ESS ELLIPTICAL CRYOMODULE ESS CRYOMODULE FOR ELLIPTICAL CAVITIES

ESS ELLIPTICAL CRYOMODULE ESS CRYOMODULE FOR ELLIPTICAL CAVITIES Unité mixte de recherche CNRS-IN 2 P 3 Université Paris-Sud 11 91406 Orsay cedex Tél. : +33 1 69 15 73 40 Fax : +33 1 69 15 64 70 http: //ipnweb. in 2 p 3. fr G OLIVIER / JP THERMEAU SAFETY REVIEW LUND June 9 th, 2016 LUND June 9, 2016 1

ESS ELLIPTICAL CRYOMODULE G OLIVIER / JP THERMEAU LUND June 9, 2016 2

ESS ELLIPTICAL CRYOMODULE G OLIVIER / JP THERMEAU LUND June 9, 2016 3

CIRCUITS - CHARACTERISTICS Circuit Temperature (K) Pressure (bara) Volume (l) Control valve Safety device Thermal shield 40 - 50 19 - 19, 5 3 CV 60 (Kv 0. 8 m 3/h) SV 60 (24 barg) Helium inlet 4. 5 3 1 CV 03 (Kv 2. 8) SV 02 (3 barg) Couplers 4. 5 3 1. 3 Cooling down 4. 5 1. 5 CV 02 (Kv 0. 2) 2 - 4. 5 1 CV 01 (Kv 0. 04) Filling Low pressure Vacuum G OLIVIER / JP THERMEAU 2 0. 030 – 1. 43 219 (Diph. pipe half filled) CV 04 (Kv 71) 300 K RD 90 / RD 91 (0. 99 barg) CV 91 (1. 5 bara) SV 90 (0. 64 barg) SV 70 (0. 02 bar) LUND June 9, 2016 4

HELIUM DISTRIBUTION Jumper VLP circuit (8 l) Rupture disk & safety valves Rupture disk & purge valve + pressure gauges JT valve CV 01 Exchanger Cooling down valve (CV 02) Diphasic pipe (27 l) Helium tank (48 l) Coupler circuit (1, 3 l) Thermal shield circuit (3 l) G OLIVIER / JP THERMEAU Cooling down circuit (1. 5 l) LUND June 9, 2016 Filling line (1 l) 5

CAVITIES Ø neck 80 mm Øext tank 418 mm Medium beta High beta Internal volume: 48 l G OLIVIER / JP THERMEAU LUND June 9, 2016 6

CRYOGENIC INTERFACES Rupture disk & safety valves CV 01 Vacuum safety valve Jumper connections Rupture disk & purge valve & press. gauges CV 02 He coupler outlet (x 4) G OLIVIER / JP THERMEAU LUND June 9, 2016 7

VACUUM VESSEL : SAFETY DEVICE Minimum Set flow section pressure (mm²) (barg) 11200 Considered worst scenario: Rupture of 2 K phase separator Þ liquid helium fills the vacuum vessel Þ liquid helium mass : 30 kg Þ Volume of vessel : 6. 3 m 3 Þ helium mass flow : 4. 1 kg/s (1. 04 bara, 4. 76 K) G OLIVIER / JP THERMEAU 0. 02 Diameter of relief valve SV 70 : 200 mm LUND June 9, 2016 8

THERMAL SHIELD : Safety devices Minimum Set flow section pressure (mm²) (barg) 34 Considered worst scenario: loss of insulation vacuum Þ air fully condensates onto the CM thermal shield surface covered with 30 MLI Þ considered heat power density : 1. 5 k. W/m² Þ thermal shield (~24 m²): 36 k. W Þ helium mass flow : 0. 1 kg/s (25 bara, 66 K) G OLIVIER / JP THERMEAU LUND 24 Diameter of relief valve SV 60 : 10 mm June 9, 2016 9

