nium from other by-products of nuclear power generation may provide plutonium for nuclear reactor fuel, for building nuclear weapons, or both.2

The nuclear nonproliferation regime developed out of international efforts to manage these tensions. The regime, which is built upon the foundation of the Treaty on the Non-Proliferation of Nuclear Weapons (also known as the Nuclear Non-Proliferation Treaty, or NPT), comprises an evolving complex of treaties, export control agreements, and other formal and informal arrangements. The NPT, which entered into force in 1970, endeavored to halt and reverse the proliferation of nuclear weapons while ensuring access to nuclear energy for all member states. It attempted to accomplish this by restricting possession of nuclear weapons to states that had tested nuclear weapons prior to 1967. These “nuclear-weapon States” (China, France, Russia, the United Kingdom, and the United States)3 promised to work toward eliminating their nuclear arsenals and to not share nuclear weapons technology with “non-nuclear weapon States.” At the same time, the nuclear-weapon States (NWS) promised to share the benefits of peaceful nuclear technology with non-nuclear weapon States (NNWS). In exchange, the NNWS, which comprised the balance of the treaty signatories, pledged not to obtain or develop nuclear weapons, and to accept the application of international safeguards to their nuclear programs to verify their compliance with the treaty.4

The International Atomic Energy Agency was established in 1957 to promote the peaceful use of nuclear energy and to ensure as far as possible that any nuclear energy programs with which it was associated were managed safely and used only for peaceful purposes. The activities of the agency are governed by its member states, and the decisions of the member states are implemented by the agency’s secretariat, which is based in Vienna. After the NPT entered into force, the IAEA was assigned the responsibility of applying the safeguards required by


The nuclear materials (usually uranium and plutonium) that are used in a nuclear reactor to produce heat through nuclear fission are considered nuclear fuel. Prior to irradiation in the nuclear reactor, the fuel is considered “fresh fuel.” After irradiation, the fuel is considered “spent fuel.” Irradiation of the most common types of nuclear fuel converts some uranium into plutonium. Chapters 7 and 14 of David Bodansky, Nuclear Energy: Principles, Practices, and Prospects (Woodbury, N.Y.: American Institute of Physics, 1996) provide excellent background on the nuclear fuel cycle and its consequences for nuclear proliferation.


The United Kingdom, United States, and Russian Federation are the depositary states for the NPT. China and France acceded to the treaty as nuclear-weapon States in 1992. See Joseph Cirincione et al., Deadly Arsenals: Tracking Weapons of Mass Destruction (Washington: Carnegie Endowment for International Peace, 2002), pp. 25-26.


See the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), available at as of April 20, 2005. In the context of the international nuclear nonproliferation regime, “safeguards” are measures taken by the IAEA to verify the accuracy and completeness of a state’s claims about the activities and scale of its nuclear complex, including its nuclear material inventories. Domestic safeguards are measures taken by a state to prevent theft or unauthorized use of weapons or weapons usable material.

The National Academies of Sciences, Engineering, and Medicine
500 Fifth St. N.W. | Washington, D.C. 20001

Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement