Oops. The assembly went prompt supercritical, instantly spiking at over 100 million watts. A blue flash, of course, over-lit the room. Obviously, there was too much reflector under the core. The assembly scrammed, dropping to the floor, but there was nothing to drop away from. All the reactivity was present on the lower half of the assembly, and the top of the machine had been moved out of the way. The experimenter, knowing what he had done, ran out of the room, closed the vault behind him, told two guys in the control room what had happened, and died of severe radiation poisoning two days later. His radiation dose from neutrons alone was several times the lethal level.[56]
The assembly heated up to 865 °C, expanded, and settled down to a stable power level of 480 watts, fissioning away for six and a half days until the emergency crew was able to position a vacuum gripper on it and pull off the copper tamper-piece on top.
In 1957 an additional atomic city was built in the Chelyabinsk Oblast in the Urals district of Southern Russia. It was named Chelyabinsk-70, home of the All-Russian Scientific Research Center of Technical Physics, or the VNIITF. After the end of the Cold War it was reassigned the name Snezhinsk, which was easier to pronounce. The extensive research facilities included an FKBN vertical split table, just like the one at Arzamas-16.
On April 5, 1968, two very knowledgeable, experienced criticality specialists were experimenting with a special reactor setup on the split table. The goal was to make a tiny reactor to be used in pulse-mode to investigate the effects of the radiation spike from a nuclear weapon detonation. All day they had tried different configurations. At the center of the reactor was a hollow sphere of 90 % enriched uranium, or 43.0 kilograms of uranium-235 in a 47.7 kilogram ball, 91.5mm in diameter with a 55mm cavity inside. The reflector halves were natural uranium, making a hollow sphere 200mm in diameter. In the last configuration they tried, the uranium sphere had nothing but air in the center. They had lowered the top reflector half onto the ball using an overhead electrical winch, then retired to the control room, closing the shielding vault door, and slowly drove the lower reflector up toward the assembly until it went critical. Satisfied with the result, they then drove the bottom reflector down until the assembly went subcritical, which was with the southern hemisphere 30mm below the stop.[57]
It was late and after hours. The health physicist and the control room operator had gone home. The two specialists had tickets to the theater, and they were in a hurry to leave, but there was one last thing they wanted to try. Not bothering to turn on the criticality alarm, they used the winch to lift off the top reflector half, removed the top core half, and inserted a polyethylene ball in the empty cavity. For some inexplicable reason, these two experts did not expect a hydrogen-containing moderator at the center of the reactor to change anything, but they just wanted to make sure. One operated the control box for the overhead winch while the other steadied the heavy, 308-kilogram hemisphere as it came down on the core-ball at 100mm per second.
Blue flash! With his hands on the reflector, one felt a shock, as if the thing had been struck with a mallet. Both were hit in the face by the wave of heat as the system’s reactivity flew past the prompt critical level. When the power level hit one kilowatt and rising, the scram activated, and the bottom of the assembly fell away, but it was too late for the specialists. Before they left the control room the lower reflector should have been lowered to the bottom stop, but it was kept at the level that was barely subcritical for the assembly with a hollow center. The one with his hands on the uranium absorbed between 2,000 and 4,000 rem, and he died three days later in the Bio-Physics Institute in Moscow. The man who was holding the winch control only received something between 500 and 1,000 rem, and he managed to cling to life for 54 days.
These two men suffered from the same supreme confidence in what they were doing that had killed Louis Slotin. They had violated many rules, including the most important one: Every unmeasured system is assumed to be critical. It is the same as finding a pistol sitting on a table. Assume that it is cocked and loaded.
The nuclear age had arrived with a pronounced bang, and by 1947 two experts had died trying to achieve zero-power criticality in the simplest possible reactor configurations. It had become obvious that an extraordinary level of caution would be needed to do anything practical with this new discovery, this new, novel, and dangerous way to heat the old cave. Be careful, or the innocent-looking ball of metal could pin you to the wall like a mule with a long-festering grudge. And a radioactive one at that.
Nuclear reactor systems were about to get a lot more complicated, with more moving parts, pumps, valves, controls, indicators, and data recorders, and a great deal of plumbing. The heart of the system, the reactor core, was going to be covered up by layers of safety-ensuring machinery and made abstract by the interpretive instrumentation; but we must never forget that at the center of it all, danger still lurks. Remain alert, capable of terror, and never so familiar with the routine that you are certain that nothing could happen.
Chapter 3:
A Bit of Trouble in the Great White North
“A scientist need not be responsible for the entire world. Social irresponsibility might be a reasonable stance.”
The decade of the nineteen-fifties is often cited as a dull period of time, lacking the excitement and colorful excesses of the following decade, the sixties. The sixties exploded with John Kennedy, the Beatles, recreational pharmaceuticals, space travel, and hippies. What did the fifties give us? Dwight Eisenhower and black-and-white television?
Deeper research indicates that this comparison of two decades is upside down. The utter wildness of the nineteen-fifties, a decade in which 100 new religions were formed, psychedelic drug experimentation was on an industrial scale, and vast scientific experiments outstripped science fiction, makes the sixties a wind-down.[58]
Eisenhower, the subdued old Republican who liked to play golf, reversed everything that his predecessor, Harry Democrat Truman, had worked so hard to nail down. He stopped Harry’s Korean War in mid-advance. He played a clever game with the Soviet Union, forcing them to be the first to orbit a satellite that passed over the United States, thus setting the international precedent for down-looking reconnaissance from space. Most surprising, he opened the files of the Manhattan Project, insisting that every document, scientific finding, and gained expertise that did not relate directly to the weapons be declassified and released to the entire world. Truman, seeing this knowledge as proprietary property of the United States government, had denied access to our most trusted allies. Even the British and the Canadians, who had participated in the development work, were allowed no access. Eisenhower wished to give all the world enough knowledge to pursue civilian-owned nuclear power. He railed at the “military-industrial complex,” warning of its desire to make profits from developing new, more advanced weaponry.
56
Technically, he absorbed 4,500 rad of neutron radiation and 350 rad gamma rays. The rad is an obsolete measurement that does not take into account the “Q,” or the radiation quality factor and how it affects humans. Assume a Q of one, and he got a body dose of at least 4,850 rem. It was probably closer to 40,000 rem or 400 sieverts, which would drop an elephant.
57
If you are amazed by some of the detailed information available concerning Soviet nuclear work, read an example of
58
A prime example of a wide, government-sanctioned program of psychedelic drug experimentation on uninformed civilians was project MK-Ultra, enthusiastically administered by the Central Intelligence Agency beginning in 1953. Experiments were performed at 44 universities and 36 other venues, including hospitals, prisons, and pharmaceutical companies. Citizens were subjected to drugs, hypnosis, sensory deprivation, torture, and abusive language. Today, they would not let us do any of this to a goat. (Don’t ask me how I know.) Records of this project were declassified in 2001.