The Elephant’s Foot stands as a stark reminder of the 1986 Chernobyl nuclear disaster, embodying the immense destructive power unleashed during the catastrophic event. This iconic formation symbolizes the enduring legacy of the world’s worst nuclear accident.
What is the Elephant’s Foot?
The Elephant’s Foot is a solid mass of corium, a material formed during a nuclear meltdown. Corium results when nuclear fuel and parts of a reactor’s core structures overheat and melt together. Its composition includes melted nuclear fuel, concrete, sand, steel, and other structural materials from the Chernobyl reactor.
Discovered in December 1986, months after the accident, the Elephant’s Foot is located in a maintenance corridor beneath the damaged Reactor No. 4. It earned its nickname due to its dark, wrinkled appearance and large size, resembling the foot of an elephant. This solidified “lava” flowed through pipes and fissures, melting through reinforced concrete, before cooling and hardening into its current form.
Its Initial Extreme Heat
Immediately following the Chernobyl disaster, the Elephant’s Foot reached extremely high temperatures. Initial estimates suggested temperatures could have exceeded 2,000 degrees Celsius (3,632 degrees Fahrenheit) due to intense nuclear fission reactions and subsequent decay heat from highly radioactive materials. Some components within the corium, like uranium oxide, were capable of generating temperatures up to 2,000 degrees Celsius through nuclear fission alone.
The molten corium remained above 1,660 degrees Celsius (3,020 degrees Fahrenheit) for at least four days after its formation. Directly measuring these extreme temperatures at the time posed significant challenges for researchers. Estimations were primarily made based on the melting points of the materials involved and the observed destructive power of the molten mass, which included burning through steel and concrete.
Current Temperature and Ongoing Heat
While significantly cooler than its initial state, the Elephant’s Foot continues to generate heat from the ongoing radioactive decay of its constituent isotopes. Over time, the short-lived radioactive isotopes responsible for much of the initial heat have largely decayed. However, longer-lived isotopes still present within the corium contribute to a sustained, albeit diminished, heat output.
Currently, the Elephant’s Foot’s surface is often described as warm, typically around room temperature or slightly above ambient conditions. Its internal temperature is estimated to be a few hundred degrees, well below any melting point. This remaining warmth is enough to be detectable but does not cause it to glow. Monitoring efforts track its temperature and the long-term implications for the stability of surrounding structures.
Understanding Its Danger
The primary danger posed by the Elephant’s Foot is its extreme radioactivity, rather than its current temperature. It emits lethal levels of radiation, particularly gamma radiation, making even brief exposure highly hazardous. At the time of its discovery, radioactivity near the Elephant’s Foot was approximately 8,000 to 10,000 roentgens per hour.
Exposure to such levels could deliver a lethal dose of radiation within minutes; for instance, five minutes of proximity would result in death within two days. Even after decades, the radiation levels remain dangerous, requiring continuous monitoring and containment efforts. Historical attempts to photograph and study the Elephant’s Foot necessitated stringent protective measures and extremely short exposure times due to the intense radiation. While its heat has substantially diminished, its radioactivity remains a significant and lasting threat.