Nuclear Regulation

In February 1993, the operator of the South Texas Project Electric Generating Station--a nuclear power plant--shut down its two reactors because of continuing malfunctions with a portion of the reactors' emergency equipment. The plant, located near Houston, Texas, was shut down for more than a year to correct these and other problems. The plant had a long history of problems in its design, construction, and operation. This report (1) discusses the circumstances surrounding the plant shutdown and the seriousness of the incident, (2) determines whether the Nuclear Regulatory Commission (NRC) was aware of problems at the plant before the shutdown, and (3) identifies factors that may have prevented NRC from having complete and timely information about the contractor's performance.

GAO found that: (1) malfunctioning pumps caused the South Texas licensee to shut down the plant's reactors and equipment outages increased the likelihood that the reactor's core would be damaged in an emergency; (2) NRC was aware of the problems with the emergency pumps and of maintenance work taking place on one of the reactor's generators before the shutdown, but did not realize that one reactor's pump and two of its generators were simultaneously inoperable for extended periods of time; (3) NRC relies on licensees to identify and report problems, since it rarely detects major problems before they do; (4) after NRC completed a comprehensive evaluation of the plant, it revised its overall assessment of the licensee's performance from good to poor and included the plant on its list of plants needing additional oversight; (5) NRC assessment of its inspection program at the plant showed that NRC did not adequately integrate information to determine whether the plant's problems indicated systemic weaknesses in the licensee's operations; and (6) these and other program weaknesses resulted in missed opportunities to inform the licensee about the extent of its performance problems.