Nuclear Regulatory Commission staff plans to request more information on Southern California Edison\u2019s proposal for a trial restart of San Onofre Nuclear Generating Station\u2019s unit 2. Staff advised Edison executives of that upcoming request and an expansion of their concerns during a packed public meeting Feb. 12 in Dana Point. Staff also noted regulators wouldn\u2019t be making a decision on the trial until the end of April \u201cat the earliest.\u201d Among the outstanding concerns raised are: -Whether installing new steam generators with a change in vibration bars constituted a \u201cdesign change\u201d without going through regulatory proceedings; -Edison\u2019s modification of stability ratios in its plans; -The lack of available information for benchmarking anti-vibration bars in the generators; and -Uncertainties of instability on modeling integrity margins. \u201cMore requests for additional information are to be issued shortly\u201d to San Onofre primary owner and operator, Edison, Art Howell, NRC team manager, said. Staff did not address concerns of several local government officials--including the mayor of San Diego--over the lack of an evacuation route if there is a malfunction and radioactive release at the plant. Federal regulators are responsible for health and safety issues, including emergency evacuations and earthquake preparedness. The California Public Utilities Commission is tasked with economic decisions on nuclear plants. The state commission is currently investigating whether ratepayers should continue paying for the non-working plant, as well as looking into operator Edison\u2019s management. Edison is requesting approval for a five-month trial to run unit 2 at 70 percent power, after which the utility, regulators, and the steam generator manufacturer are set to evaluate the plant\u2019s operation. If the nearly new steam generators at the 1,050 MW unit 2 did rupture during a trial start-up, Greg Werner NRC branch chief said a single tube would leak 400-500 gallons\/minute. A tube rupture in January 2012 in unit 3 caused a radioactive leak and subsequent facility shutdown. Edison has revealed no plans for a unit 3 restart. Steam generator tubing at both units has been plugged where it\u2019s shown excessive wear. Commission staff noted that of the nation\u2019s reactors, San Onofre\u2019s steam generators have the highest incidence of tube plugging. While Edison executives, including chief executive officer Ted Craver, remained silent in the front row of the meeting--with a crowd estimated at 1,000--union members employed at the plant made so much noise in support of a restart they were repeatedly cautioned by regulatory staff to quiet down. The majority of public speakers asked regulators to err on the side of health and safety and keep the plant closed. As well as a pending decision on the proposed restart, a nuclear commission board is considering a legal motion by Friends of the Earth for a retroactive evidentiary hearing on steam generator installation. The $670 million investment, according to the group, constituted a \u201cdesign change.\u201d Under commission process, that triggers a full adjudicatory-like hearing. In this case, it was not flagged as such, and there was no full, commissioner-led hearing. That motion awaits a decision.