SAN LUIS OBISPO (AP) — California officials and the operator of the Diablo Canyon nuclear power plant are mulling whether the plant will spend up to $12 billion to redesign its cooling system, blamed for sucking in fish larvae and disrupting the marine ecosystem.The San Luis Obispo Tribune reported that a review committee will take up the issue Monday and make final recommendations to the state in December.One option includes digging up the hills north of the plant to make room for 600-foot-tall cooling towers, with an estimated cost of $8 million to $12 billion. Some people have opposed the plan, fearing the giant towers would be an eyesore.Plant manager Pacific Gas and Electric Co. has until 2024 to make changes as part of a state effort requiring more than a dozen coastal power plants to reduce the damage caused by once-through cooling systems.PG&E has said costs would be passed on to ratepayers.The Diablo Canyon plant filters an estimated 2.5 billion gallons of ocean water through its cooling system every day. The water then gets dumped back into the ocean 20 degrees warmer.