Dem' bombs, they can be tetchy !!
Quote:The Second Incident.
'On May 21, 1946, physicist Louis Slotin and seven other personnel were in a Los Alamos laboratory
conducting another experiment to verify the closeness of the core to criticality by the positioning of
neutron reflectors.
Slotin, who was leaving Los Alamos, was showing the technique to Alvin C. Graves, who would use
it in a final test before the Operation Crossroads nuclear tests scheduled a month later at Bikini Atoll.
It required the operator to place two half-spheres of beryllium (a neutron reflector) around the core to
be tested and manually lower the top reflector over the core using a thumb hole on the top.
The Saviour, Louis Slotin & where the screwdriver had to 'slot-in' to the Demon Core.
As the reflectors were manually moved closer and farther away from each other, scintillation counters
measured the relative activity from the core. The experimenter needed to maintain a slight separation
between the reflector halves in order to stay below criticality. The standard protocol was to use shims
between the halves, as allowing them to close completely could result in the instantaneous formation
of a critical mass and a lethal power excursion.
Under Slotin's own unapproved protocol, the shims were not used and the only thing preventing the
closure was the blade of a standard flat-tipped screwdriver manipulated in Slotin's other hand. Slotin,
who was given to bravado, became the local expert, performing the test on almost a dozen occasions,
often in his trademark blue jeans and cowboy boots, in front of a roomful of observers.
Enrico Fermi reportedly told Slotin and others they would be "dead within a year" if they continued
performing the test in that manner. Scientists referred to this flirting with the possibility of a nuclear
chain reaction as "tickling the dragon's tail", based on a remark by physicist Richard Feynman, who
compared the experiments to "tickling the tail of a sleeping dragon".
On the day of the accident, Slotin's screwdriver slipped outward a fraction of an inch while he was
lowering the top reflector, allowing the reflector to fall into place around the core. Instantly, there
was a flash of blue light and a wave of heat across Slotin's skin; the core had become supercritical,
releasing an intense burst of neutron radiation estimated to have lasted about a half second.
Slotin quickly twisted his wrist, flipping the top shell to the floor. The heating of the core and shells
stopped the criticality within seconds of its initiation, while Slotin's reaction prevented a recurrence
and ended the accident.
The position of Slotin's body over the apparatus also shielded the others from much of the neutron
radiation, but he received a lethal dose of 1,000 rad (10 Gy) neutron and 114 rad (1.14 Gy) gamma
radiation in under a second and died nine days later from acute radiation poisoning.
The nearest person to Slotin, Graves, who was watching over Slotin's shoulder and was thus partially
shielded by him, received a high but non-lethal radiation dose. Graves was hospitalized for several
weeks with severe radiation poisoning. He died 19 years later, at age 55, of a heart attack.
While this may have been caused by Graves' exposure to radiation, his father also died of a heart
attack (suggesting that the event may have been hereditary).
The second accident was reported by the Associated Press on May 26, 1946:
"Four men injured through accidental exposure to radiation in the government's atomic laboratory here
[Los Alamos] have been discharged from the hospital and 'immediate condition' of four others is
satisfactory, the Army reported today.
Dr. Norris E. Bradbury, project director, said the men were injured last Tuesday in what he described
as an experiment with fissionable material."...'
Read The TV Guide, yer' don't need a TV.