Despite the high-profile accidents, we need nuclear energy

The general safety record of nuclear power is excellent when compared to other ways of producing power

I HAVE BECOME convinced that we should add nuclear energy to Ireland’s mix of power generation technologies and the information I outline in this article is pertinent to the current debate on nuclear energy.

The most serious accident in the history of nuclear power generation happened on April 26th, 1986, at Chernobyl. The reactor was destroyed, considerable amounts of radioactive material were released, and large areas of Belarus, the Russian Federation and Ukraine were contaminated. Chernobyl releases were detectable in all northern hemisphere countries.

Within a few weeks, the accident caused the deaths of 30 workers and radiation injuries to over 100 others. Up to the year 2005, about 4,000 thyroid cancer cases in children/adolescents around Chernobyl were mostly attributed to ingestion of radioactive iodine. Some 99 per cent of these cases were treatable but 15 deaths occurred. Apart from the early deaths of emergency workers and the increased incidence of thyroid cancers, the scientific evidence indicates that the health effects of the Chernobyl accident were very small. (United Nations Sub Committee on the Effects of Atomic Radiations Report, 2011)

Two decades after the Chernobyl accident there is no evidence of any major public health impact attributable to radiation. There is no scientific evidence of increase in overall cancer incidence, mortality rates or rates of non-malignant disorders (eg, congenital deformations) that could be linked to radiation. Incidence of leukaemia in the general population, the first cancer to show up after radiation exposure, does not seem to be elevated (Unscear). Those most highly exposed to radiation are, of course, at increased risk of late radiation-associated effects.

More than 300,000 people were evacuated from their home areas causing severe social disruption. The general area suffered massive economic consequences and vast numbers of people still suffer from psychological depression, believing that exposure to radiation has seriously damaged their health, even though there is no scientific evidence that their health is impaired (Unscear).

On March 11th, 2011, an earthquake measuring 8.9 on the Richter scale hit Japan, followed by a tsunami, causing massive damage and disruption. Many of Japan’s nuclear reactors shut down automatically. At the Fukushima Daiichi nuclear site, loss of electrical power affected reactor cooling and four reactors overheated causing the second most serious accident in the history of nuclear power generation.

There was some release of radioactivity from the affected nuclear plants but this is not expected to cause health effects generally in Japan. However, 21 out of 370 workers trying to stabilise the plants received radiation doses in excess of 100mSv (mSv, milliSievert is a technical measure of radiation dose, emergency workers are allowed to receive a maximum dose of 200 mSv).

The current death toll in Japan from the direct effects of the earthquake/tsunami is 14,000 dead (and more than 14,000 missing). Released radioactivity has not killed anyone.

Irish people know remarkably little about nuclear power. In a 2005 EU environment poll, Ireland came second last, ahead of Portugal, with only 31 per cent of the relevant questions answered correctly.

The general safety record of nuclear power is excellent when compared to other ways of producing power. Life-cycle analysis of the carbon dioxide output of nuclear power shows that it only emits 4 per cent of the warming greenhouse carbon dioxide gas output of coal-fired power (Oko Institute, Germany).

Nuclear power plants generate small volumes of high-level waste that must be segregated from the environment for up to 100,000 years. This is undoubtedly undesirable, but a practical solution has been found – store this waste underground in a stable geological repository. Evidence from natural nuclear reactors at Oklo, in Gabon, Africa, indicates that such storage securely contains the waste. Uranium in the rocks at Oklo naturally underwent fission about two billion years ago and this natural reactor was active for hundreds of thousands of years. The evidence from the rocks now shows that the high level waste generated has not moved from its site of origin over two billion years.

The Irish target is to produce 40 per cent of our electricity from renewable sources (mostly wind) by 2020, but, in my opinion, generation of power from renewables cannot displace the need for nuclear energy, at least not at any reasonable cost. Wind is too intermittent, wave power too far from full development and biofuel production is too greedy for arable land. Denmark is the world leader in wind power but has never succeeded in generating more than 20 per cent of its electricity from wind. Renewable energy has an important role in a sensible mix of power generation mechanisms, but that mix should include nuclear energy.

William Reville is professor of biochemistry and public awareness of science officer at UCC. understandingscience.ucc.ie