wanted something that would be quite—

Groueff: The one you described, the spectrometer?

Nier: Yeah, part of the spectrometer was—the spectrometer tube itself was of glass. And while that was good enough around the laboratory, this wouldn’t work on a foundry floor or places like this. So we built metal ones, worked out other details of the electronics that went with it and other phases of it, and perfected this. And this model was turned over to General Electric, who essentially copied it in the form of—

Groueff: They actually produced it?

Nier: They produced it and they produced hundreds of them.

Groueff: Who were your collaborators? Still Ney?

Nier: No, Ney had left. You see, he was in Virginia. He was completely out of this part of it. I took with me several – three – young students, in particular. One of them whose name is Charles Stevens, who is now at the Argonne Laboratory. Another one whose name was Donald Drukey, D-R-U-K-E-Y, who worked with me on general instrument problems. The third one was Wallace Leland. And these were all boys who had graduated from the university just about that year. They were all about twenty-two, see. And Stevens carried on the development on the leak detector for me because I had many other problems. I could no longer find time to work myself because I had been having many people working for me.

Groueff: At the age of twenty-two! 

Nier: Well, I was thirty.

Groueff: Right, but he was—

Nier: He was in charge.

Groueff: Such an important position.

Nier: He was the man who had to perfect the leak detector. Now there were some real problems, I might say, in connection with the Draft because these young men, you see, were prime targets to be taken into the military service. So this was a continual battle to keep these boys deferred.

Groueff: In spite of the Manhattan Project?

Nier: In spite of the Manhattan Project. Because there were such things as quotas, the company was supposed to turn over so many bodies, you know, [laugh] certainly this kind. So we had quite a bit of trouble, in particular, with Stevens because somehow he had a draft board that was more difficult than others. And at one time, he was even right in the middle of this leak detection development where it was very crucial because they needed these badly for testing this plant, you see, in Oak Ridge. And here, the only man I had to work on this was going to be drafted. It was unbelievable as you look back on this, but manpower was very thin. I mean, it was very hard.

Groueff: And you couldn’t explain to the draft board?

Nier: What it was, you see.

Groueff: Did they ask why?

Nier: Well, it was just all handled through, you know, personnel. Kellex had a personnel office. It turned out that the military people within the Manhattan District refused to support my request on this chap, Stevens. And the personnel manager, assistant personnel manager, whose name I’ve forgotten now carried this thing up to Hershey’s office. See, General [Lewis Blaine] Hershey was in charge of all Selective Service and succeeded in getting the deferments in spite of, you might say, General Groves. Of course, General Groves didn’t personally know about this, but I mean, in spite of any of the – and that was the end of the serious difficulty I had. But this was a very crucial matter at this time.

Groueff: So imagine that he would be just a simple soldier?

Nier: Yes, that’s correct.

Groueff: And in the meantime, the whole plant—

Nier: That’s right. Well, we just didn’t have the manpower. You see, we were late. All the other projects had gotten going earlier, you see. This, you remember, was the end of 1943, and the manpower was all used up on other things.

Groueff: But was the whole team very discouraged? Or on the contrary, you always thought that you will succeed?

Nier: Oh, I think that it was rather encouraging, in a way. There were many difficulties, but progress was being made.

Groueff: And in spite of this, you knew that some answer would be found to that barrier?

Nier: Yes. And I think Dunning deserves a great deal of credit for that. I mean, Dunning, you see, kept everyone—

Groueff: Enthusiastic.

Nier: —enthused about it. I mean, he is a remarkable person, as you realize. And he was always enthusiastic about this and kept things going.

Groueff: The morale.

Nier: He was a real morale builder. Very important.

Groueff: Because I had read about Urey’s attitude was exactly the contrary.

Nier: Urey really was very pessimistic.

Groueff: That it couldn’t work?    

Nier: Yeah. But Dunning had the ability to work with the industrial people, for instance. And I think [Percival] Keith had a good deal of confidence in Dunning because he talked their language. I mean, he had this kind of a feeling for dealing with people.

Groueff: And he had some industrial experience?

Nier: Well, I don’t know what he had, but he certainly had this engineering sense.

Groueff: Engineering, yeah.

Nier: And I think he probably came up through engineering himself. I think he had. I had, too, you know. As a student, I was an engineer, electrical engineer, and I think Dunning was, also.

