a b s t r a c tLoad following is the potential for a power plant to adjust its power output as demand and price for electricity fluctuates throughout the day. In nuclear power plants, this is done by inserting control rods into the reactor pressure vessel. This operation is very inefficient as nuclear power generation is composed almost entirely of fixed and sunk costs; therefore, lowering the power output doesn't significantly reduce generating costs and the plant is thermo-mechanical stressed. A more efficient solution is to maintain the primary circuit at full power and to use the excess power for cogeneration. This paper assesses the technical-economic feasibility of this approach when applied to Small Modular Reactors (SMR) with two cogeneration technologies: algae-biofuel and desalinisation. Multiple SMR are of particular interest due to the fractional nature of their power output. The result shows that the power required by an algae-biofuel plant is not sufficient to justify the load following approach, whereas it is in the case of desalination. The successive economic analysis, based on the real options approach, demonstrates the economic viability of the desalination in several scenarios. In conclusion, the coupling of SMR with a desalination plant is a realistic solution to perform efficient load following.

This is a repository copy of Load following of Small Modular Reactors (SMR) by cogeneration of hydrogen: A techno-economic analysis.

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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 L F C 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 MWt 1 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) for 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 suitable for coupling with a NPP for load following. The results show that district heating, desalination and hydrogen might be technically and economically feasible.

The nuclear “renaissance” that is taking place worldwide concerns the new build of GW size reactor plants, but smaller GenIII+ NPP (Small Modular Reactors, SMR) are on the verge to be commercially available and are raising increasing public interest. These reactor concepts rely on the pressurized water technology, capitalizing on thousands of reactor-years operations and enhancing the passive safety features, thanks to the smaller plant and equipment size. On the other hand, smaller plant size pays a loss of economy of scale, which might have a relevant impact on the generation costs of electricity, given the capital-intensive nature of nuclear power technology. The paper explores the economic advantages/disadvantages of multiple SMR compared to alternative large plants of the same technology and equivalent total power installed. The metrics used in the evaluation is twofold, as appropriate for liberalized markets of capital and electricity: investment profitability and investment risk are assessed, from the point of view of the plant owner. Results show that multiple SMR deployed on the same site may prove competitive with investment returns of larger plants, while offering, in addition, unique features that mitigate the investment risk.