THE NUCLEAR DEATH OF A NUCLEAR SCIENTIST

BARBARA MOON October 7 1961

THE NUCLEAR DEATH OF A NUCLEAR SCIENTIST

BARBARA MOON October 7 1961

THE NUCLEAR DEATH OF A NUCLEAR SCIENTIST

BARBARA MOON

In Moscow Nikita Khrushchov threatens that his country can

build and dispatch a monster thermonuclear bomb equal to one hundred million tons of TNT and capable of wiping out all life over hundreds of square miles. ■ In Washington the latest corridor talk is of a conjectural neutron bomb, refined of old-fashioned heat and blast into a simple death ray—instantaneous, invisible, piercing the honeycombs of civilization to destroy humankind while leaving his foyers and chambers intact. ■ In the Sahara Desert fused quartz mottles the wastes of sand to mark the place where the wilful French set off their fourth A-bomb this summer, while off the Australian coast ships are warned that the Monte Bello Islands, contaminated nine years ago by a British A-bomb explosion, remain too hot to permit their approach. ■ In Geneva the discussions about a permanent suspension of nuclear tests drag on. ■ Enormity is a strong inoculation, and breeds strong antibodies. So, though we are only sixteen years into the atomic age, there is a curious nonchalance in the way men speak of such things these days, and in their debates about “ultimate weapons” and “limited warfare” and “banning the bomb” and “fallout shelters” and “the nuclear arms race.” ■ Perhaps it is merciful that minds can be immunized against dread. But in the circumstances it is also dangerous. And so it seems well, from time to time, to recall such events as may serve to keep comprehension fresh and exquisite. Among these events may be counted the last days of Dr. Louis A. Slotin, physicist and biochemist, who was born in Winnipeg in 1910 and who died fifteen years ago in the secret atomic city of Los Alamos at the age of thirty-five.

Atomic poisoning killed the Canadian physicist who delivered the Hiroshima bomb to the USAF. His story [)

LOUIS SLOTIN: A TINY SLIP, A TERRIBLE DEATH

The atomic age was ten months old when he died, and World War II was over. Occupation-army observers had long since made their first sketchy, secret reports on the ruins of Hiroshima and Nagasaki and on the hundred and fifty thousand Japanese who had there been blasted or grilled or irradiated. Behind closed doors the bitter debates had started: on military versus civilian control ol atomic energy; on scientific freemasonry versus national security; on the morality of racing to make and test still more bombs. The scientists-turnedartificers had indeed begun to know whereto they had given their soul’s consent.

In time of sick aftermath — of guilt, reappraisal, foreboding — there were facts about Slotin and circumstances about his death that seemed, and still seem, most memorable to his fellows. It was as though it were a ritual death. □

In one sense Louis Slotin may be considered interchangeable with all the other bright, disciplined, idealistic young scientists who helped the army make a bomb.

He was born to prosperous and gentle Russian-Jewish parents living in the polyglot north end of Winnipeg. He grew' up and went to school there and it was early obvious that he was not cut out for the traditional eldcst-son’s succession to the family business, which was a livestock commission agency. He was a studious, self-possessed, bespectacled little boy and at the University of Manitoba he grew' into a brilliant student of chemistry, with a particular knack for designing the swift, imaginative experiment that would test a theory and for improvising the necessary apparatus. He also grew into a seemly youth, reserved and quiet but with a quizzical air that lent him poise, and also what a friend later called “a romantic and elaborate view of himself and the world.” For example, it was at this time that in response to some private need for style he arbitrarily adopted the middle initial, “A.”

Later he earned his doctorate at the University of London and at the same time turned himself into a crack bantamweight boxer.

On his return from England he applied unsuccessfully for a job with the National Research C ouncil and then was captured by the fascinations of a pioneer atom-smashing cyclotron at the University of Chicago. With others of a small ardent group he helped build it. begging copper wire from business firms and blowing glass components himself, and from 1937 to 1940 he worked there for nothing. "What have I?” his father asked fondly. "A student prince on my hands?" But he was proud of his educated son, the doctor. When a friend asked what kind of doctor Louis was, Mr. Slotin reached out for a light switch and turned it oil and on. “Do you know where the

light went to?” he asked, and answered himself. “You don’t know. I don't know. But my son Louis knows. That’s the kind of doctor he is.”

