Speaker
Description
The CERN Neutrino to Gran Sasso (CNGS) facility was commissioned in 2006 and operated from 2008 to 2012. It was designed to observe muon to tau neutrino oscillations with an intense muon-neutrino beam generated on the CERN side and directed over 732 km toward the Gran Sasso National Laboratory in Italy. 400 GeV/c protons were extracted from the CERN SPS and interacted with a carbon target, producing pions and kaons that subsequently decayed into muons and neutrinos. The CNGS facility accumulated a total of 1.8 × 10²⁰ protons on target with an average beam power of 510 kW.
The primary motivation for decommissioning the CNGS target area is to reduce the amount of radioactive material requiring long-term on-site storage at CERN. Additionally, decommissioning irradiated target areas allows future projects or experiments to re-use these areas. A specific motivation is the extension of the AWAKE facility, designed to study an innovative particle acceleration method based on proton-driven plasma wakefields. The CNGS target area is in a 100-m-long cavern, located 60 m below ground. It contains around 600 m³ of items to be removed: beamline elements, shielding blocks, supports, ventilation ducts, cables, and other small components.
This study details the radiation protection aspects of the ongoing decommissioning of the CNGS target area planned for completion in 2026. It covers the preparation phase, including FLUKA estimates of the residual dose rates and radionuclide inventories of the main components. It also presents benchmark comparisons between FLUKA simulations and measurements performed during the decommissioning phase. Finally, operational aspects and challenges encountered during the project are discussed, providing valuable feedback for future decommissioning campaigns.
| Topics | T5. Induced radioactivity and decommissioning |
|---|