The Chernobyl nuclear power plant exploded more than three decades ago, in 1986, but you can watch it unfold on HBO’s TV miniseries “Chernobyl,”


A view of the Chernobyl nuclear power plant in April 1986, two to three days after the world's worst nuclear accident.

A view of the Chernobyl nuclear power plant in April 1986, two to three days after the world’s worst nuclear accident.

About 30,000 people were near Chernobyl’s reactor when it exploded on April 26, 1986. Those exposed to the radiation are thought to have received about 45 rem (rem is a unit of radiation dosage), on average, which is similar to the average dose received by survivors after the atomic bomb was dropped on Hiroshima in 1945, according to the book “Physics for Future Presidents: The Science Behind the Headlines” (W. W. Norton & Company, 2008) by Richard Muller, a professor emeritus of physics at the University of California, Berkeley. 

While 45 rem is not enough to cause radiation sickness (which usually occurs at about 200 rem), it still increases the risk of cancer by 1.8%, Muller wrote. “That risk should lead to about 500 cancer deaths in addition to the 6,000 normal cancers from natural causes.”

However, a 2006 estimate from the International Atomic Energy Agency (IAEA), which is associated with the United Nations, calculated much higher cancer fatalities. The IAEA looked at the total distribution of the radiation, which reached across Europe and even to the United States, and estimated that the cumulative radiation dose from Chernobyl was about 10 million rem, which would have led to an additional 4,000 cancer deaths from the accident, Muller wrote.

The initial blast was enormous..

But the greatest harm from the radiation happened within the first few weeks. You can think of radiation as fragments that fly outward as a nucleus explodes, like shrapnel from a bomb, Muller wrote.

  • Just like popped bubble wrap, each nucleus can explode and release radiation only once.
  • Just 15 minutes after the Chernobyl explosion “the radioactivity had dropped to one-quarter of its initial value; after 1 day, to one-fifteenth; after 3 months, to less than 1%,” Muller wrote.
  • “But there is still some left, even today,” he noted. “Much of the radiation literally went up in smoke, and only the radiation near the ground affected the population.”
  • The Chernobyl explosion not only released a lot of radiation; it also started a fire at the power plant.
  • The firefighters who rushed in to stop the flames were exposed to high levels of radiation, and dozens died from radiation poisoning, Muller wrote.
  • Gamma rays — a penetrating kind of radiation that is released from nuclear weapons, dirty bombs and reactor explosions — is like an extremely energetic X-ray. There are about 10 trillion gamma rays in every 1 rem of radiation, Muller wrote.
  • People hit with 300 rem have a good chance of dying unless they get immediate treatment, like a blood transfusion, Muller wrote.
  • Chernobyl didn’t have an important safety measure in place: a containment building.

The numbers of moose, roe deer, red deer and wild boar living in the exclusion zone are similar to population numbers in nearby uncontaminated nature reserves, a 2015 study found. Wolves are doing especially well, with a population that is seven times the size of wolf populations in neighbouring reserves, the study researchers found. “This doesn’t mean radiation is good for wildlife, just that the effects of human habitation — including hunting, farming and forestry — are a lot worse,” Jim Smith, the study’s observation team coordinator and a professor of environmental science at the University of Portsmouth in the United Kingdom, said in a statement.

Chernobyl has become a refuge for wildlife 33 years after the nuclear accident