"Negotiated by the Reagan Administration nearly 30 years ago, the current U.S. peaceful nuclear cooperation agreement with the People's Republic of China (PRC) is set to expire on December 30, 2015. President Obama submitted a new 30-year U.S.-China nuclear cooperation agreement for congressional review on April 21, 2015. Among other provisions, the agreement would allow for uranium enrichment up to a level less than 20% U-235 and Chinese reprocessing of U.S.-obligated material at safeguarded facilities. The required congressional review period ended on July 31. Such agreements are often called '123 agreements' because they are required by Section 123 of the Atomic Energy Act of 1954, as amended (P.L. 95-242). They are a prerequisite for any significant nuclear cooperation with another country, such as exports of nuclear power plants and components and the transfer of nuclear material. Since the original agreement was concluded before China was a member of the Nuclear Nonproliferation Treaty (NPT), some changes to the text were required. The recently submitted renewal agreement complies with the relevant provisions of the Atomic Energy Act and therefore was subject to a review period totaling 90 days of continuous session. If no resolution of disapproval is passed into law before that deadline, then the agreement may enter into force. No resolution of disapproval was passed."
CRS Report for Congress, RL33192
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html