The Lady Godiva device was an unshielded, pulsed nuclear reactor originally situated at the Los Alamos National Laboratory (LANL), near Santa Fe, New Mexico. It was one of a number of criticality devices within Technical Area 18 (TA-18). Specifically, it was used to produce bursts of neutrons and gamma rays for irradiating test samples, and inspired development of Godiva-like reactors.
Experimenters produced bursts of gamma rays and neutrons by assembling Godiva I's three parts and dropping a burst rod through the center. This image shows it in the safe, scrammed, state.
A cylindrical wire cage encloses the spherical uranium mass at the top of this image of Godiva II.
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 critical. Any such event involves the unintended accumulation or arrangement of a critical mass of fissile material, for example enriched uranium or plutonium. Criticality accidents can release potentially fatal radiation doses if they occur in an unprotected environment.
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.
