Introduction:

F. Pedrosa started the meeting announcing that this is the second of several HI-ECN3 WP7 focus meetings that will be organised, and this one specifically will be focus in Civil engineering and the two presentation that could not be delivered in the past meeting

Target Station

G. Humphreys presented the target station configuration as is with the different type of shielding, the load distribution (maximum load 45T/m2) and the concerns on having a pit just below the vacuum vessel. The pit is required by HSE-RP to increase the shielding below the target, but it is a challenge for the civil engineering team and a concern for the target station team. Most of the discussions during the presentation focused on the pit and the associated issues that could arrive. The same amount of shielding below the target cannot be achieved without the pit, otherwise the beam line would have to be raised and consequently the SHiP experiment.

From the presentation and the discussions, the following actions were defined:

• Action 1: [SCE] study the possibility of creating a pit with the dimensions shown in slide 7, identify if the solution would require drilling through the tunnel water insulation system (which would increase the water infiltration risk), define in the study the drainage requirements, and define a cost estimate. [deadline: end of May 2025]
• Action 2: [SCE]: if the study performed as part of action 1 defines that the tunnel water protection will be damaged, then define the maximum depth of the pit that could be performed without damaging the water protection of the tunnel [deadline: end of May 2025]
• Action 3: [HSE-RP] simulate the actual configuration with the pit and without the pit to allow the project to take an informed decision by June 2025 [deadline: end of May 2025]
• Action 4: [Project] decide by end of June 2025 the option that should be considered in the TDR (with or without a pit) [deadline: end of June 2025]

Target complex service building

J.-L. Grenard presented an overview of the services building the floor load capacity requirements, the RP classification for the different areas of the building, the sump requirements, …

From the presentation and the discussions, the following actions were defined:

• Action 5: [SCE] define the floor finishing properties based on the HSE-RP classification shown in 13 [deadline: end of June 2025]
• Action 6: [SCE] define the different drainage systems based on the information available on slide 16 [deadline: end of June 2025]
• Action 7: [J.-L. Grenard] define the load capacity to the EN-EL area to “False floor – 500kg/m2 and rack support structure – 750kg/m2” (information provided by E. Cano after the meeting) [deadline: end of April 2025]
• Action 8: [J.-L. Grenard] define two envelops in which the contractor that will defined the service cell should remain [deadline: before passing a contractor with the company that will study the options for the service cell]
• Action 9: [J.-L. Grenard] ensure that the final service cell design is delivered by the company before the end of 2025 [deadline: end 2025]
• Action 10: [SCE]  study the what would mean to reach the floor load capacity of 20T/m2 and 60T/m2 for the two service cell envelops, and defined a cost estimation for the different options [deadline: end of 2025]
• Action 11: [SCE] define the door between 911 and 754 to withstand 10Pa difference. The door can smaller for the normal operation, but the full size is needed in case the B754 overhead crane has to be replaced [deadline: end of June 2025]
• Action 12: [J.-L. Grenard] define a position for the evaporator in case the target cooling option selected is water [deadline: end of June 2025]

SHiP Experiment: 

P. Santos Diaz presented the preliminary civil engineering requirements for the SHiP project, highlighting updates on the layout drawings, building model integration, and infrastructure planning. The discussion covered service connection layouts between surface and underground levels, load constraints for equipment such as the muon shielding, straw tracker, and spectrometer magnet and drainage requirements for mineral oil-based systems. The need for a dedicated support structure for the He balloon and a potential liquid scintillator collection system was discussed. Additional topics included the feasibility of placing gas tanks near Building 920, the installation of the tent, and the minimal works needed in buildings B911, B918, B920, and ECN3. 

From the presentation and the discussions, the following actions were defined:

• Action 13: [B. Martinez Sutil and SCE] confirm the location of the drainage system with respect to the spectrometer magnet inside ECN3 shown in 9 [deadline: end of April 2025]

• Action 14: [M. Averna] evaluate a water collection system (like the one in BA2) for the underground and include it in the TDR. This collection system will be useful to separate the contaminated water leaks that might appear from the rest of the waste waters [deadline: end of 2025]
• Action 15: [P. Santos Diaz] check the type of power converters needed for the spectrometer magnet and the desired location. Send the specifications to E. Cano so they can be included in the EN-EL power request study [deadline: end of April]
• Action 16: [SCE] needs to provide the drawings of the building to be able to check the connections between the surface (B918 and B920) and the underground facilities. This information is necessary to determine the path of the services [deadline: end of May]
• Action 17: [SCE] check the location of the concrete platform to be built next to the B920 is compatible with the road to access the tent [deadline: end of May] 
• Action 18: [Project] confirm the structural needs of the tent [deadline: end of May] 
• Action 19: [SCE and EN-HE] check if there is enough space at the entrance of the tent for the lorry to turn shown in 11 [deadline: May 2025]
• Action 20: [SCE] share the building model and to perform a structural check for slab loading capability [deadline: May 2025]
• Action 21: [B. Martinez Sutil] integrate the B920 model to be able to perform future integration of the services inside the building [deadline: July 2025]