PANDA TESTS FOR INNOVATIVE PLANTS WITH PASSIVE SAFETY SYSTEMS

摘要

A new test series is being planned for the PANDA facility to experimentally investigate the containment loss-of-coolant accident (LOCA) response of innovative nuclear power plants with passive safety systems. PANDA is a thermal-hydraulic containment test facility located at the Paul Scherrer Institut (PSI) in Switzerland. The modular representation of the containment in PANDA gives flexibility to investigate a variety of different passive decay heat removal systems for the next generation of Light Water Reactors (LWR). Modularity and a large scale allow examination of the effects of non-uniform spatial distribution of steam and non-condensable gas in the system. The recently completed test series focused on the longterm response and performance of the passive containment cooling system of the Simplified Boiling Water Reactor (SBWR). One of the planned PANDA test series will utilize the European Simplified Boiling Water Reactor (ESBWR) configuration to study several new features introduced in the more advanced containment design of this plant. A major design change (with respect to the SBWR) is related to the passive emergency core cooling system. The gas space above the water pool of this Gravity Driven Cooling System (GDCS) is now connected to the wetwell gas space rather than the drywell. As a consequence, the wetwell gas space volume increases during the GDCS injection phase as water drains from the pool to the reactor pressure vessel. This provides an additional pressure margin under hypothetical accident scenarios and allows for a compact containment design. The effect on containment response due to the time-dependent change in wetwell gas space volume will be investigated for different LOCA scenarios. A series of eight transient system tests is planned. The new PANDA test series will provide an extensive data base, which will contribute to containment design of innovative passive plants, system code assessment and analysis of particular phenomena.