Title: PACKAGING OF RADIOACTIVE WASTES FOR GEOLOGIC DISPOSAL

The agency has recently published environmental standards addressing disposal of high-level radioactive wastes (40 CFR Part 191) for public review and comment (47 FR 58196). An important part of this effort is the evaluation of how effective mined geologic repositories are for isolating these wastes from the environment for many thousands of years. This technical report presents the methodology used to assess the potential annual individual doses and human exposure and geologic media contamination probabilities from projected releases of radioisotopes from a geologic repository. It describes the models that the Agency employed for this analysis and reviews the various assumptionsmore » which were made. Since this analysis is necessarily generic in nature, the methodology uses very general models of environmental pathways and considers a range of values for the various parameters used in the models.« less

The technical report presents the methodology used to assess the potential annual individual doses and human exposure and geologic media contamination probabilities from projected releases of radioisotopes from a geologic repository. It describes the models that the Environmental Protection Agency employed for this analysis and review the various assumptions which were made. Since this analysis is necessarily generic in nature, the methodology uses very general models of environmental pathways and considers a range of values for the various parameters used in the models.

This technical report presents these assessments of long-term repository performance. It describes the models that the Agency developed specifically for this project, reviews the various assumptions made, and identifies the data used in these models. In general a relatively simple analytical methodology was formulated that should tend to overestimate the long-term risks from geologic repositories. Because much of this methodology is new, and because these risk assessments are a key part of our rulemaking, the Agency is publishing this as a draft report. During the public comment period on 40 CFR 191, a Subcommittee of the Agency's Science Advisory Boardmore » will conduct an independent technical review of our risk assessments (48 FR 509). All meetings of this Subcommittee will be announced in the Federal Register and will be open to the public.« less

This report discusses the different technical issues that must be considered in developing an environmental standard for geologic disposal of high-level radioactive wastes. These issues include: (1) defining acceptable risk; (2) specifying acceptable risk in the standard; (3) formulating the standard so that reasonable demonstrations of compliance can be obtained; (4) applying the standard to protection of individuals or the population; (5) applying the standard to expected occurrences only or to unexpected processes as well; (6) determining a time limit for the standard; and (7) specifying conditions to be assumed for demonstrating compliance. It is concluded that many issues aremore » not resolvable on technical grounds alone, but that an effective standard will allow flexibility and the exercise of subjective scientific judgments in reaching licensing decisions.« less