Hydrogen Delivery System – R&D Activities

1. Hydrogen Delivery System – R&D Activities T W Bradshaw M Courthold M Hills J Rochford Daresbury Controls Group etc…

2. AS Scientific status Buffer Volume:Complete and radiographed, awaiting certification Buffer volume pipework

3. AS Scientific status Cryostat:50% complete overall

4. AS Scientific status Cryostat:Condenser and condensing pot complete

5. AS Scientific status Absorber base plate

6. AS Scientific status Gas panel:Layouts agreed; fabrication not yet started Relief valves decided. Delivery of relief valves on critical path. Transfer Line: Complete

7. Metal Hydride Storage Tank Nominal capacity: 2450 g (27 Nm3) H2 Volume of overall storage tank: 250 litres Overall weight: 375 kg Dia 470 Top removable thermal insulation cover Hydrogen connection with shut-off valve and safety valve Hull cooling Water/Glycol Outlet, 1” 1680 1590 Internal cooling Water/Glycol Inlet/Outlet Hull cooling Water/Glycol Inlet, 1”

8. Ventilation & Vacuum Systems Proposed Area for Vacuum Pump Enclosure Hydrogen Extraction Vents Conduits for vacuum lines installed during August shutdown MICE Hall South Wall

9. Hall Installation Ventilation Ducts Enclosure (containing Gas Panel, Hydride Bed and Buffer Tank) Transfer Line Heater/Chiller Units for Hydride Bed Test Cryostat

10. Plans & Schedule • Ongoing issues with commissioning the Decay Solenoid and Linde refrigerator have taken effort off this project (MJDC, JHR, MJH) • H2 R&D team at RAL still chronically short-staffed, having lost two key team members earlier this year; although Alan Ruddell joined team in May (25% effort). Still no technician effort available. • Ian Mullacrane (DL) taken over from Graham Charnley, and coordinating DL effort re controls & instrumentation. The work will need to comply with IEC 62508/61511 (Functional Safety), and Safety Integrity Level (SIL) of H2 R&D system will need to be assessed & implemented. Progress is good in this area, thanks to DL team. Some discussion between DL & RAL teams currently re appropriate level of compliance. • Key members of RAL & DL teams will be trained in December in SIL assessment according to IEC 61508/61511, although consultants still required to ensure system complies with IEC 61508/61511. • Work on cryostat build at AS Scientific currently very slow (still 50% complete). Work on gas panel not yet stated, although final decision on choice of safety relief valves and LH2 level detectors has now been taken.

11. Plans & Schedule • Design of H2 ventilation system and external pump housing well advanced. Mound excavation complete. • Hydrogen System Control Room has been assigned. • As much control & instrumentation hardware will be purchased as possible by December, including pumping systems. • H2 system purging pump, along with backing-pump for cryostat pumping rig, will be housed outside MICE Hall. • Exact location of turbo-pump for the R&D cryostat pumping rig still to be decided. It needs to be located outside magnetic shielding wall, but its location might differ from that of final system, and it is important not to cut more holes in shielding wall than absolutely necessary. • Initial tests will be conducted with Helium in Cryogenics Laboratory, to avoid interference with installation of ventilation system

12. Plans & Schedule • Schedule has been revised: • It is anticipated that the ventilation system in the hall will be installed by the end of December. • It is planned to submit H2 R&D commissioning plan to ISIS/MICE Safety Committee in November. • HAZOP 2 review will be held as soon as practical in the near future, hopefully Nov/Dec. • Final Safety Review will follow as soon as possible after HAZOP 2.

13. Testing Helium Tests Check instrumentation Pump and purge Check relief valve settings and operation Check cryocooler operation at LH2 and LHe temperatures Liquify helium in the cryostat Test emptying sequence Thermally cycle the system, to check for leaks from thermal stresses Hydrogen Tests Check alarms and interlocks Liquify hydrogen in the cryostat Check empty and purge sequence Test effect of using Helium top-up gas to maintain positive pressure Measure H2 desorption rate Measure H2 absorption rate

14. Hydrogen R&D System

15. Gas Panel Bottle Store Venting Vac. Pumps Cryostat Heater/ Chiller Unit Hydrogen Bottle Hydrogen System P&ID

16. Cryostat Cryocooler and Compressor Nitrogen Jacketing on Pipes Temperature sensors Pressure Transducers Electrical heater for operation of cryocooler with H2 Temperature sensors on base-plate Level Sensors Electrical heating of base-plate Pre-cooling loops

17. Gas Panel and Hood Extraction Hood Fill/Purge Valves Hydride Bed Buffer Volume Absorber Relief Valves Cryostat Relief Valves

18. Fill/Purge Valves • Pneumatically actuated valves • Arrow indicates position on failure

19. Vacuum System • 2 Elements • Purging Pump • for H2 system • Cryostat Vacuum system

20. Venting • Hydrogen detectors in extraction hood, vent line and vacuum exhaust • 2 fans provide redundancy in venting from hood • Flame arrestors used throughout • Helium flow in vent line to dilute leaks Whessoe – Varec Flame Arrestor

21. Hydrogen R&D System Layout Hydrogen R&D System Test Cryostat

22. Control Valves • Ball Valves • Pneumatically actuated • Spring Return Actuators ensure valve returns to default position on failure • Control Valves • Pneumatically Actuated • Large range on throttling • Suitable for use with hydrogen

23. Relief Valves & Bursting Discs • Seetru AD2000:A2 / TDR 421 for gas • Media Hydrogen gas • Temperature – minus 80 Deg C • Flow rate – 1000 Ltrs/sec • Set pressure 0.5 BarG • Valve fully open at 0.6 BarG • Reseat at 0.3 BarG • Atex approved • BS&B Low Pressure Reverse Buckling Disc • ±10% tolerance on burst pressure • Vacuum/back pressure resistant • Designed to rupture without fragmentation • Appropriate certification to be obtained for all valves

24. Instrumentation • Temperature Sensors • Platinum Resistance • Fast response time (<0.5s) • Cernox for cooler cold head temp. • Level Sensors • AMI Capacitance Level Transmitter • Useable with Hydrogen • Problem with obtaining ATEX certification • No solution • Ametek Drexilbro, Endress & Hauser, Impress, Omega, Synatel • Pressure and Vacuum Gauges • Leybold can supply capacitance vacuum gauges, which are safe for use with hydrogen. • Explosion proof pressure transducers available from Honeywell • ATEX approved pressure transducers also available from SensorsOne Temperature sensors Pressure Transducers Level Sensors

25. Vacuum System Pumps TRIVAC D40B • Proposal received from Leybold based on combination of rotary vane and turbo-molecular pumps • TRIVAC D40B for hydrogen system purging pump (VP1) • Special Pumpset with active control suggested for cryostat vacuum (VP2) • D25BCS backing pump • Turbo-molecular TMP151C to achieve high vacuum (10-3 mbar) • Both pumps can be operated with purge gas (e.g. He) if pressure rises (indicating a leak) TRIVAC D25BCS TMP151C

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