TGA technique for determining the dose and dose-rate susceptibility of organic materials in nuclear power systems

Since organic materials in nuclear power systems are radiation age-sensitive, it is critical to determine their degree of susceptibility. These materials applied for example in cables, packaging for electronics, shielding, insulation, etc. experience a radiation environment consisting of both a dose level and dose rate. The latter is significant when considering that some materials as discussed in several Sandia documents show a dose-rate dependence with regard to degradation. This paper addresses a practical means of establishing a radiation threshold and dose-rate dependences for organic materials. Thermogravimetric analysis (TGA) is the test vehicle and the results for Teflon TFE are presented to demonstrate the method. This technique which is being applied in a limited fashion in ground-based nuclear power systems should be successful in a space-based nuclear power system as well