Mass Spectrometric Isotope Analysis of Plutonium in Neutron Irradiated Uranium Dioxide

New Shift-register Electronics for Improved Precision of Neutron Coincidence and Multiplicity Assays of Plutonium and Uranium Mass

Active and passive neutron-coincidence counting (NCC) is used routinely for nondestructive assay (NDA) of uranium and plutonium, in many forms. Passive neutron multiplicity counting (PNMC) is used routinely for NDA of plutonium scrap and waste. We’ve developed and extensively tested new electronics that significantly improves precision of double and triple coincidences, and multiplicity assays....

Reactor-Grade and Weapons-Grade Plutonium in Nuclear Explosives

The most common isotope, plutonium-239, is produced when the most common isotope of uranium, uranium-238, absorbs a neutron and then quickly decays to plutonium. It is this plutonium isotope that is most useful in making nuclear weapons, and it is produced in varying quantities in virtually all operating nuclear reactors. As fuel in a reactor is exposed to longer and longer periods of neutron i...

Investigation of Plutonium and Uranium Precipitation Behavior with Gadolinium as a Neutron Poison

Plutonium and uranium in Japanese human tissues.

Plutonium and uranium in human tissues obtained from residents of the Tokyo area were determined by a-spectrometry and the fission track method, respectively. The distribution pattern of each element was estimated on the basis of mean concentration obtained. Plutonium is concentrated in some special organs, while uranium is distributed rather generally throughout the whole body. This difference...

Configurational analysis of uranium-doped thorium dioxide

While thorium dioxide is already used industrially in high temperature applications, more insight is needed about the behaviour of the material as part of a mixed-oxide (MOX) nuclear fuel, incorporating uranium. We have developed a new interatomic potential model, commensurate with a prominent existing UO2 potential, to conduct configurational analyses of uranium-doped ThO2 supercells. Using th...