TOTAL SYSTEM MATERIAL CONTROL

Prevention of significant diversions of material from the facilities compris- ing the nuclear industry is a primary objective of national and international ma- terials safeguards systems. It is conceptually helpful to represent the industry as a network, in which the facilities are \"nodes\" and the paths for shipping the material between facilities are \"links.\" A simple example of such a network is given in Figure 1. Each facility receives material from one or more facilities and ships it (often in a different physical or chemical form) to one or more fa- cilities. Using the simple network representation reduces the possibilities of diver- sions to two types—within a. facility or in a transportation link between facili- ties. The points where measurements are taken to detect these diversions are shown in Figure 2, which indicates four quantities that are measured—amount shipped, amount received, loss, and physical inventory. These quantities form the basis of the total system material control that is discussed later.