The Ph.D. Thesis studies the role that nuclear plants could play in decarbonizing the European and French heating sectors. A nuclear power plant is basically a thermal plant that convert the nuclear heat into electricity using a turboalternator. But it could also be used in a cogeneration mode producing simultaneously power and heat. The latter offers many advantages including the low carbon profile and the ability to provide flexibility to the power grid.The most widely spread operation of nuclear plants today is electricity only production, which imply the dumping into the environment a large amount of heat that has not been converted to electricity. Transferring part of this heat to nearby industrial sinks or district heating systems wou...