The state and future of nuclear waste

What this episode covers

Dr. Jen Shafer, a former ARPA-E director and professor at the Colorado School of Mines, explains the composition of spent nuclear fuel, noting that 95% is unreacted uranium dioxide while the remaining 5% contains long-lived actinides and fission products. She details the current US strategy of storing 90,000 metric tons of waste in spent fuel pools and dry casks at reactor sites, as the Yucca Mountain repository remains stalled. Shafer contrasts the waste handling challenges of different reactor types, highlighting that ceramic fuels like TRISO are stable, whereas metallic or molten salt fuels require complex conditioning or recycling. Finally, she discusses the 'take-back' model for microreactors and the political and social hurdles to establishing new centralized geological repositories.