Criticality accident
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A criticality accident is an accidental uncontrolled nuclear fission chain reaction. It is sometimes referred to as a critical excursion, critical power excursion, divergent chain reaction, or simply
The sphere of plutonium surrounded by neutron-reflecting tungsten carbide blocks in a re-enactment of Harry Daghlian's 1945 experiment
A re-creation of the Slotin incident. The plutonium "demon core" (the same as in the Daghlian incident) was inside at the time of the accident, and would not be visible.
Lady Godiva assembly in the scrammed (safe) configuration
Lady Godiva assembly, with damaged supporting rods after the excursion of February 1954. Note the images are of different assemblies.
Tokaimura nuclear accidents
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The Tokaimura nuclear accidents were two nuclear incidents which occurred near the village of Tōkai, Ibaraki Prefecture, Japan. The first accident occurred on 11 March 1997, producing an explosion aft
Criticality accident
…the initial prompt-critical excursion. The longest of the 22 process accidents occurred at Hanford Works in 1962 and lasted for 37.5 hours. The 1999 Tokaimura nuclear accident remained critical for about 20 hours, until it was shut down by active intervention. The exponential excursion is characterized by a reactivity of less…
Tokai Nuclear Plant, Japan's first nuclear power station