FEDERATION OF AMERICAN SCIENTISTS T: 202/546-3300 1725 DeSales Street NW, Suite 600, Washington, DC 20036 www.fas.org F: 202/675-1010 [email protected]

Board of Sponsors March 29, 2016

(Partial List)

* Peter Agre Dear National Leaders at the Nuclear Security Summit: * Sidney Altman * Philip W. Anderson * Kenneth J. Arrow * David Baltimore * Paul Berg We Nobel Laureates applaud you for your efforts to secure vulnerable nuclear and * J. Michael Bishop * Gunther Blobel radiological materials around the world and to further reduce the risks of nuclear * Nicolaas Bloembergen * Paul Boyer and radiological terrorism. We underscore that these threats cross national * Michael S. Brown * Linda B. Buck boundaries and thus require the concerted work of all nations to prevent these Ann Pitts Carter * Martin Chalfie terrorist acts from happening. In particular, we note that in the highly polarized * Stanley Cohen * Leon N. Cooper * E. J. Corey politics in the United States, preventing nuclear and radiological terrorism has * James Cronin * Johann Deisenhofer been one of the rare points of bipartisan support. We praise the George W. Bush Sidney Drell Ann Druyan administration for its Global Threat Reduction Initiative begun in May 2004 and Paul R. Ehrlich George Field the Barack Obama administration for extending this and related nuclear security * Val L. Fitch * Jerome I. Friedman programs and for convening the Nuclear Security Summits having started in 2010. * Riccardo Giacconi * Walter Gilbert * Alfred G. Gilman * Sheldon L. Glashow * Roy J. Glauber While we encourage you to move forward on all fronts, in this letter we call * Joseph L. Goldstein * David J. Gross attention to three technical challenges that if fully resolved, could result in * Roger C. L. Guillemin * Leland H. Hartwell eventually driving the risk close to zero in three important sectors. First, as * Dudley R. Herschbach * Roald Hoffmann security experts have agreed, highly enriched uranium (HEU) is the fissile John P. Holdren * H. Robert Horvitz material with the greatest ease of use in an improvised nuclear explosive. More * David H. Hubel * Eric R. Kandel * Wolfgang Ketterle than 80 percent of the world’s HEU is devoted to military purposes including * Brian Kobilka * Leon Lederman nuclear weapons and naval nuclear propulsion. We understand politically why * Robert J. Lefkowitz * Roderick MacKinnon certain nations have resisted phasing out military HEU. We urge serious technical * Eric S. Maskin Jessica T. Mathews studies be done to investigate the transition from HEU to low enriched uranium Roy Menninger Matthew S. Meselson (LEU) fuels, which cannot be used directly in weapons, in the naval nuclear Richard A. Meserve * Mario Molina propulsion sector. Stephen S. Morse * Ferid Murad Franklin A. Neva * Ei-ichi Negishi * Douglas D. Osheroff In a related sector, we note that the U.S. National Academies of Sciences, * Arno A. Penzias * David Politzer Engineering, and Medicine issued a report in January that outlines a roadmap for George Rathjens * Burton Richter converting or shutting down the remaining 74 research reactors worldwide * Richard J. Roberts * Phillip A. Sharp (including eight in the United States) that continue to use HEU. Over the past four * K. Barry Sharpless Stanley K. Sheinbaum * Robert M. Solow decades, more than 90 research reactors have been converted to LEU or * Jack Steinberger * Thomas A. Steitz shutdown. Given the urgency of preventing nuclear terrorism, we strongly * Joseph Stiglitz * Daniel Tsui recommend sufficient national and international technical and non-technical * Harold E. Varmus Frank von Hippel resources be devoted to addressing the remaining HEU-fuelled reactors over the Robert A. Weinberg * Steven Weinberg next decade. Also because more than a dozen of these reactors are operating in * Torsten N. Wiesel * Eric Wieschaus Russia, it is essential to reengage Russian technical experts and officials despite * Frank Wilczek * Ahmed Zewail the recent downturn in political relations.

