Chernobyl Disaster: How did the Nuclear Accident happen?

Generally, you can now watch some of the most Powerful and Eye-Opening Movies about the Chernobyl Nuclear Disaster. Moreover, Game of Thrones may be over, but HBO’s top-reviewed show is still running. The five-part Chernobyl Miniseries has quite a story behind it.

I feel that your life will never be the same again especially after watching the sleeper hit about one of the worst man-made nuclear disasters. To give you a deeper and more comprehensive understanding of the meltdown. Below is the recent Miniseries Trailer of a Nuclear Accident that changed the course of human history.

Eventually, this is a Russian film about the Chernobyl Disaster. As experienced by a young party official and his friends living in the township across the river from the plant. And as well as the true story of the failed escape.

As can be seen, from the above trailer, the date is Saturday, April 26, 1986, and official reports of the meltdown have been withheld. The residents in the neighboring towns are carrying on the usual life and breathing in radioactive air.

What happened in the Chernobyl Disaster?

The Chernobyl Disaster was a nuclear accident that occurred on Saturday, 26 April 1986 at the No. 4 nuclear reactor in the Chernobyl Nuclear Power Plant. Particularly, near the city of Pripyat in the north of the Ukrainian SSR.

It is considered the worst nuclear disaster in history and is one of only two nuclear energy disasters rated at seven—the maximum severity. Whereby, according to the International Nuclear Event Scale, the other being the 2011 Fukushima Daiichi nuclear disaster in Japan.

Above is the first documentary that was shown after the accident. The filming started a month after the tragedy and some parts were added in September 1986. Not to mention, the film mainly focuses on the human side of Chernobyl. Telling us about the heroic work of the liquidators and the consequences of the accident.

Also: Watch 9 Powerful And Eye-Opening Movies About Chernobyl

The authors did not intend to show the causes of the accident but focused on the events after the explosion. Many of those featured in the film participated in the events first-hand. However, it had a mixed reception at the West Berlin film festival in early March 1987. In that case, because of the relatively poor quality of the filming caused by radiation.

The Soviet Union Tests the Nuclear Power Plant

In the first place, the accident started during a safety test on an RBMK-type nuclear reactor, which was commonly used throughout the Soviet Union. Basically, the test was a simulation of an electrical power outage to aid the development of a safety procedure. For maintaining cooling water circulation until the back-up generators could provide power.

This operating gap was about one minute and had been identified as a potential safety problem that could cause the nuclear reactor core to overheat. Notably, three such tests had been conducted since 1982. But, all had failed to provide a solution. On this fourth attempt, the test was delayed by 10 hours, so the operating shift that had been prepared was not present.

Chernobyl Disaster
The exterior view of the Chernobyl Power Plant – Photo Credits: Lynn Hilton

Secondly, during the test preparation, the reactor power unexpectedly dropped to a near-zero level. Luckily, the operators were able to restore the power level, but in doing so they put the reactor in a highly unstable condition. The risks were not made evident in the operating instructions, despite a similar accident occurring years before.

In the end, they proceeded with the test even though the power level was still lower than prescribed in the procedure. Upon test completion, they triggered the reactor shutdown. But, a combination of reactor design and construction flaws caused an uncontrolled nuclear chain reaction instead.

How did the Chernobyl Disaster happen?

A large amount of energy was suddenly released, vapourising superheated cooling water. While at the same time, rupturing the reactor core in a highly destructive steam explosion. This was immediately followed by an open-air reactor core fire. That released considerable airborne radioactive contamination for about nine days.

See Also: Inside the abandoned city of Pripyat, 30 years after Chernobyl – in pictures

As a result, the contamination precipitated onto parts of the USSR and Western Europe. Finally, before being contained on 4 May 1986. The fire gradually released about the same amount of contamination as the initial explosion. Rising ambient radiation levels off-site.

Chernobyl Disaster
The Ukrainian city was evacuated 36 hours after the nuclear blast at Chernobyl – Photo Credit: Lynn Hilton

In fact, a 10-kilometer (6.2 mi) radius exclusion zone was created 36 hours after the accident. About 49,000 people were evacuated from the area, primarily from Pripyat. To make matters worse, the exclusion zone was later increased to 30 kilometers (19 mi) radius. When a further 68,000 people were evacuated from the wider area.