By now Slotin was nearly thirty. In the laboratory w'ith his colleagues he was a leader. At lunch with them he would neglect his food while he talked, reaching among the flatware with his finely shaped, expressive hands, smoothing out a paper napkin, covering it with diagrams to illustrate a point, glancing up at his companions through his glasses with w'hat one of them called, “a certain shy, eager expression.”

Away from his work he was reserved, and seldom said much, thodgh he regularly amused himself with the gullible by planting false clues to an imaginary and stylish past. Many of his friends came to believe, for example, that he had fought with the Loyalists in Spain and flown with the RAF, and this seemed to please some strain of romance in him.

In 1942, when the crash program to invent an A-bomb was launched and the Manhattan Engineer District of the U. S. Army began casting its dragnet for qualified people, Slotin was recruited from Chicago.

In 1944 he came to Los Alamos, the bomb assembly-point hidden away on the five-fingered mesa in the ancient pine-clad uplands of New Mexico. After a time there he became, in effect, chief armorer of the United States.

IN THE FALL HE WOULD GO BACK EAST

In the glove compartment of his cream Dodge convertible Slotin kept something that looked like a hydroelectric bill. It was the receipt made out by the U. S. Army when it took delivery from him of the epochal A-bomb core, the first one, tested at Alamogordo. For Slotin’s job, along with some others, was to run final tests on the active core of each precious Abomb to make sure it would produce the explicit nuclear burst it was supposed to. The way it was done was dangerous, but in wartime one takes shortcuts and believes them justified.

At the time of his death, of course, the war was over. The core he was testing was part of a one-sided arms race, and was destined for Bikini Atoll. Slotin himself intended to go along to the Bikini tests as an observer but then, as many of his fellows had already done, he was going to divorce himself from Los Alamos and return to his real work. In the fall he would go back to the University of Chicago and in fact he had already packed and shipped ahead eleven crates of books and belongings.

There is one other thing that it is necessary to know about Slotin. Just at the end of the war a young technician named Harry Daghlian had gone back to a Los Alamos laboratory one

night, against all

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NUCLEAR SCIENTIST

regulations, to try an experiment with fissionable materials. A moment of clumsiness had condemned him. and he was actually the first North American to die of acute radiation sickness.

Any special significance to this death was canceled by the circumstances and the crowding events of victory—except for Slotin. who as a physicist helped the doctors estimate Daghlian's radiation dose and as a friend sat with him for many hours during the twenty-four days it took him to die.

It was an unique seminar—for at Hiroshima and Nagasaki survivors had not understood what people around them were dying of and besides were too busy to analyze the process, or be able precisely to recall it later.

So it came about that on May 21. 1946. Slotin was a man specially and singularly aware of what happens to the human body when ionizing radiation deranges its fragile and miraculous chemistry.

That day. like most days at I os Alamos, was clear and sunny. Slotin left his bachelor's rooms on the central mesa in his customary expensive sports shirt and narrow khaki pants tucked into cowboy boots. At noon he lunched on chili con carne at the Technical Area PX. with his friend and colleague Philip Morrison, a brilliant young theoretical physicist w'ith a bright impudent face and a crippled leg. Afterward he attended a group leaders’ meeting.

It was held at Slotin’s own home base. Pajarito Site, on the floor of nearby Pajarito Canyon, and when it was over the visiting leaders were conducted around the premises. The tour included the outlying laboratory, south of the main building, where Slotin’s group, and a group led by a Dr. Raemer Schreiber, did their experiments. It was a bare, white-painted room, forty feet by twenty-six, unfurnished except for a metal table near the centre of the room, a counter against the east wall near an exit ramp, and the sparse, unimposing equipment of critical assembly tests. Though the sun shone obliquely through one window, the electric lights w'ere on.

The visiting group-leaders finished their inspection and moved along. But one of them. Dr. Alvin Graves—a sandy, thickset physicist from Washington, D.C.— stayed behind with Slotin. Since Slotin was leaving. Graves was being transferred to take over his work. They chatted about one experimental configuration in particular which Graves had never seen tested. Slotin said, "Why don't I run through it for you now?”

