What happens in the aftermath of a nuclear disaster? To learn, we can look at history, specifically the example of the Chernobyl disaster.
The Story of Chernobyl
On the early morning of the 26th of April, 1986, a disaster struck the Chernobyl Nuclear Power Plant near the town of Pripyat, in what is now Ukraine (at the time it was part of the USSR). A catastrophic power surge during an experimental safety procedure led to explosions inside reactor four, which threw large amounts of radioactive material into the atmosphere in plumes of smoke.
In some areas of the plant, workers were exposed to a lethal dose of radiation in less than 60 seconds (they did not die immediately, but many of these people would die within weeks). Two people were dead and more than 50 in the hospital within 12 hours. People in nearby towns began to fall sick.
The immediate reaction of the authorities was mixed: efforts were made to contain initial fires and control the spread of radioactivity, but evacuation notices and warnings of health consequences were delayed (the town directly around Chernobyl was not evacuated for 36 hours) or simply wrong. The radioactive plume spread across much of Europe. Within two days, workers at a nuclear plant in Sweden detected elevated levels of radioactivity on their clothing, which was the first international hint that something had gone wrong.
The initial cleanup at Chernobyl continued for about 6 months, a period during which a massive concrete containment structure was built around the damaged reactor. Since each individual could only be exposed to a limited amount of radiation, around half a million workers participated in this initial process. The cleanup process at Chernobyl continues to this day. Work is currently underway to complete a new replacement containment dome, which will be rolled into place over the current, aging structure. Economic costs of the meltdown are massive: over $300 billion and counting. About 5% of the national budget in Ukraine is dedicated to Chernobyl-related costs, and extensive international aid is still used for the project.
The exact death toll from the accident is hard to define. Around 28 emergency workers died from direct radiation poisoning related to the incident, but many more have died due to cancers and other health issues that take longer to appear. Experts estimate the total death toll due to the accident may be around 4000. Many believe the true toll is much higher, up to the tens of thousands. These people assert that official numbers underestimate the impact due to stonewalling and political coverups (especially in Belarus, one of the hardest-hit regions).
Why is it So Hard to Clean up?
The reason nuclear accidents cause such extended trouble is due to the nature of radioactivity. We’ve written about this subject before, but in short, radiation is released from unstable isotopes of certain elements. These isotopes release ionizing radiation due to radioactive decay, released as their unstable nuclei lose energy. When all the energy in a given nucleus has been released, the atom is in a new, more stable state. This process is measured in half-lifes: the amount of time when half the atoms of a given isotope in a given sample will have undergone decay and ceased to release radiation. The meltdown at Chernobyl released many different radioactive elements, including the following (the half-life is in parentheses):
- iodine-131 (8 days)
- caesium-137 (30 years)
- tellerium-132 (78 hours)
- xenon-133 (5 days)
- zirconium-95 (64 days)
- strontium-90 (28.8 years)
- niobium-95 (35 days)
- cerium-144 (285 days)
- plutonium (various isotopes with half-lives between 80 and 24,000 years)
These materials, once emitted into the atmosphere and water, are extremely hard to clean up. That’s why Chernobyl is now at the center of a 1000 square-mile human exclusion zone. No one is allowed to live inside this area (although a few elderly people defy the ban).
Effects on the Environment
Although generally considered to be incredibly harmful to plant and animal life, radiation has had unexpected consequences for the zone around Chernobyl. One interesting area of research at Chernobyl has been related to fungi. Scientists have shown that many of the fungi present in the human exclusion zone seem to concentrate radioactive elements in their tissues, even using it as an energy source. Not much is known about this amazing ability, but it does point to the resilience of life.
In fact, somewhat surprisingly, Chernobyl has been a case study in the resilience of the natural world. When the exclusion zone was declared in 1986, no one predicted that the area would become the largest (and completely unplanned) wildlife sanctuary in Europe. With human activity from agriculture, roads, and other impacts removed, wild creatures have flourished. The region is now home to wolves, lynx, wild boar, elk, deer, bison, otters, owls, rare Przewalski’s horses, bats, and brown bears among many other species.
While many are optimistic about this, some scientists still call foul. Timothy Mousseau, a biologist from the United States, has been studying wildlife in and around Chernobyl and has concluded that impacts of the radiation have been powerful, reducing the number of species in some areas by 50%. But his research also shows that some birds are adapting to higher radiation.
The Cleanup Timeline
The issues at Chernobyl aren’t over, either. In May of 2015, wildfires in the area were running wild, releasing radioactive particles from the vegetation and soil to be carried through the atmosphere. Officials warn this could be a serious health risk for communities in the region, and firefighting efforts have continued to this day. Health risks continue as well; today, workers are only allowed to work 5 hours per day in the area for a period of 4 weeks, and then must have a mandatory two weeks of leave.
But what about the future? Well, radioactivity is a problem that goes away only very slowly. Experts believe that the area around Chernobyl will be habitable again for humans — but not for as many as 20,000 years.
Meanwhile in Japan, the 2011 earthquake and tsunami that touched off the Fukushima Daiichi nuclear disaster have left a lasting legacy. More than 100,000 people remain evacuated from the region surrounding the plant, as officials work to contain radioactivity and decommission the plant — a process they estimate could take decades. Much of the contaminated land will also be uninhabitable for at least 20-40 years.
Back at Chernobyl, in the infamous Red Forest (a region of pine trees adjacent to the nuclear plant that were killed by the initial radiation), the trees aren’t decaying. They just lie dead where they are. Populations of bacteria and fungi still aren’t at normal levels.
So how long does it take to recover from a nuclear accident?
A long, long time.
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