Evaluating Environmental, Health and Safety Impacts from Two Nuclear Fuel Cycles: A Comparative Analysis of Once-Through Uranium Use and Plutonium Recycle in Light Water Reactors
Smith, Bethany Lee
Prioritizing the finite resources available to advance research, development and demonstration of the nuclear industry requires a comprehensive evaluation of potential advanced nuclear technologies to inform decision making. A number of advanced nuclear technologies and fuel cycle options present promising improvements that are only realized when deployed and running at steady-state. However, an advanced nuclear fuel cycle will not be implemented all at once. Moreover, there is little work to understand how transitioning to new nuclear energy systems could affect waste management and human health, when compared to the presently deployed, once-through nuclear fuel cycle. A potential transition from the U.S. once-through nuclear fuel cycle to a modified-open nuclear fuel cycle has been modeled, using a phased approach, including reprocessing of both plutonium and uranium within a simplified dynamic energy demand scenario. Low-radioactivity waste generated and worker collective doses were estimated based on data from industry experience and then these metrics were compared to the baseline U.S. once-through nuclear fuel cycle. Overall observations regarding the comparison between the two nuclear fuel cycles were that worker collective doses were not significantly different but a significant amount of radioactive waste was avoided by using recycled uranium and plutonium from used nuclear fuel. Important outcomes of this work were that the once-through nuclear fuel cycle, as implemented in the U.S., is not as simple as depicted in textbooks and fuel cycle evaluations and must be updated to serve as an accurate baseline against which to measure performance of future potential advanced nuclear fuel cycles. It was also concluded that the two major contributions to occupational radiological impacts in the once-through nuclear fuel cycle, from uranium recovery operations through reactor operations, had reversed in recent years; this is different from historical data and conventional wisdom which says that impacts from the front-end of the once-through nuclear fuel cycle are dominant.