Search results
Results from the WOW.Com Content Network
Criticality accidents are divided into one of two categories: Process accidents, where controls in place to prevent any criticality are breached;; Reactor accidents, which occur due to operator errors or other unintended events (e.g., during maintenance or fuel loading) in locations intended to achieve or approach criticality, such as nuclear power plants, nuclear reactors, and nuclear ...
The demon core (like the core used in the bombing of Nagasaki) was, when assembled, a solid 6.2-kilogram (14 lb) sphere measuring 8.9 centimeters (3.5 in) in diameter.. It consisted of three parts made of plutonium-gallium: two hemispheres and an anti-jet ring, designed to keep neutron flux from "jetting" out of the joined surface between the hemispheres during implosi
The plutonium, dissolved in an organic solvent, flowed into the center of the vortex. Due to a procedural error, the mixture contained 3.27 kg of plutonium, which reached criticality for about 200 microseconds. Kelley received 3,900 to 4,900 rad (36.385 to 45.715 Sv) according to later estimates.
Nuclear power plants operate between these two points of reactivity, while above the prompt critical point is the domain of nuclear weapons, pulsed reactors designs such as TRIGA research reactors and the pulsed nuclear thermal rocket, and some nuclear power accidents, such as the 1961 US SL-1 accident and 1986 Soviet Chernobyl disaster.
The Windscale fire resulted when uranium metal fuel ignited inside plutonium production piles; surrounding dairy farms were contaminated. [33] [34] The severity of the incident was covered up at the time by the UK government, as Prime Minister Harold Macmillan feared that it would harm British nuclear relations with America, and so original reports on the disaster and its health impacts were ...
The $1.8 billion project will aid in stockpile stewardship, a program designed to ensure the safety and reliability of the nation's nuclear weapons without the use of underground explosive testing ...
The pits of the first nuclear weapons were solid, with an urchin neutron initiator in their center. The Gadget and Fat Man used pits made of 6.2 kg of solid hot pressed plutonium-gallium alloy (at 400 °C and 200 MPa in steel dies – 750 °F and 29,000 psi) half-spheres of 9.2 cm (3.6 in) diameter, with a 2.5 cm (1 in) internal cavity for the initiator.
A criticality accident occurred on December 30, 1958, at Los Alamos National Laboratory (LANL) in Los Alamos, New Mexico, in the United States It is one of 60 known criticality events that have occurred globally outside the controlled conditions of a nuclear reactor or test; though it was the third such event that took place in 1958 after events on June 16 [1] at the Y-12 Plant in Oak Ridge ...