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 fixedcost and low variablecost technologies such as nuclear energy 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