[en] This work plan establishes the operable unit setting and the objectives, approach, tasks, and schedule for conducting the Resource Conservation Recovery Act facility investigation/corrective measure study (RFI/CMS) for the 100-DR-2 Operable Unit in the 100 Area of the Hanford Site. This work plan is intended to cover the entire RFI/CMS program, but it is focused on limited field investigation (LFI) activities. The 100 Area is one of four areas at the Hanford Site that are on the U.S. Environmental Protection Agency's (EPA) National Priorities List under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980. The 100-DR-2 Operable Unit is one of two remaining source operable units in the 100 D/DR Area. Source operable units are those that contain facilities and unplanned release sites that are potential sources of hazardous substance contamination. In order to more efficiently manage the environmental restoration of the 100 D/DR Area, 100-DR-3 was incorporated into 100-DR-2. The 100-DR-2 contains liquid, sludge, and solid waste units that were used to support the operation of the DR Reactor. The 100-DR-3 mainly consists of solid waste burial grounds, which are presently on the interim remedial measure (IRM) pathway. The approach described in this work plan is based on the Hanford Past-Practice Strategy. This strategy streamlines the past-practice remedial action process with a bias for action through optimizing the use of interim actions. This approach culminates with decisions of final remedies on both an operable unit and 100 Area scale. The pathway selected during the scoping process for the high-priority liquid waste sites and solid waste burial grounds in the 100-DR-2 Operable Unit is the IRM pathway