Robert S. Norris: The first thing we should do is to identify yourself.
Andrew Hanson: My name is Andrew J. Hanson, and I’m the son of Alfred O. Hanson, who was at Los Alamos just having finished his PhD, and coming down from Ray Herb’s nuclear physics research group at Wisconsin. He was working for his PhD on nuclear physics experiments with the Van de Graaff generators. There were two Van de Graaff generators, the long tank and the short tank. There were two Van de Graaff generators at Wisconsin. So he came down as one of the people from Ray Herb’s group to use the long tank to measure neutron cross sections. That was my father.
I was born on February 22, 1944 in the apartment downstairs from the apartment then occupied by Hans and Rose Bethe. I am referred to, but not by name, in Rose Bethe’s narrative as, “The big baby who was born downstairs.” In Rose Bethe’s interview, she makes some sort of a comment about how it’s important to have your baby late term and so on in order to have a large baby. In fact, I checked with my mother, who is still living—Elizabeth Hanson, age 97—and she said I was two weeks premature.
Norris: How much did you weigh?
Hanson: I believe it was ten pounds, four ounces.
Henry Frisch: This is at high altitude, mind you, where birth weights are lower, because Los Alamos is very high.
Norris: It is. It’s about 6,000 feet or 5,000 feet. Okay, thank you, Dr. Hanson. We also have here—
Frisch: Yes, I’m Henry Frisch. Andy and I, there are many parallels. My Dad also was a graduate student in Ray Herb’s group. I didn’t know your father already had his degree. My Dad didn’t.
Hanson: Your father had to go back and took his degree with Viki Weisskopf.
Frisch: With Vicky at MIT.
Hanson: My Dad was already done with Ray Herb.
Frisch: The group was basically hijacked to Los Alamos. My mother was studying for a PhD. I’m a little unclear as to what point she was. She already had a Master’s, I’m sure, but she was also a scientist. Rose Frisch. She just passed away in January at age 96.
Andy and I were classmates in college. We have skied together. We’re still very good friends.
Hanson: We hired the Harvard band together.
Frisch: He caused me to almost die of liquor poisoning at one point. I can tell you lots of stories about Andy. But anyway, there are lots of parallels.
Our fathers worked together on the Van de Graaff. Actually, one of the questions I have that I’d like to ask this crowd is that we’ve seen a picture, and I’m sure I’ve seen it, of a flatbed large truck carrying the Van de Graff’s up the dirt road to the mesa, with his father and my father on the back with the load out in the open. That road was famously spectacular. Hairpin turns. It was dirt. So if you got too close to the edge, you lost it. I would love to find that picture again. I’ve seen it. I even had it, I think, at one point.
Hanson: We spoke earlier yesterday to Richard Rhodes, He said he remembers such a picture and he thinks it’s in the Los Alamos archives. But neither Henry nor I currently know where a copy is, if we have it someplace.
Frisch: We would love that picture, because I’ve had it and I may still have it.
So there’s lots of parallelism. What they were doing with the Van de Graaff was measuring neutron cross sections on the very early samples of plutonium. They came very early to the Hill; this was April ’43, I think, is when they arrived. There was almost nobody there. It was very early. They were very young, and they were given very important jobs. In fact, another question is—Andy has this story of his father and plutonium. Do you want to tell?
Hanson: Okay. This is a story that my mother told me. I can’t remember my father ever actually telling it, and I can’t find any record of it. There is a record of a similar incident, where a large quantity of the world’s supply of plutonium exploded out of an [inaudible] and bounced into someone’s mouth. They were subsequently able to recover that plutonium. But that was not my father’s incident.
Apparently—according to my mother, I have no verification of this—there was an incident where my father presumably was preparing what was at that time the world’s supply of metallic plutonium for use in the Van de Graaff in order to measure the cross sections. It was very important to measure the cross sections, because previously how a fission would work had been done with only slow neutrons. So they didn’t know whether in the actual bomb scenario whether the fast neutrons would behave the same way.
