Chemical Reactivity Test for Thermal Stability

Lawrence Livermore National Laboratory LLNL has developed a thermal stability test procedure that is currently being evaluated by the Department of Defense DOD Explosives Safety Board as an equivalent alternate test to the DOD Technical Bulletin 700-2 Thermal Stability Test at 75 degrees Celsius. This procedure will also be submitted for evaluation for acceptance under the similar test specified in the United Nations Recommendations on the Transport of Dangerous Goods, Tests and Criteria Manual. The LLNL Chemical Reactivity Test CRT is significantly more severe than the existing Thermal Stability Test at 75 C and is also quantitative in nature. It has been approved by the Department of Energy DOE Explosives Safety Committee as an equivalent alternate thermal stability test and has been in use by LLNL for over 30 years. It is currently used by other DOE and DOD organizations as the standard small-scale safety test for determining thermal stability and material compatibility. The LLNL CRT is run on a 0.250 gram sample for 22 hours at 120 degrees Celsius rather than the 50 gram sample for 48 hours at 75 C as required for the Thermal Stability Test. Thus the CRT is a much more severe test since it is run at 120 C rather than 75 C. Simple Arrhenius kinetics predict a material decomposition rate of approximately 25 times greater at 120 C than at 75 C. Any material under test that exhibits gas evolution exceeding 4 cubic centimetersgram approximately 0.8 decomposition is considered suspect and additional testing andor evaluation is then performed to determine if the material is thermally unstable. In addition to the CRT being significantly more severe and quantitative, there are significant other advantages for using the CRT.