Groueff: So that helps, and Dunning was, also.

Nier: See, I started out as an engineer, and so this isn’t surprising that people are [laugh] just congregated in that kind of a situation.

Groueff: So the few laboratory scientists have had some difficulties in communicating?

Nier: Some of them did, certainly. But on the other hand, it turned out the old engineers, many of them were not very practical in this new age. You see, this was really a new age then. And just like in the radar work at the Radiation Laboratory at MIT, for instance, it wasn’t the old-fashioned electrical engineers who did this, but it was the nuclear physicists who understood, who had studied electromagnetic theory and things of this kind, who were the practical people in developing radar.

It was the same way in our project. It was the people who had the background in physics and chemistry who were really the practical ones because they had the background in this field, you see.

Alfred Nier: Well, the leak detector was, but one of the instruments we worked on in the Kellex Lab, the main thing which we actually did was to develop a recording mass spectrometer which, for the purpose of following the composition of the process stream in the K-25 Plant, this was our principal assignment. Because it was recognized that the plant, when it was running, could very easily be shut down and destroyed, as a matter of fact, if it developed a bad leak, if some of the refrigerants leaked or if it developed a leak to the outside so the air could get in. So it was important to watch, to monitor the plant at many places.

This is a long plant. It’s a huge plant with many stages in the separation process. And so it was important to, at regular intervals throughout the plant, to look at the composition of the process gas stream. And we undertook, then, the development of this recording mass spectrometer, which we called a line recorder, kind of a code name, line referring to the fact that it was on the line. And so we spent a good deal of time on this development, as most of our efforts went into this particular problem. We worked—

Groueff: Was it a different spectrometer—?

Nier: It was just a small one, a small one, which would automatically pick out certain components to look at, which we suspected would be there. We could tune it to whatever we want it to. And then it would automatically look at these in sequence and record the data on recorders. There were both local and then slave recorders, which were in a central control room of the entire plant.

Now, this kind of principal of looking at the operation of a large chemical plant in a central room by instruments is nothing new, but that you would have mass spectrometers sprinkled throughout the plant and have the central room was something new. It was the first time.

Groueff: Nobody’s in the thing during the process, yeah.

Nier: Yeah, that is right. So this was the first time that mass spectrometers had been used in this large and industrial, an automated plant, really. See, so this plant was a first in many ways. It had many features. Of course, it was the largest continuous operating thing in the world then. And it had, in this one feature of it, it was the first time that automatic operating mass spectrometers were used to follow the performance of the plant.

And so we worked on that development of these recording mass spectrometers. Again, they were constructed, the actual instruments were constructed by the General Electric Company, but we built the prototype models, which we sent up to General Electric, who then copied them and engineered them further, because a lot of the features we had would not lend themselves to production. So they engineered these things further. Although, actually, when it came to start the operation of the plant, in early 1945, General Electric didn’t have the instruments on hand and so we provided the first half dozen or so, which we built ourselves in our laboratory. Again, I was back in the production business. But we built something like a half a dozen for the first work, when they were needed in the plant. And soon the production began and, of course, they began to turn these on.

Groueff: But it’s such a huge plant. It’s three times half a mile, something like that, a mile and a half and four floors, so it’s physically, it’s enormous. What was the tolerance of leakage?

Nier: I don’t remember the figures now.

Groueff: But, I mean, is it something that in a normal plant—?

Nier: It was specifications well beyond what they were accustomed to anything done before. You see, one of the problems they had was to find welders who could weld the pipes and things like this well enough, because they had never been required to do that good a job on things.

Groueff: But in normal welding, are there leakages?

Nier: There may be, for instance in a steam pipe or something, it doesn’t matter, you know. But here, it really mattered. And so they had – well, it was very complicated plant. There was all the piping, and I think one of the very remarkable achievements was the development of the blowers that they called, these compressors that were pumping the gas up. This was a remarkable achievement. And that and the barrier were probably the important two things. The fact that these compressors could be driven and would compress this very corrosive gas without contaminating it and without losing it was a fantastic, the bearings that they developed for this. And the barrier development, I think, were the two really outstanding things.

Groueff: I was talking about the calutrons to [Judson] Swearingen, who promised to send me some material.

Nier: Well, he was on the pumps, wasn’t he?

Groueff: Yes, yeah.

