[en] The combined experimental/analytical investigation has resulted in identifying General Plastics FR-9606 polyurethane foam as the best wall insulation currently available for TRUPACT applications under anaerobic conditions. This overall conclusion is based on the experimental and analytical studies conducted in this program, as well as practical considerations, such as fabricability and cost. Analytical studies were conducted to develop predictive models representative of the thermal performance of this material. The studies produced the following results: a one-dimensional charring model, compatible with an existing charring materials code, was developed that produced very representative performance predictions for environments in which surface temperatures do not exceed 1144 K; a noncharring effective thermal properties model for the candidate foam was derived that provides equivalent accuracy as the charring thermal model; and the thermocouples used in the mockup test series are not an important source of error in the measured data