Nuclear power plants are used extensively as base load sources of electricity. This is the most economical and technically simple mode of operation. In this mode, power changes are limited to frequency regulation for grid stability purposes and shutdowns for safety purposes.

However for countries with high nuclear shares or desiring to significantly increase renewable energy sources, the question arises as to the ability of nuclear power plants to follow load on a regular basis, including daily variations of the power demand.

This report considers the capability of nuclear power plants to follow load and the associated issues that arise when operating in a load following mode. The report was initiated as part of the NEA study “System effects of nuclear power”. It provided a detailed analysis of the technical and economic aspects of load-following with nuclear power plants, and summarises the impact of load-following on the operational mode, fuel performance and ageing of large equipment components of the plant.