Several system studies have concluded that the small size and steady-state nature of magnetic mirror systems provide attractive features for nuclear testing applications such as blanket testing, fissile fuel production, tritium production, or decontamination of high-level radioactive nuclear reactor wastes. A summary of the data base is presented, and next-generation experiments that could be carried out to explore plasma physics issues associated with the production of high neutron fluxes in magnetic mirror configurations are described.