1. 1 MICE Hydrogen System Elwyn Baynham, Tom Bradshaw, Iouri Ivaniouchenkov RAL MICE / RAL Safety Meeting @ RAL, 30 October 2003

2. 2 Hydrogen system: Conceptual points Closed system concept : - hydrogen absorber and a storage unit form a single closed system in a way that hydrogen is either stored as a gas in the storage unit or is liquefied in the absorber; - pressure in the system is always higher than the atmospheric pressure. Individual hydrogen system for each absorber MICE / RAL Safety Meeting @ RAL, 30 October 2003 Ideally it is a truly passive system Air can not leak inside the system Safety pros: Minimal amount of hydrogen per system

3. 3 Hydrogen system: Options Hydrogen storage unit = large (about 30 m 3 ) tank Pros: truly passive system Cons: about 100 m 3 for the location of tanks (=> on the roof ?) MICE / RAL Safety Meeting @ RAL, 30 October 2003

4. 4 Hydrogen system: Options Alternative option: Hydrogen storage unit = compact (< 1 m 3 ) metal hydride bed Pros: - very compact system (easier to collect hydrogen in case of leak) - hydrogen is stored as a solid compound Cons: not a passive system (requires active heater/cooler) A question then: is it a reasonable compromise from the safety point of view ? MICE / RAL Safety Meeting @ RAL, 30 October 2003

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7. 7 Hydrogen system layout: Option with a hydrogen tank Concrete radiation shielding Steel magnetic shielding Hydrogen storage tank H 2 absorber H 2 buffer tank

8. 8 H 2 Storage unit Ventilation duct Radiation shielding wall H 2 Buffer Tank (1m 3 approx) H2 absorber Vacuum jacket MICE / RAL Safety Meeting @ RAL, 30 October 2003 Hydrogen system layout: Option with a hydrogen bed

9. 9 MICE / RAL Safety Meeting @ RAL, 30 October 2003 Hydrogen system layout: Option with a hydrogen bed

10. 10 MICE Layout Version: 28 October 2003 MICE / RAL Safety Meeting @ RAL, 30 October 2003

11. 11 MICE / RAL Safety Meeting @ RAL, 30 October 2003 Preliminary HAZOP recommendations Hydrogen storage unit Implement: active pressure gauge temperature monitor Hydrogen absorber internal vessel with hydrogen windows Implement: active pressure gauge temperature sensor active liquid level meter (additional) Hydrogen absorber vacuum jacket with safety windows Implement: active hydrogen sensor Buffer tank Implement: active pressure gauge active oxygen sensor Hydrogen module enclosure Implement: ventilation system equipped with hydrogen detector.