Schreiber, the group-leader w'ith whom Slotin shared the lab. had also stayed behind. together w'ith his twenty-three-yearold assistant, Theodore Perlman. They set to work at the counter against the east wall completing observations on an experiment they had done that morning. It was around three o'clock.

Three men from the regular lab staff— Marion Cieslicki. Allan Kline and Dwight Young—as well as the customary security guard, a PFC Patrick Cleary, were also in the room and they watched as Slotin set up the experiment on the centre table.

It involved a nickel-plated core of plutonium, weighing about thirteen pounds, in the form of two hemispheres which, when put together, rather resembled a gray metallic curling stone. They were the active guts of one of the three A-bombs due to be shipped to Bikini for Operation Crossroads. It is perhaps worth noting that it was this identical core that had killed Harry Daghlian nine months earlier.

The plutonium rested in a half-shell of beryllium, a metal that can bounce escaping neutrons back into the mass of an active metal so they are conserved for the fission process.

There was a matching upper half-shell of beryllium, with a hole in it. through which Slotin thrust his left thumb so that he was holding the shell rather as a southpaw' holds a bowling ball.

The technique of the experiment consisted of lowering this upper shell until it almost met the lower shell. As the reflectors enclosed the core they would bounce

back more and more leaking neutrons. And so at a certain point the total of neutrons available inside the core for fission would slightly exceed the total neutron loss. A slow, controlled chain reaction would start, like a car's motor idling. This could be nudged to higher speeds—but there was a danger point. If the two half-shells came to within an eighth of an inch of each other—thus making a critical surplus of neutrons available simultaneously—a fast, uncontrolled reaction called a "prompt burst” would ensue. There would be no explosion, for in the heat generated the

components would expand, become less dense and therefore subcritical again. (And for the core to become a bomb, its components would have somehow to be grappled together from outside long enough to explode rather than expand.) But for one millisecond there would be a flare of free neutrons, an excursion of gamma rays and beta particles, and a wave of heat.

It was one of the wartime, makeshift, experiments and some months earlier Enrico Fermi, the Nobel-prizc-winning physicist, had told Slotin, "If you keep on doing

that you’ll be dead in a year.” Because he was leaving, Slotin expected that this would be his last time.

He proceeded to put the assembly through its paces for Graves, taking it from idling speed almost up to the critical point much as a test pilot strains the outside limits of his plane’s performance. The stages were both audible and visible to the watchers, for an instrument similar to a Geiger counter clicked ever faster as the assembly approached the critical point and a neutron monitor recorded the increasing radiation in a red-ink graph on a roll of paper.

What Slotin did next has been called by one colleague, "something different— not extraordinary but not routine.” Another colleague said recently. "This assembly had been run many times before and its characteristics were known. But this time it didn't perform according to Hoyle. So Slotin improvised.” Still other colleagues insist it was normal procedure. And there is no real arbiter among these points of view.

What Slotin did was to remove two tiny safety devices — spacers — that served to block the upper beryllium hemisphere from closing absolutely on the lower one. Then, still holding the upper shell with his cocked thumb and spreading fingers, he lowered one side of it onto the blade of a screwdriver held in his right hand, and allowed the other side to rest on the bottom shell. The screwdriver blade still held the two parts more than the crucial eighth of an inch apart. As the Geiger counter chattered more hectically, he waggled the handle of the screwdriver back and forth to work the shell a little farther down on the bevel and a little closer to the bottom shell.

Graves, standing just behind Slotin, shifted his weight slightly and leaned to get a better view. Cieslicki of the lab staff had paused behind Graves and to his left. Clustered seven or eight feet out from the other side of the table were Cleary, the

security guard, and the two other lab staffers, Kline and Young. Schreiber, busy at his own work, happened to be facing outward into the room but Perlman, his assistant, was still bent over the counter.

At exactly three-twenty Graves heard a click as the screwdriver blade escaped the crack and the beryllium shell came down on the rest of the assembly.

A judgment ... a slip of the hand . . . a fractional blink of the mind . . . the odds running out . . .?

