PROGRESS TOWARD MUTUAL RECIPROCAL INSPECTIONS OF FISSILE MATERIALS FROM DISMANTLED NUCLEAR WEAPONS

In March 1994, the United States and the Russian Federation announced their intention to conduct mutual reciprocal inspections (MRI) to confirm inventories of fissile materials from dismantled nuclear weapons. Subsequent interactions between the two countries have established the basis for an MRI regime, covering instrumentation, candidate sites for MRI, and protection of information deemed sensitive by the countries. In this paper we discuss the progress made toward MRI, stressing measurement technologies and observables, as well as prospects for MRI implementation. An analysis is presented of observables that might be exploited to provide assurance that the material being measured could have come from a dismantled weapon rather than other sources. Instrumentation to exploit these observables will also be discussed, as will joint US/Russian efforts to demonstrate such instrumentation. Progress toward a so-called \"program of cooperation\" between the two countries in protecting each other's sensitive information will be reviewed. All of these steps are essential components of an eventual comprehensive regime for controlling fissile materials from weapons.