personnel protection system (pps) – definition
DESCRIPTION
Personnel Protection System (PPS) – Definition. Interlock system, to protect personnel from Ionising Radiation (and other hazards) (Note: does not include equipment protection) Intended to satisfy the requirements of – [UK] Ionising Radiation Regulations 1999 (IRR99) - PowerPoint PPT PresentationTRANSCRIPT
1
Personnel Protection System (PPS) – Definition
• Interlock system, to protect personnel from Ionising Radiation
(and other hazards)– (Note: does not include equipment protection)
• Intended to satisfy the requirements of –
– [UK] Ionising Radiation Regulations 1999 (IRR99)
– IEC 61508 (?)“Functional Safety of Electrical / Electronic / Programmable-Electronic Safety-Related Systems” –>
2
• Assisted search system, to clear personnel from (shielded) areas
• Door locks, to keep area clear of personnel
• Door switches, to make area safe on entry
• Warnings – audible and visual
(– People!)
(– People!)
• Permit / Prevent operation of equipment, to control the hazard(s)
– via “Permits to Operate” (PPS outputs) –>
PPS – What it does
3
PPS Design Criteria (for Accelerators)
• Very low probability of ‘fail to danger’
• Use ‘failsafe’ techniques
– implies safety is achieved by switching things off –>
4
The Daresbury Laboratory Personnel Safety (PS) System (1 of 2)
• Used on: SRS, ESRF, Diamond, ERLP, ISIS (from 2007)
• Relay-based, modular, logic system
• ‘Dual Guardline’ System– duplicated inputs, logic, & outputs– both circuits must agree it’s safe to operate ( 2oo2 system)
• ‘Failsafe’ techniques– Current flow = safe– Relay logic (relays mostly fail open circuit)– Inputs from ‘Positive break’ safety switches –>
5
– Disable equipment by two independent means
– Disable equipment in a failsafe manner
– Disable via hardware, not software (but safety-PLC ok?) –>
The Daresbury Laboratory Personnel Safety (PS) System (2 of 2)
• Provides audible and visible warnings (IRR99: ‘failsafe’?)– Search tone
– Internal illuminating ‘Danger’ signs
– Internal blue lighting
– External illuminating signs
• Annual check to ensure that both guardlines are fully functional
• PS ‘Permits’ – principles for controlling equipment:
6
7
8
9
10
11
MICE PPS
• Search Areas
– MICE Decay Solenoid Area
– MICE Hall
12
1
2
3
MICE Hall
Decay Solenoid Area
(shielding: schematical representation only)
4
13
MICE PPS – Controlled equipment
• ISIS Synchrotron Beam (to enable: Decay Solenoid Area vacated)– via ISIS PPS (hooks already included)
• MICE RF System (to enable: MICE Hall vacated)– switch off RF drive to IOTs– switch off HT to IOTs
14
• Superconducting Magnets – sequence to enable
1) MICE Hall searched (but ‘Limited Access’ permitted)
2) Hall inspection for loose magnetic material – not PS function
3) Insert and turn ‘Magnet Enable’ key
Dropping search does not disable magnet PSU, – turn off key does
– Interface to magnet PSU t.b.d.
• Other systems … ? (over to you)
MICE PPS – Controlled equipment, contd.