Engineered alternatives cost/benefit study. Draft report

The Waste Isolation Pilot Plant (WIPP) is a United States Department of Energy (DOE) project designed to demonstrate the safe disposal of Transuranic (TRU) waste in deep, geologic, bedded salt. The WIPP site is located in southeastern New Mexico. By law the WIPP site has been withdrawn from public use and has been set aside for use in the safe disposal of TRU waste. Also by law, disposal of TRU waste must comply with rules and regulations promulgated by the U.S. Environmental Protection Agency (EPA). The disposal system design consists of multiple barriers, both natural and man-made, located in a geologic salt deposit, 2,150 feet (655.3 meters) below ground. These barriers were selected because of their ability to permanently isolate the waste from the accessible environment as required to comply with subparts B and C of Title 40 Code of Federal Regulations Part 191 (40 CFR 191). As a part of the assurance requirements, 40 CFR section 191.14 requires that barriers of different types shall be used to isolate the waste. The WIPP design uses both a geologic (natural) and engineered barriers for waste isolation as specified by these regulations. However, to provide additional confidence in containment prediction calculations used to demonstrate compliance with the containment requirements, Engineered Alternatives (EA) could be used as additional assurance measures beyond those used to meet the containment requirements. This report uses the term EA to represent engineered barriers that are technically feasible processes, technologies, methods, repository designs, or waste from modifications which make a significant positive impact on the disposal system in terms of reducing uncertainty in performance calculations or improving long-term performance. These EAs, if used, function as barriers to the release of radioactive material