nuclear reactions are the source of the sun's energy
nuclear_reaction is not natural_process. nuclear_reactions is not_chemical_reactions. sun is giant_fusion_reactor. thermal_reactor is nuclear_reactor. nuclear_reaction is natural_process. fusion is nuclear_reaction. gas_cooled_reactor is not nuclear_reactor. gas_cooled_reactor is nuclear_reactor. sun is not giant_fusion_reactor. water_cooled_reactor is nuclear_reactor.