How scared should we be of nuclear power?

The accident in Japan should not obscure the fact that nuclear power is less deadly than many other industrial activities and types of energy

As if a mega-earthquake and a devastating tsunami were not enough, two major nuclear accidents have now been reported in Japan, calling to mind the Chernobyl catastrophe of 1986.

Comparing the recent incidents to that calamity has caused a lot of confusion. Contrary to what happened in the Soviet Union, the Japanese authorities were quick to inform citizens and call for the preventive evacuation after the building hosting reactor 1 in Japan's biggest nuclear plant, Fukushima Daiichi, experienced an explosion due to the excess pressure of gas.

The Tokyo Electric Power Company (TEPCO), which operates the two damaged plants, also gave instant updates on its website of developments.

Immediately after the earthquake, all four operating reactors at the plant were shut down (in addition to two others, which were in maintenance). The same occurred at the Fukushima Daini power plant, which is located in the same region.

But no nationwide power outage was reported due to the ability of the Japanese electricity generation capacity to compensate, at least temporarily, for the unavailability of several reactors. Japan has 55 reactors on its territory that produce close to one-third of its electricity.

The accidents at reactors 1 and 3 of the Fukushima Daiichi plant seem to have been of a "perfect storm" type: multiple failures of various security and safety systems leading to a worst-case scenario. In both cases, there seems to have been a partial meltdown of the core due to the failure of cooling systems: the nuclear fuel overheated because it was no longer properly cooled.

But nuclear plants cannot explode like atom bombs. At the moment, catastrophic human and environmental consequences seem nonexistent.

All modern second and third-generation reactors have at least two major physical barriers to avoid dangerous levels of radioactivity from escaping. One is the reactor vessel, which is made of metal; the other is a containment building, made of concrete. At reactor 1, some radioactive water vapour was deliberately released into the atmosphere, but with little risk to nearby populations. Inside the plant, however, three workers are reported to have been exposed to excessive levels of radiation.

Given these conditions, the relevant comparison so far should not be the Chernobyl catastrophe, but the Three-Mile Island accident in 1979. There, a partial meltdown of the reactor led to a brief emission of radioactive gases, without any consequence for the population or the environment.

Radioactivity itself is not dangerous: our bodies are radioactive, and we are constantly submitted to low levels of natural radioactivity coming from cosmic rays, the soil, and even from what we eat. We also absorb relatively high doses of artificial radioactivity when we get a medical exam.

And while nuclear power is of course dangerous, a major accident would be no reason to condemn a whole industry, as many did after Chernobyl.

As it happens, nuclear power kills far fewer people than traditional power sources. Oil and coal accidents were responsible for 40,000 direct deaths in the last 30 years of the 20th century. Thousands die every year in Chinese coal mines. Even hydropower can kill thousands: 30,000 died in China when a dam ruptured in 1975.

Chernobyl was also less deadly than it is generally thought. Besides the 34 rescuers who died quickly after the catastrophe, the number of deaths attributed to the radioactivity released in that accident may eventually reach a few thousand. Contrary to popular belief, there is also little stock in the theory of "Chernobyl mutants": the number of birth defects in the region is not significantly higher than those of other areas in the former Soviet Union, which were plagued by alcohol abuse and heavy metal pollution.

Nuclear power is also less deadly than many other industrial activities. Did anyone suggest to close down India's chemical industry after the horrible accident that took place in Bhopal in 1984 that killed 10,000?

One could respond that we need chemicals but we don't need nuclear power - we just need electricity. The argument is partially true. But nuclear power has its advantages. It does not produce greenhouse gases, it does not emit polluting substances in the course of normal operations, and it does not rely on highly-fluctuating prices of energy sources such as oil and gas. It can also easily respond to changes in the domestic demand for electricity. Nuclear power is certainly not a panacea, but it is a useful part of the energy mix for a modern country.

Japan's particular situation, with a high concentration of nuclear reactors near a dense population in one of the most earthquake-prone regions on Earth, has no parallel. The accidents will probably call into question the standards adopted by the Japanese nuclear industry. Some will claim that the so-called nuclear "renaissance", happening around the world today, is now doomed. But it would be misguided to condemn once again a whole industry because of a series of tragic accidents which, so far, have not killed a single person.

Bruno Tertrais is a senior research fellow at the Foundation for Strategic Research in France