Categorical Exclusions (CXs) are “classes of actions that DOE has determined do not individually or cumulatively have a significant effect on the human environment” (10 CFR 1024.410(a)). Those classes of actions are listed in 10 CFR 1021 Appendices A and B.
If DOE has determined that applying a CX to the proposed action is appropriate, DOE may make a CX determination. The DOE NEPA regulations require that CX determinations under Appendix B are “documented and made available to the public by posting online, generally within two weeks of the determination” (10 CFR 1021.410(e)).