Cogeneration: An option to facilitate load following in Small Modular Reactors

Nuclear Power Plants (NPPs) have been historically deployed to cover the base-load of the electricity demand. Nowadays some NPPs might perform daily load cycling operation (i.e. load following) between 50% and 100% of their rated power. With respect to the insertion of control rods or comparable action to reduce the nuclear power generation, a more efficient alternative might be the “Load Following by Cogeneration”, i.e. diverting the excess of power, respect to the electricity demand, to an auxiliary system. A suitable cogeneration system needs: 1. To have a demand of electricity and/or heat in the region of 500 MWe–1.5 GWt; 2. To meet a significant market demand; 3. To have access to adequate input to process; 4. To be flexible: cogeneration might operate at full load during the night when the request of electricity is low, and be turned off during the daytime. From the economic standpoint, it is essential that the investment in the auxiliary system is profitable. This paper provides a techno-economic assessment of systems potentially suitable for coupling with a NPP for load following. The results show that district heating, desalination and hydrogen might be technically and economically feasible.