When Science Goes Wrong (24 page)
The reactor where the three men died became operational in 1958. It was called Stationary Low-Power Reactor Unit 1, or SL-1 for short. The ‘stationary’ in its name set it apart from the reactors then being developed for submarines, ships, and even aircraft. The ‘low-power’ referred to the fact that SL-1 was designed as a compact, easily transported and easily operated device that could provide modest amounts of electricity and heat. Its main intended application was to power the stations of the Distant Early Warning Line – the radar and radio installations that had been strung out across the North American Arctic to alert the USA to a Soviet bomber or missile attack.
The SL-1 reactor was located, like all the other Testing Station reactors, on a sagebrush desert in the middle of nowhere. The nearest sizeable community, the town of Idaho Falls, lay 40 miles to the east, and was where the reactor operators lived. Because of the lack of a nearby population that might be put at risk by a nuclear accident, and because the reactor was designed for use in even more remote locations, it had no concrete containment structure. Instead, it was housed in a simple silo-like building, about 50ft high and clad in sheet metal.
The building had three levels. In the lowest level sat the reactor itself, buried in a bed of gravel. The middle level – the reactor room – gave the operators access to the top of the reactor and the all-important control rods, as well as to the turbine generator that converted the reactor’s heat to electricity. The top level (the ‘attic’) contained a condenser and fans to convert the steam that exited the generator back to water. In addition, a long, low building directly abutted the silo. This contained the control room and offices.
The design of the reactor was quite simple. At the bottom of a 15ft-high steel vessel was the reactor core, a set of fuel plates containing uranium metal that had been moderately enriched in the radioactive isotope uranium-235, or
235
U. The nucleus of a
235
U atom will disintegrate when it absorbs a low-energy neutron, and the disintegration is accompanied by the release of several high-energy neutrons. For a nuclear chain reaction to occur, the energy of the emitted neutrons must be reduced to a level that can trigger further disintegrations. In the SL-1 reactor, this was accomplished by water that circulated between the fuel plates. Thus, SL-1 was a ‘water-moderated’ reactor. Water also served to carry heat from the reactor to the generator.
The essential requirement for a nuclear reactor is that the nuclear chain reaction be controllable. For that purpose, SL-1 was equipped with five control rods whose lowermost portions were blades made of cadmium metal, an efficient absorber of neutrons. Each rod weighed about 100lb, or 45kg, and was seven feet long. When the rods were all dropped to their lowest position, so that the blades lay between the fuel plates, they absorbed enough neutrons to terminate the chain reaction. Raising the rods by a few inches allowed the reaction to begin. During normal operation, the control rods were raised and lowered by motors located in the reactor room above the reactor, and the motors were controlled remotely by operators in the control room.
Jack Byrnes and Dick Legg joined the SL-1 staff in the autumn of 1959. Byrnes was 20 years old; he came from Utica, New York, and he brought with him his 19-year-old wife, Arlene, and their one-year-old son. Legg was a single man from rural Michigan, but he married a woman from the local Mormon community soon after he arrived in Idaho Falls. Byrnes had enlisted in the US Army and Legg in the US Navy, but the two men knew each other before they arrived in Idaho because they had taken the same training programme in Virginia over the previous months.
By the time of the accident on January 3, 1961, Byrnes and Legg had more than a year of experience operating the SL-1 reactor. Legg, in fact, had already been designated a chief operator and shift supervisor. Richard McKinley, on the other hand, was a new arrival and was still a trainee. He had much more experience in the military than the other two men, however; he was 28, and he had served both in the Army and the Air Force. He was married with two children.
On December 23, 1960, 11 days before the accident, SL-1 workers shut the reactor down for the Christmas holiday. They did this, as usual, by dropping the five control rods to their lowermost position. Several of the rods failed to drop under their own weight, however, and had to be driven down. This ‘sticking’ behaviour had been noticed before, but it wasn’t considered a serious problem. The key central rod which, on account of its position, was capable of starting and stopping the nuclear chain reaction by itself, had never stuck, nor did it do so on this occasion.
