First, the term externality is very much associated with environmental externalities. This holds in particular for the power generation sector, which in the 1990s was the subject of three influential and since updated studies on environmental externalities.6 The environmental impacts of electricity generation, in particular in the area of climate change, remain of course an important issue. The NEA discussed this in a publication on Carbon Pricing, Power Markets and the Competitiveness of Nuclear Power (NEA, 2011).