Load Following by Cogeneration: Options for Small Modular Reactors, GEN IV Reactor and Traditional Large Plants

Abstract

Nuclear Power Plants (NPPs) has been historically deployed to cover the base-load of the electric power demand. Nowadays this scenario is changing and some NPPs are requested to perform daily load cycling operation (i.e. load following) between 50% and 100% of their rated power. The traditional methods to perform the load following are by inserting negative or positive reactivity into the core, moving the control rods. This strategy reduces the produced thermal power and in turn the electric power output with respect to the base-load strategy. From a technical standpoint this strategy submits the primary circuit to thermodynamic transients, which causes thermomechanical stresses on some components. From an economic standpoint this operation is very inefficient since, in NPPs, costs are mainly fixed and sunk, and there is a negligible cost saving (if any) in reducing the power of the reactor. A more efficient alternative might be doing the “Load Following by Cogeneration”, i.e. performing the Load Following by diverting the excess of power to an Auxiliary Plant. This paper assesses the technical feasibility of the coupling between a NPP and hypothetical cogenerate plants producing: diesel-like fuels from plastic pyrolysis, or desalinated water, or pellets from waste wood, or hydrogen from water splitting.

An overview of sustainable energy development by using cogeneration technology and opportunity for improving process

“…The temperature ranges of existing reactors, developing reactors, and the future reactors is presented in Figure 4. Recently, the International Atomic Energy Agency (IAEA) has introduced small modular reactors with capacities higher than 300 MWe as the advanced reactors for the construction and operation, wherein their use in nuclear cogeneration is a turning point in improving operational and energy efficiency 15 . For example, in 2014, the use of the high‐temperature gas‐cooled reactors in the cogeneration processes was accounted by the Japan Atomic Energy Agency (JAEA) 16 …”

Siting of small modular reactors with renewable power generation support

“…Under this scenario, future SMRs regardless of their electrical ramp rate can be operated at a high thermal output and an electrical grid response rates allowing effective support of intermittent renewable sources. This can be one of the highest return on investments an SMR investment could provide [3].…”

Megaproject Management

“…Another key SMR advantage to consider is the possibility to have multiples units on the same site [8,12,20]. Other factors to consider in SMR economic and financial evaluation are: suitability for cogeneration [21][22][23][24], expected higher learning rate [10,25], better adaptability to market [8], equal or higher capacity factor than current LRs [26]. Once these factors are taken into account, the capital cost is comparable between the two technologies [27].…”