HARRISBURG — Gov. Ed Rendell said it is "totally unacceptable" state officials heard about a radiation leak at the Three Mile Island nuclear power plant five hours after it was detected.

Rendell said Tuesday he spoke to Exelon Chairman John Rowe about Saturday's accident, and Rowe agreed with him.

The accident at the central Pennsylvania plant exposed employees to small amounts of radiation.

Government regulators said the accident was so minor it didn't trigger a federally required report to state authorities.

It happened during major maintenance work.

Plant officials said ventilation fans in the reactor building unexpectedly blew radioactive dust out of a reactor cooling system pipe that had been cut open.

A spokeswoman said plant officials will speak with state officials to see where improvements can be made.