In the same millisecond a blue glow surrounded the assembly: the Geiger counter needle hovered shuddering; the red-ink neutron monitor line leapt off the graph; those in the room felt a quick flux of heat. That was all.

In the next milliseconds Slotin moved his left hand and shook the beryllium shell from his thumb onto the floor. It was still three-twenty and he had just been killed.

It is now known by physicists that the reaction was over, quenched by thermal expansion, before Slotin’s — any human’s —reflexes could work. Bia his action remains a disciplined, instinctive move to do what was then believed necessary: to dismantle the assembly and stop the burst. And his body, just by being there, shielded Graves and undoubtedly saved him. The others, though no one knew how to tell at the time, proved beyond lethal range.

The official report of the accident is still classified material, but some unclassified excerpts from it are available. One of them describes the actions of those in the lab immediately after the accident. It reads:

"Kline, Cleary and Young and probably Cieslicki ran out the east door of the laboratory as soon as they could react after the accident. Kline, Cleary and Cieslicki went to the MP guard at the gate, had the gate opened, the other MPs collected and the group ran up the road a short distance. Young stopped behind an earth barricade and, not seeing Slotin, went back to the end of the ramp and looked into the laboratory after perhaps a minute. He saw no

Early days on the frontier of the atom-bomb age

one and walked around to the main laboratory building at the north end of the corridor leading from the northeast corner of the assembly room. Perlman had run up this corridor immediately after the accident. Slotin, Graves and Schreiber had followed him to the main laboratory. Slotin immediately called an ambulance, called back those who had run up the road and prepared a sketch showing the approximate positions of everyone present at the moment of the accident.”

Slotin made one other phone call—to his friend Philip Morrison. Morrison recalls, "Lou said. We’ve had an accident. It went prompt critical and you’d better come down here. I’ve called the hospital.’ Then either he said or I asked, There was a blue glow.’ We both knew that was very bad."

While they waited silently for the ambulance Schreiber, at Slotin’s suggestion, went back into the lab with a radiation meter. It went full scale near the assembly so he hurried back, pausing only to pick up his and Slotin's jackets.

Inside an hour the eight men were bedded in three adjoining wards of the Eos Alamos hospital, a sprawling, green-painted barracks up on the central mesa. Slotin and Graves shared the third ward.

Even while they were being settled in, radiation biologists and physicists from the project, including Philip Morrison, were moving into the lab to make what measurements were possible so they could attempt the complex academic reconstruction of the accident that might give a clue to how' much of which kind of rays and subatomic particles had hit the men where, and in what strength, and for how long. They would not indeed be much the wiser for there was no set of rules yet for translating their exotic new kinds of dose into biological effects.

For a while at the hospital there was a bustle of nurses taking temperatures and blood samples and collecting little piles of coins from the men’s pockets, tie clips, belt buckles, rings, watches — any metal things whose induced radioactivity could be measured to give another clue to the dosage.

Slotin had vomited once, on the way up in the ambulance. Now Graves found himself waiting for symptoms and wondering, “Did it really go critical?” and “How bad was it?” and "Am I beginning to be nauseated?” The first moment they were left alone Slotin said. “AI. I’m sorry I got you into this. I’m afraid 1 have less than a fifty-fifty chance of living. I hope you have better than that.” Graves privately agreed with him.

Around six p.m. one of the radiation biologists. Dr. Wright Langham, came into the wards to pick up all the little piles of metallic belongings collected by the nurses. Nine months earlier he had collected a similar miscellany from Harry Daghlian and Slotin later had helped him with some of his mathematical calculations. Now Slotin cocked an eyebrow at Langham and said wryly, “I know why you’re here.”

Shortly afterward Morrison dropped in on his way back from Pajarito Site. They talked about the dosage. In a sense it w-as the only thing there was to talk about, for there was no antidote—nor is there now— for acute radiation sickness. There was only the faint hope that Slotin had not got enough to kill him. Before Morrison left he asked if there were anything Slotin would like and Slotin requested something to read. That night Morrison, who had seen the aftermath of Hiroshima, consulted workmen in the special machine shop attached to the lab and together they began to invent a contrivance with a book-rack to stretch across a hospital bed, strings to

Where Louis A. Slotin spent his last painful days

clip to every page of a book, a ratchet system to turn the pages and a switch to invoke the ratchet. The switch was placed so it could be operated by the reader’s elbow. It was a reading-machine — for someone who was not going to have hands to use.