One of his jobs with the long tank Van de Graaff was to measure cross sections with fast neutrons. That was actually, as I understand it, one of the critical results of the entire project early on, to discover that fast neutrons worked and did not diffuse too quickly. So there was more than enough reactivity to sustain a chain reaction, which was unknown until they measured these results in the long tank Van de Graaff. Presumably he had to prepare this microscopic amount of plutonium to use as a target, in order to make these measurements.
According to my mother, at one point he was heating it on a hot plate or something in order to change its shape. He turned his back, and it boiled away. I don’t know exactly how you do that without dying, because inhaling plutonium was—
Norris: Very bad for you.
Hanson: He lived until ninety so it wasn’t something that happened right away, if he was damaged by it. Although he did die of pancreatic cancer, which is associated with that kind of radiation. It just took a long time.
Frisch: As did my Dad.
Hanson: As did Henry’s Dad. Both died of pancreatic cancer.
Norris: How old was your father?
Frisch: Seventy-three.
Hanson: And mine was ninety. It was still very sudden pancreatic cancer.
According to my mother, he essentially lost the world’s supply of plutonium. A crew of people already prepared to do this came in and recovered it from the walls, tables, and chairs, apparently most of it. According to my mother, “They recovered all but a couple thousand dollars’ worth.” How she knew it was a couple thousand dollars’ worth, I don’t know. My father apparently did this, had this mishap with the plutonium. Most of it was recovered, so that they could continue the experiments.
The other thing, which I did not know until I asked my mother recently, is that the laboratory in which this happened was next door to [J. Robert] Oppenheimer’s office. Oppenheimer heard about it immediately. A couple days later—there was a movie theater, so people would go on maybe Friday or Saturday night and go and watch a movie, because that was like the only recreation available on the base. So a couple days later, my mother and father were standing in line at the movie theater to get into the theater. I believe—this is what she says—Oppie and Kitty [Oppenheimer] were a couple of people behind them in line. She turned, and Oppenheimer was giving my dad the evilest evil eye you could imagine.
Norris: “You lost the plutonium.”
Hanson: So that’s my story.
Frisch: That’s a source of one of my questions, which is, what was the source of that plutonium?
Norris: What was the source?
Frisch: They had micrograms of plutonium in early ‘43. My dad was running cross sections.
Norris: From California?
Frisch: From the calutrons?
Norris: It could have been, if it was just this little tiny bit. I think the plutonium that was processed in the X-10 at Oak Ridge came a little later.
Frisch: That’s the point. This is very early.
Norris: So this had to be from California, calutrons. This was Ernest Lawrence’s. I even think, just to add a little more—I’m not sure that it’s the same amount, but General [Leslie] Groves was around at one point. I think he asked [Ernest] Lawrence about the plutonium and was showing a speck of it. Groves could not believe—”I just spent ‘X’ amount of millions of dollars and you have this little speck of plutonium? This is all there is?” Then to have it boil away—
Frisch: Were there multiple incidents involving ingestions of plutonium?
Norris: This was an accidental one.
Frisch: Were there multiple? Because as Andy said, there was a reference of this in a book, but with his Dad’s story—
Norris: I had never heard that before.
Hanson: About the ingestion?
Norris: Yeah.
Hanson: Not only was that in the book, but the reason went and looked for it was that it appeared as the semi-fictional centerpiece of the “Manhattan” TV show episode. So the “Manhattan” TV show had an episode centric on this particular episode. When I checked on it to see whether it possibly could have been based on an elaboration of my father’s, I found that there was a document incident in this book that I found on the web, very, very close to the one that appeared in the Manhattan episode.
Norris: I do recall when Hazel O’Leary was the Secretary, she was beginning an openness initiative and declassifying things, like tests, how many tests did the Americans do. There was a component of that where she talked about these plutonium experiments, where people were purposely at hospitals given doses of plutonium to see what would happen. There is a whole study of this that came out of this initiative by Hazel O’Leary.
