Science & Global Security 

About: Science & Global Security is an academic journal published by Taylor & Francis. The journal publishes majorly in the area(s): Plutonium & Nuclear weapon. It has an ISSN identifier of 0892-9882. Over the lifetime, 291 publications have been published receiving 4000 citations. The journal is also known as: Science and global security.

Explosive properties of reactor-grade plutonium

Abstract: The following discussion focuses on the question of whether a terrorist organization or a threshold state could make use of plutonium recovered from light-water-reactor fuel to construct a nuclear explosive device having a significantly damaging yield. Questions persist in some nonproliferation policy circles as to whether a bomb could be made from reactor-grade plutonium of high burn-up, and if so, whether the task would be too difficult for a threshold state or terrorist group to consider. Although the information relevant to these questions is in the public domain, and has been for a considerable time, it is assembled here for use by policy makers and members of the public who are concerned about preventing the spread of nuclear explosives.

Detecting nuclear warheads

Abstract: In the absence of shielding, “ordinary” nuclear weapons—those containing kilogram quantities of ordinary weapon‐grade (6 percent plutonium‐240) plutonium or uranium‐238—can be detected by neutron or gamma counters at a distance of tens of meters. Objects such as missile canisters can be radiographed with high‐energy x‐rays to reveal the presence of the dense fissile core of any type of nuclear warhead, or the radiation shielding that might conceal a warhead. If subjected to neutron irradiation, the fissile core of any type of unshielded warhead can also be detected by the emission of prompt‐or delayed‐fission neutrons at a distance on the order of 10 meters.

Tomographic Imaging with Cosmic Ray Muons

Abstract: Over 120 million vehicles enter the United States each year. Many are capable of transporting hidden nuclear weapons or nuclear material. Currently deployed X-ray radiography systems are limited because they cannot be used on occupied vehicles and the energy and dose are too low to penetrate many cargos. We present a new technique that overcomes these limitations by obtaining tomographic images using the multiple scattering of cosmic radiation as it transits each vehicle. When coupled with passive radiation detection, muon interrogation could contribute to safe and robust border protection against nuclear devices or material in occupied vehicles and containers.

U-232 and the Proliferation- Resistance of U-233 in Spent Fuel

Abstract: The factors influencing the level of U‐232 contamination in U‐233 are examined for heavy‐water‐moderated, light‐water‐moderated and liquid‐metal cooled fast breeder reactors fueled with natural or low‐enriched uranium and containing thorium mixed with the uranium or in separate target channels. U‐232 decays with a 69‐year half‐life through 1.9‐year half‐life Th‐228 to T1–208, which emits a 2.6 MeV gamma ray upon decay. We find that pressurized light‐water‐reactors fueled with LEU‐thorium fuel at high burnup (70 MWd/kg) produce U‐233 with U‐232 contamination levels of about 0.4 percent. At this contamination level, a 5 kg sphere of U‐233 would produce a gamma‐ray dose rate of 13 and 38 rem/hr at 1 meter one and ten years after chemical purification respectively. The associated plutonium contains 7.5 percent of the undesirable heat‐generating 88‐year half‐life isotope Pu‐238. However, just as it is possible to produce weapon‐grade plutonium in low‐burnup fuel, it is also practical to use heavy‐water reactor...

Reducing the Hazards from Stored Spent Power-Reactor Fuel in the United States

Abstract: Because of the unavailability of off-site storage for spent power-reactor fuel, the NRC has allowed high-density storage of spent fuel in pools originally designed to hold much smaller inventories. As a result, virtually all U.S. spent-fuel pools have been re-racked to hold spent-fuel assemblies at densities that approach those in reactor cores. In order to prevent the spent fuel from going critical, the fuel assemblies are partitioned off from each other in metal boxes whose walls contain neutron-absorbing boron. It has been known for more than two decades that, in case of a loss of water in the pool, convective air cooling would be relatively ineffective in such a "dense-packed" pool. Spent fuel recently discharged from a reactor could heat up relatively rapidly to temperatures at which the zircaloy fuel cladding could catch fire and the fuel's volatile fission products, including 30-year half-life 137 Cs, would be released. The fire could well spread to older spent fuel. The long-term land-contaminatio...