Hydrogen Delivery System – R&D Activities

T W BradshawM CourtholdM HillsJ RochfordDaresbury Controls Group etc…

AS Scientific statusCryostat vessel:Now complete

Cryostat:Condenser and condensing pot complete

AS Scientific status

AS Scientific statusCryostat: Following AFC design change,mods underway to 1st stage thermal cooling

Plans & Schedule

•Ongoing issues with commissioning the Decay Solenoid and Linde refrigerator are still taking effort away from this project (MJDC, JHR, MJH)

•H2 R&D team at RAL still chronically short-staffed, but recruitment of two additional team members has now been approved by STFC.

•Ian Mullacrane (DL) coordinating DL effort re controls & instrumentation, which need to comply with IEC 61508/61511 (Functional Safety). Key members of RAL & DL teams now trained in Safety Integrity Level (SIL) assessment; and are now assessing SIL level of H2 R&D system prior to forthcoming safety review. Consultants will still needed to formally assess system, to ensure compliance with IEC 61508/61511.

•Work on cryostat build at AS Scientific now proceeding more satisfactorily. Final decisions re instrumentation & control hardware for Gas Panel have been taken, and purchasing now underway. The choice of LH2 level detectors is being revisited, following the discovery that AMI now has a UK office and ought now to be able to ATEX certify the sensors.

Plans & Schedule

•Design of H2 ventilation system and external pump housing complete, and tender action underway. There is an issue re explosion-proofing the ventilation system, which is still to be resolved. Mound excavation complete.

•Hydrogen System Control Room has been assigned.

•H2 system purging pump, along with backing-pump for cryostat pumping rig, will be housed outside MICE Hall. The design of the enclosure is in progress.

•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

Ventilation & Vacuum Systems

MICE Hall South Wall

Hydrogen Extraction Vents

Proposed Area for Vacuum Pump Enclosure

Conduits for vacuum lines installed during August shutdown

Hall Installation

Ventilation Ducts

Enclosure(containing Gas Panel, Hydride Bed and Buffer Tank)

Heater/Chiller Units for Hydride Bed

Transfer Line

Test Cryostat

Plans & Schedule

•Schedule has been revised:

•It is anticipated that the ventilation system in the hall will be installed by the end of March.

•It is planned to submit H2 R&D commissioning plan to ISIS/MICE Safety Committee in February.

•A MICE/ISIS Safety Review will be held as soon as practical in the near future, hopefully Feb/Mar, at which the next steps towards a final Safety Review will be decided.

Testing

Helium TestsCheck instrumentationPump and purgeCheck relief valve settings and operationCheck cryocooler operation at LH2 and LHe temperaturesLiquify helium in the cryostatTest emptying sequenceThermally cycle the system, to check for leaks from thermal stresses

Hydrogen TestsCheck alarms and interlocksLiquify hydrogen in the cryostatCheck empty and purge sequenceTest effect of using Helium top-up gas to maintain positive pressureMeasure H2 desorption rateMeasure H2 absorption rate

Instrumentation update

• 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,

but there is now an AMI UK office, so a solution should now be possible

• 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

Level SensorsPressure Transducers

Temperature sensors