Performance Assessment for the E-Area Low-Level Radioactive Waste Disposal Facility at the Savannah River Site: Chapter 3

Abstract

are the PA for the INTEC calcined solids storage facility at the Idaho National Laboratory site (DOE-ID, 2019) and the PA for Waste Management Area C at the Hanford site (Mehta et al., 2016). The PA evaluates the potential impacts of changes in performance of different features of the system and demonstrates that the safety functions represent multiple and redundant barriers. Barrier analyses, assuming a safety function is not present, also test the robustness of the system in the event of the loss of one or more safety functions. Such evaluations also support a qualitative illustration of the concept of defense-in-depth.The safety concept for closure of the ELLWF encompasses a variety of different features (i.e., administrative controls, natural site features, and engineered barriers) that reduce the potential impacts on human health and the environment from the residual waste that will remain after closure. These features can be represented as a collection of safety functions acting independently and as a system to provide for overall safety. In some applications, attempts are made to assign numerical expectations to specific safety functions, but that is not the intent in this case. The concept of safety functions is used more qualitatively in two ways for this PA: 1. To illustrate the robustness of the ELLWF design, operational practices, and closure approach by documenting features that are and are not credited in different modeling cases.