Time for Uranium Waste: a New Radioactive Waste Category

Work on previously unquantified aspects of uranium waste is presented, including total burden, gamma fields intensification, connection to ecological safety thresholds, and inequitable distribution of uranium waste risks

Nuclear energy mobilizes uranium far beyond natural levels. While natural uranium deposits are geochemically stable, mill tailings (UMT), depleted uranium (DU), and spent fuel (SF) are chemically reactive, bioavailable, and more likely to contaminate water sources. Per ton of U-235 consumed in fission, 288 metric tons of uranium and 200,000 tons of UMT remain, requiring indefinite management. More than 99.5% of all uranium mined remains a perpetual environmental liability.

Traditionally, uranium is seen as inert due to the long half-lives of U-238 and U-235. However, it is highly chemo-toxic, with drinking water thresholds more constrained by toxicity than radiological risk, even compared to Ra-226. Its impact on freshwater biota is even more severe. Humanity has mined approximately 4.48 million metric tons of uranium, distributed as follows: 8.4% in SF, 19.4% in UMT, and 69.2% in DU. The remaining 3%—reprocessed and low-enriched uranium—is managed similarly to DU. While DU and SF are primarily uranium oxide, mill tailings contain 0.03% uranium and nearly 100% of the equilibrium radioactive progeny of all mined uranium. Real-world cases show groundwater contamination from uranium and its progeny will continue, especially from mill tailings. Over time, radioactive progeny will accumulate in SF and DU, making them prone to additional, similar contamination. Gamma fields from these uranium wastes will intensify, reaching levels tens to hundreds of times above background, posing direct exposure risks indefinitely.

Current uranium waste management is inadequate. Policies focus narrowly on radiological risks, ignoring uranium’s chemical toxicity, mobility in groundwater, and long-term ecological impact. DU and UMT are often treated as industrial byproducts rather than perpetual hazards. A new category, uranium waste, must be recognized, subject to strict containment policies, revised drinking water and ecological standards, and long-term environmental monitoring of dispersion and bioaccumulation.

In the 1970s, a scientific panel under President Jimmy Carter recommended that UMT be managed as strictly as high-level waste (HLW). Yet, for over four decades, their large volume has been used as justification for weaker containment. The premise that higher volume warrants weaker controls is flawed. The vast scale and accessibility of mill tailings make them an even greater cumulative hazard than HLW. With an estimated 3 billion metric tons of UMT spread across thousands of sites worldwide, far stricter management and global oversight are needed. This regulatory failure, unaddressed for 45 years, warrants dedicated sociological studies.

Countries managing only SF shift the larger risks of DU and UMT  to uranium-producing regions. Long-term safety must be seen as a shared responsibility. Currently, only 10% of humanity’s uranium waste burden is being addressed. Recognizing uranium waste as a specific category is essential. Beyond categorization, it must be managed with containment standards equivalent to HLW, independent global oversight, long-term ecological monitoring, and deeper engagement with environmental justice. Without these measures, humanity is setting the stage for irreversible and perpetual environmental and health crises.