I recently attended a meeting of environmentalists interested in climate and energy issues. In one of the introductory talks, a speaker stated categorically that “nuclear power is a disaster”. I argued that this is not supported by evidence, and was rebuked by some in the audience.

I wasn’t given a chance to respond, but will do so here because I think that this is an important issue that society needs to grapple with.

Climate change is the greatest long term threat to humanity. The death toll from global warming is already in the hundreds of thousands every year. Fossil fuel emissions must peak this decade if we are to limit global warming to 1.5°C as per the Paris agreement.

The need to address global warming is urgent, and all options for reducing greenhouse gas emissions – including nuclear power – must be on the table. The Intergovernmental Panel on Climate Change (IPCC) was clear on this point in its most recent assessment.

That being said, nuclear power is not a silver bullet for solving the climate problem. Opponents will rightly point out that wind power is less expensive, and that there is now more wind capacity installed worldwide than there is nuclear. I will try to convince you that continued use and refurbishment of existing nuclear power plants can make good economic and environmental sense.

The Ontario Experience

Figure 1 shows how electricity generation has been partitioned in Ontario since 2008, using data from Statistics Canada.

The most striking aspect of the chart is that nuclear power represents about two thirds of Ontario’s electricity generation. That is an enormous proportion, and it will not be easily replaced by any one technology.

A closer examination shows that the share of electricity genrerated by nuclear increased 13.5% between 2008 and 2015. At the same time, conventional steam turbine use – powered mostly by coal – declined by about the same amount. Ontario was the first province or state in North America to eliminate coal-fired power plants, and the chart confirms that this was accomplished on the back of the nuclear industry. This is something for which Ontarians can rightly be proud.

Hydro makes up a significant portion of Ontario’s electricity mix, as does generation using (natural gas) combustion turbines. Wind makes only a small contribution (2.1% in 2015) and others, including solar, hardly register.

There is obviously room for growth in wind and solar, but any renewable capacity must be used to replace greenhouse-gas emitting combustion turbines first. Any present reduction in the use of nuclear power will mean unnecessary greenhouse gas emissions at a time when reducing them is of the highest priority. I would expect this to be the same for other nuclear-powered juridictions. Nuclear power is an asset in the battle to reduce greenhouse gas emissions.

Deaths

Opponents of nuclear power often point out the human toll of accidents. Indeed, when something goes wrong the cost is high. It is fortunate that there have been few major accidents.

The most serious nuclear accident by far was the 1986 Chernobyl meltdown, which is expected to result in 4000 deaths from radiation exposure over the long term (World Health Organization, 2005). The disaster itself has been attributed to poor reactor design (IAEA, 1992).

By contrast, a variety of studies place the yearly death toll of climate change in the hundreds of thousands (McMichael et al., Lancet, 2006; Global Humanitarian Forum, 2009; DARA International, 2012). The 2003 European heat wave, which has been attributed to climate change, caused 15,000 deaths in France alone (IPCC AR5, WGII, pg. 720).

The grim reality is that the scale of human misery caused by climate change dwarfs the impact of nuclear accidents by many orders of magnitude. If nuclear power can safely help to eliminate greenhouse gas emissions, then this should be viewed positively.

Nuclear Waste

A common misconception is that we don’t know how to dispose of nuclear waste. Deep geological storage has been known since the 1970s to be safe and technologically feasible. The Canadian Nuclear FAQ has a good discussion of current nuclear waste management practices in Canada.

The fact nuclear waste is contained means that it is, in principle, manageable. The big problem with fossil fuel burning is that the waste – carbon dioxide (CO₂) – is not. Once released into the atmosphere, greenhouse gases cause global warming and acidify our oceans.

Cost

Another misconception is that nuclear power is too costly. In its Annual Energy Outlook 2015, the US Energy Information Administration (EIA) estimated levelized costs for new electricity generation sources. Levelized costs represent the costs in 2013 US dollars for building and operating generating plants over an assumed financial life and duty cycle. A summary of their results is given in the table below.

Source	Cost ($/MWh)
Geothermal	48
Wind	74
Natural gas	75-114
Hydroelectric	84
Nuclear	95
Coal	95-144
Biomass	101
Solar PV	125
Offshore wind	197
Solar thermal	240

As you can see, nuclear is for the most part less expensive than coal, biomass, solar, offshore wind and some natural gas generation. The notion that nuclear power isn’t cost competitive is false.

Discussion

One’s position on nuclear power has become something of an ideological purity test amongst environmentalists. There is little stomach for acknowledging the good nuclear power does when it displaces the use of fossil fuels.

Arguments that nuclear power is unsafe or costs too much are not supported by the evidence, and run against common experience in places like Ontario. Ignorance or rejection of facts by some nuclear opponents undermines efforts to do something about the very real problem of climate change.

Although there are good reasons why we might choose not to build new nuclear capacity, maintaining and refurbishing existing facilities is not unreasonable from an environmental perspective. Decisions on how to proceed with nuclear power should be based on a cold, hard assessment of the facts.