Ken wrote: ↑Sun Mar 12, 2023 8:42 amMy understanding is that they can modulate the output electricity but not the core reaction and basically they waste the difference. ??
After reading that article by Marshman not so sure.
In theory that's possible. In practice it requires such a massive impact on the rest of the plant that it isn't practical. Nowadays they use control rods and sometimes boric acid injection into the coolant to provide an additional neutron absorber to compensate for Xe131 effects.
Perhaps they can but do they. My understanding is they just waste the excess heat if not used.
Looking at gridwatch France i dont see much load following except between seasons but even then that may be down to maintenance.
With very low running costs nuclear would be the last perhaps to modulate as leccy prices fall. The first to modulate is those plants with higher running costs eg gas and coal would reduce to tick over. As prices drop further to zero the interconnectors will export.
Dont see when a nuclear plant would modulate and i dont think they do in practice. Their production contracts must cover yrs in advance at min cost knowing full well they will get payed the going rate set at the time by gas. It certainly cannot be worth their while to modulate for a few hours here and there.