Welcome....
First, you have to get offered a job at a commercial nuke, then your hiring company will have you submit the forms to start your security clearance, whether direct hire or contractor. Most contractor companies want you to already have your unescorted access (or at least less than 1 year since you had one) before they submit you for acceptance at the utility.
You don't do it the other way around (get cleared, then find work). It's an expensive and time-consuming process.
Good luck with the job search.....