Nuclear Iran: A Glossary of Terms

| May 2013 Update


At a time when the possibility of military action against Iran's nuclear program is being debated, the need for a clear understanding of the issues and the controversial science and technology behind them has never been more acute.

Toward that end, the Washington Institute for Near East Policy and Harvard Kennedy School's Belfer Center for Science and International Affairs have updated their interactive online glossary of terms used in the discussion about Iran. This new version, published in May 2013, updates the original August 2012 report prepared by proliferation expert Simon Henderson of the Washington Institute, and Olli Heinonen, former deputy director-general of the International Atomic Energy Agency (IAEA) and now a senior fellow at the Belfer Center.

International diplomacy concerning Iran’s nuclear program continues to center on the country’s compliance with agreements designed to ensure that peaceful nuclear work is not used as a cover for the develop­ment of nuclear weapons. The authors write that the challenge of discovering what may be going on in Iran is difficult not only because of Tehran’s obstructionism, but also because the same technologies, particularly uranium enrichment and spent fuel reprocessing, can be used for both civilian and military purposes.

This online glossary is intended to improve comprehension of the main issues and important technical details surrounding the program. The core of the document explains the terms used by the IAEA, the world’s watchdog in ensuring that nuclear science and technology are used for peaceful purposes only. Separate sections offer explanations of basic nuclear terms and the use of centrifuges for uranium enrichment.

In addition, because some of Iran’s technology came from nuclear-armed Pakistan, another section is devoted to explaining the main portions of Islamabad’s program. And since media coverage often compares sus­pected Iranian nuclear work to initial U.S. development of atomic weapons in the mid-1940s, the basic terms often used in describing this history are defined separately.

This online glossary includes an interactive index that provides quick, hyperlinked access to all of the terms discussed in the various glossaries. By clicking on a term in this index, users can instantly jump to the page on which it appears, then click another link to return to the index.


Simon Henderson is the Baker fellow and director of the Gulf and Energy Policy Program at The Washington Institute. He has lived in both Pakistan and Iran and has written extensively on nuclear proliferation.

Olli Heinonen, a senior fellow at Harvard Kennedy School's Belfer Center for Science and International Affairs, previously served as deputy director-general and head of the Department of Safeguards at the International Atomic Energy Agency in Vienna, inspecting facilities in Iran and other countries.

Watch online as Institute proliferation expert Simon Henderson and former IAEA deputy director-general Olli Heinonen share a new study on the Iranian nuclear program and international responses and discuss the latest developments ahead of a key IAEA report on Tehran's atomic activities.

For more information on this publication: Please contact the Belfer Communications Office
For Academic Citation: Heinonen, Olli and Henderson, Simon. “Nuclear Iran: A Glossary of Terms.” , May 2013 Update.

The Authors