Humanity has created enough highly enriched uranium (HEU) and separated plutonium to produce well over 100,000 nuclear explosives. Most of this material is a legacy of the U.S.-Soviet Cold War nuclear arms race but separation of about half of the plutonium was initiated to provide startup fuel for plutonium breeder reactors that were never built.
Today, excess Cold War HEU is being blended down to low-enriched uranium (LEU) for use in power reactor fuel and some of it is being placed in reserves for future use as naval-reactor fuel. Excess separated plutonium is also mostly being disposed of in power reactor fuel.
A small part of the HEU -- but still hundreds of weapon equivalents -- was spread to more than 40 nations in reactor fuel for research reactors that the U.S. and Soviet Union supplied during the 1950s and 60s under their Atoms for Peace Programs. Today, a major effort is focused on converting those of these research reactors that are still operating to LEU and retrieving the fresh and spent HEU fuel. As France has demonstrated, naval reactors also could be converted to LEU fuel.
Previous lectures in this series:
- 2012 Physics Nobel laureate William D. Phillips: Time, Einstein, and the Coolest Stuff in the Universe
- 2010 Terry Tao: The Cosmic Distance Ladder
- 2009 Alan Guth: Inflationary Cosmology: Is Our Universe Part of a Multiverse?
- 2008 Margaret Geller: Newton Meets Einstein: Mapping Dark Matter in the Universe
- 2007 Kip Thorne: The Warped Side of the Universe from the Big Bang to Black Holes and Gravitational Waves
- 2006 Physics Nobel laureate Saul Perlmutter: Supernovae, Dark Energy, and the Accelerating Universe -- What Next?
- 2005 Physics Nobel laureate Wolfgang Ketterle: When Freezing Cold is Not Cold Enough -- New Forms of Matter at Close to Absolute Zero Temperature
- 2004 Physics Nobel laureate Robert B. Laughlin: The Emergent Age
- 2003 Physics Nobel laureate Carl E. Wieman: Bose-Einstein Condensation: Quantum Weirdness at the Lowest Temperature in the Universe
- 2002 Sir Michael Atiyah: Geometry and Physics: A Marriage Made in Heaven
- 2001 Mildred S. Dresselhaus: Frontiers in Nanoscience