Frisch: I was trying to track down a little of this history.
Norris: This one’s a new one.
Frisch: Could I ask—what building were the Van de Graaff’s in, and what happened to them?
Hanson: It was next to Oppie’s office.
Frisch: There weren’t many buildings.
Hanson: I have a picture, which I’ve sent to Alexandra [Levy], who’s the archivist here [at the Atomic Heritage Foundation]. This is a picture of my Dad at the controls of the long tank. That picture must in the Los Alamos archives.
Norris: It’s a great picture. He looks so young.
Hanson: They were.
Frisch” He was thirty. He was born in 1914.
Norris: They were all young, and you were the youngest. [Laughter]
Frisch: I wanted to ask about another accident, which I just told Charles Oppenheimer about. My Mom worked with Kitty in the blood lab. Oppenheimer’s son, Peter—Charles’ father—who was three or four flushed Kitty’s badge down the toilet. The sewage, my Mom told me, all ran out of a sealed pipe into a canyon. But you couldn’t leave Kitty’s badge outside the fence. So a squad was detached to go search for the badge. This had to be, if you had it in for somebody, you would make a list of who should go find this badge. So I told that to Charles. I don’t know if this was true or not, but my Mom told me, so I’m sure it was.
There was a related thing to the cross sections, and I don’t know at what point this happened. I’m a high-end geophysicist and the field has gotten pretty crazy about estimating uncertainties. You measure a number and then you spend the next two years working on getting the uncertainties right, whether they matter or not; generally, they don’t. You could make a good guess.
My Dad told me that there was an all-hands meeting called by Oppie in which Fermi was going to announce the multiple fission factor in a neutron.
Norris: Did your Dad ever talk about this?
Hanson: I don’t remember this.
Frisch: So my Dad said the front row was [Niels] Bohr, [Hans] Bethe. It was the big guys, the luminaries, they were all there. Oppenheimer stood up and said, “This is a very happy occasion. I’ve got a very important announcement to make. Enrico is going to announce the multiple fission factor.”
Norris: It must have been early on.
Frisch: This must have been very early.
Norris: At some of these seminars, maybe?
Frisch: No, it was a special meeting. Oppenheimer said, “This is really a great occasion and I’ll let Enrico tell you.”
Fermi stands up, and he says— I’m making this up—”The number is 2.3,” and he sits down.
Everybody applauds and such, and Oppie says, “I can’t tell you how important this is. This means it’s going to work.”
Then he says, “However, Enrico, you’ve told us the number, but you haven’t told us the uncertainty of it. What is the uncertainty of it?”
Fermi stands up and says, “I do not know, but don’t worry about it.” And then he sits down.
Oppenheimer says, “Enrico, we need to know the number. Tell us the number.” My Dad said that at that time Oppenheimer got very frosty and he said, “I have been charged by the President of the United States for this project. The future of the free world may depend on this, and I cannot go to the President of the United States and tell him not to worry about it. If you can’t tell me the uncertainty, at least can you put a limit on the uncertainty?
My father said at this point Fermi stood up, grinned ear to ear, and said, “The uncertainty is not smaller than point one,” and he sat down. It’s the wrong limit. You’d like to know that the uncertainty is not larger than something, so that’s a completely useless number. At that point, my Dad said, Oppie was like—
Norris: What can you do with this guy? They called him The Pope. He was a pretty smart guy.
Frisch: He was a very smart guy. But that raises a question in my mind. Did this meeting happen? I’m sure it did. My Dad was there. Is it recorded? Who else was there? I’d like to know more, because this is a really great story about uncertainties and about the Fermi interaction with others, but I’ve never heard it described.
Norris: It deserves to be looked into. There’s a wonderful book called Critical Assembly by a woman historian of science, Hoddeson.
Frisch: By Lillian. I know her.
