Draining analyses of the primary cooling circuits of the SPIDER Beam Source

The SPIDER in-vessel actively cooled components shall be drained in case of major maintenance to limit, as much as possible, atmospheric corrosion inside the circuits, to prevent water spreading, and finally to allow the execution of vacuum leak tests of the components before re-installation of the SPIDER Beam Source (SBS) inside the Vacuum Vessel. Draining of hydraulic circuits is first foreseen by gravity after opening the end connections of hydraulic circuits and then by blowing out with nitrogen. Injection of pressurized nitrogen is simulated by means of one-dimensional and three-dimensional models to perform transient two-phases analyses in order to calculate the minimum required inlet pressure and estimate the process time.