In a recent study, researchers from the European Environmental Bureau (EEB), the Stockholm School of Economics (SSE), and the Potsdam Institute for Climate Impact Research (PIK) questioned the planned development of new nuclear capacities in the energy strategies of the United States and certain European countries.
I think they might be referring to turning down the reactors, which I think is an actual difficulty with them. By no means however is it a reason to not use them, it just means you employ it wisely. Have it meet most of the demand, and use solar and wind and others to supplement to full demand.