Helium cooling system ODH - Follow up

Wednesday 1 Oct 2025, 09:00 → 10:00 Europe/Zurich

73/1-031 - 73-1-031 (CERN)

Conversation on assessing all of the potential leak scenarios in the BDF helium cooling system and look toward building a comprehensive and complete ODH assessment.

Addressing key areas:

• Service building
• Target complex
• Experimental areas

 

Dear all please find the notes from this meeting:

·       The CV room in the service building is where the assessment must be focused with a particular focus on the valves and connections of the equipment. This being a relatively small area of 644.4m3, with a volume of 8m3 of helium in the circuit.

·       The target complex area in TCC8 would see a negligible change in oxygen percentage due to the volume of the room in the event of a release.

·       From the service building to the underground, pipes will be welded securely to reduce the chance of accidental releases. They are to undergo 100% x-ray tests, and the further option of inexpensive leak testing with the Cryogenics group can follow.

·       The subject of providing an additional layer around the pipes was discussed. However, although some marginal additional safety may be achieved it would be expensive to install and would create additional challenges to address a situation where this is a leak.

·       2 additional racks of bottles will need to be stored somewhere. Some of the helium bottles could be stored outside.

·       Evidence of similar uses of helium are to be used to support this process such as in HiLumi.

·       EN-CV will draft a document with the support of HSE-OHS.