Building near the coast is pretty useful to get access to seawater for cooling. You could build near the coast and not near known faults, but that doesn't prevent faults from being discovered later as happened to Diablo Canyon.
But discharging that heat directly into seawater adversely affects sea life. This is what causes bleaching death of corals in warmer waters.
The environmental impact studies alone would likely take years, especially because Mothers For Peace, the Surfrider Foundation, the local Chumash band, and every other group under the sun would tarpit the project. They hate nuclear like Everytown hates guns, and no amount of logic will change their minds.
FWIW, I think the damage is done and DCPP shouldn't need to put in cooling towers — the output cove has different sea life than the ocean just a bit beyond it and has for decades. However, I don't make the rules.