This is the twenty-eighth edition of Reference Data Series No.2, which presents the most recent reactor data available to the IAEA. It contains summarized information as of the end of 2007 on: power reactors operating, under construction, and shut down; and performance data on reactors operating in the IAEA Member States, as reported to the IAEA. The information is collected through designated national correspondents in the member States and the data are used to maintain the IAEA's Power Reactor Information System (PRIS).