Good luck with your search.
Currently, I don't think Diablo Canyon (PG&E) or SONGs (Edison) is hiring for security right now though if you can find a contact number for their HR department, I am sure you would get a more definitive answer. I believe the White Stone Group is out of Ohio if I read correctly. I am not certain on their reputation either. Their website is:
http://www.whitestonegroup.us/index.htmI am not fond of the idea of moving across the country for a job, however if I had to choose the east coast, PA is at the top of my list for relocation. Especially since Exelon is supposed to be one of if not the biggest companies. (They recently canned Wackenhut and implemented their own security team.)
I am shooting for something on the West Coast to Mid West, however San Luis Obispo is really expensive for a new hire's budget without dual income, but from reading the forums it seems to be one of the best places to work in this field due to management treating their employees great. SONGs to me would be a little more affordable but I would most likely have a 45 minute drive to and from work if I moved to San Diego County (hour and a half from where I am now).
Here is the website for PG&E:
http://www.pge.com/ In the last couple months PG&E had 1 spot for something called Temporary Zebra Security Officer... I'm guessing that is what they called their Nuclear Security Officers.
I am still on the search for positions and researching what I can. The security jobs are very mysterious and not a lot of information is shared on google. To me, this is the best place to look for and find information on jobs in the industry. I have been lurking around trying to learn all I can.
The reason for me wanting to stick with a company with their own security team is job security.
Best of luck!