Nier: It was field, yes. I met him, but I don’t remember—

Groueff: [George] Watts and Swearingen, Watts and [O. C.] Brewster, I think.

Nier: Brewster, yes. These are familiar names. I hadn’t thought of them in many years now. Well, that’s about it. We had some other work. We developed some other methods of special problems, like they were interested in knowing if they know uranium hexachloride out from the stacks at the end of the plant. And we developed some instruments for detecting this. And they were interested in the hydrogen fluoride content in our laboratory. We did some of the development on those instruments.

With the addition of these younger boys, I had one very good chemist, Dr. Greenspan, Joseph Greenspan, who now has a company of his own, I believe, in Brooklyn somewhere. I know he was in business. And he took care of many of the chemical problems. And we were helped a good deal later on in the war, when a certain number of GIs were assigned to us.

The Army had had this program, I believe it was called The Army Special Training Program, something like that, where college boys were put in the army and then sent back to school. These are very intelligent young fellas. And they were supposed to be officer material. But the war was moving on so fast, it was realized that there would not be time.

And they were then, in these areas, where they needed technical people, they had had engineering type of training as students here in other schools. So they, then, were assigned to programs like this. And Kellex got a lot of them. And a lot of them went to Los Alamos and all these different Manhattan project sites where we were so terribly short of good people, they were assigned to them. And they were very important. I’ve forgotten how many I had there, but it must have been, I had something like a dozen of these GIs. They worked along with us.

Groueff: All within the Nash [Garage] Building?

Nier: All in the Nash Building, yes.

Groueff: Did you go to Oak Ridge?

Nier: Yes. Well, then as the plant began to go together, then I spent a lot of time in Oak Ridge.

Groueff: In ’44?

Nier: ‘44 yes, beginning in ’44 and then the spring of ’45, especially, I spent almost every other week.

Groueff: You didn’t live there?

Nier: No. I never lived there. I lived in New York. But I went back and forth. We were training the [Union] Carbide people, who were going to take over the operation of the plant. And they had some of their people spend time in our labs, getting acquainted with the instruments.

Groueff: [Manson] Benedict went, also, to teach them –

Nier: Yes, he went down to help them on this and there were a lot of people going back and forth.

Groueff: But you were not at Redmond?

Nier: No, never, never. But those were very hectic days, the spring of ’45, as the plant began to operate, because there were many, many problems and there was a shortage of good personnel to do most of these things. Because, as I said before, what happened is that everybody else, like the Radiation Laboratory and radar had taken up a lot of the good men. And there were other, more glamorous parts of this program. This was the thing, also, there was a difficulty was that this part of the program was later than other parts and the pumping gasses through diaphragms with little holes on it is not the most glamorous thing to be doing during the war. So the result was that this program did not have the appeal that other parts of the program. For instance, Ernest Lawrence, with his super salesmanship, and the dramatic business of having a mass spectrometer, where you could do the separation all at once, but—

Groueff: Was more spectacular.

Nier: –was much more spectacular than this, where you just plugged away and had pumps and things of this kind. But there were enough good people that seemed to be around at just the right time. So somehow or other this thing—

Groueff: Well, what were some more difficulties, which one was the one, more than any difficulty that you considered as practically impossible to solve, with the knowledge that you had at that time, with the precedence of industry or of instrument, were the problems that would look like impossible?

Nier: Yeah. So as a matter of fact, the idea of monitoring this process stream, where this had to go on twenty four hours a day, day after day, after day, seemed almost impossible. The—

Groueff: The leakage—

Nier: Well, yes, but the problem of making our instruments run that long. You see, this material was also very hard on our instruments. And when you use the instrument for analytical purposes, such as we had when we were doing the work here, we would have to take it apart and clean it up every week or so, you see. And so we thought the maintenance problem would just get out of hand, that you just couldn’t keep this much equipment maintained. But gradually, we improved our techniques. And I had the help of a very able chemist, who is now a professor and a very close friend of mine at Columbia. He then was working at the Bureau of Standards, [T.] Ivan Taylor, who is a professor at Columbia, and a very knowledgeable person. He had been one of [Harold] Yuri’s students before the war. I had become acquainted with him. And he came and helped me out for a while there in New York, at the Nash Building and was very helpful on some of the chemical fronts, since I knew very little about chemistry.

