Comprehensive WM/ER/D and D/LTS Risk Model for the INEEL

The Idaho National Engineering and Environmental Laboratory (INEEL) is investigating the development of a comprehensive and quantitative risk model framework for environmental management activities at the site. Included are waste management programs (high-level waste, transuranic waste, low-level waste, mixed low-level waste, spent nuclear fuel, and special nuclear materials), major environmental restoration efforts, major decontamination and decommissioning projects, and planned long-term stewardship activities. Also, program risks cover all activities up through final disposition, including storage, handling, treatment, transportation, and disposal. Types of risks addressed include environmental cleanup costs (from accidental releases of radionuclides or chemicals), fatalities from radiological or chemical exposures, and fatalities from standard industrial accidents. Risks are estimated for workers, other site personnel, and the public. Unlike environmental impact statements, safety analysis reports, and performance assessment risk evaluations, the risk model framework being investigated is planned to result in best estimates for environment, safety, and health risks. Two basic types of risk estimates are included: risks from environmental management activities, and long-term legacy (no action) risks from wastes/materials. Both types of risks are estimated using the Environment, Safety, and Health Risk Assessment Program (ESHRAP) developed at the INEEL. Given these two types of risk calculations, the following evaluations can be performed: risk evaluation of an entire program (covering waste/material as it now exists through disposal or other end states); risk comparisons of alternative programs or activities; comparisons of risk benefit versus risk cost for activities or entire programs; ranking of programs or activities by risk; ranking of wastes/materials by risk; evaluation of site risk changes with time as activities progress; and integrated performance measurement using indicators such as injury/death and exposure rates. Final development of the ESHRAP code and the INEEL risk model is expected to be complete in 2002