Even shutting down nuclear plants would adversely impact the climate

The United States is facing a dilemma over what to do with its ageing nuclear power infrastructure, with the decision to retire or upgrade the reactors that currently supply about 20% of the nation's electricity.

United States has the world's largest nuclear fleet with 92 operating reactors, many of which have already been in operation for more than 50 years and are nearing the end of their expected useful lives.

While nuclear power is considered a low-carbon alternative to fossil fuels, a recent study by MIT researchers has added a new dimension to the debate by examining the impact of nuclear power on air quality.

The study, which was published in the journal Nature Energy, looked at a what-if scenario in which all nuclear power plants in the US are shut down and replaced by other power sources such as coal, natural gas, and renewable energy for a whole year.

The results suggest that air pollution will actually get worse as the use of fossil fuels accelerates to offset the downsides of nuclear power. The research team quantified this effect and estimated that an additional 5,200 pollution-related deaths could occur each year as a direct result of increased air pollution.

MIT study: Nuclear power, air quality

The analysis revealed that the addition of fossil fuel above the current scenario would result in an increase in PM2.5 and ozone concentration leading to an additional 5,200 deaths per year. This figure was for the US only, but similar scenes could be expected around the world if nuclear power plants disappear.

MIT researchers developed a model to estimate carbon dioxide, nitrogen oxide, and sulfur dioxide emissions from each electricity-generating unit, incorporating these emissions into a chemical transport model to calculate the effects on ground-level ozone and fine particles (PM2.5).

The team found that even in this more abundant renewable scenario, there is still a slight increase in air pollution in some parts of the country, resulting in a total of 260 pollution-related deaths over a year.

"This adds another layer to the environmental health and social impacts equation when thinking about nuclear shutdowns, where the conversation often turns to local risks due to accidents and mining or long-term climate impacts," says lead author Lyssa Freese, a PhD Student at MIT's Department of Earth, Atmospheric and Planetary Sciences (EAPS).

While the model estimated 5,200 deaths a year, it is also likely that more people will die prematurely due to the climate impacts of increased carbon dioxide emissions, as the grid compensates for the absence of nuclear power.

The climate-related effects of this additional carbon dioxide input could result in an additional 160,000 deaths over the next century in the US alone.

“We have to think about how we're retiring nuclear power plants if we're trying to think of them as part of an energy system,” Freese said.

Impact of Nuclear Power Reduction

The closure of nuclear power plants in the past has resulted in an increase in the use of fossil fuels to make up for the loss of electricity generation.

To investigate the potential impact of a complete phaseout of nuclear power on air quality and public health, a team of MIT researchers developed a power grid distribution model. This model simulates the production of all power plants in the country, estimating energy demands per hour in 64 regions across the country.

The team fed the model data on changing emissions and energy costs from each plant over the course of a year and ran it under different scenarios.

They found that a complete phaseout of nuclear power could lead to an increase in the use of fossil fuels and air pollution, resulting in a risk of premature death for people in the path of pollution.

Retiring nuclear power: potential consequences

Freese said that retiring nuclear power plants should be considered as part of the energy system, as their closure can lead to increased emissions from the grid system.

"In the debate about keeping nuclear power plants open, air quality has not been at the center of that discussion," added study author Noelle Selin, a professor at the Institute for Data, Systems and Society (IDSS) and EAPS at MIT.

She further explained that air pollution caused by fossil fuel plants is so harmful that any increase, such as that resulting from a nuclear shutdown, will have significant impacts on some populations more than others.

Selin highlighted the need to focus on renewable energy sources to fill the gap left by nuclear power, which is a zero-emissions power source.

The study provides an in-depth analysis of the potential consequences of phasing out nuclear power in the US, including the impact on air quality, public health, and energy infrastructure.

By examining the interaction between different energy sources and their emissions, the study can inform policymakers and energy industry stakeholders about the future of nuclear power in the energy mix.

The US Environmental Protection Agency partially funded the research, underscoring the seriousness of the findings and their implications for public health and environmental policy.

Support us to keep independent environmental journalism alive in India.

Keep Reading

Part 1: Cloudburst  in Ganderbal's Padabal village & unfulfilled promises