Is A Nuclear Power Plant Exothermic Or Endothermic?

Is A Nuclear Power Plant Exothermic Or Endothermic? Nuclear reactors use exothermic fission to generate power. However, examples of endothermic fission exist, as well as endothermic fusion. Is nuclear energy exothermic reaction? Nuclear fission produces heat (also called an exothermic reaction), because if you add all the masses together of the products of reaction you