The ESS Target Installation Team has completed a significant milestone with the installation of the Target Moderator cap, sealing the Target Monolith vessel confinement. This installation enables upcoming pressure and vacuum leak tests of the Monolith vessel and its components, marking a crucial step towards the commissioning of the ESS Target Station.
On 22 May, the Target Moderator cap was installed onto the previously installed head of the vessel to cover the opening to the moderator pit in the heart of the ESS Target Station. This is the last piece of the puzzle to seal the Target Monolith vessel, and will enable extensive pressure and leak tests of the entire volume. Like many of the technical components in the ESS Target Monolith, the moderator cap is an In-Kind Contribution from Spanish ESS Bilbao.
The Moderator cap is a substantial component, weighing approximately 12 tons, with a 3.25 metre diameter and standing 2.5 metres tall. The pressure bearing part of the cap is made of stainless steel, whilst the upper part also includes an additional shielding barrier of concrete.
Following the installation, a pressure test of the entire Monolith confinement is scheduled for this coming weekend. After the pressure test, comprehensive vacuum leak tests will be conducted on the same volume to ensure the entire system's integrity and readiness for operation. These tests will include the Monolith vessel confinement, extending to the 42 port tubes, each sealed with a Neutron Beam Window at their ends.
The successful installation of the Moderator cap was prepared with the expertise from the ESS Vacuum Team and the precise lifting operation was carried out by the ESS Rigging Team. Installation Lead Krister Blomberg noted that the lid “fitted like a glove,” a testament to the meticulous planning and execution involved.
Watch this video clip showcasing the installation:
The ESS moderator cap is an In-Kind delivery from:
