A small ammonia (NH3) leak of refrigerant occurred at 10:30 am at the level of evaporator no. 8 below the ramp on a men’s bobsled run. The installations, which had been maintained on Monday, were idle when the leak was detected by an employee’s sense of smell and then confirmed using pH paper. Three holes were pierced into the ice to identify the section of defective pipeline, which was subsequently insulated and neutralised. A finer localisation could then be performed at the level of the ice and afterwards on the ramp concrete. The baring of several pipes the next day revealed the presence of a 5-mm orifice on one pipe, extending 33 mm in diameter and 2.8 mm thick; an adjacent pipe was also deteriorated. Operations of the bobsled run were suspended by Prefectural order 3 days hence. inspection authorities for classified facilities proposed additional emergency measures imposing the facility operator to conduct an expert appraisal and verifications of all pipes carrying NH3, along with a set of repairs necessary prior to service restart. A third-party appraisal concluded that the tube had been punctured by external corrosion at this spot due to the combination of a wet environment and the presence of aggressive agents like chlorine and sulphur, both of which were caused by a permeability break in the cover concrete. Repairs were performed according to a dedicated protocol and approved by the relevant administrative agency; next, the welds were X-rayed. A refrigeration specialist vouched for the quality of these repairs and, instead of the conventional hydraulic test rendered impossible by the negative temperatures experienced this time of year, proposed a pressure resistance test of all pipelines under 14 bar of nitrogen, i.e. 1.1 times the maximum 12-bar service pressure. Operations of the bobsled run were re-authorised in January for 1 year, i.e. corresponding to the period of validity of the completed resistance test. Moreover, comprehensive inspections of the facility had to be carried out by certified staff wearing appropriate equipment and recorded on a register made available to inspection authorities for classified facilities. The inspection frequency was raised as high as necessary throughout the operating life cycle to detect any possible NH3 leak. State-of-the-art thermal imaging controls conducted the next year ultimately determined whether the installation would continue to operate.