From the Overview: "Since the United States and Vietnam established diplomatic relations in 1995, the two countries have expanded relations and cooperation across a wide range of sectors. As U.S.-Vietnam bilateral economic, military, and diplomatic ties have grown, so has interest in strengthening cooperation in the nuclear energy sphere. A civilian nuclear cooperation agreement was initialed by the two countries in December 2013 and signed in May 2014 under Section 123 of the Atomic Energy Act of 1954 (as amended). Such '123 agreements' are necessary for the export of nuclear reactors and components and can help facilitate the transfer of nuclear energy technology. The U.S.-Vietnam 123 agreement is subject to congressional review. Congress received the agreement with the required supporting documents on May 8, 2014, for review. It will enter into force upon the 90th day of continuous session after its submittal to Congress (a period of 30 plus 60 days of review) unless a Joint Resolution disapproving the agreement is enacted. […] Vietnam also has nuclear cooperation agreements with Russia, France, China, South Korea, Japan, and Canada. The U.S. nuclear industry contends that billions of dollars of exports could result from the Vietnam 123 agreement. While it is unclear what, if any, contracts the U.S. nuclear industry would conclude with Vietnam's nuclear energy sector, it is likely that U.S. companies would provide services as part of a reactor supply agreement that Vietnam signed with Japan in 2010. Such services would not necessarily require a U.S. 123 agreement, but transfers might be facilitated if one were in place."
CRS Report for Congress, R43433