A Systematic Approach to the Evaluation of RCRA Disposal Facilities under Future Climate-induced Events

Abstract

The Department of Energy (DOE) is responsible for the cleanup of nuclear waste at former nuclear weapons sites across the United States. Cleanup activities of particular interest include the containment of waste in near surface disposal facilities. There is a need to build confidence in the predictive nature of long-term cover performance models, particularly when considering long-term impacts from climate change. This research aimed to develop an approach to assessing long-term performance of near surface disposal facilities under climate change impacts. This was accomplished by: (1) defining a methodology using historical precipitation and temperature data; (2) using a Monte Carlo approach to assess performance based on past events; (3) performing a proof of concept application; and (4) developing and assessing future climate change scenarios relative to percolation thresholds. From this research, it was determined that the HELP model is a useful tool to assess the hydrological performance of near surface disposal facilities in humid climates when degradation of designs is considered by modifying various hydraulic inputs. In addition, changes in both precipitation and temperature have been found to influence landfill cover performance; in many cases, the potential negative effects of additional precipitation on landfill cover performance can be offset by warmer temperatures. These developments and findings can have meaningful implications on future regulatory policies and guidelines when considering naturally occurring climatic change and anthropogenic forcing.