I found this from Court House News. It looks like it's just business as usual, an extension of an executive order in place under Clinton:
President Barack Obama extended an executive order protecting the assets of the Russian Federation used in a program to stabilize the security of nuclear material. The provisions are extended for a year.
The original order was signed by former President Bill Clinton in 2000 to protect payments the U.S. made to the Russian Federation under the Agreement Between the Government of the United States of America and the Government of the Russian Federation Concerning the Disposition of Highly Enriched Uranium Extracted from Nuclear Weapons, commonly called the HEU Agreements. Read more
This executive order was posted yesterday. It hasn't been covered by any mainstream media -- yet.
BLOCKING PROPERTY OF THE GOVERNMENT OF THE RUSSIAN FEDERATION RELATING TO THE DISPOSITION OF HIGHLY ENRICHED URANIUM EXTRACTED FROM NUCLEAR WEAPONS
By the authority vested in me as President by the Constitution and the laws of the United States of America, including the International Emergency Economic Powers Act (50 U.S.C. 1701 et seq.) (IEEPA), the National Emergencies Act (50 U.S.C. 1601 et seq.) (NEA), and section 301 of title 3, United States Code,
I, BARACK OBAMA, President of the United States of America, in view of the policies underlying Executive Order 12938 of November 14, 1994, and Executive Order 13085 of May 26, 1998, and the restrictions put in place pursuant to Executive Order 13159 of June 21, 2000, find that the risk of nuclear proliferation created by the accumulation of a large volume of weapons-usable fissile material in the territory of the Russian Federation continues to constitute an unusual and extraordinary threat to the national security and foreign policy of the United States, and hereby declare a national emergency to deal with that threat. I hereby order:
Section 1. A major national security goal of the United States is to ensure that fissile material removed from Russian nuclear weapons pursuant to various arms control and disarmament agreements is dedicated to peaceful uses, subject to transparency measures, and protected from diversion to activities of proliferation concern. As reflected in Executive Order 13085, the full implementation of the Agreement Between the Government of the United States of America and the Government of the Russian Federation Concerning the Disposition of Highly Enriched Uranium Extracted from Nuclear Weapons, dated February 18, 1993, and related contracts and agreements (collectively, the "HEU Agreements") is essential to the attainment of this goal. The HEU Agreements provide for the conversion of approximately 500 metric tons of highly enriched uranium contained in Russian nuclear weapons into low-enriched uranium for use as fuel in commercial nuclear reactors. In furtherance of our national security goals, all heads of departments and agencies of the United States Government shall continue to take all appropriate measures within their authority to further the full implementation of the HEU Agreements. Read the rest