Nuclear power is frequently considered a pure baseload technology working at the rated power level for long periods of time. This baseload working mode has two advantages: (a) technical, commercial and organisational simplicity, and (b) it is the commercially most advantageous form of operation in a context of stable prices for electricity. High load factors over long periods of time are essential to pay back the investment costs of high fixed-cost and low variable-cost technologies such as nuclear energy.7 Unsurprisingly, nuclear energy is thus used in baseload mode in most OECD countries. A high ratio of fixed costs to variable costs is a characteristic that nuclear energy shares with most renewable technologies.