Efforts to halt proliferation of nuclear weapons are threatened by vulnerability of weapons-usable material to smuggling especially in Russia. Mixing 232 U into highlyenriched uranium (HEU) makes it readily observable and harder to steal. Adding a proportion of 233 U associated with a specific storage site enables attribution to be performed on stolen HEU that has been recovered. Incorporating ...

Exposure to radiation in all its forms is part of being alive. Ionising radiation is taken to mean radiation of high-enough energy to displace electrons from atoms and includes cosmic rays, gamma rays, X-rays, alpha and beta radiation. The average level of exposure to natural background radiation varies throughout the world dependent mainly on the geology of the underlying earth. In the UK it i...

A “proliferator” seeks to complete a first small batch of fission weapons as quickly as possible, whereas an “interdictor” wishes to delay that completion for as long as possible. We develop and solve a max-min model that identifies resourcelimited interdiction actions that maximally delay completion time of the proliferator’s weapons project, given that the proliferator will observe any such a...

Contemporary world is faced with numerous threats and dangers. None of them can be solved by war, military action and economic sanctions. Neither disagreement nor conflicts can be solved by war. Humans are “eusocial” species (the technical term for displaying altruistic behaviour), like ants. Humans are cooperative and competitive, selfish and altruistic. Even if we accept that humans may have ...

When does nuclear counterproliferation succeed? When does it lead to preventive war? We argue that as the ratio between (i) the effect of nuclear acquisition on the balance of power and (ii) the costs of preventive war increases, counterproliferation becomes more successful but mistaken preventive wars also become more likely. We apply this logic to comparing the dynamics of proliferation durin...

A magnitude 9.0 earthquake and tsunami originating off the east coast of Japan triggered the explosive release of radioactive isotopes from one of four nuclear power plants in the affected area. This event has been compared with the 1986 nuclear accident at Chernobyl, the 1945 atomic bombing of Hiroshima and Nagasaki, and the intervening era of atmospheric nuclear weapons testing. The credibili...

We assess the potential damage and smoke production associated with the detonation of small nuclear weapons in modern megacities. While the number of nuclear warheads in the world has fallen by about a factor of three since its peak in 1986, the number of nuclear weapons states is increasing and the potential exists for numerous regional nuclear arms races. Eight countries are known to have nuc...

Over a period of 50 years, the Soviet Union built a giant infrastructure dedicated to designing, manufacturing, and maintaining nuclear bombs and warheads for a wide variety of strategic and tactical weapons systems (see Table 1). Under the conditions of the Soviet economic and political system, this nuclear weapons production complex developed into a self-sufficient, vastly redundant, and high...