Search results
Results from the WOW.Com Content Network
Plutonium-240 undergoes spontaneous fission at thousands of times the rate of plutonium-239, and the extra neutrons thereby released made it likely that plutonium in a gun-type fission weapon would detonate too soon after a critical mass was formed, producing a "fizzle"—a nuclear explosion many times smaller than a full explosion. [12]
Feb. 19—Los Alamos National Laboratory reached what federal officials say is a key milestone in developing its first plutonium pit that can be placed in a nuclear warhead as it seeks to produce ...
A hollow plutonium pit was the original plan for the 1945 Fat Man bomb, but there was not enough time to develop and test the implosion system for it. A simpler solid-pit design was considered more reliable, given the time constraints, but it required a heavy U-238 tamper, a thick aluminium pusher, and three tons of high explosives.
Fission product yields by mass for thermal neutron fission of U-235 and Pu-239 (the two typical of current nuclear power reactors) and U-233 (used in the thorium cycle). This page discusses each of the main elements in the mixture of fission products produced by nuclear fission of the common nuclear fuels uranium and plutonium.
Tell the whole story of plutonium’s use. Our entire region should be extremely proud of the B Reactor. A massive edifice, built in a year, under tight security. The B Reactor is an underutilized ...
To reduce the concentration of Pu-240 in the plutonium produced, weapons program plutonium production reactors (e.g. B Reactor) irradiate the uranium for a far shorter time than is normal for a nuclear power reactor. More precisely, weapons-grade plutonium is obtained from uranium irradiated to a low burnup.
Watchdogs are raising new concerns about legacy contamination in Los Alamos, the birthplace of the atomic bomb and home to a renewed effort to manufacture key components for nuclear weapons.
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.