Safety Review and Consolidation Actions for LS2 and LS3

1. Report from NA-CONS Safety Reviewheld 6, June 2019 F. Gautheron, Y. Kadi, A. Papageorgiou Koufidou, E. Solodko,M. Wilhelmsson (EN-EA-PE) 112th EATM meeting, 11 June 2019

2. The mandate given to the NA-CONS Study team defined at the 2016 Chamonix Workshop and Consolidation Day: • Undertake the necessary and urgent consolidation actions required prior and during LS2 (2019 – 2020) in order to guarantee a stable and reliable beam operation until LS3. • Prepare cost estimates for a more profound consolidation of the existing facilities, to be executed in (or after) LS3 (2025), including all possible staging options. • Prepare alternative scenarios covering increased performance linked to the “Physics Beyond Colliders” future requirements and energy optimizations. “There is an urgent need to put the installation in conformity with modern safety standards” A safety survey has been performed covering several aspects

3. Schematic view of the North Area • A few numbers: • Overall surface 60000 m2: • underground 16600m2, • experimental halls 31000 m2, • service buildings: 12000 m2 • 6 beam lines, ~ 6.3 km cumulated • ~ 1600 visitors / year Underground beam tunnels, caverns Underground Technical galleries Service buildings Exp. Halls

4. Agenda

5. Risk assessments, Safety audits (HSE, DSO) Following the statistics from the safety survey, a study was launched in collaboration with DSOs, the HSE department and the BE-ICS group to address them : Risk Assessments, Safety Audits and Technical Notes to obtain recommendations and cost estimates for the required consolidations.

6. Safety aspects reviewed • Radiation protection & Radiological surveillance  Claudia Ahdida (HSE-RP) • Access control  Rui Nunes (BE-ICS) • Fire Safety  Art Arnalich (assessment, HSE) & Silvia Grau (Technical solution, BE-ICS) • Gas detection  Simon Cherault (assessment, EN DSO), Silvia Grau (Technical solution, BE-ICS)

7. Items not covered by this review • Asbestos diagnostic • Gas network • Electrical non-conformities • Emergency lighting • Barracks on false floors • Roofs and floods

8. Points to be assessed … and referring to the section 6 (timeline) of the Study Report:

9. Radiological Safety  Claudia Ahdida (HSE-RP) • Do we need to extend the actual monitoring inside experimental areas ? • Should we review the “zonage” more regularly? • How should we handle the access to the transversal underground galleries under the beam lines? • deployment of an access control system (“ZORA”) or use of padlocks ? • Is the actual access control system adequate w.r.t. possible future requirements? And in the vicinity of the CERN domain ….: • What is the impact of NA on the environment ? • Specific studies required?

10. Radiological Safety  Claudia Ahdida (HSE-RP) • Replacement of RP monitors: ARCON to CROME (74 monitors in NA) by end-LS2 • Summary of consolidation actions (buffer zones, fences, indexation of air ventilation, RP surveys => shielding improvement) in TDC2/TCC2, EHN1, EHN2 and TCC8/ECN3. • Access Controls: • lack of monitoring in underground galleries => prevent access during beam time => use of padlocks considered sufficient • Is the actual access control situation adequate w.r.t. possible future requirements? • EHN1: NA61++ => Access restrictions required during high intensity runs for underground galleries + shielding to be significantly improved • EHN2: COMPASS++ , NA64++, NA64mu, MuonE: current proposal within given intensity limits • ECN3: NA62++ => OK, KLEVER => further RP optimization needed, DIRAC++ => may require ventilation modification • Hydrogeological Study to be urgently performed in order to assess contamination risks (TDC2/TCC2 + PBC in future)

11. Access Control  Rui Nunes (BE-ICS) • Is the actual Personal Protection access control system (ZORA) still adapted to the present situation? => Not certain that the current system in place is adequate post-LS2 ! need adequate study and risk assessment • Is it extendable to control the underground galleries access (EHN1 & EHN2) if required? • What might be the staging options to accommodate possible new safety requirements if PBC is endorsed (beam intensity increase)? • Should we have a control access system proportional to the risk encountered in each area? • Should we adapt the actual system or migrate to a new technology? • What would be the impact on the consolidation cost? The combination of: • increase of beam energies • new and more complex hazards • increased complexity of zones • uncoordinated modifications may not provide the adequate safety personnel protection that could be expected in the post LS2 operation scenarios. For this reason, a risk-based review and functional safety redesign of the post-LS2 ZORA Personnel protection system seems adequate at this time.

12. Fire Safety • Expected outcome from the assessment: • Provide a detailed analysis and a full set of recommendations w.r.t worst-case credible scenarios: • Life safety – What are the mandatory measures to be taken? But also: • Environmental protection (release of smoke and radio-activity) • Property protection • Continuity of the North Area operation • What are the technical solutions to be deployed to address the assessed risks? • What would be the corresponding cost estimate and strategy of deployment? Recommended measures to be taken for each?

13. Fire Safety  Art Arnalich (assessment, HSE) For the NA underground: • HSE came to similar findings of those in the SPS and prescribed the SPS FIRE concept for the protection of life, environment, property and continuity of ops. • The SPS FIRE concept is also applied at BDF, HiLumi, FCC or CLIC. For the NA surface: • HSE prescribed some evacuation upgrades (sirens, alarm buttons) for life safety. • HSE prescribed a campaign to rationalize excessive fuel load in storage areas for life safety. • HSE advised that full loss of a BA building is a plausible scenario and recommended fire protection improvement measures for property protection to be studied by risk owner.

14. Fire Safety  Silvia Grau (Technical solution, BE-ICS)

15. ODH and CO2 Safety  Simon Cherault (assessment, EN DSO) Expected outcomes from the assessment: • Should we generalize deployment of fixed ODH & CO2 detection? • In the underground galleries (EHN1, EHN2)? • In the technical galleries throughout the North Area? • Should it be done together with the deployment of a ventilation system in the galleries? • What risk if the ventilation accidentally stops? • Other solutions to mitigate ODH and CO2 risks?

16. ODH and CO2 Safety  Simon Cherault (assessment, EN DSO)

17. ODH and CO2 Safety  Silvia Grau (Technical solution, BE-ICS)

18. Summary • Most of the questions addressed to the expert panel have been answered • Remaining open questions concern: • Access controls: scope to be defined by additional risk analysis and functional safety studies • Installation of fixed ODH and CO2 detectors in galleries: further clarification required from HSE and Dep. DSOs • Hydrogeological Study to be urgently performed in order to assess contamination risks • Final Report will be available within 1 month