What were the After Effects of the Chernobyl Disaster?

The reactor explosion killed two of the reactor operating staff. In the emergency response that followed, 134 firemen and station staff were hospitalized with acute radiation syndrome. Due to absorbing high doses of ionizing radiation.

Of these 134 men, 28 died in the days to months afterward and approximately 14 suspected radiation-induced cancer deaths followed within the next 10 years. Among the wider population, an excess of 15 childhood thyroid cancer deaths was documented as of 2011.

Not forgetting, the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has, at multiple times, reviewed all the published research. Especially on the incident and found that at present, fewer than 100 documented deaths are likely to be attributable to increased exposure to radiation.

Unfortunately, determining the total eventual number of exposure-related deaths is uncertain based on the linear no-threshold model. After all, a contested statistical model, which has also been used in estimates of low-level radon and air pollution exposure.

Are there any Safety & Precaution Measures?

Of course, Yes! Whereas, to reduce the spread of radioactive contamination from the wreckage and protect it from weathering, the protective Chernobyl Nuclear Power Plant sarcophagus was built by December 1986. It also provided radiological protection for the crews of the undamaged reactors at the site, which continued operating.

Due to the continued deterioration of the Sarcophagus, it was further enclosed in 2017 by the Chernobyl New Safe Confinement. By all means, a larger enclosure that allows the removal of both the sarcophagus and the reactor debris. At the same time, while containing the radioactive hazard. On the other hand, nuclear clean-up exercise is scheduled for completion in 2065.

The Chernobyl disaster is considered the worst nuclear power plant accident in history, both in terms of cost and casualties. Also, the struggles to safeguard against hazards immediately after the accident, together with later decontamination efforts of the surroundings.

Ultimately, it involved more than 500,000 personnel and cost an estimated 18 billion Soviet rubles—roughly US$68 billion in 2019, adjusted for inflation. The accident prompted safety upgrades on all remaining Soviet-designed RBMK reactors, of which 10 continue to be operational as of 2019.

How is a Nuclear Power Plant cooled?

If coal or nuclear plant is next to a large volume of water (big river, lake or sea), cooling can be achieved by simply running water through the plant. And also, discharging it at a slightly higher temperature. There is then hardly any use in the sense of consumption or depletion on-site. Though some evaporation will occur as it cools downstream.

The amount of water required will be greater than with the recirculating set-up, but the water is withdrawn and returned, not consumed by evaporation. For instance, in the UK, the water withdrawal requirement for a 1600 MWe nuclear unit is about 90 cubic meters per second (7.8 GL/d).

Cooling Power Plants
Cooling Power Plants – Photo Credits: Lynn Hilton

Many nuclear power plants have once-through cooling (OTC) since their location is not at all determined by the source of the fuel. But also, depends first on where the power is needed and secondly on water availability for cooling.

Using seawater means that higher-grade materials must be used to prevent corrosion, but cooling is often more efficient. In a 2008 French government study, siting an EPR on a river instead of the coast would decrease its output by 0.9% and increase the kWh cost by 3%. Read more about Reactor Cooling during a Power Outage.

How do we Prevent Nuclear Disaster?

Serious nuclear accidents have been few and far between—but their stories will help prevent future catastrophes. For a start, there’s the problem of the sheer volume of dangerous nuclear material that exists. Individual countries normally don’t publicize the size of their nuclear material holdings.

But, the world’s estimated stockpile of fissile material is sufficiently large to make approximately 100,000 nuclear bombs. Roughly 1,600 metric tons of HEU and 500 metric tons of plutonium have been produced around the globe. For both civilian and military purposes.

Simply put, manufacturing a simple (although inefficient) Hiroshima-type atomic bomb requires as little as 50 or 60 kilograms of highly-enriched uranium by some estimates. And less than half that amount to power a sophisticated Nagasaki-type implosion bomb.

Read more about Preventing Nuclear Disaster.

Resourceful References;

I hope the above-revised guide on the Chernobyl Nuclear Disaster was informative enough. However, if you have additional content, contributions, suggestions or even questions, please feel free to Contact Us.

Also, let us know how we can help you by sharing your insightful thoughts in the comments box below this post. Finally, below are more useful and related topic links;

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  2. Nagasaki: The Last Bomb
  3. Hiroshima Atomic Bomb
  4. Brief History of Nuclear Accidents
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