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Robert Nobles’s and William Sturm’s Interview – Part 2

Manhattan Project Locations:

Robert Nobles and William Sturm were physicists at the University of Chicago’s Metallurgical Laboratory. They contributed to the creation of experimental nuclear reactors, including the world’s first heavy water reactor, the Chicago Pile-3. In this interview with author Stephane Groueff, Sturm and Noble discuss the security of the bomb project in Chicago, and the movement of scientists between the different sites. They also recall Eugene Wigner’s graciousness, Leo Szilard’s excitability, and Walter Zinn and Enrico Fermi’s leadership styles. They praise the scientific community for its embrace of international cooperation and respect.

Date of Interview:
April 20, 1965
Location of the Interview:


Stephane Groueff: [Enrico] Fermi was not considered as a foreigner?

William Sturm: Oh, no.

Groueff: There was no jealousy by the American top scientists?

Sturm: No, no, no, no. Science at this level is absolutely international. There is an international aspect.

Groueff: Did he speak good English?

Sturm: No, a heavy accent.

Groueff: Heavy accent but—

Robert Nobles: I would say he spoke good English, but with an accent.

Sturm: Very definite accent.

Groueff: But, fluently he could express everything he wanted and he was quite articulate?

Sturm: Yes, yes, yes, he was.

Nobles: He had a very effective sense of humor, very sophisticated. You know, he could get this across in English very well.

Sturm: But you had no doubt – even again, from a point of view of a graduate student working there – if he walked into the room, you became a friend, actually. Whatever it is that you wanted to talk about, you could talk about with him.

Groueff: What did you call him? Mr. Fermi? Dr. Fermi?

Sturm: Dr. Fermi, Professor Fermi.

Groueff: So it was a very informal relationship?

Sturm: Oh, yes, yes, yeah. I think the fact that we were all interested in attaining the same goal and Fermi, whatever apparently he meant to us, we meant a lot to him, too. Because he could not get to this goal without our help, and there was a mutual appreciation.

Nobles: That is one thing you remember about the time, the esprit de corps or whatever.

Sturm: Yeah.

Groueff: Yeah.

Sturm: People worked long hours and there was no thought of extra pay or anything.

Nobles: He never showed impatience with people who might unfortunately ask a stupid question, because this is the hallmark of many people of higher intellect. It is not a good trait but it is one.

Sturm: Well, firstly, you are not going to get people out of that group asking stupid questions because, say, his first corps that he is in, [Herbert] Anderson and so on – well, they probably asked one or two, what might have been to Fermi, stupid questions but they were really exceptional men themselves as scientists. The other people, insofar as they were scientists, were actually graduate students largely from the University of Chicago and they, too, were among the better—

Groueff: They were rather careful to formulate a question, right?

Sturm: Yes, they knew, yes. And they had had quite [inaudible] trainings, too. Nonetheless, if there were to have been an idiotic question asked, because you were tired or something, he would only smile and he would straighten you out.

Nobles: Very tolerant, yeah.

Sturm: Yes, extremely. Never out of sorts, never impatient, never irritated, never nervous.

Nobles: Do you ever remember him ever bawling someone out of anything? I never—

Sturm: No, no.

Groueff: He was not bossy.

Sturm: Oh, no.

Nobles: One gift that I think he had was, he knew what you could do. If he asked you to do something and you thought you could not do it, you could take this as a great compliment that he thought you could do it and you could probably do it or he would not have asked you to.

Sturm: Yes.

Groueff: But I understand [Walter] Zinn was a more authoritarian man, no?

Sturm: Yes.

Groueff: Sort of strict. Was he the boss that administered the things in the group?

Sturm: He was probably the senior man among the experimentalists after Fermi.

Groueff: Fermi, he [Zinn] was his assistant more or less.

Sturm: Yeah.

Groueff: He was more of a distant man, sort of strict and severe?

Sturm: Yes.

Groueff: Bossy? And nervous?

Sturm: Not unapproachable. I mean, he was essentially also a friend, but he was hardworking and somewhat driving, though not excessively.

Groueff: But he would bawl somebody if he had to?

Sturm: Oh yes. He would get involved and he, too, felt that he was doing it—that you muddled something, he felt almost as if he had muddled.

Nobles: You could argue with him, though.

Sturm: Oh, yes.

Nobles: In fact, that is where a lot of the level of the argument would be. He did not resent anyone – well, no, that is not right. You had to have a good argument to support that.

Groueff: And did you have regular contact with [Leo] Szilard?

Nobles: I never—

Sturm: No, I do not think I did either. I do not think below Fermi, particularly. You see, Szilard was over at Eckhart most of the time, at least, his offices were there. He was in closer proximity toward this later stage with [Eugene] Wigner.

