You may find this paper by Rigby et al. interesting. https://dx.doi.org/10.2139/ssrn.4528600

Abstract

High capacity of renewable generation on energy grids of the future will require improved flexibility of typical base-load generators such as nuclear power stations. Integrated energy systems are a route to such flexibility with one option being considered by nuclear reactor vendors being Nuclear-Solar hybrid systems. Integrating solar generated heat from parabolic troughs into the feedwater line allows the plant to alleviate turbine bled steam and transiently power boost above nominal power in Rankine cycles.

This article presents a parametric study of the design of such a nuclear solar hybrid thermal system for a nominal small modular reactor cycle and provides a full system dynamic model written in DYMOLA with the Modelica language to analyse the dispatch in transient load following operation. The control of the system is presented and the impact on key variables are analysed due to step changes in electricity demand given to the plant.

The parametric study investigates the trade off in design between improved degrees of power boosting and system nominal efficiency. The work also suggests that higher final feedwater temperatures offer improved opportunities for power boosting flexibility. The transient analysis of the system allows a simple method for sizing the concrete storage and parabolic trough arrays under variable demand and solar insolation profiles and provides a viable route to a digital twin of such a system.