Intruder scenarios for site-specific low-level radioactive waste classification.

摘要

The US Department of Energy (DOE) has revised its low-level radioactive waste (LLW) management requirements and guidelines for waste generated at its facilities supporting defense missions. Specifically, draft DOE Order 5820.2A, Chapter 3 describes the purpose, policy, and requirements necessary for the management of defense LLW. The draft DOE policy calls for LLW operations to be managed to protect the health and safety of the public, preserve the environment, and ensure that no remedial action will be necessary after termination of operations. The basic approach used by DOE is to establish overall performance objectives, in terms of groundwater protection and public radiation dose limits, and to require site-specific performance assessments to determine compliance. As a result of these performance assessments, each site will develop waste acceptance criteria that define the allowable quantities and concentrations of specific radioisotopes. Additional limitations on waste disposal design, waste form, and waste treatment will also be developed on a site-specific basis. As a key step in the site-specific performance assessments, an evaluation must be conducted of potential radiation doses to intruders who may inadvertently move onto a closed DOE LLW disposal site after loss of institutional controls. This report (1) describes the types of intruder scenarios that should be considered when performing this step of the site-specific performance assessment, (2) provides the results of generic calculations performed using unit concentrations of various radionuclides as a comparison of the magnitude of importance of the various intruder scenarios, and (3) shows the relationship between the generic doses and waste classification limits for defense wastes.