In a letter, she requested documentation on design changes made to the generators in 2009 and 2010. She wants to know whether Southern California Edison sidestepped any federal requirements, as one environmental group claims.
This comes as a 13-page report released Tuesday by Friends of the Earth showed running the reactors at reduced power could worsen pre-existing damage at the plant. They also said doing so would raise safety issues.
The group does not believe Southern California Edison's plan will solve the problems with badly worn tubing as engineers suggest. Earlier this month the company announced a tentative plan to restart and run the seaside reactors at lower power, at least for several months, because engineers believe that will ease vibration that could be causing unusual wear in the tubes.
The twin reactors have been offline for months. There is no date for a restart.
The Associated Press contributed to this report.