Following the decision earlier this month to partially shut down its San Onofre nuclear plant, Edison International (NYSE:EIX) announced Wednesday that it will be laying off 600 non-union workers at the plant this summer.

By next year, the station will have laid off a total of 1,100 employees, dropping its workforce at the San Onofre plant to just 400 as decommissioning continues, the company said.

Per regulatory policy, Edison International's Southern California Edison (SCE) subsidiary has notified non-union workers that they will be let go in about two months' time. For unionized workers, the utility will be working with union groups to develop transition plans.

"The premature shutdown of San Onofre is very unfortunate," said SCE's Senior Vice President and Chief Nuclear Officer Pete Dietrich in a statement. "We have an extraordinary team of men and women. We appreciate their years of dedicated service and will continue to extend to them the utmost respect and consideration."