Section 1021.400 - Level of NEPA review(a) This subpart identifies DOE actions that normally:(1) Do not require preparation of either an EIS or an EA (are categorically excluded from preparation of either document) (appendices A and B to this subpart D);(2) Require preparation of an EA, but not necessarily an EIS (appendix C to this subpart D); or(3) Require preparation of an EIS (appendix D to this subpart D).(b) Any completed, valid NEPA review does not have to be repeated, and no completed NEPA documents need to be redone by reasons of these regulations, except as provided in § 1021.314 .(c) If a DOE proposal is encompassed within a class of actions listed in the appendices to this subpart D, DOE shall proceed with the level of NEPA review indicated for that class of actions, unless there are extraordinary circumstances related to the specific proposal that may affect the significance of the environmental effects of the proposal.(d) If a DOE proposal is not encompassed within the classes of actions listed in the appendices to this subpart D, or if there are extraordinary circumstances related to the proposal that may affect the significance of the environmental effects of the proposal, DOE shall either:(1) Prepare an EA and, on the basis of that EA, determine whether to prepare an EIS or a FONSI; or(2) Prepare an EIS and ROD.