A class of nuclear pumped lasers (excited by reactor‐produced thermal neutrons) in which the laser levels are populated by negative ion‐positive ion neutralization is proposed and an analysis of two particular systems,3He/N2O/O2and3He/N2O/N2, is performed. Laser action is predicted in atomic oxygen and nitrogen as a result of O−‐O+and O−‐N+neutralizations. The source of negative ions is dissociative attachment to N2O. A threshold neutron flux of ≊1015cm−2 s−1, peak power of >500 W/cm2, and a fission power to laser power conversion efficiency of ≊0.4% may be possible in these systems. This is as a result of efficient utilization of the large thermal electron density in the attachment process, and the highly selective nature of the ion‐ion neutralization in producing product‐excited states.