Boards of Trustees and Experts * Nobel Laureate

Gilman Louie Rosina Bierbaum Stephen Hamblen Charles D. Ferguson Chair Vice Chair Secretary-Treasurer President

Alton Frye Robert Gard Lisa Gordon-Hagerty Martin Hellman Lawrence Krauss Martha Krebs Jan Lodal Rodney Nichols Scott Sagan Maxine Savitz Michael Telson Peter Thiel Valerie Thomas

Ex officio: Robert Solow and Frank von Hippel

Finally, we point to progress made by several governments and companies in developing commercially viable means of irradiation using techniques other than highly radioactive sources for blood treatment, cancer treatment, as well as medical and other scientific research. These highly radioactive sources include thousands of Curies (or more than 37,000 Gigabecquerels) of cesium-137 or cobalt-60 and would result in massive disruption and huge economic consequences if dispersed in a city. More concerted international work is needed to make commercially useful non-radioactive source alternative technologies that provide comparable benefits while eliminating the risk of radiological terrorism in this sector.

We urge you to devote the necessary resources to make further substantial progress in the coming years to real risk reduction in preventing nuclear and radiological terrorism.

Sincerely,

Dr. Burton Richter Dr. E. J. Corey Dr. Sheldon Lee Glashow Stanford Linear Harvard University Boston University and Accelerator Center 1990 Nobel Prize in Harvard University 1976 Nobel Prize in Chemistry 1979 Nobel Prize in Physics Physics Dr. Robert Curl, Jr. Dr. Peter Agre Rice University Dr. Paul Greengard Johns Hopkins Malaria 1996 Nobel Prize in The Rockefeller University Research Institute Chemistry 2000 Nobel Prize in Johns Hopkins Bloomberg Physiology or Medicine School of Public Health Dr. Johann Deisenhofer 2003 Nobel Prize in UT Southwestern Medical Dr. David Gross Chemistry Center Kavli Institute for 1988 Nobel Prize in Theoretical Physics, UC, Dr. Bruce Beutler Chemistry Santa Barbara UT Southwestern Medical 2004 Nobel Prize in Center Dr. Andrew Fire Physics 2011 Nobel Prize in Stanford University Physiology or Medicine 2006 Nobel Prize in Dr. Roger Guillemin Physiology or Medicine Salk Institute Dr. Martin Chalfie 1977 Nobel Prize in Columbia University Dr. Jerome Friedman Physiology or Medicine 2008 Nobel Prize in MIT Chemistry 1990 Nobel Prize in Dr. Leland Hartwell Physics Fred Hutchison Cancer Dr. Leon Cooper Research Center Brown University Dr. Walter Gilbert 2001 Nobel Prize in 1972 Nobel Prize in Harvard University Physiology or Medicine Physics 1980 Nobel Prize in Chemistry Dr. Dudley Herschbach Harvard University 1986 Nobel Prize in Chemistry

Dr. Roald Hoffmann Dr. Arno Penzias Dr. Jack Steinberger Cornell University New Enterprise Associates CERN 1981 Nobel Prize in 1978 Nobel Prize in 1988 Nobel Prize in Chemistry Physics Physics

Dr. Wolfgang Ketterle Dr. William Phillips Dr. Daniel C. Tsui MIT 1997 Nobel Prize in Princeton University 2001 Nobel Prize in Physics 1998 Nobel Prize in Physics Physics Dr. David Politzer Dr. Brian Kobilka California Institute of Dr. Steven Weinberg Stanford University School Technology University of Texas at of Medicine 2004 Nobel Prize in Austin 2012 Nobel Prize in Physics 1979 Nobel Prize in Chemistry Physics Dr. Richard J. Roberts Dr. John Mather New England Biolabs Dr. Torsten N. Wiesel NASA’s Goddard Space 1993 Nobel Prize in The Rockefeller University Flight Center Physiology or Medicine 1981 Nobel Prize in 2006 Nobel Prize in Physiology or Medicine Physics Dr. Brian Schmidt Australian National Dr. David Wineland Dr. Mario Molina University 2012 Nobel Prize in 1995 Nobel Prize in 2011 Nobel Prize in Physics Chemistry Physics

Dr. Ei-ichi Negishi Dr. George F. Smoot Purdue University Lawrence Berkeley 2010 Nobel Prize in National Laboratory Chemistry 2006 Nobel Prize in Physics