Technicians have found and fixed two holes in an underground pipe that were allowing radioactive tritium to flow into the groundwater at the Vermont Yankee nuclear reactor, the plant’s owner, Entergy, said Thursday.

The leak did not contaminate any drinking water, but it did cause a political uproar in Vermont; the State Senate overwhelmingly approved a measure last month that will force the plant to shut in 2012.

Reversal is possible, but sentiment in Vermont is running firmly against the plant, which is in Vernon, near the Massachusetts border, because Entergy executives had assured state officials who asked about the potential for underground leaks that it had no pipes that could do so.

The source of the leak has been clear for weeks, and the company gave daily updates during the two and a half months of repair work. The Vermont Department of Health has also issued frequent updates.