LH2 Infrastructure

1
LH2 Infrastructure

• M Hills
• M Courthold
• T Bradshaw
• I Mullacrane
• P Warburton

2
Outline

• RD System Manufacture
• Cryostat
• Instrumentation selection
• Ventilation System
• Safety
• Next Steps
• Controls (PW)

3
Cryostat modifications (1)
Increased heat exchange with 1st stage of
cryocooler to utilise the cooling power available
at 50K
4
Cryostat modifications (2)
Condensing pot
Upper radiation shield/1st stage heat exchange
Dummy absorber pot
Radiation shield
Pre-cooling loops
5
Cryostat Instrumentation

• Level sensors
• ATEX approved gauges either not available
  commercially or prohibitively expensive
• Therefore chosen to use a chain of resistors
• Heaters
• Cartridge heaters on condensing pot (50W 20W)
• Absorber pot 3 x cartridge heaters to boil off
  liquid
• Thermometry
• PRTs on condensing pot and absorber
• Cernox on cryocooler 2nd stage

6
Gas Panel Instrumentation

• All valves identified
• Suppliers identified for instrumentation and
  discussions on exact specification underway

7
Ventilation System
8
Ventilation System (2)
9
Ventilation System (3)

• Case for standard ducting has been made to ISIS
  safety representatives and accepted
• Initial quotation received for ductwork and
  negotiations ongoing with contractor.
• Decision still to be made on fans
• DSEAR compliance
• What is a safe time of persistence for an
  explosive mixture?

10
Safety Issues

• Specification of ventilation system fans
• Approval of ventilation system design against
  DSEAR requirements
• Design of safety functions in control system
• Production of documentation to demonstrate
  compliance with both DSEAR and IEC61508 this is
  not insignificant.
• Timing and scope of safety reviews
• Internal MICE project review
• External review before full operation

11
Next Steps/Priorities
1. Complete manufacture of the components of the RD system that are being produced at AS Scientific.
2. Produce a prototype control system that, as a minimum, will allow the cryostat and gas panel to be tested.
3. Test system with Helium.
4. Produce the documentation required for a full safety case (including the controls).
5. Complete preparation of Hydrogen Control Room
6. Place contract and install the ventilation system in the hall.
7. Install bottle store along with N2 and He supply infrastructure
8. Integrate the hydride bed with the system and test with H2.
12
MICE Hydrogen Control System

• MICE Collaboration Meeting 24
• June 2, 2009
• PJ Warburton - Daresbury Lab

13
Control System Tasks

• Safety Functions - Hardwired
• Valve Control - PLC
• H2 Control Room Layout
• SIL Rating (BS EN 61508)

14
Safety Functions

• Operation Of The Ventilation System On Detection
  Of A Hydrogen Leak
• Shut PV20 If There Is Pressure Rise In The
  Cryostat During Operation
• Gas Panel Enclosure Interlocked to Prevent Access
  When Hydrogen Present

15
Other Interlocks

• A Shut-off Facility For The Hydride Bed
  Heater/Chiller On Detection Of Bed Overpressure
• Cryocooler Shut-off If Temperature Drops Below
  Hydrogen Freezing Point (14k) or Heaters Faulty

16
Control PLC

• Omron CJ1M Modular PLC with Ethernet
• Existing Software for Link to EPICS
• NS8 Programmable Terminal (HMI), 8.4 inch Touch
  Screen with Ethernet
• Feedback From Devices in Hazardous Areas Using
  Intrinsic Safety (Ex i)
• Key Switches on Selected Functions

17
Control Sequences

• Helium Purge
• Cryostat Evacuation
• Helium Fill
• Helium Empty
• Hydrogen Fill
• Hydrogen Empty
• Diagnostic

18
Hydrogen Control Room Layout

• Room Cleaned Out
• New Door
• Pipe Work to be Removed
• Cabinet Support Frames
• Cable Routes Established

19
SIL Rating

• Tolerable Risk 10-5 Fatalities per Year From RAL
  Safety
• How Safe is H2 System
• Work In Progress

10-4 10-3 10-2
SIL 1 SIL 2 SIL 3
20
Questions