Chernobyl: The Numbers Game

20 April 2006

 Chernobyl: The Numbers Game

 By Gwynne Dyer

April 26 is the 20th anniversary of the explosion and fire in the Chernobyl-4 nuclear reactor, so the long-running dispute over how many people actually died as a result of the accident is back. And now the growing public argument in Western countries about ending the de facto ban on new nuclear power stations has lent wings to the debate.

Last Tuesday the World Health Organisation published a report estimating that 405 people died in the first decade after the accident, almost all of them former plant workers, firefighters and soldiers who were exposed to massive radiation doses in the initial explosion or during the nine-day struggle to put out the fire in the reactor core. But over 200,000 people were involved in some aspect of the clean-up operation, and some of them as well as some people living near the site will also develop cancers from their lesser exposure to radiation sooner or later.

The WHO’s best estimate is that about 9,300 people will eventually die from Chernobyl-related cancers. Greenpeace International, on the other hand, has just issued a report predicting that the number of cancer deaths directly attributable to Chernobyl will ultimately reach 93,000.

This is as much an argument about the future as the past, since the outcome of the revived debate in the West about the desirability of nuclear power depends heavily on the public’s perception of the risks involved. It’s not how the debate SHOULD be settled, but both sides know that it’s how it will be.

The West effectively abandoned building new nuclear power stations after the accident at the Three-Mile Island reactor in the US in 1979 (which killed nobody) and the Chernobyl accident in 1986 (which killed quite a lot of people). Few existing plants were shut down, and in a few countries, notably France and Japan, nuclear energy continues to supply most of the nation’s electricity, but the global population of big nuclear power reactors has fluctuated in a narrow band between 400 and 450 for the past twenty years.

Now there is a new wave of reactor-building in Asian countries where rapidly growing economies have created a huge demand for electricity, and few voices have been raised against it in those countries. Even in the West, the debate has been re-opened as concern about global warming has grown. Apart from hydro-power, which is only available in certain areas, nuclear energy is the only available short-term option for producing very large amounts of base load electricity without adding to the greenhouse gases that cause the warming.

The real arguments for and against nuclear power are about complicated technical and financial issues. Would the same amount of investment in “renewables” like wind power produce as much electricity, and how do you allow for the fact that the wind does not always blow? Would investing in techniques like “sequestering” the carbon-dioxide output from conventional coal, oil and gas-fired power-plants (capturing it and pumping it into underground reservoirs) be a better way to spend the money — and how soon could such technologies be available on a large-scale?

Those are the real issues, but everybody involved in the argument knows that “safety” will be what decides the outcome in the public debate. Since Chernobyl is the only accident involving a nuclear power plant in the past fifty years that has killed any members of the public, just how many died has become a bitterly contested question. Unfortunately, it is also a hugely misleading one.

There is no doubt that thirty people died in the immediate struggle to contain the accident, twenty-eight of them from massive radiation overdoses. Of the 139 people who were treated for acute radiation sickness, another nineteen died. But after that, all the other deaths attributed to Chernobyl are statistical inferences. That doesn’t mean they did not occur, but it does mean that the range of plausible conclusions, given the state of the medical and demographic data in the affected area (Ukraine, Belarus and western Russia), is very wide indeed.

Moreover, predictions about the “final death toll” are almost meaningless, because everybody dies eventually, and about 30 percent of people in developed societies die of cancer. Whether it’s ultimately 9,300 or 93,000 people who die as a delayed effect of the Chernobyl accident, they will mostly die from cancers that develop late in their lives, only a few months earlier than they were statistically likely to anyway.

The massive hydrogen-bomb tests in 1962, which released about a hundred times as much radiation as Chernobyl into the atmosphere, had a similar effect. Worldwide, the average radiation dose from those tests was ten milliSieverts, roughly the same as most people living within a few hundred kilometres (miles) from Chernobyl received in 1986. Ten milliSieverts of radiation is calculated to shorten a person’s lifespan, on average, by four days — but averages lie. What those tests really meant was an early death for an unlucky few, and nothing for everybody else.

In the case of nuclear power, the number of lives that might be at risk from accidents is certainly only a tiny fraction of those that are at risk from global warming, but that’s not how the argument will be pursued in public. The debate will be mostly about the alleged dangers of nuclear power, not about whether it is really the best way to produce huge amounts of power without also producing huge amount of carbon dioxide.


To shorten to 725 words, omit paragraphs 5 and 6. “The West…the warming”