Can a ex-felon work at a nuke plant?

There are only two conditions in which you're an ex-felon:

• You were convicted of something which was only a felony under state law, and not under federal law, and have since applied for and have received relief of disability.
• You were convicted of a felony, and the convicted was later overturned, meaning you're no longer a felon.

If you've been convicted of a felony, and neither of the above apply to you, then you are not an ex-felon - you are a felon, and will be for life. A job at a nuclear power plant is not an option.