My experience with staffing the DOE sites are that its similar to the commercial world in that you may gain access to one site but not others - each site kinda marches to their own drum beat. Good rule of thumb to go with is no felony convictions, no more than 1 dui in 5 yrs no more than 2 in 10. Multiple FFD's, and in some cases only 1 FFD, will normally keep ya out. Multiple drug and/or alcohol charges./convictions will sink ya also. It all comes down to the individual site you are trying to get to.
Eric