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An introduction to DIAMOND Personnel Safety System. By Martin Wilson Principle Personnel Safety Engineer. Contents. The Requirements Hazard Management Access Zones Personnel Safety Hardware Test strategy EPICS. The Requirements. Why do we need PSS?
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An introduction to DIAMOND Personnel Safety System By Martin Wilson Principle Personnel Safety Engineer
Contents • The Requirements • Hazard Management • Access Zones • Personnel Safety Hardware • Test strategy • EPICS
The Requirements Why do we need PSS? 1. We can’t separate the hazard from the product 2. Required by LAW Legal Requirement under Health and Safety at Work act 1974 / IRR99 • Senior management are liable to prosecution and punishment • Persons ignoring or interfering with processes or equipment may also be liable to prosecution
The Requirements Personnel Safety, the Legal and Site Requirements • Designation of controlled and supervised areas • Prior examination of plans • Risk assessments and hazard management • Conduct of investigations • Regular calibration of equipment • Periodic examination and testing
Hazard Management • Identify and Log Hazards • Assess and control Risk • Operate • Monitor and Log events • Review • Decommission
Hazard Management • Risk Matrix • Reduce severity • Reduce likelihood
Hazard Management Mitigation for a Radiation Hazard • Shielded enclosure with access via locked labyrinths 2. Captive Permit key allowing access or beam operation 3. A personnel safety system with the following features : • Micro-switches on doors as interlocks • Search required prior to operation • Audible Warnings • Annunciator indicating vault status • Blue lights in vault when access is not allowed • Signs in vault indicating danger
Daresbury Hardware ESRF DIAMOND
Hardware PLC verses Hardware • Simple failure modes • Established system based on DL SRS system • User confidence in system • Easier to maintain over a 30 year life • Many of the advantages of a PLC are not requirements of high integrity system • Configurability • Upgradeability • Ease of change
Hardware • Dual guard rail interlock system • Based on Relays • Redundant • Diverse • Interfaced to VME/EPICS via a G64 adaptor • PPC VME processor to readout module status
Test strategy Markov model of dual guard rail System
Test Strategy • Modules Test • Crate test • System test • On line test
EPICS 1. Each PSS rack is an IOC 2. Develop device driver for VME/G64 and PSS modules – This gives access to the PSS status and allows the modules to be RESET
EPICS 3. VxWorks applications to check guard line operations and test routines - detect faults as they develop and help to prevent double faults 4. Scripts to sequence resets as part of the search 5. EDM extension to show logic process graphically and to allow resets
Additional safety measures • Local Rules • Formal Analysis (Fault Tree analysis) • Change control • Safety committee