safety aspects in the north experimental area

Safety Aspects in the North Experimental Area Consolidation Study

F. Gautheron, Y. Kadi, A. Papageorgiou Koufidou, E. Solodko,M. Wilhelmsson (EN-EA-PE)

NA-CONS Safety Review, 6 June 2019

Schematic view of the North Area

F. Gautheron, NA-CONS Safety Review, June 6th 2019 Safety Aspects in the North Area Consolidation Study 2

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






Exp. Halls






Exp. Halls

Undergroundbeam tunnels,caverns






Exp. HallsUndergroundtechnical galleries







Exp. Halls


UndergroundTechnical galleries

Servicebuildings

The mandate given to the NA-CONS Study team

1. 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.

2. 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.

3. 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”

defined at the 2016 Chamonix Workshop and Consolidation Day:

A safety survey has been performed covering several aspects

Safety Survey: Identified Safety Issues

• Accidents and injuries in NA (2010 – 2017), working days lost

NA is a very large domain where different categories of persons intervene:


Category of person Accidents Days of sick leave

MPE (staff, fellows) 8 58

MPA (associates, users) 9 0

Entreprises 19 215

Total 36 273


• Accidents and injuries in NA (2010 – 2017), working days lost

• False floors and barracks problems in EHN1 and EHN2


False floors and barracks – Safety hazards


Accident - 28.07.2016

Accident – 11.10.2017

Doors in narrow walkwaysFalse floor slabs tumblingGround floor:

fall of min 40cm 1st floor:Metallic slab absent= risk of 3m fall

Highest Risks already addressed during the last YETS LS2 Opportunity to remove part of false floor in EHN1 ground floor

and replace/relocate old counting rooms but postponed due to the lack of budget

https://edh.cern.ch/Document/General/Accident2/6469047

https://edh.cern.ch/Document/General/Accident2/6982449


• Accidents and injuries in NA , working days lost


• Undetected event of CO2 leak – “near incident”

• 486 m3 (~900 kg) of CO2 released in a H8 beamline “bunker” in two days (2017)

• CO2 can travel through openings in the floor and cumulate in the underground galleries

• Compensatory measures now in place to access underground gallery (IMPACT registration + portable ODH & CO2 detector)






• Fire brigade interventions – various alarms, fires, smoke,…


Fire Brigade interventions in NA

Building 2014 2015 2016 2017 (1/2 year) Total

808 (TT20) 1 1

810 (TT81) 1 1

887 (EHN1) 5 9 14 13 41

888 (EHN2) 1 1 2 4

889 (BA80) 6 2 3 11

890 (BA81) 7 2 6 3 18

891 (BA82) 4 2 3 9

895 (BB81) 1 1 3 4 9

900 (ECN3) 2 3 1 6

901 (TCC8) 2 2

918 (BX83) 1 1

Total 26 20 29 28 103






• Fire brigade interventions – various alarms, fires, smoke (AWAKE plasma cell, …)

• Non conformities (electrical, mechanical, chemical, civil engineering, ….)


7 11 6 0 11 6 5 11

306

33 4210 3

69

1 5 023 40

14 3 2

70

4 1 16 14

050

100150200250300350

NU

MB

ER

OF

OB

SE

RV

AT

ION

S

BUILDING

713 electrical non conformities pointed out in 2017

Risk assessments, Safety audits (HSE, DSO)

15Safety Aspects in the North Area Consolidation StudyF. Gautheron, NA-CONS Safety Review, June 6th 2019

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.

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 measuresto be taken for each?

ODH and CO2 Safety

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?


Radiological Safety

• 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?


Access Control

• Is the actual Personal Protection access control system (ZORA) still adapted to the present situation?

• 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?


Safety aspects to be reviewed today

1. Radiation protection & Radiological surveillance Claudia Ahdida (HSE-RP)

2. Access control Rui Nunes (BE-ICS)

3. Fire Safety Art Arnalich (assessment, HSE) & Silvia Grau (Technical solution, BE-ICS)

4. Gas detection Simon Cherault (assessment, EN DSO), Silvia Grau (Technical solution, BE-ICS)


Items not covered by this review

1. Asbestos diagnostic

2. Gas network

3. Electrical non-conformities

4. Emergency lighting

5. Barracks on false floors

6. Roofs and floods


Points to be assessed


The reviewers are asked to assess the identified safety needs, the technical solutions considered, the timetable envisaged to implement them and to answer the following questions:

• Have all the consolidation needs been identified in order to guaranty the safety of the North Area and ensure the conformity to present regulations and safety standards ?