During the day on January 3, a work crew detached the control rods from the motors that normally raised and lowered them, in order to conduct some tests. The workers left the task of reconnecting the rods and restarting the reactor to the night crew, which consisted of Byrnes, Legg, and McKinley. The three men came on duty in the late afternoon. The last contact that anyone in the outside world had with them was around 7pm, when Byrnes’s wife spoke to him on the telephone.
At 9.01pm, an automatic alarm sounded at the Testing Station’s firehouse, signalling a problem at the SL-1 reactor. There had been two such alarms earlier that day, and both had turned out to be false, having been triggered by a faulty fire detector. Thus the firemen suspected that this alarm was false, too. Nevertheless they set out in a car and fire truck, reaching the reactor at 9.10pm. When they entered the control room, they found it deserted, but radiation alarms were sounding and a radiation detector carried by one of the firemen confirmed potentially dangerous levels of radiation.
The fire crew decided to check the reactor room, which was reached by a metal staircase that wound around the outside of the reactor building. By the time they were halfway up the staircase, their radiation detector was pegging out at 500 roentgens per hour, meaning that the men would absorb one year’s permissible dose of radiation in less than two minutes. They retreated. Then one of them climbed quickly to the top of the staircase and took a glance inside the reactor room before descending again. He saw that the floor of the room was awash with water from the reactor and was littered with broken equipment and gravel from the shielding bed. He didn’t see any of the three missing men.
A major disaster alarm was now sounded, and officials were roused at the Testing Station in Idaho Falls, and even in Washington DC. Among the men who raced to the site was Ed Vallario, the health physicist responsible for the SL-1 reactor. At around 10.30pm, wearing respirators but no other protective gear, Vallario and another man ran up the staircase to the reactor room. Again, their radiation detectors went off scale. When they reached the entrance to the reactor room and looked inside, they saw Richard McKinley. He was lying by the control panel, moaning and twisting his body in an apparent attempt to reach the controls. The right side of his face was severely injured. Near him lay the lifeless body of Jack Byrnes. Dick Legg was nowhere to be seen.
The two rescuers beat a hasty retreat. Vallario knew that McKinley must have absorbed a lethal dose of radiation, but he was still alive so he had to be rescued. Vallario and four other men found a stretcher and made another foray into the reactor room. They were able to get McKinley onto the stretcher and out of the building, but not before two of the men’s respirators malfunctioned, forcing them to remove the respirators momentarily and to inhale the unfiltered, contaminated air of the reactor room.
The rescuers placed McKinley in a truck and then transferred him to an arriving ambulance. In the ambulance he was tended to by a nurse, Hazel Leisen, but within moments – before the ambulance could even get onto the main road – he died. Health physicists quickly pulled Leisen out of the ambulance, for radiation levels inside the vehicle were 500 roentgens per hour – enough to kill anyone who drove in it for more than a few minutes. The driver was wrapped in a lead blanket and told to drive the ambulance off into the sagebrush, so as not to expose people passing on the road. He did so, and then made a run for it.
With McKinley and Byrnes both dead, there was but one urgent question remaining: where was the third member of the night crew? To find the answer, another team of four volunteers entered the reactor room. They searched around futilely and in increasing desperation as the seconds ticked away. Then one of the men’s flashlights happened to point upward.
Dick Legg’s body was pinned to the ceiling by one of the reactor’s control rods, as if by a giant thumbtack. Evidently, the control rod had shot explosively out of the reactor and had passed through Legg’s pelvis and abdomen on the way to the ceiling, carrying his entire body with it. Now he dangled, limply; he was very obviously dead. The men ran from the room.
An hour or two after midnight, teams went to the homes of the three dead men to notify their wives – now widows – of the tragedy.
The acute emergency was over, but two difficult problems lay ahead. The dead men needed to be removed from the site, decontaminated, autopsied, and buried. And the reactor needed to be rendered safe, broken down, and analysed so that the cause of the accident could be established.
