In the early morning hours of April 26, 1986, reactor number four at the Chernobyl nuclear power plant exploded. As the reactor building was destroyed, over 100 radioactive elements were launched into the atmosphere.  

Today, Chernobyl remains frozen in time. A protective radiation shield entombs the nuclear reactor’s remains. The Ukrainian city of Pripyat lies abandoned, as does everything in the 30-kilometer exclusion zone around the plant.  

The Chernobyl disaster marked a fundamental and tragic shift in our understanding of nuclear safety. The events that transpired on that fateful day could have been avoided had Chernobyl’s designers and operators heeded the warnings that stared them in the face.  

The Rise of Nuclear Power and Chernobyl’s Role 

In the late 20th century, the Soviet Union took pride in its pioneering achievements in nuclear engineering. And why not? They had built the world’s first nuclear power plant at Obninsk in 1954, heralding a new era of nuclear energy.   

Chernobyl, with its four RBMK-1000 nuclear reactors, was part of this ambitious nuclear program. Each reactor could produce 1,000 megawatts of power, and two additional reactors were under construction at the time of the disaster. The plant was meant to power the Soviet Union’s rise to global prominence. Instead, it helped bring about its fall.  

1:23:45 AM: Disaster 

Ironically, the Chernobyl disaster happened because of a safety test.  

Engineers wanted to see if, in the event of a power loss, inertia from a slowing turbine could create enough electricity to keep cooling pumps running until emergency generators kicked in.  

The test began on April 26, 1986. Operators shut down the number four reactor’s turbine generator, but a delay forced them to rush the test. To speed things up, they reduced the reactor’s power too quickly, causing a buildup of xenon-135, a neutron-absorbing isotope that “poisoned” the reactor and suppressed its power output.  

To compensate, operators withdrew nearly all of the reactor’s 205 control rods, leaving only six to eight inserted—well below the safe operating limit. Control rods regulate nuclear fission, and withdrawing so many made the reactor dangerously unstable.  

Alarmed by a sudden power surge, one of the operators hit the emergency shutdown. The control rods, including emergency protection rods, were driven back into the reactor’s core. But the control rods had a design flaw: Their graphite tips initially displaced coolant. Designed to reduce reactivity, the control rods momentarily increased reactivity.  

The coolant turned to steam, increasing power output, which generated more steam. More power. More steam. Until … 

Boom. 

The first explosion ruptured the reactor vessel at 1:23 AM. A second explosion, likely caused by hydrogen buildup, blew the reactor building apart and spewed radioactive material into the night sky.  

The Fallout 

Reactor number four released 400 times more radioactive material than the atomic bomb dropped on Hiroshima.  

Winds spread radioactivity over Western Europe, contaminating a combined 150,000 square kilometers in Belarus, Russia, and Ukraine. The exclusion zone around the former plant remains uninhabitable and will be for up to 20,000 years.  

But this environmental devastation, already beyond comprehension, is nothing compared to the disaster’s toll on human life.  

The Human Cost 

31 people died as an immediate result of the Chernobyl disaster—at least, according to the official death toll. The reality was far worse.  

Hundreds of thousands of people, known as “liquidators,” were involved in the cleanup. These firefighters, engineers, police, miners, and military and medical personnel were exposed to high levels of radiation. Residents near the plant absorbed internal radiation doses of up to 3.9Gy—about 37,000 times the dose of a chest X-ray. But the radiation, like cancer, spread far beyond the source.  

Millions in Belarus, Russia, and Ukraine were also exposed to Chernobyl’s fallout. An estimated 4,000 people exposed to high radiation levels could die from cancer, and another 5,000 with lower exposure could face the same fate. Yet the true cost—physical, psychological, and environmental—is immeasurable.  
 

Could Chernobyl Happen Again?  

The world has seen other nuclear disasters, from Three Mile Island in 1979 to Fukushima in 2011. Whenever the world is faced with an atomic horror, the initial reaction is to abandon nuclear energy. 

But Chernobyl wasn’t so much an accident as it was a cascade of human errors: a badly designed and operated nuclear reactor, housed in a plant built without a containment structure, overseen by Soviet officials with a blatant disregard for safety concerns. Today, reactor designs have evolved, and safety measures are far stricter.  

As for Russia, the country overhauled its 11 operating RBMK reactor, following recommendations from the International Atomic Energy Agency (IAEA). Shutdown mechanisms have improved, and there is a renewed focus on operational safety and regulatory oversight. 

Could Chernobyl happen again? Never say never, but the specific flaws behind the Chernobyl meltdown have been addressed. However, the need for nuclear energy is stronger than ever. 

Nuclear Energy Is the Future 

Nuclear energy remains one of the safest and most sustainable power sources. And with U.S. electricity demand set to skyrocket, we need every energy solution available.   

Become a Part of the Energy Revolution 

The University of Texas Permian Basin offers three online graduate programs designed for professionals interested in taking a leading role in the energy revolution: 

These online programs will provide you with more than just a credential. You’ll also gain operational knowledge and leadership skills that will pay dividends throughout your career in the energy sector. Plus, our courses are entirely online, so you don’t have to hit pause on your career.  

The energy sector is growing. Shouldn’t you grow along with it?  

Check out our online energy business programs, and when you’re ready to take the leap, apply to UT Permian Basin!  

Sources: 
https://www.iaea.org/newscenter/focus/chernobyl/faqs
https://www.pbs.org/wgbh/pages/frontline/shows/reaction/readings/chernobyl.html
https://whatisnuclear.com/chernobyl-main.html#short
https://www.un.org/en/observances/chernobyl-remembrance-day/background
https://www.britannica.com/event/Chernobyl-disaster#ref349687  
https://www.forbes.com/sites/rrapier/2019/05/19/could-a-chernobyl-happen-again/