By six-thirty that first night—only three hours after the accident—Slotin’s left hand was fat and reddened: the thumb that had crooked through the beryllium shell was numb and tingling and its nailbed was black.

By Wednesday afternoon — twenty-four hours after the accident — the hand was distended till the skin looked as though it would burst; the right hand, too, was swollen. Both were increasingly painful so the doctors ordered ice packs and morphine. Slotin’s lower abdomen, which had been directly opposite the assembly, was also beginning to redden. Otherwise he felt well, appeared cheerful and had stopped vomiting. So. nine months earlier, had Daghlian. For the cells of an organism are doughty, will rally even after such an insult, and will endure until they must try to reproduce themselves. For a short space, while the major conformations of cells work through their particular cycífcs to this fatal point, the body may seem to carry on.

By Wednesday night the first of the huge, tightly swollen blisters had formed, on Slotin's left thumb. On Thursday more arose, as big as cookies, on the palm and between all the fingers; the left arm, too, was swollen, and the right hand and part of the forearm. For that one millisecond both had been in the play of the blue glow and they were, quite literally, cooked.

Several other things happened on Thursday.

For example, there was a meeting that night of the chemists, physicists and biologists all of whom, with different techniques, had been trying feverishly to work out dosage assessments. Dr. Wright Langham. who had taken away Slotin’s small change and ring and watch, had already made quick calculations based on their induced radioactivity. They indicated that Slotin’s dosage had been roughly four times that of Daghlian. "Being a relatively simple person,” he recalled recently, "I didn't see how he had much of a chance. But the physics boys were still calculating, calculating, calculating. I walked in and told them what I thought. Phil Morrison picked up my data and pitched it the length of the desk. He said, ‘Hell. It can’t be.’ ” The physics boys kept on for three more days trying to save Slotin with their pencils.

Thursday was also the day when the Army—for Los Alamos was still an army post—decided some sort of press release about the accident would have to be made. Their automatic tack was to protect the public from radiation hysteria. So they were shaping the same sort of noncommittal statement (. . . accident . . . laboratory . . . technical personnel involved . . . satisfactory condition . . .) as had cloaked Daghlian’s death when Morrison got wind of it and threatened to go to the newspapers himself if the release failed specifically to say the victims had been exposed to radiation. The actual release said almost exactly that, though it said very little else.

On Thursday, too. since a public statement had been made, Slotin was allowed to get in touch with his family. Just at nightfall he dictated a wire to his father, which read, “My trip to Pacific indefinitely postponed, will write details love Louis.” Then, late that evening, with a nurse holding the receiver, he telephoned. He sounded calm and what he said was that he’d had a little accident and he’d be in the hospital a while and since that meant he couldn't visit home as he’d planned to after

the Bikini trip perhaps his parents would come down to see him. The Army would arrange about plane priorities for them.

Mr. and Mrs. Slotin left the next day, Friday; they would arrive in Los Alamos on Saturday at noon.

By now morphine and ice packs could no longer control the pain in Slotin’s dying hands. So the doctors completely encased the right hand and the left hand and arm in ice, which would have the same effect as amputation but without the attendant shock. Otherwise Slotin still seemed comfortable and alert. He was getting daily blood transfusions—friends lined up from the clinic door to the street to give blood—but his appetite was good and he still grimaced ruefully as he asked each visiting physicist, "Well, what’s the dose?” Morrison was coming whenever he could to read aloud to Slotin from technical books. Wives of colleagues brought sheaves of gladioli from their gardens, for there was no florist in Los Alamos. A technical photographer w;as sent over from the central pool, set up his lights and took color pictures of Slotin’s arms and hands and abdomen: since the case was such a rarity, records would bo invaluable.

On Saturday, when Slotin’s parents ar rived, he was still in the phase of apparent latency and was sitting up to greet them. Driving north to Los Alamos from Albu-

querque, where the plane had landed, Mr. Slotin had explained to Phil Morrison why he had felt it necessary to come. “Louis is my oldest son,” he said, “and every father loves his son. But there is more than that. There is respect for Louis, for a learned man.” Now' he asked, “How are you, Louis?”

