Regulators Delay Decision on Nuclear Plant Probe California utility regulators are delaying a decision on whether to launch an investigation into the troubled San Onofre nuclear plant. The twin reactor plant between Los Angeles and San Diego has been shut down for nearly five months after the discovery of excessive wear on tubing that carries radioactive water. A Public Utility Commission meeting agenda shows the panel intended to consider an order Thursday to launch a probe into the shutdown and its possible impact on electricity rates for customers of Southern California Edison and San Diego Gas & Electric. Commission spokesman Christopher Chow said Wednesday that the proposal is not finished and is being postponed until Aug. 2.