And we ended up by developing a method of—it turned out that the contaminants that we were concerned about were not corrosive, particularly; whereas, the uranium hexachloride was. And so what we did was simply remove all of the uranium hexachloride before it went into our instruments, because we had a chemical way of removing it. So, since we knew it was there anyhow, why bother to measure it?

And the other thing is impure and air and these various refrigerants that they used to cool off the gas after it had been through the compressors. So, what we did was we worked out a system whereby the uranium hexachloride was removed before it came to the mass spectrometers. So all the mass spectrometers had to work on was the relatively nice impurities, which were nice gases, like nitrogen, and oxygen other refrigerants that might have been present.

Groueff: That was also a completely new technique.

Nier: A completely new technique.

Groueff: The problems were completely new.

Nier: They were all new.

Groueff: In case of difficulty there was no place to go to or to report.

Nier: No, that’s right.

Groueff: Or go back to somebody—

Nier: Yeah, we were the authorities, you see. To be sure, of course, we based all this on earlier developments, like these instruments had been similar to what had been used. But the problems of applying to these special problems was really unusual. And this was one of the, I think the whole geniuses of the Kellex organization was that you had this collection of experts, who – there were remarkable people there, who were experts on just almost anything you wanted to find, and who solved problems there that just had not been solved before. And they did this on schedule. This was the interesting thing about it.

Groueff: Because the whole plant, if you were told that such a plant would be built the way it was a couple of years before you worked there—

Nier: Impossible.

Groueff: Impossible. It’s great even to think.

Nier: Yeah, yeah. Of course, part of one’s thinking there would be that no one would ever spend that amount of money. You see, many of us who said, I mean, I was quite pessimistic in 1940, for instance, because I never dreamt that anybody would spend as much money.

Groueff: Hundreds of millions.

Nier: Hundreds of millions, you see, was just way beyond what any of us thought was possible. And had it not been for the war, it would have been years before this would have been done.

Groueff: And also, the big credit goes to the people who were taking decisions.

Nier: Yes, yes. This took a lot of the risks in choosing alternative things. When you view this in retrospect, for instance, the decision to go ahead with the electromagnetic plant to make the first bomb, for instance, while the electromagnetic plant could not compete in the long run. This is one of the reasons I got out of that kind of separation, because I didn’t think it was very practical. And while I cast my lot with the diffusion people—

Groueff: That was the thing of the future.

Nier: That was the thing of the future, and I think I was right. I mean, because to me—

Groueff: It is more economic?

Nier: Oh, yes. You know, just many times.

Groueff: But one thing I cannot understand here, according to [Percival] Keith, he pretends that contrary to what he said in The New World, the book, that the second bomb – the first bomb was plutonium in New Mexico and the second bomb in Hiroshima, according to Keith, was entirely produced by 235, produced in Oak Ridge. In the book New World, they say that it was, from what I understand, it was the electromagnetic thing, but probably receiving enriched material.

Nier: Very likely.

Groueff: And yesterday, when I talked to [Lew] Kowarski, he was very surprised. He said, “No. Everybody knows that diffusion was a marvelous thing but came too late. It wasn’t used at all.” The whole, because he doesn’t know the foreign scientist but he thinks that the second, the Hiroshima bomb, was entirely made with uranium from Lawrence.

Nier: I think this is correct. This has always been my feeling.

Groueff: That Keith probably it is overly patriotic—

Nier: Well, the records are certainly clear on that somewhere. You’ll have to check on that.

Groueff: General [Leslie] Groves would know.

Nier: Yes. He’d know exactly what had happened there. But, you see, there was one plutonium bomb and one uranium-235.

Groueff: Yes, and the third, again, plutonium, I think.

Nier: I believe that’s right but the diffusion plant did not produce it.

Groueff: Wait, wasn’t that a—? 

Nier: But immediately after the diffusion plant began to run, then they closed the others down, yeah. It was one of those things.

Groueff: And tell me, did you have personal contacts with Keith or with Groves?

Nier: Well, I met them both. I mean, I met Groves on several occasions during the war. Keith I saw from time. He was very busy. But, you see, they dealt with the Woolworth Building and I was up in the Nash Building. So I didn’t see too much of these people.

Groueff: Who did you ever deal with, Benedict or no, he was in a different—?

Nier: Well, he was in a different, in the process, but he was in the design part. My main contacts were with Watts, who was my immediate supervisor.

