March 19, 2018 Andrew Weston-Dawkes Director, Office of Classification US Department of Energy Dear Dr. Weston-Dawkes: This is a proposal for declassification pursuant to 10 C.F.R. 1045.20 regarding information classified under the Atomic Energy Act. We request the declassification of the amount of the US inventory of Highly Enriched Uranium. As you know, the HEU inventory was last declassified by the Obama Administration in 2016, reflecting the total HEU inventory as of September 30, 2013. We are now requesting that this information be updated to the present, or at least to a more recent date. We believe the proposed declassification would provide appropriate transparency and would promote security: As the Obama White House stated in 2016 when it declassified the 2013 HEU inventory, "This type of information sharing, subject to respective national laws and procedures, is an important part of the effort to strengthen global nuclear security." We therefore request that the Department consider declassifying this information, as provided in 10 C.F.R. 1045.20. Thank you for your consideration. Steven Aftergood _____________________ Steven Aftergood Project on Government Secrecy Federation of American Scientists 1112 16th Street NW, Suite 400 Washington, DC 20036 email: saftergood@fas.org voice: (202)454-4691