Groueff: But I heard about him that he was considered the sort of troublemaker, too many ideas and disturbing other people’s regular work.

Nobles: Right.

Groueff: Changing, shifting, and getting very emotional and sort of very enthusiastic about things.

Nobles: He had the highest motivation I would say.

Groueff: Oh, yeah.

Sturm: Yes. I do not know whom he had such authority over. He had only a couple of physicists working for him. As I recall, it was three or four.

Nobles: He was the type who would walk on the balcony and then maybe say to Fermi, “Well, why don’t you do this?”

Fermi would be down in where the work is going and maybe not doing it himself and saying, “Well, let’s put this here and start here and build this side up now,” or something like that.

Sturm: He could get emotional, I expect, about things that he is convinced of, because his sophistication in physics was extraordinary. If he came upon something that looked like a good thing to do, maybe he did not have the patience to explain it in all detail just how he came to this conclusion. He might tend to appear excitable.

On the other hand, he would always be reasonable, too, and I do not think – I do not see any particular reason for him – an excited conversation of more than a minute or two with Fermi, because they could very quickly see what the issues are and recognize the situation.

But again, I personally did not have too much to do with—

Groueff: Wigner or Fermi.

Nobles: Wigner, I do not know how well you know him, but he was down at Oak Ridge, too, you know. I have met him since then. Wigner was a wonderful man. He was a very gracious man.

Groueff: Very polite, I understand, no?

Sturm: Extremely. I had an office up the second floor over here. There was a shuffling outside the door and I heard [Arthur] Compton’s voice and I heard Fermi’s voice and there was some question. They were coming in the office to see me, and there was a loud discussion and noise and the door burst open and a man was thrown in, or pushed strongly in. This was Wigner. Because he, in the presence of Fermi and Compton, would not go first through a door [laughter]. But they had had enough of this. Apparently, they had been going first through a lot of doors and they decided, this is the door he is going first through [laughter].

Nobles: Well, this is my impression. I was going to say that if he were walking – approaching the doorway with somebody who was a couple of orders of magnitude below him in prestige, he would still step aside and sort of almost click his heels.

Sturm: Well, yeah, he would bow, yeah, he was very gracious. In fact, during the course of that visit, he wanted to borrow the telephone, like the company phone. At the end of the visit, he insisted on paying me a nickel. I explained to him, “It is not my phone.” [Laughter] It sounds like the man is disoriented from the state of things, but this is not at all—

Groueff: I understand he has a strong personality?

Sturm: Technically.

Groueff: Yeah.

Strum: He is extremely knowledgeable. But he is also a very gracious man and I think an extremely human man. I mean, it is not a synthetic graciousness, you know, as you might – well, excuse it from an American point of view, sometimes Europeans give us this impression, but this was absolutely—

Groueff: It was genuine.

Sturm: Yes. I recall when he was first married, we were in Eckhart and he and his wife were so close that his wife used to come. We were on the fourth floor and the third floor was a reception desk and there was a waiting place in the room. Unless you were authorized, you could not go through there. His wife used to have to sit there all day, all morning. Put this one off the record but it is true that she would sit there all morning waiting to go out to dinner with him, and then waiting to go out to supper with him. He might have come down to exchange a few greetings during the day, but she would sit there. This went on for months after they were first – extremely close.

Groueff: And it was Wigner who worked after December of ’42, he started working on the water-cooled reactor design?

Sturm: I am not sure what he did.

Groueff: What happened after ’42, what happened? All of you, the physics group switched to building different kinds of reactors?

Sturm: No, no. There were several projects in front of the group. There was a matter of making a pilot plan, a bridge. It was a matter now of getting about making the Hanford plans. There was a matter of moving the laboratory from the University to the site near here. And that is it.

Nobles: That’s what happened to me right away. I came out to Site A and we built the CP-2 [Chicago Pile-2] from CP-1 [Chicago Pile-1].

Sturm: Well, no, it was across the river, but it was near here.

Nobles: In the old site, Site A.

Sturm: Over here, across Site A. Then there is at that time, a whole group of DuPont people came in and they were supposed to help us build a pile and get the experience.

Nobles: This is where a tremendous chance was taken, unlike most of the conservative approach, science, traditional science. Didn’t they go ahead with the Hanford pile design and construction prematurely from the traditional point of view, based on incomplete data?

Groueff: Yeah, they did not wait for Clinton [Engineer Works].

Nobles: Right.

Sturm: Well, I always felt that there was more pressure, you see, and you had to telescope wherever you could.

Nobles: This is a role that Wigner played, I believe, in these piles, didn’t he?

