The Causes of the Chernobyl Nuclear Disaster and the Role of Nuclear Energy.
- Born For Stem
- 9 août
- 4 min de lecture
By Sanzana Sadat
Abstract.
The Chernobyl nuclear disaster of 1986 stands as one of the most catastrophic
technological failures in history, primarily caused by a combination of design flaws and critical
human error. This paper examines the mechanical and procedural causes that led to the
explosion of Reactor 4, focusing on the role of control rods, moderators, and the absence of
automated safety systems. It also explores the broader implications of nuclear energy, weighing
its high efficiency and low greenhouse gas emissions against its potential risks. By analyzing
the failures at Chernobyl and the safety measures developed in its aftermath, this study
highlights how nuclear energy can continue to play a critical role in the transition to a
sustainable and low-carbon energy future—provided that stringent safety protocols and modern
technologies are enforced.
Introduction.
The Chernobyl nuclear disaster, which occurred on April 26, 1986, remains the
most devastating nuclear accident in history. Caused by a combination of design flaws and
operator errors, the explosion at Reactor 4 of the Chernobyl Nuclear Power Plant released vast
quantities of radioactive material into the environment. Understanding the mechanical and
human failures behind this catastrophe is essential not only for historical context but also for
improving nuclear safety today. Despite the risks, nuclear energy remains a viable and essential
source of low-emission power, and the lessons learned from Chernobyl continue to shape safer
reactor operations globally.
The Functioning of a Nuclear Reactor.
A nuclear reactor functions through a controlled chain
reaction of nuclear fission. When uranium-235 atoms split, they release neutrons and energy.
This chain reaction is moderated by components like:
● Moderators: Slow down neutrons to sustain a consistent and manageable chain
reaction.
● Control Rods: Absorb neutrons to regulate or halt the fission process.
● Coolant Systems: Absorb the energy produced by the reaction and transfer it to a
secondary system (steam generators) to drive turbines and generate electricity.
● Shielding and Control Systems: Constructed of neutron-absorbing materials to provide
additional layers of safety in case of malfunction.
A balance among these systems is crucial for reactor safety. Disrupting that balance, as
happened at Chernobyl, can lead to catastrophic failure.
The Technical Failures Behind Chernobyl.
One of the main technical failures at Chernobyl
was the improper use and removal of control rods. Designed to absorb neutrons and slow the
reaction, the control rods were nearly all withdrawn during a late-night safety test; only 8 of 211
rods remained in the core. This was a direct violation of standard operating procedures. By
removing so many rods, operators unintentionally increased neutron availability, triggering a
rapid and uncontrolled chain reaction.
Additionally, the reactor's power had previously been reduced too low, causing a buildup of
xenon gas, a neutron absorber that further suppressed the reactor's power. In response, the
operators removed even more control rods to increase power, inadvertently creating conditions
for a power surge.
As the reaction intensified, the coolant began to boil excessively. The resulting steam pressure
built up to the point that the reactor vessel could no longer contain it, leading to a massive
steam explosion. The lack of an automatic shutdown system based on rising temperature
thresholds exacerbated the situation. Ideally, such a system would have released neutron-
absorbing materials like boron to prevent the uncontrolled fission and resulting explosion.
Safety Measures and Lessons Learned.
The Chernobyl disaster highlighted the importance of
implementing automatic emergency shutdown systems. Modern reactors now include systems
that detect rapid temperature rises and automatically deploy control rods or boron to suppress
neutron activity. These advances aim to prevent the type of overheating that led to the steam
explosion at Chernobyl.
Furthermore, adherence to operational protocols is now treated as essential. The disaster
demonstrated how procedural violations, such as removing too many control rods, can lead to
catastrophic consequences.
The Case for Nuclear Energy.
Despite the dangers illustrated by Chernobyl, nuclear energy
continues to offer significant benefits:
● Low Greenhouse Gas Emissions: Nuclear power emits far less CO₂ than fossil fuels;
about 12 grams per kilowatt-hour compared to coal’s 820 grams, making it vital in the
fight against climate change.
● High Energy Output: A small amount of nuclear fuel yields an immense amount of
energy. One kilogram of uranium can generate as much electricity as a million kilograms
of coal.
● Reliability: Unlike solar and wind energy, which are intermittent, nuclear plants operate
consistently, providing a stable energy supply 24/7.
Although concerns persist about accidents and radioactive waste, modern engineering and
safety practices have significantly reduced the risks. Innovations in waste storage and reactor
design continue to make nuclear power a safer, more sustainable option.
Conclusion.
The Chernobyl nuclear disaster was the result of flawed reactor design, operator
errors, and procedural violations, most notably the dangerous withdrawal of control rods and the
absence of a responsive shutdown system. While the consequences were dire, the global
nuclear industry has since evolved, prioritizing safety and efficiency. Nuclear energy remains
one of the most promising solutions for a carbon-neutral future. As long as safety protocols and
technology continue to improve, the benefits of nuclear energy far outweigh its risks.
References
● Nuclear-Power.com. (n.d.). Reactor shutdown. Nuclear Power. Retrieved October 23,
operation/reactor-shutdown/
● Reactions. (2019). What Exactly Happened at Chernobyl? YouTube.
● Unwin, J. (2019, May 28). Nuclear power: The pros and cons of the energy source.
Power Technology. https://www.power-technology.com/features/nuclear-power-pros-
cons/?cf-view
● Chemistry LibreTexts. (2019, August 22). 19.08: Nuclear Reactors.
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