Steel and concrete containment models: Analyses and tests conducted to failure

In the wake of the Three Mile Island incident, attention was focused on the capability of the reactor containment building for loadings beyond its design basis. The containment building, whether it is made of steel, reinforced concrete, or prestressed concrete, is the last engineered barrier to prevent the release of fission products and radioactive gasses that could be generated during the severe-accident loading conditions. Containments are designed to withstand accident conditions and environmental loadings, such as loss-of-coolant accident and earthquake loadings. The containment function not only relies on its structural capabilities but also on its leaktightness. To investigate the performance of containment buildings for nuclear reactors, Sandia National Laboratories (SNL) has been engaged in an experimental and analytical effort to assess the behavior of containments subjected to pneumatic overpressurization. The objective of this program is to qualify analytical methods using experimental data, so that the analytical tools can be used to assess full-sized containment structures when subjected to a variety of accident scenarios. The major area of testing has been scale-model containment structures, but testing has also included other containment components that are critical to the containment structure, such as seals, gaskets, and full-sized electrical penetration assemblies and personnel air locks