1. Powering and Safety day Underground access during powering tests
M.Solfaroli

2. Underground access during powering tests
Before September 19th
Below 1 kA
Above 1 kA
THE RULE:
Access to tunnel and UAs allowed only to people involved in powering tests
No restriction for experiments
No restriction for adjacent sectors
THE RULE:
No access to the tunnel
Access to UAs – UJs allowed only to people involved in powering tests
No restriction for experiments
No restriction for adjacent sectors
MEANS TO ENFORCE:
Tunnel in restricted mode with patrol
UAs - UJs in general mode
Experiments access left to exp.
MEANS TO ENFORCE:
Tunnel in closed with patrol
UAs - UJs in general mode
Experiments access left to exp.
11 September 2019
M.Solfaroli - Underground access during powering tests

3. Underground access during powering tests
Before September 19th
This mode of operation was not too constraining during powering tests
We wanted to keep this principle but…
…improve it in the light of what happened on Sept. 19th!!
11 September 2019
M.Solfaroli - Underground access during powering tests

4. Underground access during powering tests
EDMS number:
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M.Solfaroli - Underground access during powering tests

5. Underground access during powering tests
LOW CURRENT phase
Underground areas and tunnel
accessible for people involved in
powering tests
Similar to “Below 1 kA” phase
PHASE I
HIGH CURRENT phase
No access for anybody
Similar to “Above 1 kA” phase
but more constraining
PHASE II
Please refer to Mirko’s presentation…
11 September 2019
M.Solfaroli - Underground access during powering tests

6. RISKS Underground access during powering tests Phase I ELECTRICAL:
CRYOGENIC:
Risk of an accidental massive helium release
HAS BEEN CONSIDERED NEGLIGIBLE
ELECTRICAL:
In the UAs
In the tunnel
11 September 2019
M.Solfaroli - Underground access during powering tests

7. Underground access during powering tests
Phase I
Access condition (the rule)
Assumed that the current is limited:
Only people with “test related” activities are allowed to access the tunnel
Power tests may continue in the powering subsectors where NOBODY works
Means to enforce the rule
Current limitation:
Hardware current limitation for RB and RQD/F power converters
Software current limitation on the other converters
Software interlock
Access control:
All doors closed and emergency handles rearmed
Tunnel area in restricted mode
UAs in general mode with a panel signalizing “electrical tests ongoing”
11 September 2019
M.Solfaroli - Underground access during powering tests

8. Underground access during powering tests
Phase I
How to deal with access requests:
Access for “test-related” interventions:
Tests in other powering subsectors may continue
ADI approved
Access for NON “test-related” interventions:
Schedule when no powering, if possible
if needed
stop powering tests
lock circuits with global PIC (see later)
Access kept in Restricted mode
ADI approved
11 September 2019
M.Solfaroli - Underground access during powering tests

9. Underground access during powering tests
Phase I
How to deal with EXCEPTIONS (i.e. door forced):
Finish the tests ongoing
Close and re-arm the door
Re-start powering tests
11 September 2019
M.Solfaroli - Underground access during powering tests

10. Underground access during powering tests
Phase II
RISKS
CRYOGENIC:
Accidental massive helium release CANNOT BE EXCLUDED!
ELECTRICAL:
In the UAs
In the tunnel
11 September 2019
M.Solfaroli - Underground access during powering tests

11. Underground access during powering tests
Phase II
Access condition (the rule)
As that the current is NOT limited:
Nobody is allowed in the tunnel nor in the related underground areas
Means to enforce the rule
Access control:
All doors closed and emergency handles rearmed
All related zones patrolled
All related areas in closed mode
Software interlock
11 September 2019
M.Solfaroli - Underground access during powering tests

12. Underground access during powering tests
Phase II
EDMS number:
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M.Solfaroli - Underground access during powering tests

13. Underground access during powering tests
Phase II
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M.Solfaroli - Underground access during powering tests

14. Underground access during powering tests
Phase II
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M.Solfaroli - Underground access during powering tests

15. Underground access during powering tests
Phase II
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M.Solfaroli - Underground access during powering tests

16. Underground access during powering tests
Phase II
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M.Solfaroli - Underground access during powering tests

17. Underground access during powering tests
Phase II
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M.Solfaroli - Underground access during powering tests

18. Underground access during powering tests
Phase II
Area under powering tests
Closed areas
NB: This is not a reference!
Merci Julie…
11 September 2019
M.Solfaroli - Underground access during powering tests

19. Underground access during powering tests
Phase II
How to deal with access requests:
For punctual interventions:
Finish all tests ongoing
Block the whole sector via global PIC (see next slide)
Switch the area in restricted mode
Authorize people with an approved ADI in
For longer interventions we could eventually think to step back to Phase I:
Special procedure to be used in special cases
Procedure described in the document: “Transition from Powering phase 1 to Powering Phase 2 and vice versa” (going to Engineering check)
11 September 2019
M.Solfaroli - Underground access during powering tests

20. Underground access during powering tests
PIC global-lock
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M.Solfaroli - Underground access during powering tests

21. Underground access during powering tests
ADIs
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M.Solfaroli - Underground access during powering tests

22. Underground access during powering tests
ADIs
WHO
It has to be done by a CERN staff for
the people intervening
WHERE
To access all zone in Restricted Mode.
To check access status, please go to:
WHAT
WHEN
WHY
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M.Solfaroli - Underground access during powering tests

23. Underground access during powering tests
ADIs
11 September 2019
M.Solfaroli - Underground access during powering tests

24. Underground access during powering tests
ADIs
WHO
It has to be done by a CERN staff for
the people intervening
WHERE
To access all zone in Restricted Mode
to check access status, please check on:
WHAT
Mandatory for all interventions
WHEN
As early as possible!!!
Do not send ADI at midnight for 8am
FOR COORDINATION!!!
NB: signature of an ADI IS NOT a stamp on the
safety of the intervention
WHY
11 September 2019
M.Solfaroli - Underground access during powering tests

25. Underground access during powering tests ADIs vs AOC
ADI: Avis D’Intervention
Small works in the tunnel when the access mode is restricted, which enable you to have a number to enter when you contact the CCC.
THIS IS A COORDINATION TOOL
AOC: Avis d‘Ouverture de Chantier
Work performed by firms (civil engineering or installation of infrastructure or equipment) on the CERN site shall be contingent on a "Notice of Start of Works" drawn up by the works supervisor before the work starts. The aim is to draw attention to the risks and problems caused in the surroundings by the work, and to ensure a good collaboration between the firms and all services affected.
For more information see CERN notice IS 39
11 September 2019
M.Solfaroli - Underground access during powering tests