Norris: Her book may have this account, because she did use all of the Los Alamos documents. I think she’s moved onto other things, but if you contacted her and you know her, with this incident, she may know about it and may know, “Oh yes, we have this document.”
Hanson: I think I had a question, another one that that Henry and I had discussed, that relates to a narrative I got from my mother just quite recently. She sent me an e-mail regarding her experience on the day of the Trinity shot. What she said is, “Reviewing the test shot as your Dad told it to me and as I experienced it.” This is from my mother, Elizabeth Hanson.
She said, “Al was there as a scientist observer. A soldier has been assigned a small ground experiment of some kind to take place 10,000 yards north of Ground Zero. I don’t remember who, but there was a joker among the senior scientists who had been going around scaring the soldiers about what was going to happen. The soldier assigned the ground experiment refused it.” Whereupon my Dad, Al, was assigned to step in to take his place. Or it says, “Al stepped in to take his place.” Maybe he wasn’t assigned, maybe he volunteered.
Then it says, “The test shot went off and the radioactive cloud started to blow northward”—he was at this station 10,000 yards north—in his direction. Apparently the command center sent a jeep to pick him up and take him away from the drifting cloud. That much I remember. But I had thought that he was in a bunker at some point with dark glasses, and that part my mother does not remember. I kind of remember my Dad mentioning some other elaborations upon this particular situation. But for sure, the cloud blew towards him and he was raced up out of the area.
This is July 16th. So that morning, my father had disappeared. He wasn’t there in the house, but of course, as I said, we lived downstairs from the Bethes. My mother went out into the front yard for some reason. She says that Rose Bethe was standing there looking off into the distance. Rose turned to her and said simply, “It worked.”
Norris: She saw it?
Hanson: My mother said that this was the first time that she knew that it was about something that could work or not. Later in the day, a pickup truck pulled up at her house and Al got off. He looked a little strange and seemed whitish, as if he was dusted with flour. She didn’t know whether that was from the sand or from something else. So my question is—I hope this isn’t getting anybody in trouble many decades later—but how did Rose know?
Frisch: How did she know to look at 5:30 in the morning?
Hanson: And was she up at 5:30 looking? So we have to tell the story of the people in the discussion yesterday that said they were walking along the street, looked south, and all of a sudden the sun rose in the south. So you could see it from there. So clearly if someone had known to get up and look out, they could have seen it, the sun rise in the south. But we have no idea of whether Rose actually saw that or whether someone told a story.
Frisch: In 1970 or thereabouts, Ellen Weisskopf said she didn’t know, that Vicky [Victor Weisskopf] couldn’t tell her anything. Jane [Wilson] said, “Oh, Bobby told me everything. We would lie in bed.” Jane was explicit enough that all of us youngsters in the audience were cringing a little bit, because of the pillow talk. She said, “Oh, Bob told me everything.”
Norris: There was some of that. The question of, why get up at 5:30 in the morning? I mean, many of the men had disappeared. They had left, right? They had gone down to Trinity.
Frisch: Well, some wives knew and some wives didn’t. Jim Nolan was the—
Norris: Doctor.
Frisch: Captain Nolan was the doctor, and his grandson is here. So we’ve been telling stories, because Nolan played a very important role in many, many aspects. But for personal things, he delivered both of us.
I was asked to be the house physicist for the Chicago Big Opera Company, Lyric Opera. It’s a major opera company. It’s on the scale of the Met, it’s a big, big deal. So they did John Adams’ “Doctor Atomic,” and they needed a physicist. I’d been on the TV talking for the Bulletin of the Atomic Scientists, and so they called me.
We held the cast party in the accelerator high bay where Fermi’s cyclotron was at the Enrico Fermi Institute at the University of Chicago. So the big shielding blocks were still there with the 100-ton crank, right across from where CP-1, the first pile, was, right across the street. This is where the Met Lab was. We held the cast party, and so I went up afterwards. It was a wonderful production, but I found the young singer who played Captain Nolan. We were all having a very good time. Norm Ramsey was there. It was the only time I’d ever heard Norm talk about the use of the bomb. So Ramsey, Jim Conant spoke, John Adams spoke, Peter Sellars spoke. Good times.