Groueff: No, I know the barrier people, you had nothing to do with.

Nier: No, but I knew them. See, Bill [Willard] Libby was there in the Nash Building. And we worked with them and—

Groueff: Clarence Johnson?

Nier: Clarence Johnson, yes. And there was that whole group, the names I don’t remember. Now, I’d remember quickly, if you mentioned them, so we worked with them, too.

Groueff: There was a fellow that they mentioned called Frazier Groff, from Bakelite but he’s dead now.

Nier: I see, I don’t believe I knew him.

Groueff: And Keith mentioned two other guys. I’ll try to see them. Both of them are in Florida. One is [James] Hobbs.

Nier: Yes, Hobbs, the valves man.

Groueff: He was the valves man, yeah. And the other one was [Ludwig] Skog, electric.

Nier: Yes, yes. I didn’t know him very well. I got acquainted with Hobbs because valves were a very serious problem. You had to switch these gases from one place to another, whether you were doing it in the plant or in the laboratory, for working with them. And there were no satisfactory valves available. So, I got acquainted with Hobbs because of the valve question, because this was a big concern to us. Because, you see, our instruments had to tie into the plant somehow. And that meant you had to divert some of the gas past our instruments so we could sample. So we got acquainted with him then. And he did a very nice job on—

Groueff: I was told he was quite a genius in his field. He was a very unorthodox man. What kind of—?

Nier: Well, he had certain principles. As he looked further ahead, I think, than some of the regular valve people. I mean, all of the people that built valves before were thinking of switching water around or something like this. And just, there was, you see, there was no real vacuum technology in those days. Now, of course, vacuum technology is a terrifically important field. But there were very few people who understood what a vacuum was or how you produced it, how you worked with vacuum. And he had the understanding of what it meant to have something really tight. He had a real good common sense, but this would have been quite counter to what, I think, many of the other people, who would have been considered valve experts at that time.

Groueff: So you had frictions and conflicts?

Nier: Yes. I think so, although I was never very close to that part of it, no.

Groueff: I have an idea already about Keith, his personality, because he also a driving, strong, energetic, dictatorial type of man. I think that Benedict is the type of modest man, who doesn’t talk too much about himself.

Nier: That is correct, very self-effacing.

Groueff: He is not pushing.

Nier: No, not at all, that is right.

Groueff: Very enthusiastic, but then he has a good sort of public relations attitude, and he is more aggressive, more variant.

Nier: An extremely intelligent person, and has this sort of aggressive thing. I think it might get under some people’s skin. But he could deal with the industrial people and talk their language.

Groueff: He showed me some of his notebooks. He has thirty-seven, eight, nine. It is amazing the things he already was discussing it—

Nier: That is right. Yes, he was ahead of times and a very imaginative person, who had this intuition. Because he might not be able to write down a formula for the thing, but he just had a feeling of how things ought to go. He understood that.

Groueff: And when I saw them in his own writing, with the dates, it is amazing to think that years later proved to be correct. But he was too young man to be listened to. [00:21:24]

Nier: Yes, he was kind of a brash young man.

Groueff: Urey, was a great man of science then.

Nier: That is right.

Groueff: And it didn’t take him through.

Nier: I think that he and Urey never got along very well.

Groueff: No, he was kind of. But tell me now, before we finish, tell me about your career and your background.

Nier: Before or after?

Groueff: Before yeah.

Nier: Well, I grew up here, in this community in St. Paul. My parents were immigrants. My mother had come, I am of German extraction, as you probably would gather from my name. My mother came as a child. Her family came here. There were six or seven children, one of these things, in the early 1880s. My father came as a young man, eighteen years old or so. They happened to be next door neighbors and were married. I grew up in the same—

Groueff: You were the first generation born here?

Nier: Yes, yes. And now, I guess, in school, in grade school, I showed a certain aptitude in arithmetic and subjects of this kind. And it’s very interesting. I think this patter runs very true. My parents have had very limited education.

Groueff: And they were not people connected with science?

Nier: No, not at all. My father was a machinist, which was my father’s trade which he had learned. He had been more or less an orphan, actually, and had no educational opportunities at all. And my mother’s family, her father was a cabinet maker. These were working people.

Groueff: So a machinist, I mean, sort of mechanic?