“Why don’t you speak Yiddish, father?” Slotin asked gently. "There’s nothing to be ashamed of.” They talked for a while and Slotin made light of his condition—“Just a bit of a burn” — but Mrs. Slotin, who touched his dark hair, exclaimed, “it’s stiff and dry, like wire,” and after they left Mr. Slotin sought out Morrison and asked hesitantly if there were somewhere in Los Alamos it would be possible to get a bottle of whisky.

There had been two other arrivals in town. One was a doctor from C hicago who had been experimenting w'ilh lethally irradiated animals; he had found that in dogs the terminal stage was intricate massive hemorrhage and had had some success in treating it with a dye called toluidine blue. If Slotin’s illness followed the same course, the medical staff might w'ish to try tolnidj/>; blue on him.

The second arrival, also from Chicago, was a Dr. Hermann Lisco. He was a pathologist, and had prudently been alerted against the need of an autopsy.

For Dr. Slotin — the road to success and death

..„day was the fifth day after the accident and it was on Sunday that it became clear that, whatever the dosage was, it was too much. Annamae Dickie, the nurse in charge of the blood studies, did her routine count of white cells in the blood and burst into tears. The count had plummeted. The white cells—the lifesavers in the blood—had stopped reproducing themselves and were dying. Graves, on the pretext that Slotin's parents were entitled to visit him in privacy, was moved to another room that day.

Slotin was still coherent and alert. He noticed that his tongue was ulcerating opposite a gold-capped tooth and himself suggested that gold foil would effectively baffle the cap's obvious radioactivity. F.vcryone of course realized he knew that radioactivity strong enough to cause ulceration was itself an ominous sign. Morrison, in a letter describing the course of Slotin’s illness to their colleagues in the field, reported with careful brusquerie, "The fifth and sixth days were evidently very hard ones.”

After this Slotin passed quickly into a toxic state: his temperature and pulse rate rose rapidly; his abdomen became stiff and distended; his gastro-intestinal system broke down completely and had to be drained continuously by gastric suction through a nasal tube; all his skin turned to a deep angry puce. His body was dissolving into protoplasmic debris.

On Tuesday, the platelets in the blood, which govern its healthy clotting, suffered a fateful drop. “This w'as a sure sign of the onset of the hemorrhagic phase,” wrote Morrison later, in his report to their friends. "Both Louis and I knew enough about this to be unhappy about its coming. It is likely the next four or five days would have been very unpleasant.”

But Slotin was already having periods of mental confusion and by Wednesday he was in delirium. His lips turned blue and he was placed in an oxygen tent. By nightfall he had passed into coma and at I I a.m. on the morning of Thursday, May 30 — the ninth day after the accident— he died. Afterward the Army stripped a plane, bolted in a sofa and fiew' the Slotins and the coffin back to Winnipeg, and more than two thousand people came to the funeral and wept for a brave man.

But first, before the body left Los Alamos, Phil Morrison and Captain Paul Hagemann, head of the Los Alamos hospital. explained to Slotin’s father about the need for an autopsy. Mr. Slotin said it was against his religion and that he would be criticized for it when he returned to Winnipeg, but he gave permission. He said that Louis had been a scientist all his life and that, when it could do him no harm, it would be wrong to prevent his adding to knowledge. j—j

The newspapers and the IJ. S. Army and many well-meaning acquaintances managed to find decency in Slotin’s death because at the critical moment he acted like a hero. And of course it all happened long ago.

So it is interesting to f^d that the scientists who were then, or had been, at Los Alamos choose to avoid thinking of him.

This summer at Los Alamos one of them said, "I don’t w'ish to talk about him at all.” Others spoke of the accident "reluctantly” and held the event at arm’s length. Philip Morrison, who is now' at Cornell University, said leve 11 y, "It was the most painful time of my life and I don’t like to go back to it.”

They do not say why they are unwilling. But it may be that if they must remember Louis Slotin they must also feel again what they felt in those first days after mankind lost his innocence, iç