The monolith vessel including covers and penetrations is a pressure vessel enclosing the monolith internals, like the target wheel and moderator/reflector plug as well as central shielding block structures and other components. It separates the interior void volume, including potential contamination therein, of the monolith from the ambient air atmosphere, both during normal operating condition and in off-normal situations. Specifically, the covers shall be designed to allow access of all monolith internals in accordance with their expected lifetime and reliability. The monolith also shall act as structural support for components, plugs and shielding block. Appropriate and repeatable alignment precision is needed especially for the target wheel unit and the moderator and reflector assemblies, relative the incident proton beam as well as the neutron beam extraction system.
The Monolith Vessel has been divided in several sub assembling:
- Lower and medium vessel (LMV): _ 30 tonnes after the optimization process. Large volume for handling and on-site welding’s.
- Connection ring (CR): considerable number of penetrations and difficult interface system. After 8 months, still minor modifications of connection positions. Vacuum test is challenging.
- Head of the Vessel (HV): Challenging vacuum test and not complete define interface with Target System.
- Proton Beam Window Vessel (PBWV): Very simple component but no yet defined the interface with the PBW and the neutron ports.