A comparative evaluation of vitrification and emerging waste treatment technologies for U.S. department of energy tank waste

Abstract

The United States Department of Energy (DOE) manages millions of gallons of legacy radioactive tank waste generated during nuclear weapons production. Long-term treatment and immobilization of this waste remain among the most technically complex and financially substantial environmental challenges within the DOE complex. Although solidifying waste into glass, also known as vitrification, is widely implemented at sites such as the Hanford Site in Washington state, alternative technologies such as grouting and fluidized bed steam reforming have been deployed or evaluated at other facilities, creating variability in technology selection strategies across sites. However, a comprehensive comparative evaluation of these approaches under consistent decision criteria remains limited. Therefore, my study evaluates DOE tank-waste treatment technologies through structured case analysis of selected DOE sites at Hanford, Idaho National Laboratory in Idaho, and the Savannah River site in South Carolina. I examined regulatory frameworks, waste composition characteristics, performance assessment modeling, lifecycle cost considerations, and long-term stewardship requirements to assess how these factors influence technology selection. Publicly available technical reports, environmental impact statements, and site-specific planning documents were reviewed to identify key decision drivers and performance outcomes. My analysis indicates that vitrification provides superior long-term waste form durability and regulatory defensibility for high-activity waste streams, but it involves substantial capital investment and schedule risk. Grouting and reforming technologies may offer cost and operational advantages for certain low-activity or supplemental waste streams, but present limitations related to long-term performance uncertainty and disposal pathway constraints. Technology selection across DOE sites is strongly influenced by site-specific regulatory agreements, infrastructure maturity, and risk tolerance. My findings support a strategic, risk-informed approach to technology selection that aligns waste characteristics, regulatory commitments, and lifecycle cost considerations. I provide recommendations to enhance decision transparency and improve alignment between technical performance objectives and long-term environmental stewardship responsibilities.