The commercial nuclear age started on December 2, 1957, when the Shippingport Atomic Power Station in Pennsylvaniabegan operating—the first use of a nuclear power plant dedicated solely to peaceful purposes. Five months earlier, the International Atomic Energy Agency (IAEA) was founded with a dual mandate—promote the peaceful uses of atomic energy and prevent its military uses. Ever since, the tension inherent in this mission has strained and constrained the application and evolution of IAEA safeguards.
Safeguards comprise a set of nuclear material accountancy and surveillance tools and techniques that are supposed to help ensure that a country’s civilian nuclear program remains peaceful. The first formal safeguards agreement wasn't established until 1961, and throughout the 1960s, uranium enrichment was exempt from safeguards agreements. (A prevailing belief during that time was that developing countries wouldn’t be able to master the advanced technology of uranium enrichment—a false pretense given Pakistan’s ability to enrich uranium in the late 1970s.) The primary concern was that these countries could divert spent nuclear fuel from reactors to reprocessing plants where weapons-usable plutonium would be extracted. Thus, safeguards focused on reactors and reprocessing plants.