Compressible response of thin liquid film/porous substrate first walls in IFE reactors

The compressible response of a thin film of liquid subjected to a rapid surface pressure pulse and isochoric nuclear heating is investigated in an attempt to determine the spallation behavior. The use of such films to protect the cavity wall of inertial confinement fusion reactors is currently envisioned. The magnitude and temporal dependence of the surface pressure impulse and nuclear heating are estimated based on data from the Prometheus-L, Osirus and Hiball design studies, all of which use the thin film wall protection concept. Compressible hydrodynamic calculations are performed with the CFDLIB code package from LANL. In both the Prometheus and Osirus cases, no spallation is predicted based on the results of these calculations. However, calculated tensile stresses are less than an order of magnitude below theoretical limits, and uncertainties in data and material behavior may push the film response closer to spallation.