Studies have been carried out to determine the extent of damage to petroleum and synthetic lubricants resulting from the exposure to various types of nuclear radiation. Means to reduce this damage have also been studied. Three types of exposures have been used, namely, high energy electrons from a Van de Graaff Accelerator, gamma photons from Cobalt 60 and mixed neutrons and gamma particles from a nuclear reactor.
Results indicate that radiation damage to lubricating oil base stocks and finished products involves viscosity change, loss of oxidation stability and development of corrosive tendencies.
To evaluate lubricants for nuclear reactor systems, preliminary work indicates that static radiation is a useful technique. However, on an equal energy absorbed basis, there appear to be some differences in product damage caused by electrons and gamma rays and indirectly by neutrons. Furthermore, dynamic radiation testing appears to be a more realistic method for evaluating lubricant performance under specific conditions of speed, load, dose rate and temperature.
