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

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

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

Underground access during powering tests EDMS number: 1001985 11 September 2019 M.Solfaroli - Underground access during powering tests

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

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

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

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

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

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

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

Underground access during powering tests Phase II EDMS number: 1010617 11 September 2019 M.Solfaroli - Underground access during powering tests

Underground access during powering tests Phase II 11 September 2019 M.Solfaroli - Underground access during powering tests

Underground access during powering tests Phase II 11 September 2019 M.Solfaroli - Underground access during powering tests

Underground access during powering tests Phase II 11 September 2019 M.Solfaroli - Underground access during powering tests

Underground access during powering tests Phase II 11 September 2019 M.Solfaroli - Underground access during powering tests

Underground access during powering tests Phase II 11 September 2019 M.Solfaroli - Underground access during powering tests

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

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

Underground access during powering tests PIC global-lock 11 September 2019 M.Solfaroli - Underground access during powering tests

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

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

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

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

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