Nier: Mechanic, yes. You know, make machine parts with lathes and things.

Groueff: I see. And it was that modest financial labor—?

Nier: Yes, very modest but always working. And the interesting thing was that this, I think, is very typical. The immigrants in looking for careers, thinking ahead for careers for their children, think as something a step up. This is their thing. And to them, for me to go into engineering was obvious.

Groueff: Were you the only child?

Nier: No. I had an older sister, quite a bit older than I, but I was the only boy. So I went through high school and did quite well, and did well in technical subjects, physics, and chemistry, and mathematics, did very well. I was not greatly interested in other subjects, unfortunately. One realizes this too late, but this is the way it was. And so I came to university in engineering and enrolled electrical engineering and entered university in 1927, here in Minnesota. And I was just sixteen years old. I had just turned sixteen a few months before.

Groueff: So you were very good in high school.

Nier: In high school. In grade school, I had been skipped, I’d skipped several grades. In those days, the psychologists hadn’t taken over yet and told them it was bad for the child to hear this. And so I skipped a year and a half of grade school so I was about two years younger. This was unfortunate in a way. I think there is something to it. I would never recommend—they have given this up now. I was rather unhappy because I was just two years’ difference in age, in high school age, makes quite a difference, you know. And so I was never in on social events and things of this kind.

Groueff: Sports and, yeah, you were not accepted by—

Nier: I was too small. I was always very small and it was especially small in those days. So I was never acceptable for those things. And I was too young for the girls and I wasn’t in on anything, you see. So, but this was lucky in a way, because I carried newspapers for several years and saved a fair amount.

Groueff: You were selling?

Nier: No, a newspaper route, where you actually delivered them from house-to-house.

Groueff: I see, yeah.

Nier: So I had regular customers. And I, when I was fourteen years old, was earning, which in those days, it was 1926, ’25, ’26, I was earning close to forty dollars a month, which was pretty good money in those days. I know the one year, I saved about $500 or something like that, so that was – well, it couldn’t have been that much. Now, in one year, but I mean, a number of hundreds of dollars I saved. So I came to the university here and enrolled in electrical engineering. And I graduated in 1931.

Groueff: Electrical engineering.

Nier: Electrical Engineering. And this is kind of interesting how I ended up in physics. The former head of the department, his name is mentioned in this letter, this thing I have written for our archives, but taught a beginning physics class. And when I was a sophomore, in the second year, we all took physics. And I got hundreds on the first four tests. There was a test every week. And I got hundreds on the four tests. And so he called me in. This was a large class, 200 students, I think, at this time. And in those days, we had numbered seats and they knew where everybody sat. And so he came to me one day and said he’d like to see me. I didn’t why he knew who I was, but he knew from the seat number, you see, and he thought I ought to consider being a physicist.

Well, I said, well, I’ll consider it, but I really planned to go into engineering. Well, it turned out that I was offered an assistantship in 1931 when I graduated. But in physics here to continue on, but I thought I would like to go out and get a job and work for a while. But this was 1931 in the very bottom of the depression years, and jobs were not easy to come by. And so—

Groueff: Were you working at that time?

Nier: I was a student, and I worked part time. I had been working as a part time assistant here, as an undergraduate, so I had some income of my own then. But the head of the electrical engineering department was a man who really saved me, because I had turned down the assistantship here. And then I didn’t have anything. But then I was offered an assistantship in electrical engineering by the head of the department, his name was Henry Hartig. And he saved me, really, because there’s no telling what would have happened to me then.

So I became an assistant and pursued graduate work in electrical engineering. So I got a master’s degree in electrical engineering and then for two years. But in the meantime, they did not have much of a program to go on for a doctor’s degree. And so I kept up my contacts with physics and took as many physics courses. And so, then, after finishing two years there, I came here into the department again in physics and got a PhD degree in 1936 and had been fairly successful in some research I had done as a graduate student. And as a result, I got a National Research Consul Fellowship. These were rather rare in those years. There were only a few in the whole county in physics awarded, and I got one of them and went to Harvard.

Groueff: On the scholarship?

Nier: On this fellowship, and spent two years there. And then, in the meantime, this was still – these were still tough times. There weren’t too many jobs around then. And in the meantime, the man who had originally urged me to go into physics retired here and so there were two openings there that year. And, as a matter of fact, two of us from Harvard came here. One of them was John Bardeen, who won the Nobel Prize for inventing the transistor.

