San Onofre

Unit 2 at the San Onofre nuclear power plant has been shut down for three weeks of maintenance work, Southern California Edison announced. No safety hazard is involved in the work, which consists of replacing shaft seals on the reactor’s four coolant pumps.

Edison spokesman David Barron said the repairs are routine and have been made frequently since Unit 2 opened in 1982.

Another of the plant’s three reactors is also out of commission while it is being refueled with uranium, a task performed every 12 to 15 months. It is expected to back in operation by the end of the year, Barron said.