LOS ANGELES (AP) — Costs tied to the long-running shutdown of California’s San Onofre nuclear power plant have soared to $553 million, while the majority owner raised the possibility Tuesday of retiring the plant if it can’t get one reactor running later this year.

The twin-domed plant between San Diego and Los Angeles has not produced electricity since January 2012, when a tiny radiation leak led to the discovery of unusual damage to hundreds of tubes that carry radioactive water.