Unsteady Two-Phase Jet Forces" (in Italian)

The paper (in Italian) deals with the analysis of experimental data measured in the PIPER facility which are relevant to evaluate the safety of Nuclear Power Plants (NPP). PIPER was installed at the Scalbatraio Laboratory managed by IIN (Istituto di Impianti Nucleari) of University of Pisa. PIPER consisted of a pressure vessel equipped with electrical heaters and rupture nozzle, other than suitable instrumentation (typically temperature and pressure transducers). Namely original instrumentation was developed to measure the jet thrust, the jet impingement loads and the load on internal components following the break opening and the propagation of the depressurization wave upstream from the rupture into the vessel. In this paper experimental data of jet thrust and jet impingement are connected with the boundary conditions of the experiments in such a way to allow the derivation of expected loads acting upon the constraints of Reactor Pressure vessel and the containment walls in NPP.