[en] This paper presents an overview of the US Nuclear Regulatory Commission's (NRC's) effort to complete an early review of the Canada deuterium uranium (CANDU)-3 reactor design prior to formal submittal of an application for standard design certification. The NRC is conducting a review of the CANDU-3 design in support of a request by AECL Technologics, the US sponsor of the design. The purpose of this review is to encourage early interactions by applicants, vendors, and government agencies with the NRC. The CANDU-3 design is being developed by Atomic Energy of Canada, Limited (AECL), whose CANDU operations are based in Mississauga, Ontario. AECL Technologies, a US subsidiary of AECL, Incorporated, informed the NRC of its intent to seek design certification of the CANDU-3 design under the provisions of 10CFR52 in a letter to the NRC dated May 25, 1989. This paper describes the commission's basis for this type of early review, its purposes and objectives, key elements of the review, the intended product, and the schedule