Southern California Edison reported to federal regulators Jan. 31 a potentially radioactive coolant leak at the San Onofre Nuclear Generating Station. The nuclear power plant\u2019s unit 3 was manually shut down after a leak was discovered in the steam generator. The 82 gal\/day leak was increasing, according to a Nuclear Regulatory Commission report. The \u201csteam generator tube rupture\u201d did not affect unit 2, which is currently shut down for refueling. The leak was staunched Feb 1, according to commission spokesperson Lara Uselding. Once that was done, she said, airborne radiation was \u201cnot an issue.\u201d \u201cSensitive monitoring instruments at unit 3 continue to show no change in radiation levels that would be detectable off-site,\u201d the utility reported Feb. 1. The steam generator at unit 3 went online a year ago--February 2011. California ratepayers are paying $670 million for that steam generator installation and another put in the year prior at unit 2. Uselding would not comment on the newness of the steam generator. She did say that federal inspectors are checking into the equipment. Edison is also pursuing another $9 million in turbine work on the plant. That investment is also subject to a utility rate of return of up to 11.5 percent. The investment was controversial at the California Public Utilities Commission 2005-2008. Prior to the nuclear meltdowns at Fukushima Daiichi in March 2011, Edison publicly stated it would file for a 20-year license extension for the facility. While it has not dismissed a future application for license extension, the idea was \u201cput on the back burner,\u201d according to a company executive, after the Japanese disaster.