Richard McKinley’s body needed to be dealt with first, because it was still lying in the abandoned ambulance out amongst the sagebrush. Operating in minute-long shifts, workers approached the ambulance and, using poles and other tools, succeeded in removing McKinley’s clothes and wrapping the body in lead blankets. After roads were closed to other traffic, a volunteer put on a lead-lined jacket and drove the ambulance at high speed to the Testing Station’s uranium reprocessing plant, where the body was placed in a steel bath containing ice and alcohol. The hope was that this would leach radioactive contamination off the body. Later that day, other teams of workers dashed into the reactor room and, working in relays, removed the body of Jack Byrnes, which was then also brought to the reprocessing plant.
Removing Dick Legg’s body, impaled as it was to the ceiling of the reactor room, presented a far more challenging task. Not only was it in an extremely high-radiation environment; there was also the risk that, if it fell onto the broken and exposed reactor during the recovery effort, it might trigger a second nuclear accident.
At least the rescuers had time on their side, for the radiation was so intense that Legg’s body had been completely sterilised: every bacterium inside and outside of his body had been killed, and the body would therefore not decompose.
As a first step in the recovery, radiation specialists built a full-scale mock-up of the reactor room, where they could test various strategies for reaching and removing the body. By five days after the accident they had settled on a strategy and put it into effect. First, they opened a large freight door that gave access to the reactor room from outside the building. Then they obtained a crane with a long boom and attached a netlike structure to the end of it. The crane operator, working blind behind a lead shield but guided by a distant spotter, manoeuvred the net through the cargo door and under Legg’s body. Then volunteers, working in minute-long relays, ran into the reactor room with long, hooked poles and attempted to drag the body down from the control rod. After several relays, the mangled body did indeed fall into the net, and it was removed from the building and taken to the reprocessing plant.
In an official film made to document the SL-1 accident and its aftermath, the narrator stated that the three bodies were successfully decontaminated by washing, and thus were brought into a state in which they could be safely returned to their families and buried. This was a complete fiction, however. In reality, repeated washing and even shaving of the men’s body hair had little effect in reducing radiation levels near the corpses, which still ranged up to 1,500 roentgens per hour. Countless particles of nuclear fuel had penetrated all three men’s bodies, in effect converting them into high-level nuclear waste. No one could safely remain close to them for more than a minute or so. Performing autopsies and dealing with the ultimate disposal of the bodies therefore presented an extraordinary challenge.
Three physicians from Los Alamos National Laboratory took on the task. Working behind lead shields set up several feet away, the doctors manipulated the bodies with instruments attached to long steel pipes. They first documented the injuries caused by the blast. Richard McKinley, the only one of the crew who was not killed instantly, had major wounds to his scalp, face and eyes, and to his left hand and left leg. Jack Byrnes, whose dead body had been found lying next to the reactor, had more severe injuries. His face, throat, rib cage, left arm, left leg and back were completely crushed, and his pelvis had been driven up into his abdomen. As for Dick Legg, who had been found impaled into the ceiling of the reactor room, his body had suffered devastating damage. The top off his head had been sliced off, exposing his brain, and his face was collapsed inward. The upper half of his body had been twisted by 180 degrees with respect to the lower half, and his internal organs had been destroyed or displaced by the control rod as it blasted through his pelvis and abdomen. His left leg was cut almost in two.
With the clumsy tools available to them, the doctors cut open the bodies and removed the internal organs for microscopic study. A more difficult task was to reduce the radiation levels to a point that would permit the bodies to receive normal burial. Guided by radiation detectors, the doctors sliced away great swathes of skin and underlying tissue, but that wasn’t enough. With McKinley, the doctors had to remove his left arm. With Byrnes, they removed both legs. With Dick Legg, they had to go even further: They removed all four limbs and – after consultation with their superiors – his head, which was the most radioactive body part of all. All these removed body parts were packed in a drum, driven to a remote spot and dropped into a deep trench designated to receive high-level waste from the accident.