ATLAS shielding machining [JFSU and JFC3 rotation] + ATLAS TAS removal [Minivan use]

Monday 16 Jun 2025, 14:00 → 15:00 Europe/Zurich

57/1-031 (CERN)

From JFC shielding machining during LS2 one lesson learned was that machining of horizontal planes are faster and with less complications than machining vertical planes.

For this reason JFC3s and JFSUs require to be rotated in building 191. The transport service studied what tooling would be required to do the rotation. The goal of this meeting was to discuss the different options and what preparatory steps need to be realized (e.g. drilling of threads for fixing the tooling) . 

14:00 → 14:45 Rotation of JFC3s and JFSUs

Speakers: Caterina Bertone (CERN), Francisco Sanchez Galan (CERN), Maria Perez Ornedo (CERN), Oliver Boettcher (CERN), Sergio Di Giovannantonio (CERN)

MAB-825.pdf

Maria presented lifting attachments available on the market including 50t capacity, proposing that 2 of these could be bolted by 6x - 8x M36 holes to each unit to be rotated. 

Discussion was about how to machine the M36 holes. Experience with thread machining with the robot goes only up to M16. In addition the proper thread finishing cannot be guaranteed, which means that in any case parts of the machining need to be realized manually.

During LS2 magnet drilling machine (taken from CMS) was used for realizing M16 holes into JFC2s. The same machine can probably be reused. However following datasheet (find attached) threads machining with that machine goes only up to M30. It was further discussed that the threads machining could be partly realized with the robot (e.g. core drill) and finishing could be done manually with the magnet drill. 

Timely planning (preliminary):
- It has been agreed that the 1st JFSU should be brought to b.191 in July 2026 before road works will start blocking the crossing in front of Meyrin Gate B. 
- The 2nd transport operation will be planned to happen in March 2027 and consists of 2 transfers back and forth between SX1 and b.191. 
- For machining of the 2nd JFSU 4 months of time will be considered, so 3rd transport operation will fall to end of July 2027. 
- 1st JFC3 would then be available for machining as from August 2027. (Considering the experience won during machining the JFSUs, an estimated machining time of 4 months seems to be appropriate.) 
- 4th transport operation and the exchange of JFC3s would fall to November 2027.
- 5th transport and end of the project would then be in March/April 2028. 

The following decisions had been taken: 

• Maria looks for similar lifting devices that require threads of max 30 mm that could be machined manually. 
• Oliver and Sergio contacts RP to check dose rates related to manual machining of threaded holes and get their advice on how this kind of work should be carried out. 
• Oliver prepares a preliminary planning with the main milestones of the project for communication (objective mid July)
• Thin rubber sheets will be put between shielding pieces and the floor for protection (less for dampening)

 

14:45 → 15:00 ATLAS TAS removal-TAXS installation - with minivan

Speakers: Caterina Bertone (CERN), Francisco Sanchez Galan (CERN), Maria Perez Ornedo (CERN), Oliver Boettcher (CERN), Sergio Di Giovannantonio (CERN)

While the actual baseline for the TAS removal and TAXS insertion foresees the use of a cantilever structure Maria and Caterina lately brought to discussion if the use of the available mini-van support structure would be supported by ATLAS. Michel Raymond supports the proposal and confirmed that related logistics in the caverns seem to be feasible for him. The new approach would require 2 more moves of the Big Wheel.

The use of the mini-van for this operation has several advantages: 

• mini-van available - adaptation to TAS / TAXS operation seem to be easier and less expensive to transport experts
• no cantilever system load test or TX1S hole quality checks required
• workers expose to radiation - mini-van allows to position to workers more favorable during extraction
• access to work via mini-van - less risk that MEWP get stuck with workers in non-favorable situation related to radiation exposure 

 

3d model numbers for further studies:

• ST1591094_01 (BW in open position over TX1S)
• ST..._02 (BW in closed position - ATLAS Run configuration)
• ST0858083_01 (minivan + extension + JTT)
  

 

We agreed that we further investigate the use of the mini-crane for TAS removal and TAXS installation scheduled for January 2027.