Summary of the presentation: Gas supply in the north area Network configuration Accidental scenarios Result of the risk analysis Safety prescription Thanks to : HSE-OHS, EP, FGSO and TE safety officers ! 9/12/2019 Document reference

Gas supply in the north area – ECN3 EHN2 side 908: 920: 9/12/2019 Document reference

Gas supply in the north area – EHN1 side LN2 32 m3 10 bar – Saleve side LAr 6000 L 10 bar – Saleve side LAr Jura Side NP platform LN2 Jura Side NP platform 907: iC4H10, C2H2F4, CO2 909: Ar, CO2, CF4, C3F8, CO2,iC4H10,C2H2F4, SF6, H2, Ne 895: He – TE VSC 9/12/2019 Document reference

2) Configuration and layout of the network Gas network going inside the technical galleries. More than 1 km of pipes inside the galleries in the north area (He, N2, Ar, CO2) 9/12/2019 Document reference

2) Configuration and layout of the network Detail of EHN1 galleries Detail of EHN2 galleries 9/12/2019 Document reference

2) Configuration and layout of the network Picture of the gas network inside the galleries 9/12/2019 Document reference

2) Configuration and layout of the network Galleries volume: 3m x 2.5m - length detailed in the risk analysis depend of the area 9/12/2019 Document reference

2) Configuration and layout of the network EHN2 Access to the gallery GT806 Access to the gallery GT807 No lock, no signs, open to anyone 9/12/2019 Document reference

3) Accidental scenarios Small leak due to corrosion on tubes, flanges, seals or valves Temperature variation, Water leaks, Shock during worksite. Human error: (already happened twice in the last 3 years) - Bad connection, - Tap left open, - Untrained persons. Additional factors : No live monitoring of the gas consumption, no ventilation in the galleries, partial fix detection, free access, no lock on the access doors, no warning signs. 9/12/2019 Document reference

3) Method of the risk analysis 𝐹𝑙𝑜𝑤=𝐶∙𝐴∙ 2∙𝛥𝑃 𝜌 𝐿 𝑚 3 𝑠 𝑡 𝑐 1 =− 𝑉 𝑅 ∙𝑙𝑛 𝑐 1 0.21 C = a value of 0.62 assumed for a square hole R = leak rate (m3/h) A = size of the hole in m2 V = free volume (m3) C1 = final concentration ex:18% P = difference in pressure between the gas line and the atmosphere L the density of the leaking gas Fermilab ES&H Manual : http://esh-docdb.fnal.gov/cgi-bin/RetrieveFile?docid=387 9/12/2019 Document reference

3) Result of the risk analysis Leak size N2 Time to 18% O2 CO2 Time to 19.5% (toxicity) EHN1 Large leak 45.8 min longitudinal gallery 5.7 min transversal gallery 16 hours longitudinal gallery 2 hours transversal gallery EHN2 Large leak 50 min GT806 15 min GHN21 14.4 minutes GT806 few seconds GHN21

3) Result of the risk analysis Probability : 1: No event during the last 5 years 3: On average 1 event/ years during the last 5 years (CO2 leak EHN1, Rupture of valve) 5: More than 5 events / years during the last 5 years Reasonable maximum Severity : 1: Slight injury (1st degree burn, contusion…) 5: Injury with days off (broken legs, 2nd degree burn…) 10: Injury with work disability or fatality – major environmental damages Current level of control : 1: A safety management system is continuously improving the OHS level 3: A safety management system is in place but still have to be improved 5: Non-compliant with the applicable safety rules (no detection of the hazard) Probability x Severity x Level of control = 150 1 250 9/12/2019 Document reference

4) Prescription on going EHN1 only Implemented in EHN1 only IMPACT TRAKA ODH Portable + Key Not yet Implemented in EHN1 only 9/12/2019 Document reference

4) Prescription for the consolidation project Technical solutions: Install the ventilation system for the gas barrack certified ATEX Priority 1 Mandatory by law Add lock on the access doors to the galleries – add safety signs, safety consign on all the access. Install a ventilation system in the gallery in order to avoid local accumulation of gas Priority 2 Reduction the risk of accumulation Installation of detector inside the galleries Priority 3 Reduce the risk Install an instrumentation to monitor and secure the gas consumption in the north area Priority 4 9/12/2019 Document reference

4) Prescription for the consolidation project Organizational solutions: Procedure for portable ODH- CO2 detectors mandatory – lone work forbidden Priority 1 Mandatory by law Perform regular inspection (non-destructive testing) on the areas of piping Check on the “blue pipes type Rilsan ” in all the areas Reinforce the “user installation process” in collaboration between EP and EN Priority 2 Safety improvement Coherence between ODH risk analysis process amongst department (access, detection, procedure, signs, acceptation, risk assessment methodology…) 9/12/2019 Document reference

Thanks for your attention ! 9/12/2019 Document reference