Groueff: He designed, I think, the model of the Hanford, the water-cooled because it—

Nobles: —was air-cooled but then they had the Columbia River.

Sturm: In that sense, you mean. Well, it was a graphite reactor.

Nobles: Yeah.

Groueff: No, because I understand it was a question of building a helium-cooled reactor. All of the air-cooled, which was in Clinton, and finally, when they saw this problem of isolating the slugs, canning the slugs, they made it to be more – but mentioning DuPont.

When DuPont was assigned to build the thing, I understand there were some mixed feelings here among you scientists. Some of you thought, probably the earlier ones, that it was your baby and the scientists had to continue with the building of that, even if you had to hire the services from a company. But you had to be in control. But Compton agreed with the Army point of view that it became a completely different engineering problem and the scientists, none of you had any industrial experience.

Sturm: I have no comment here.

Nobles: I know, I was in the group out at Site A building, Harold Lichtenberger and I. All of these, we had about twelve DuPont fellows and they were supposed to work for us in all this, muscles building up the pile. We of course worked with them and then later, all of these people who became leaders and bosses of different sections and so on in Hanford. We knew that is what they were there for.

Sturm: The principal was–well, below Fermi in the place that such a thing was – we were aware of such a thing, yeah.

Groueff: It was between people like Compton and Fermi [interruption] and Szilard and Wigner.

Sturm: Yeah, yeah.

Groueff: Probably Zinn and people like that.

Sturm: Yeah, he may have gotten, I have no idea. Because there is a lot of technology and I suppose the point, which only the group knew at that time and wanted to make some point about that, but I don’t recall.

Nobles: And then shortly after CP-2 was built, it was already in the wind that they were thinking about the first heavy water moderated piles in CP-3.

Groueff: You never had close contact with the Army people either, no? General Groves?

Nobles: No, only would come around and inspect once in a while.

Groueff: But they would be in contact with Compton and [Norman] Hilberry and those people?

Sturm: Yes, yes.

Nobles: Hilberry helped select some of the sites, I think, and he probably told you that.

Groueff: He told me about that. But the Army influence was not felt to your level then?

Sturm: No, no. We were really remote from it. We saw the General coming through occasionally and we knew him and we knew what he was there for. But we could not talk to him and he to us really. We were not thinking of the same thing. There was no point to it. When the Army put in their security measures and they had Colonel [Arthur] Peterson, who climbed the fence one time – we laughed [laugh]. That was also really removed from us.

Nobles: The big guy? The six-foot-five guy?

Sturm: Well, a big blonde fellow. I do not know if he is six-foot-five.

Nobles: We have got a picture of him in there. Yeah.

Sturm: Well, he was slim in those days. You remember Peterson. He climbed the fence to prove that the security was not perfect and the guards were watching him, I think, and they said, “Why is Colonel Peterson climbing the fence for?” But they let him do it and you know, they figured. For a long while, for some days there, if anybody strayed off a path, the guards would be weighted for letting this man in, you see?

Groueff: That was in the camp there?

Sturm: That was at Site A.

Sturm: Site A.

Groueff: Oh, Site A. But this particular site where we are today, that did not exist during the war, no?

Sturm: This is Site D. Things were moved here after ’46, I believe.

Nobles: 1946.

Groueff: ’46?

Nobles: We built the Van de Graaff over at Site A and then moved it over here to the new site.

Groueff: What did you do after you built the CP-2 here? Then what did you do until the end of the war? Did you continue here or did you move to Oak Ridge or to Hanford?

Sturm: Various people did various things. We supplied a group to Oak Ridge, actually, including [Alvin] Weinberg, Wigner. Some of our other people, Pollacki, who was not here, went down for that. Sort of a shocking little breakup.

I went down only a few times to consult, but I did not stay. We stationed a whole skeleton crew down there to start the reactor. Some of whom, as I say, are still there, including Weinberg. Others came – and starting when, I do not know – but to say it was immediately after December ’42. Others set about translating the lab here. Ultimately, sometime later, I went to Los Alamos to work on bomb things.

Groueff: Including Fermi?

Sturm: Fermi, yeah, Anderson. I do not think Zinn went for that. Al [Weinberg] stayed there, he is still there. Some went to Hanford. I do not think anyone stayed there.

Nobles: Dr. [John] Manley. Do you remember Manley? Well, he was in charge of the group that went first, the small group from University Chicago that went out to—

Groueff: To Los Alamos.

Nobles: My brother went with Al Graves and Mrs. Graves.

Sturm: Well, that is Los Alamos. But how about Hanford?

Groueff: Hanford—

Sturm: Hanford, let’s see. Who did go to Hanford? He was here.

Groueff: Yeah, Princeton and here.

