Across the Pacific, a concrete dome on a remote atoll is cracking under the pressure of rising seas, while in Washington State, aging underground tanks are leaking radioactive waste into the soil. These are not hypothetical risks. They are active, documented failures in America’s nuclear waste infrastructure, and climate change is accelerating the timeline for each one.
The Cracking Dome on Enewetak Atoll
On Runit Island in the Marshall Islands, a massive concrete cap built in 1979 sits atop tens of thousands of cubic yards of radioactive debris from dozens of Cold War-era nuclear weapons tests. Known informally as the “nuclear coffin,” the Runit Dome was never designed as a permanent fix. The structure was poured directly over contaminated soil and coral without a concrete floor, meaning the lagoon water beneath it has always been in contact with the waste. As earlier reporting has highlighted, the dome houses tons of radioactive debris and has already shown signs of degradation, raising concerns among island residents and nuclear experts alike about its long-term stability in a warming ocean.
Some patching of the concrete has taken place over the years, but according to researchers at the Woods Hole Oceanographic Institution, those repairs are not a long-term solution and do not change the fact that contaminated material is in contact with groundwater. Increased seawater inundation over time threatens the structure’s integrity and could accelerate the movement of radionuclides into the surrounding lagoon. A 2024 Department of Energy congressional report modeled storm scenarios for both 2015 and 2090 conditions, estimating changes in radiological doses from contamination under the assumption that the dome remains intact. That assumption itself is the problem: if the dome does not hold, the modeling baseline collapses, and the contamination pathway into Pacific waters widens significantly. No publicly available DOE assessment since 2020 has confirmed real-time structural monitoring of the dome, a gap that limits confidence in any forward-looking projection and leaves island communities with more questions than answers.
Hanford’s 54 Million Gallons of Aging Waste
The Runit Dome may be the most visible symbol of neglected nuclear waste, but the largest active cleanup challenge sits along the Columbia River in southeastern Washington. The Hanford Site stores approximately 54 million gallons of radioactive waste in underground tanks, many of them single-shell designs built decades ago, according to a recent Government Accountability Office report. That report found that the Department of Energy has not fully evaluated the effects of different treatment and tank-management options, leaving a cleanup effort that has stretched across decades without a clear finish line and with escalating projected costs. GAO analysts concluded that without a comprehensive comparison of alternatives, DOE risks locking itself into technically complex strategies that may be difficult to adapt as conditions at the site change.
Two of Hanford’s tanks, B-109 and T-111, are already leaking. The Washington State Department of Ecology and DOE negotiated a legally binding order to address the problem, including estimated annual leak rates, tank inventories in gallons, and the proportion of contents that remain liquid, all outlined in the state regulator’s enforcement notice. The order requires surface barriers, enhanced monitoring, and contingency planning to limit the spread of contamination toward groundwater. On DOE’s side, the Hanford Site portal for Tank B-109 provides attributed estimates of daily leakage rates and the expected travel time for contaminants to reach the water table, underscoring how slowly migrating but persistent plumes can threaten the Columbia River over decades. A separate GAO audit, designated GAO-15-40, found that inspections had revealed tank conditions worse than previously assumed, including active leakage and rainwater intrusion in single-shell tanks and a primary-shell leak in the AY-102 double-shell tank. Workers have emptied 21 large underground tanks so far, but the volume that remains dwarfs what has been removed, and each additional year of delay increases the odds that more tanks will fail.
When Containment Fails: WIPP and Monticello
The risk at Hanford is not theoretical. The United States has already experienced what happens when nuclear waste containment systems break down at other sites. On February 14, 2014, a confirmed radiological release occurred at the Waste Isolation Pilot Plant (WIPP) in New Mexico, the country’s only deep geological repository for transuranic defense waste. The release exposed underground workers to airborne contamination, and subsequent bioassay testing produced measurable positive results among monitored personnel, according to the Department of Energy’s accident investigation. Investigators traced the event to a breached waste drum, identifying issues with waste packaging, procedural controls, and oversight. The facility’s recovery required extensive decontamination, redesign of ventilation systems, and multi-year operational restrictions that sharply reduced the nation’s capacity to dispose of legacy defense waste.
