The “Elephant’s Foot” is a notorious mass formed during the 1986 Chernobyl disaster. It is a highly radioactive corium formation, a lava-like material created from the melted reactor core. This substance symbolizes the immense destructive power unleashed by the accident and highlights the lasting consequences of nuclear meltdowns.
What is the Elephant’s Foot?
The “Elephant’s Foot” is a solid mass of corium, a material that forms when a nuclear reactor core overheats and melts through its containment structures. This process involves nuclear fuel, control rods, and reactor components mixing with melted concrete, sand, and other building materials. The resulting substance is dense and rock-like, with a dark, wrinkled, brownish appearance, which led to its distinctive nickname.
This formation is located in a maintenance corridor beneath the No. 4 reactor core at the Chernobyl Nuclear Power Plant. Discovered in December 1986, eight months after the disaster, it had melted through about 2 meters (6.6 feet) of reinforced concrete. The “Elephant’s Foot” is primarily composed of silicon dioxide, along with uranium, calcium, iron, zirconium, aluminum, magnesium, and potassium, and contains uranium oxide fuel. Though one of several larger corium masses in the area, it is arguably the most recognized.
The Extreme Danger It Poses
The “Elephant’s Foot” presents an immense radiological hazard due to its highly radioactive fission products and actinides. Corium retains these radioactive elements, resulting in a significantly high dose rate. In 1986, radiation levels near it were estimated to be 8,000 to 10,000 roentgens per hour. This level would deliver a lethal dose of 4.5 grays within three minutes of exposure.
Exposure to such extreme radiation levels leads to severe and rapid health consequences. Thirty seconds of exposure would cause dizziness and fatigue, while two minutes would lead to hemorrhaging of cells. Five minutes of exposure would result in death within 48 hours. The danger stems from the ionizing radiation emitted by the mass, which damages human cells, leading to acute radiation syndrome, cancer, or organ failure. While its radioactivity has decayed over time, the ‘Elephant’s Foot’ continues to pose a significant external gamma radiation hazard, primarily due to cesium-137.
Viewing Conditions: Past and Present
Directly observing the “Elephant’s Foot” has always been an extremely hazardous undertaking. In the immediate aftermath of the disaster, lethal radiation levels necessitated initial observations and photography using remote cameras mounted on wheeled trolleys. This allowed researchers to capture images from a safe distance, as prolonged proximity would have been fatal. The high radiation levels were so intense that they often warped the film and affected camera equipment.
Limited, high-risk excursions were made by highly protected individuals, often called “liquidators,” to gather samples or assess the situation. These brief visits involved stringent precautions, including heavy shielding and extremely short exposure times to minimize radiation dosage. Even today, despite significant radioactive decay, direct viewing remains incredibly dangerous and virtually impossible for the general public. The damaged reactor building still harbors substantial residual radiation, necessitating specialized equipment and extreme safety measures for any access. Images available now are primarily historical, taken during controlled, high-risk access periods.
Containment and Monitoring Efforts
Measures have been implemented to manage the ‘Elephant’s Foot’ and the broader Reactor 4 site at Chernobyl. Following the disaster, a temporary structure known as the “sarcophagus” was hastily constructed around the damaged reactor to contain radioactive materials. This initial shelter was not designed for long-term containment and began to deteriorate over the years.
More recently, the New Safe Confinement (NSC), an immense steel arch, was constructed over the entire Reactor 4 building, including the “Elephant’s Foot.” Completed in 2016, the NSC is the world’s largest movable metal structure, designed to prevent radioactive contaminant release, protect the reactor from external influences, and facilitate future decommissioning. This structure aims to contain radioactive remains for at least 100 years. The NSC is equipped with an integrated monitoring system that tracks radiation levels and structural integrity, and it includes remotely operated cranes to assist with future dismantling of unstable structures within the original sarcophagus.