Sturm: Yeah. There was a Mr. Farmer incident when Fermi got to go out—

Groueff: Yeah, I know this.

Sturm: But other than that, I do not think we had—

Groueff: Fermi used to go there for—

Sturm: Yeah. Well, he was called Farmer, when he traveled.

Groueff: Farmer, yeah.

Sturm: But he consulted there and he went out there.

Groueff: And [Samuel King] Allison probably, no?

Sturm: Very likely but again, I would not know.

Nobles: How about [Harold] Urey? Did he get into the act at all?

Sturm: The only time I saw Urey was after ’44 or so when he came around. I was diffracting neutrons and he asked me what I was doing.

Nobles: What about [Ernest] Lawrence? Did you see him at all?

Sturm: Wasn’t he there at—

Groueff: The other side.

Sturm: He came in as a visitor.

Groueff: Electromagnetic.

Sturm: Wasn’t Lawrence the—?

Nobles: I did not know him. He is not on the list. He had the Y-12 electromagnetic.

Sturm: He was around sometime as a visitor but he had this other responsibility, yeah.

Nobles: What about Farrington Daniels?

Sturm: He was only later.

Nobles: He made an ass of himself at the University of Wisconsin I do not know how many times. He disappeared and I was not on campus there at that time. So we have some – he disappeared.

Sturm: He may have gone to Los Alamos or so, but he did not appear here until – well, well after December ’42 incident.

Remember this thing I built up in the old cafeteria, this Farraday cage? That was related to bomb work in that we were going to get plutonium samples and since, in plutonium, if there is light element impurity, the alpha, n reaction makes neutrons and you do not want – that is a disadvantage in the case of a bomb. You do not want a high ambient background of neutrons. You want your neutron level to go up precipitously. So we had a device for putting a sample of the plutonium in a very sensitive neutron detector to see how impure it was, in the sense of emitting neutrons.

But beyond work of that general sort, very peripheral in a way, to the bomb, I think any work that was done by our people on the bomb was done out in Los Alamos.

Groueff: But here, the group, the physics group, what was your job in ’43, ’44?

Sturm: Well, things of this sort—

Groueff: Studies in plutonium or chemistry?

Sturm: Every one of us in those days worked very variously. You know, one day it would be this thing and one day another.

Groueff: There was not one organized effort in one direction, like to build a pile?

Sturm: No, I think having to show—

Groueff: Or produce plutonium?

Sturm: No, plutonium production was probably done there at X-10, but even before that at cyclotrons, just to get enough to see—

Nobles: I worked on plutonium myself when—

Sturm: Well, everyone—

Nobles: [interruption] I ever had there and I used to handle that stuff in billets and they were deathly afraid of it. We had very unsophisticated – yeah.

Sturm: Well, you were working with the pilot plant with the X-10 reactor.

Nobles: I remember working in a special plutonium building where we took extreme precautions because we knew it was deadly. Our equipment was very unsophisticated by present-day standards.

Sturm: Well, I think that even then, you are now getting quantities – massive quantities. I think the preliminary work was even done out of cyclotron irradiated material and they would get these little bits and pieces. Later, the pilot plant worked again to produce massive quantities and then Hanford. I know another thing we did, I did, we measured the cross section of plutonium. It had not been measured in an energy sensitive region. We got a sample of it.

Nobles: Remember the famous picture with the rubber glove and the tube with [inaudible] hand?

Sturm: I do not know about that.

Nobles: I think it is. What was the significance of that one, now?

Sturm: First visible quantities of plutonium. But I do not know if that did not come from cyclotron.

As a physics group with now reactors as a tool, we could measure cross sections, neutron cross sections, better than many because we had the reactor as a source of neutrons. [James] Rainwater and [William] Havens in New York were probably doing the same thing with cyclotrons, but there were certain advantages in both tools. In my recollection, we did this purity of plutonium thing. I did that. I did some cross sections between them. But I think mostly we worked [inaudible] – other than a peripheral group —­ relative to the bomb work.

Groueff: So the main effort was for the first pile, CP-1?

Sturm: The first pile? Yeah.

Groueff: The main organized effort as a group was called the—

Nobles: CP-3 was quite a—

Sturm: Well, there were organized – yes, that is right. The production of this water reactor, they were organized efforts, but now they were maybe not so dramatic.

Nobles: They were already becoming specialized, too.

Sturm: That is right. One group, as Sarrons did, worked on activation cross section studying the isotopes generally for their neutron process. This bore on bombs or on reactors in that you identified poisons and materials that you wanted in and did not want in and so on. [Albert] Wattenberg was testing, among other things – well, he was doing things on the energy of artificial sources, gamma end sources and so on.

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.