André Augustinus16 September 2002

Safety issues

16 September 2002DCS Workshop 2André Augustinus

Safety Systems

What is Safety:• Safety of people (prevent injuries or worse)

• Safety of equipment (protect capital investment)

What systems are involved in Safety for ALICE:• Detector Control System (DCS)• Experimental area safety system (DSS)• CERN Safety System (CSS)

16 September 2002DCS Workshop 3André Augustinus

Safety System overview

CSS

TCRFire Brigade to P2

Alice Control Room“Safety console”

smokefiregasflood

DSS

ambient temperaturewater temperaturehumiditywater leakStatus (interlock)

DCS

services:electricitygaswater

sign

als

signals

actions actio

ns

Alice Control Room“DCS console(s)”

detector equipmentcontrol and monitoringHV, LV, cooling etc.

actions (high granularity)

16 September 2002DCS Workshop 4André Augustinus

Detector Control System

DCS ensures integrity through:• Alarm reporting (for operator intervention) and automation• Detailed control on detector level and control of

infrastructure and services (with high granularity)• Interlocks on detector level

but does not necessarily cover:• Experiment environment

• Parameters not covered by a detector nor by CSS:• Ambient temperature or humidity, cooling water temperature,

small water leaks, …

• Cross-detector interlocks• Detectors could have the need to act on other detectors or services

Not their responsibility Do not endanger

personnel

16 September 2002DCS Workshop 5André Augustinus

Detector Safety System Name might be misleading, DSS covers more than

only detector safety• Think of it as experimental area surveillance system

Will be a (redundant) PLC based system Will act autonomously and with a lower granularity

as DCS We preliminary identified around 100 inputs, and

100 outputs for ALICE “Back-end” in the control room should also serve as

interface to CSS Common effort across four LHC experiments

• “basic” DSS system available in summer 2003

16 September 2002DCS Workshop 6André Augustinus

DCS vs. DSS

DCS Infrastructure (environment, rack control) will monitor temperatures, humidity etc.• Relatively high granularity• “Friendly” actions can be programmed• With “DCS reliability”

DSS will also monitor temperatures etc.• With lower granularity• Only rather coarse actions can be programmed• With “High reliability”

16 September 2002DCS Workshop 7André Augustinus

Detector integrity

Integrity of a detector is primarily that detectors responsibility

Regulation and control via software (DCS)

Ultimate protection via local interlocks

But, can only act on where it has control over

DCS

Softwareaction

interlock

Detector

16 September 2002DCS Workshop 8André Augustinus

External to a detector

Higher level DCS can implement cross-detector actions

DSS can implement cross-detector interlocks or interlock to a service

Detector

Detector

Software actionacross detectors

Software actionon service

Cross-detectorinterlock

Interlockto service

16 September 2002DCS Workshop 9André Augustinus

Experiment environment

DSS can act on problems outside the control of detectors

Can act on several detectors or services

Can only be done with lower granularity

Detector

Detector

16 September 2002DCS Workshop 10André Augustinus

Again, requirements…

We would like to know what you need• Local interlocks

• Share expertise and experience• Try to uniform interlocks

• What external signals do you need• E.g. gas, stop of primary water, magnet, …

• On what external system do you want to act• What in the environment could endanger your

detector

16 September 2002DCS Workshop 11André Augustinus

Level 3 Alarms (CSS)

Covers:• Fire/Smoke, Flammable gas, O2 deficiency,

evacuation, flood, emergency stops• New “Sniffer” project (common for all LHC experiments)

• Environment inside the experiment (magnet)

Currently using what is left from LEP times First new installation starts end this year Basic rule: It is up to Alice to define what is

needed when and where (GLIMOS, TC and TIS)

16 September 2002DCS Workshop 12André Augustinus

Cable trays

Monitoring of temperature is not a good indication• Electrical insulation tends to be a good thermal

isolator as well

Sampling the air with sensitive smoke detectors is a much better method• Perforated tube on cable trays

16 September 2002DCS Workshop 13André Augustinus

Planning overview2002 2003 2004 2005 2006

Prototyping DSS

1st DSS available

Flam. Gas/O2 Def. (surface)

‘Sniffer’ URD ready

Upgrade fire det. (surface)

Evacuation (underground)

DCS activity (TPC)

Infrastructure DCS (racks)

Flammable Gas (SG)

Upgrade fire det. (underground)

Flam. Gas/O2 Def. (undergr.)