I go up to Nolan and I said, “I just wanted you to know that you delivered me.” He couldn’t parse it. It sounded religious. I mean, this is a born again experience. Somehow I had some epiphany in the opera. “You delivered me.” But then I explained, “You were the doctor.”
Norris: When I was born.
Hanson: It was a shock to him, because he had been immersed in this part. But the fact that he had really been a doctor delivering babies—Jim Nolan here said his grandfather delivered at least eighty babies. I mean, I know [General Leslie R.] Groves complained.
Hanson: I remember this slightly differently. You sent me pictures of the party at the old cyclotron site. And then you invited Pat and me up for the opening night. You got us tickets for the opening night. Very, very unusual. The four of us, Henry and his wife and me and my wife, were invited as guests to the opening night gala banquet at Lyric Opera. It was there that I remember walking up to the actor who played Captain Nolan and presenting the fact that—
Norris: You delivered me too!
Hanson: You delivered me as a baby. Then he made some wisecrack like, “You look older now,” or something to that effect.
Frisch: That was after the opera?
Hanson: Before the opera.
Frisch: Because there were multiple.
Hanson: That was such a wonderful crew, they were so up and so enthusiastic. It was an amazing performance.
Frisch: They decorated the high bay in the cyclotron bay. There’s a big picture of the shack, the guard gate house, and a big picture of Don Hornig up in the tower. It was an enormous picture, the size of that wall. One of the things that I was told about Hornig is that at first he was very frightened. He’s up in a shack with a nuclear weapon that’s nothing but a big antenna, in terms of ground loops and pickups, in an electrical storm. Lightning is going all around us. This thing’s got to be the world’s biggest antenna for picking up sparks. He’s been given a sidearm, if I remember, to protect himself. But I was told that at some point he realized that there was no point in being frightened, because he would never know.
Norris: Yeah, he’d be gone.
Frisch: But the picture of the gate, and I don’t know whether I read this or was told this. It may have been my Dad or somebody told me. I think my Dad told me this. At the gate, Fermi and Bohr show up, and Fermi signs “Mr. Farmer.” Do you know this story?
Norris: Go ahead. I think so.
Frisch: Fermi signs “Mr. Farmer,” because that’s who he was, and Bohr never could remember who he was. Bohr has to look, and he sees “Baker” and he writes down “Baker.” The guard at the gate, some young guard GI, says, “Are you really Mr. Baker?”
Fermi says, “Look. I’ve known him for many years, and if his name’s not Baker, my name’s not Farmer.”
Norris: There was another incident where his escort—he always had somebody with him, John Baudino. He was Italian. They spoke Italian together, they got along. He says about Baudino, “Soon, Johnny’s going to need an escort as well, because he knows so much top secret stuff that he’s going to need somebody to take care of him.”
Frisch: Was there a third bomb? Everybody’s talking about it.
Norris: The three bombs that Alex was talking about were Trinity, Hiroshima, and Nagasaki.
Frisch: But there also was a third bomb on Tinian?
Norris: There was a third bomb ready to go. General Groves at that point had a supply of plutonium from Hanford coming at the rate of about one every ten days. So the next plutonium bomb would have been read, he told [George] Marshall, August 17th or 18th.
Frisch: But were there parts on Tinian?
Norris: There was enough on Tinian to assemble it. All they needed was the plutonium. Groves said, “We don’t know how long this is going to go on. I will have as many bombs as you need all the way to [inaudible].”
Frisch: Because there’s a guy in Chicago whose mother was a nurse on Tinian and shared a beach with the scientists. It’s right out of Catch-22. She knew about the third bomb.
Norris: There would have been more.
