20 Years Since Chernobyl

It was 20 years ago today (1:26 am local time in Ukraine on the 26th) that the Chernobyl disaster happened. Chernobyl was not a nuclear explosion. It was an explosion due to a high pressure buildup, like a pressure cooker whose safety valve had stuck. The result was that radioactive dust was released.

Despite the hype which claims it was the Greatest Manmade Disaster in history, this simply isn't supported by facts. It may be the disaster with the longest after effects. It was certainly devastating for the people involved in the immediate aftermath. However, the number of fatalities is surprisingly low. (Though Greenpeace have recently said that estimates are too low)

The article itself says that 'Last year, a WHO and International Atomic Energy Authority-backed report estimated that of the 600,000 people across the Soviet Union exposed to high levels of radiation by the accident, 4,000 would eventually die.' - this undercuts it's leading paragraph of 'Two decades after the world's worst man-made disaster'

According to the World Health Organisation:

A total of up to 4000 people could eventually die of radiation exposure from the Chernobyl nuclear power plant (NPP) accident nearly 20 years ago, an international team of more than 100 scientists has concluded.

As of mid-2005, however, fewer than 50 deaths had been directly attributed to radiation from the disaster, almost all being highly exposed rescue workers, many who died within months of the accident but others who died as late as 2004.

Compare this with the number of deaths in World War 2, or in the attack on the World Trade Centres - and whilst it's bad, it's not objectively as bad as people first think.

The trouble with the human assessment of risk is that we notice tragic, but rare, events much more than the continuous background risk in our lives.

For example, there was a spate of train crashes in the UK a few years ago, and lots of people avoided the railways, preferring to use the roads. This is in spite of the fact that day in, day out, more people die on the roads per mile travelled than on the railways. The difference was that as railway crashes are rare, and bad when they happen, we notice them more than the constant rate of car crashes which only affect a few individuals at a time.

It's true that a lot of people were displaced - but this is also the case with other disasters in the world - wars, famines and so forth. The WHO report states that:

Persistent myths and misperceptions about the threat of radiation have resulted in "paralyzing fatalism" among residents of affected areas.

In other words, the psychological issues, which are completely understandable, can be more of a problem for the population as a whole than the radiological issues.

Whilst tragic for individuals, when deciding energy policy we must look at the overall risks in an objective fashion, from my degree course, I have a book entitled 'The Elements of Nuclear Power' by D. J. Bennet and J. R. Thompson. It's the third edition. On page 257 there is a table entitled 'Relative Risks and Costs of powe generation'. My print is from 1991. (sources cited: the CEGB. ETSU-R30 (1985). JH Fremlin, 'Power Production - What are the Risks?' by Adam Hilger, 1985)

The risks are in Deaths/GW-year, so the fact that different amounts of power are generated is accounted for.

Method of Generation Hazard or other problem Deaths/GW-year
Nuclear Routine Discharges c. 0.05
Reactor Accidents (Chernobyl) c. 1.0
Uranium Miners c. 0.1
Coal Cancers - general public c. 10
Miners - accidents c. 2
Miners - pneumoconiosis c. 8
Acid Rain ?
Global Warming ?
Draught Proofing Natural Radon from building fabric c. 100 Deaths/GW-year saved
Wind Unreliable -
Geothermal Limited Potential -
Hydro Dam Failure c. 10
Tidal Limited Potential -
Photovoltaic Inherently unreliable -
Wave Hazard to Shipping ?
Maintenance Accidents ?

Some items here bear explanation. Firstly the nuclear risks. Yes, a nuclear accident is bad when it happens, but this data averages over all the times when accidents do no happen. The data for coal reminds us that not only radiation can give rise to cancers, chemical pollutants can also be carcinogens. It's just that this 'constant background' is not noticeable in the way that a rare nuclear accident is. Think train crashes versus car crashes. Draught exclusion is one that surprises many people, it surprised me. Essentially it's due to using rocks which contain (naturally occuring) unstable isoptopes. These can decay into Radon, which leeches into the building. With better draught exclusion, Radon can build up. This is a problem in areas such as Cornwall, especially in buildings with cellers as the Granite produces Radon, and as Radon is heavier than air it collects in the cellers.

Note, the reason I put in 'natually occuring' isn't through any delusion that 'natural' is better than 'artificial' - but rather through the exact opposite point of view, not everything 'natural' is good for you!

To see what Chernobyl is like today, the Kid of Speed website gives a unique perspective.