Groueff: The same promotion?

Nier: At the same time, yes, came here at the same time. We came here on the staff together. And during the war, we moved out in different directions, but we both came here and there were these two positions vacant at that time. Well, he went on and during the war, he worked for the Navy and then went to Bell Telephone Laboratories, where he made this discovery. But he was one of three  people, you know, who were in that. And I came back here after the war, then. In the fall of 1945 I came back here.

Groueff: And then you went to the atomic science through the measurement of the age?

Nier: Yes. Well, I had been interested. See, as a student, as a graduate student, the question came up what I should work on as a graduate student for a thesis subject, you see. You have to do this. And at that time nuclear physics was just coming in. So this was the early 1930’s. And I started to work with these, they had had instruments to this mass spectrometers, where they had done studying the bombardment of molecules with electrons to see what happens when you hit a molecule. And I thought I might work in that direction, too. But it soon became apparent that nuclear physics was the exciting thing at that time.

So I began to look into possibilities how this might be applied and this mass spectrographic technique could be applied in nuclear physics and so I became interested in looking for rare isotopes, as these would be atoms where their abundance would be very low. And as a matter of fact, as a graduate student, I found potassium-40 which was a very rare isotope of the element of potassium. And it happens to be the one responsible for the radioactivity of potassium and has to do with the age determination of minerals using the potassium-argon method, as you know. I didn’t realize then I would end up in that kind of thing, so I am a kind of a pioneer in that sort of thing.

Well, I continued that work, then, when I went to Harvard and measuring the relative amounts of these different kinds of atoms that you find in the element. And that is why the uranium turned out to be one of the things. And this famous number of 139 to 1 was a measure that was kind of routine, although it was related to the lead age measurements, too.

Groueff: And when did you get married?

Nier: In 1937, after I was at Harvard one year. And I married a girl that I knew here from St. Paul.

Groueff: And during the war, how much did you know about the bomb, or Los Alamos, or the other projects?

Nier: Actually, not very much. I knew, of course, about the heavy water work because we had made the instruments to go into these plants, and I’d been up to Trail, for example. I knew about the existence of Los Alamos because, after all, I was offered a job there and my close colleague, John Williams, had gone there. And it was general knowledge among the people who were working in the field high enough up that Los Alamos was the place where they would be working on developing—

Groueff: But you didn’t know what progress was being made—?

Nier: No, not at all, not at all.

Groueff: No details?

Nier: No details, except such information that might reach me because of some special deadline we had to meet, or something that you can’t very well cover up.

Groueff: I see. Well, what kind of vault or security – how did it work? Did you have to go to some—?

Nier: One had to fill out certain questionnaires about your background, I mean, biographical things, and your relatives and what organizations you attended, the standard sort of thing. And it developed a lot since then. It is much simpler now, I think, but there was more or less a standard set of questionnaires.

Groueff: But in Kellex work, for instance, what special measures were taken that you don’t talk, you don’t discuss the things?

Nier: Oh, yes, well, that’s understood.

Groueff: So you took it for granted?

Nier: Well, you had to sign the various things that you would agree not to discuss.

Groueff: Even not among the scientists?

Nier: Who were not part of the program. Yes.

Groueff: But you did not have any sort of agent assigned to you when you traveled?

Nier: No. I wasn’t important enough for that. As a matter of fact, it wasn’t appreciated how much critical knowledge that a few of us had on this kind.

Groueff: A man like you kidnapped and made to talk –

Nier: Yeah, see, I didn’t know a great deal. See, I knew a good deal about the plant.

Groueff: That would be important.

Nier: Yes, because, as a matter of fact, I knew the specifications on the plant, which very few people knew, because I had to know because I had to know what we analyzed for. So I knew a good deal of that information, yes.

Groueff: You didn’t have many contacts with the military or  Groves?

Nier: No, because there was no reason why I should.

Groueff: Your work was mostly with the [John] Dunning Group and Urey?

Nier: The General Electric people and the procurement and then the Union Carbide people, when the instruments – and Watts, who was my superior, yes.

Copyright 1964 Stephane Groueff. From the Stephane Groueff Collection, Howard Gotlieb Archival Research Center at Boston University. Exclusive rights granted to the Atomic Heritage Foundation.