Safety Systems for ALICE DSS = Detector Safety System under the responsibility of ALICE (“safe” part of DCS) treats Level 1 and 2 alarms CSAM = CERN Safety Alarm Monitoring under the responsibility of TS-CSE (former ST-MA, contract B1171/ST) treats Level-3 alarms SNIFFER = air sampling system for detection of - ODH = Oxygen Deficiency Hazard - Flammable gas leak - Smoke from fire and hot-spots sends alarms to CSAM Note: The Technical Coordinator holds the overall responsibility for project management, except safety ! The GLIMOS holds responsibility for safety of the experiment by delegation from EP Div.leader. he reports to the DL, he acts on safety issues via the Tech.Coord., He is assisted by Safety Coordinators.

CSS = CERN Safety System SCR = Fire Station TCR = Tech. Specialists CSAM 9 types of Detectors of Hazards SNIFFER System ; ODH, Fl.Gas, Smoke

CSAM - general Highly reliable alarm transmission system Based on PLC and SCADA industrial technology Supported by international safety standards Available 24h/d, 365d/y Defined by the AL3S working group Designed for CERN, not only for LHC Approved by SC (TIS), including experienced firemen Approved by TCR representatives INB compliant Maintenance integrated in the Maintenance Manager System

CSAM - inputs 9 possible types of entries, including the SNIFFER : Smoke detectors ~ 40 ~ 5 Flammable gas detectors ~ 20 ~ 5 ODH detectors ~ 10 ~ 5 Water detectors (flooding) ~ 10 Evacuation signals ~ 40 Red buttons ~ 50 Red telephones ~ 10 Dead-man detector ~ 1 Blocked lifts ~ 2

CSAM – some inputs Some safety systems are already in place at Pt-2: Smoke detectors in SX-2 and SXL-2 * in UX-25 * Evacuation buttons and alarm everywhere * Red buttons // * Red telephones // * (Note that the normal phones have been dismantled from underground areas.) Blocked-lift alarms in lifts * to be rejuvenated in 2005 ODH and gas detectors to be defined

CSAM – example of inputs

CSAM - outputs CSAM sends alarms to : Safety Control Room (SCR, fire station), they send the firemen. Technical Control Room (TCR), they send the relevant specialists if needed. Note: Installation planned in April-May 2004 at Pt-2. DSS/DCS sends alarms to ALICE Control Room.

Sniffers racks

Sniffer tubes

CSAM - actions CSAM sends alarms to the firemen…. What’s next ?? Cut the power (+ gas) at the place of alarm If the alarm comes from UX-25  request to stop the beam send the firemen + relevant specialists If the alarm comes from inside L3 magnet  flush N2 ? (under study)

Fire detection (and fire fighting) in Electronic Racks: Open Safety Issue : Fire detection (and fire fighting) in Electronic Racks: Proposal from TS-CSE = - 1 smoke sensor per ‘normal’ rack - signal sent to DSS for automatic action to be defined - one possible action = cut-off power of the Hazemayer powering ( 1 or ) 23 racks. Possible solution = - 2 smoke sensors per rack - wired logic cutting of power of the given rack + signal sent to DCS for info Required automatic fire-fighting ? To avoid misunderstanding; the proposal of ST/MA is not because they (e.g as CSAM) want to install something; it is rather that because there is a request of the Glimos'es to have a smoke detection system that ST/MA proposed a technical solution for that (based on the CSAM system if I'm not mistaken). Also this proposal only proposes a digital output, that can (but not necessarily need to) be connected to DSS (in fact, this is currently only foreseen for CMS and ATLAS); one could also envisage to directy connect to a Hazemeyer drawer (to cut power to the coresponding rack). Alternatively one could, as you say, combine signals to cut a group of racks; this combining could be done in DSS (as for CMS and ATLAS), or 'hardwired', or preferably directly in Rui's system, triggering the same output for a given set of smoke detectors (Rui will comment if this is unrealistic). I am not sure that doubling the smoke detector will make you gain a lot. One will eliminate the intrinsic failures of a smoke detector (that are anyway relatively low), but a human intervention (e.g. creating dust) will most likely still trigger both detectors, and its action.