North Experimental Area Cable Cleaning Campaign

11 DECEMBER, 2022 | By the NA-CONS team

As part of the NA-Consolidation Project led by the BE-EA Group, a 5 week-long campaign took place at the end of this year’s shutdown to remove a huge number of obsolete cables from the Experimental Hall North 1 (EHN1) located at the far end of the Prévessin site. At 18 500 square meters this is the largest building on the Prévessin experimental campus and contains many old cables belonging to outdated systems dating from the 1970´s. The original plan was to remove about 500 cables with a total length of 45 km. However, upon completion of the work around 1000 cables with a total length of 55 km had been removed, mainly from the technical galleries serving EHN1.

This represents some 12 tons of cables. One of the challenges was to ensure safe working conditions for the decabling team, requiring most of the electrical systems to be locked out, apart from the essential safety systems that needed to remain operational. The lessons learnt from this campaign will be considered for the continuation of the NA-CONS decabling steps, as well as similar future activities throughout the complex.

The next decabling campaigns are planned to take place during this Year-End Technical Stops (YETS), addressing the Experimental Hall North 2 (EHN2) and the service building BA82. This will be followed in Long Shutdown 3 (2026-2027) by decabling in the Transfer Tunnels TT81 to TT85, the target cavern TCC2, the service building BA80 and the Experimental Hall North 3 (ECN3). All of this is an essential part of the preparation for the consolidation of these areas with the aim of providing an adapted and reliable infrastructure for our experimentalists for many years to come.