Environmental impact of nuclear energy

The potentially greatest negative impact lies in the risk of nuclear weapons proliferation, but not only

by Lorenzo Ciotti
Environmental impact of nuclear energy

Nuclear power can have a positive environmental impact. It also requires an important and constant supply of water and modifies the environment through excavation. The potentially greatest negative impact lies in the risk of nuclear weapons proliferation, risks associated with radioactive waste management, such as groundwater contamination, accident risks, and risks associated with possible attacks on waste storage and reprocessing facilities or nuclear power plants.

However, these risks have rarely materialized in history with only a few disasters having a significant environmental impact. Nuclear power is one of the leading low-carbon methods of producing electricity; in terms of the whole life cycle of greenhouse gas emissions per unit of energy produced, it has values comparable to, if not lower than, renewable energy sources.

A 2014 review of the carbon footprint literature by the Intergovernmental Panel on Climate Change reported that the virtual lifecycle emission intensity of nuclear power has a median value of 12 g CO2eq/kWh, which is the lowest value among all commercial baseload energy sources.

This value is compared to coal and natural gas at 820 and 490 g CO2eq/kWh respectively. Since the beginning of its commercialization in the 1970s, nuclear energy has prevented the emission of about 64 billion tons of CO2 equivalent which would have resulted from the use of fossil fuels in thermoelectric plants.

Globally, the average dose from natural radioactivity background is 2.4 millisieverts per year (mSv/a). It varies from 1 mSv/a and 13 mSv/a, depending on the geology of the place. According to the UN's UNSCEAR committee, ordinary operations of nuclear power plants, including fuel cycling, increase this value by 0.0002 mSv/yr.

The average dose due to the operating plants received by the populations neighboring the structure is less than 0.0001 mSv/a. For comparison, the average dose received by those living within 50 ml of a coal-fired power plant is three times as great, at 0.0003 mSv/yr.

The Chernobyl accident resulted in an initial average dose of 50 to 100 mSv over hours to weeks for the hardest-hit surrounding populations and personnel, while the global average exposure due to the accident is 0.002 mSv/yr and has been steadily decreasing since the initial peak of 0.04 mSv per person averaged over the entire Northern Hemisphere population in 1986, the year of the accident.