Heat Transfer in Cane Fiberboard Exposed to Hypothetical Accident Conditions

Radioactive material packages containing fiberboard insulation have been subjected to Hypothetical Accident Condition (HAC) thermal tests for many years. Historically, the packages` thermal performance has always been difficult to grasp. A package designer needs to understand the effects of temperature and pyrolysis on the rate of heat transfer and performance. This paper describes in detail the one-dimensional HAC thermal tests performed on fiberboard to understand the effects of pyrolysis, its char and its gas products. The tests were conducted by the Packaging and Transportation Group at the Savannah River Site (SRS). Test fixtures were assembled at SRS and thermal testing conducted in the Radiant Heat Facility at the Sandia National Laboratories. Descriptions of the test fixtures are provided, as well as the time dependent temperature profiles. In addition, lessons learned are discussed.