In part because the NPT regime contains no required standards for the physical protection of weapons-usable nuclear materials, there is a great variation in what countries actually do to protect them. Differences in culture and in perceived dangers from terrorists or inside thieves accounts for some of the differences. So may the lack of a clear mandatory international standard.
The international Convention on the Physical Protection of Nuclear Materials, which was completed in 1980 and last reviewed by its Parties in 1992, is limited in scope. Its protection standards, as general as they are, were only made applicable to nuclear material "for peaceful purposes in international transport." The draft originally submitted by the United States would have applied standards to domestic storage and use as well. But there were some objections to this. A compromise focused on international transport as the "most urgent" matter; added a preambular paragraph stressing the importance of "domestic" use, storage and transport," and agreed that the Convention's extension to domestic materials could be reconsidered at a future review conference. There were also objections to excluding materials used for military purposes. The compromise added a preambular paragraph reporting the understanding given the negotiators by the weapon-States that this material "is and will continue to be accorded stringent physical protection." The Convention's standards for physical protection thus did not apply to most weapons-usable nuclear materials - not to those for military purposes nor to those for peaceful purposes but not in international transport. Even in those cases to which the standards do apply, the Convention does not require inspections, other transparency requirements or enforcement provisions to give assurance to all States that adequate physical protection is in fact being provided.
The IAEA in 1989 issued strengthened, detailed recommendations for standards for the protection of nuclear materials (INFCIRC/225, Rev. 2), a revision of those first issued in 1972. They are not limited to nuclear material used for peaceful purposes while in international transport. They recognized that the responsibility for physical protection rests with national governments but that the protection actually provided is "not a matter of indifference to other States." The purpose of the new standards was to "minimize the possibilities for unauthorized removal of nuclear material or for sabotage."
In 1993, the IAEA revised these recommendations somewhat to provide further guidance on such matters as irradiated fuel and nuclear material in waste (INFCIRC/225, Rev.3). In September 1997, the IAEA issued additional guidance on implementing the Convention.
During the 1980s, the Nuclear Suppliers Group (a body outside the IAEA) began seeking provisions in nuclear export agreements calling for application of the IAEA-recommended physical protection standards in the States receiving exports, in some cases when the nuclear material protected was in domestic use.
Before the 1992 review conference of the Convention on Physical Protection, there were proposals for expanding the Convention's scope to apply to more nuclear material than just that in international transport. Its Parties decided not to amend it. At that time, the focus of many was on the inadequacy of NPT safeguards to detect State acquisition of nuclear weapons rather than on the inadequacy of the Physical Protection Convention standards to prevent terrorist acquisition. As a result, nothing was done to strengthen physical protection standards while the NPT safeguards were very significantly strengthened through the IAEA's "Programme 93+2".- George Bunn.