Frisch: That I knew, but I didn’t know whether there was really one close to or ready to go on Tinian.
Hanson: I didn’t know that either. That’s interesting.
Frisch: Her claim was that those parts ended up in the ocean.
Norris: Maybe some of the casings, because they practiced with these.
Frisch: I have a piece of a practice casing in my office. I had one other thing that I wanted to ask here, and didn’t you want to talk, Andy?
Hanson: I did get a handwritten note from my mother that reminds me, and I must have seen this, that there is a book published by the Los Alamos Historical Society called “Behind Tall Fences.” In that there is a memoir by my father, Al Hanson. So that would tell us more of his history in his words, which I don’t have here.
A couple more things that she reminds me of, she said, “At the beginning, his work was with the long tank to get the research on neutron cross sections started.” She says that he helped build the platform for the Trinity shot, and apparently he stayed at night in the Alamogordo barracks while he was helping to build the platform. I did not know that. That was news to me.
Frisch: I should just say, my Dad also was down there working on the tower.
Norris: So they were both there?
Frisch: I think so.
Hanson: I have already mentioned my Dad being 10,000 yards north from Ground Zero at the test site. Did you know where your Dad was?
Frisch: He was in the bunker, I’m pretty sure. Then if my memory is correct, and I wish I has asked more, he was one of the first to go in in some kind of vehicle.
Hanson: Closer than 10,000 yards?
Frisch: Closer than the bunker. I’ve lost the glasses he saw the blast with—I had them—with the side shields and such. I feel really badly. I had those, but I never really asked enough questions.
Hanson: The last thing my Mom says was that at Los Alamos, I guess the parts for Fat Man, the Nagasaki bomb, were assembled at Los Alamos. Is that correct?
Norris: They would have checked out the plutonium.
Hanson: So it says, “At Los Alamos, Al was given the task of making final measurements that okayed the material for the Nagasaki bomb.”
Norris: Okay. Then it was transported to Tinian and assembled there and put on the plane and dropped.
Frisch: And Nolan went with it on the Indianapolis?
Norris: Nolan was with a guy named Robert Furman. Have you ever come across that name?
Frisch: Yes.
Norris: He couldn’t have been closer to Groves. Groves gave him all sorts of responsibilities. One of the responsibilities was to take the uranium. With Nolan on the Indianapolis, to Tinian. It’s recounted in my book. They get off and take off the uranium and the casings for Little Boy. The Indianapolis goes on and of course gets sunk, and it’s the worst naval tragedy of World War II. It’s a horrible thing. But Nolan at that point is on Tinian with Fermi.
Frisch: I have one other thing. I’ve been going through some of my Dad’s papers from this time. There are a set between July in ’45 and September ’45 that span the August dates that are related to the Chicago poll to the use of the bomb. My Dad was on the LASC committee, I think it was, the committee at Los Alamos of scientists. My Dad was very young. He was still a student, doesn’t have a PhD yet, and this was a distinguished bunch. But he clearly was already active in these moral and large questions, questioning the use and planning the use. I have the results of the Chicago poll, and it says that there are 170 respondents and then there were I think five or six choices. Only fifteen percent were for an active use on a city population. It was wartime.
Knowing more about how the scientists reacted during all of this, I asked my mother, “What happened when the bombs were dropped?”
She said, “We left. We all left.” The implication was that it hadn’t turned out the way they had thought it would, and there was some—I don’t know about bitterness. There had been a lot of planning and a lot of discussion among various people at very high levels. These are labeled TOP SECRET to [Norris] Bradbury and to others. I think none of that counted at all, as you can well imagine. But knowing more about that history of the internal discussions with Oppenheimer and others would be very interesting.
Norris: I think some of that is written up.
Hanson: I’m sure it is.
Norris: Well thank you very much.
Hanson: Thank you very much.
Norris: Okay. This is a fascinating topic and now we have it on film and Cindy will make good use of it.