Federal regulators conducted their own independent review of the WIPP incident. The Environmental Protection Agency compiled inspection findings, confirmatory dose calculations, and data verification records in an online event summary, concluding that public exposures remained below regulatory limits but emphasizing the need for strengthened quality assurance and monitoring. The WIPP experience shows that even facilities designed as final repositories can experience unanticipated failures when waste forms, engineering assumptions, and human performance interact in complex ways. Climate change adds yet another variable, as increased storm intensity, flooding, and heat stress can strain ventilation systems, surface infrastructure, and emergency response capacity at similar sites across the country.
Groundwater Lessons from Monticello
Commercial nuclear plants face parallel challenges in keeping radioactive materials out of groundwater and surface waters. At the Monticello Nuclear Generating Plant in Minnesota, a significant tritium-contaminated groundwater event triggered Nuclear Regulatory Commission notification pathways and state-level scrutiny. The NRC has published a detailed chronology of how and when the contamination was detected, how plant operators characterized the extent of the plume, and what corrective actions were taken to repair leaking systems and recover tritium from affected soils. The agency’s narrative describes a combination of onsite monitoring wells, offsite sampling, and public communication steps, illustrating how even low-energy radionuclides like tritium can travel with groundwater and raise public concern when they appear beyond plant boundaries.
Monticello’s more recent operating history underscores how ongoing events continue to test regulatory oversight. On May 23, 2023, the NRC logged a separate occurrence in its daily event reporting system, documenting a plant issue that met federal reporting criteria and summarizing the licensee’s initial response in the official event record. While the specific technical details differ from the tritium release, the pattern is familiar: a complex facility experiences an equipment or monitoring problem, operators report to regulators, and a combination of plant procedures and NRC oversight determines whether the issue remains a near miss or becomes a more serious incident. As climate-driven flooding, intense rainfall, and river-level swings become more common, the hydraulic pathways that carry contaminants from plant systems into groundwater will grow more dynamic, making early detection and robust maintenance even more critical.
Climate Pressure and the Need for Long-Term Stewardship
From a cracking dome in the Marshall Islands to leaking tanks at Hanford, a breached drum at WIPP, and groundwater contamination at Monticello, the pattern is consistent: nuclear waste systems that were designed for a past climate and past assumptions are being asked to perform indefinitely in a world that is hotter, wetter, and more volatile. Rising seas threaten coastal and island facilities, while more extreme precipitation and river flows increase the risk that buried infrastructure will be inundated or undermined. Many of these sites were originally engineered with time horizons measured in decades, not centuries, and with an expectation that future technologies or political decisions would eventually remove or repackage the waste. Instead, communities living near these sites are confronting the reality that “temporary” solutions have become de facto permanent features of their landscapes.
Long-term stewardship under climate stress will require more than patching concrete and updating monitoring plans. It means revisiting fundamental design assumptions, investing in real-time structural and environmental monitoring, and ensuring that affected communities have access to transparent information about risks and response options. Independent reviews by organizations such as the Government Accountability Office, technical analyses from research institutions like Woods Hole, and detailed regulatory records from agencies including DOE, EPA, and NRC provide critical pieces of the picture, but they do not, by themselves, guarantee safety. Without sustained funding, enforceable cleanup milestones, and a willingness to confront the full lifecycle costs of nuclear activities, the United States risks allowing aging containment systems to fail in ways that are both predictable and preventable. The cracks in the concrete and the leaks in the soil are early warnings; whether they become precursors to larger disasters depends on how quickly policymakers act on the evidence already in hand.
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*This article was researched with the help of AI, with human editors creating the final content.
