Abstract and subjects
Many proponents of the thorium fuel cycle have claimed and are claiming that it is proliferation resistant (see Refs. 1-5). The basis for these claims is that the bred super(233)U is contaminated with super(232)U, which possesses a decay daughter, super(208)T1, with a short half-life of 3 minutes that emits a penetrating 2.6 MeV gamma for 99.75% of the decays.[6] These proponents contend the presence of the super(208)T1 is a proliferation barrier. We disagree with this contention, because the radiation resulting from the presence of super(208)T1 is not a deterrent to adversaries who are not concerned with long-term health and safety. This paper examines the validity of these claims by assessing the material attractiveness, MA, of the special nuclear materials (SNM) bred in the thorium fuel cycle using the prescription of Ref. 7. MA < 0 is considered unattractive; 0 < MA [< or =] 1 is unattractive, but theoretically still weapons usable; 1 < MA [< or =] 2 is attractive; and MA > 2 is highly attractive.