• Are all the risk assessments and safety audits carried out, completely covering all the safety aspects ?

• Are the proposed technical solutions sufficiently well defined, complete and compatible with the future needs (Physics Beyond Colliders)?

• Is the suggested phasing of the safety consolidation acceptable for the future operation of the facility;

• Are the associated resources correctly estimated and in line with the proposed schedule?

• Are the projected operation costs, after the consolidation actions, coherent with the expected reduction of risk?

… and referring to the section 6 (timeline) of the Study Report:

Safety: Cost evolution


Cost estimate in 2011

(basis of present Target Figures)


(Consolidation days)


Safety

1.4 MCHF * 3.9 MCHF**

17.7 MCHF***[15.3 – 21.1] MCHF

[-14% / + 19%]

Class 2 of Accuracy Range

* For the gas network ; ** For the access control and gas network; *** HSE contribution 1.5 MCHF not included

0

500

1000

1500

2000

2500

3000

3500

4000

2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030

kC

HF

Communication network Experimental Gas Network Gas detection system (ODH, CO2)

Access control Fire safety Buffer zones + urgent items

Summary of the Investments in experiments located in NA


Experiment Total Investment (kCHF) CERN incl. (kCHF)

NA58 – Compass 54617 17250

NA61 – SHINE 11525 985 (+2130 for cryo and infrastructure not included)

NA62 36100 8450 (+26100 ceiling construction not included)

NA64 1075 -

NP02 – Proto Dune LBNO 13000 ~ 7800

NP04 – Proto Dune SP 15000 ~ 9000

Total investment in experiments: 131.3 MCHF

North Area Asset (help from the PPE register)


Trade 2017 Gross Value (MCHF)

Civil Engineering 101.0

Access Control 1.7 (NA incl in SPS complex ??)

Beam Instrumentation 10.5 MCHF

Beam Transfer for Exp. Areas 22.9 (only for NA62!)

Computer Networking o.13 (in 2016 & 2017 for NA62)

Cooling and Ventilation 32.1

Cryogenic installations ~ 25

Fire and Gas Detection ~15 as for the consolidation. Gross value not restorable

Electrical distribution (pulsed network) ~ 11.1 (transfo, ERD, EMD gear switches in BA80, 81 & 82)

Heavy Handling 0.7 (lifts) + 6.1 MCHF for cranes

Magnets 49.7 (only for resistive)

Personnel Safety (mainly RP) 1.7

Scientific Support 14.1 (includes 13.6 for NA62)

Power converters ~ 30 as for the consolidation. Gross value not restorable

Shielding 25.2

Targets, Dumps, Collimators EN-STI estim. (Target +2 coll): 4.8 + EN-EA (coll+dumps) partial estim : 5.06

Vacuum 3.2 + 0.95 (EN-EA)

Total 361.0 MCHF (incl. from PPE: 250.0 MCHF)

Access Control

• All the surface buildings of NA covered by SUSI (excepted BA82),

• ZORA (ZOne RAdiation) designed 15 years ago for all the secondary beam areas -> beam interlock, personnel protection function (35 doors concerned),

• Assumption: hazards and risks significantly less severe than in primary beam areas

• PPE access modes: free, key access, closed area.

• Rule: key access granted to holders of personal dosimeters: 1 person 1 key but dosimeter not interrogated !

• Problem 1: 1 person can take several keys, or opening access to other persons without key !!

• Problem 2: increasing diversity of hazards and of beam intensity & tightening of the safety regulation

• Problem 3: underground EHN galleries under RP concerned but in free access: might be interlocked !

• Short-term measures:

• Grant key access only to person with the corresponding training linked to the experimental facility

• Carry out a comprehensive risk reassessment from a personnel safety and radioprotection perspective

• Long-term consolidation:

• Abandon key distribution, replaced by token, granted with dosimeter and valid trainings

• Adapt actual system (but near end of life and hard to extend) or migrate to a new technology (being investigated)

Safety Aspects in the North Area Consolidation Study 27F. Gautheron, NA-CONS Safety Review, June 6th 2019

safety aspects in the north experimental area

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