COOLING DOWN AND COUPLER CIRCUITS A relief valve SV 90 associated with a control valve CV 90 (1. 5 bara) Minimum Set flow section pressure (mm²) (barg) 340 Considered worst scenario: Þ HP He supply: 3 bara, 5 K Þ Valves CV 01, CV 02, CV 03 fully opened (at kv max) Þ Valve CV 04 closed Þ helium mass flow : 0. 082 kg/s (1. 74 bara, 4. 85 K) G OLIVIER / JP THERMEAU 0. 64 Diameter of relief valve SV 90 : 25 mm Kv of CV 90 : 11 LUND June 9, 2016 10

LOW PRESSURE LINE G OLIVIER / JP THERMEAU LUND June 9, 2016 11

SAFETY STRATEGY FOR THE LOW PRESSURE CIRCUITS Operating constraints: Þ maximal allowable pressure of cavities is about 2 bar, Þ pressure required by the cryogenic plant is 1. 43 bar, Þ 1. 43 bar is close of the opening pressure of the safety valves, the pressure margin between the operating pressure and safety device is low. Safety strategy: Þ Two burst disks (RD 90 – RD 91) designed for accidental scenarios, Þ a safety valve (SV 90) designed for abnormal operation and to avoid the bursting of RD 90 or RD 91, Þ a control valve (CV 90) designed to limit the pressure at a level lower than the opening pressure of SV 90. G OLIVIER / JP THERMEAU LUND June 9, 2016 12

2 K VESSEL : SAFETY DEVICES FAILURE SCENARIOS (JP THERMEAU, Safety equipments for helium circuits) SCENARIOS Circuit Area (m²) Failure of the insulation vacuum Helium vessel 4 x 1. 53 Failure of the beam vacuum Cavity 4 x 1. 81 Failure of insulation and beam vacuum Vessel + cavity heat flux (k. W/m²) 6. 2 (10 MLI layers) 38 (air on cavity wall) Heat load (k. W) Mass flow (kg/s) 38 2 275 14. 5 312 16. 4 7. 25 Kg/s per bursting disk Most credible & critical Reference for the sizing of the safety devices Unlikely Minimum rupture disk diameter: 88 mm Maximum He volume to be evacuated: 200 l (about 30 Kg) G OLIVIER / JP THERMEAU LUND June 9, 2016 13

G OLIVIER / JP THERMEAU Ø 90 mm Ø 97 mm BURSTING DISK LUND June 9, 2016 Dimensions updated by Witzenmann on 2016/04/07 14

SUMMARY Name SV 60 SV 02 SV 90 CV 90 RD 90 - RD 91 SV 70 Minimum flow section (mm²) 34 Section of pipe 340 kv > 11 5300 11200 Practical diameter (mm) 10 10 25 25 100 200 Set pressure (barg) 24 3 0. 64 1. 5 bara 0. 99 0. 02 Pressure drop in the main line : Þ > 3%PS, Þ no risk to damage the cavities. The pressure margins between the burst disks and the safety valves are very low (100 to 200 mbar). G OLIVIER / JP THERMEAU LUND June 9, 2016 15

PRESSURE EQUIPMENT DIRECTIVE Breakdown of each circuit in elementary sections to check the product Ps x V and the compliance to the Pressure Equipment Directive. Each section is considered as a separate vessel. G OLIVIER / JP THERMEAU LUND June 9, 2016 16

PRESSURE EQUIPMENT DIRECTIVE 1. 04 48 Aim: remain in 3. 3 category G OLIVIER / JP THERMEAU Volume of the largest circuit vessel: the cavity helium tank LUND June 9, 2016 17

MECHANICAL BEHAVIOUR OF THE CAVITIES UNDER PRESSURE Max. pressure (test at 1, 25 Pmax): 2, 6 barg Maximum working gauge pressure: 2, 6/1, 25 = 2, 08 barg Pressure test scenario: - Cavity fully constrained - Pressure in the tank - Beam vacuum carried out The maximum pressure allowable is - 2. 60 bar for 50 MPa VM (worst scenario) - 3. 64 bar for 70 MPa VM (best scenario) (Andrea BIGNAMI, INFN LASA - PDR, LASA, 19 May 2016) Maximum Ps: 2, 08 -1, 013=1, 067 barg This value is very close to the limit of 1, 04 barg needed to stay in PED chapter 3. 3 G OLIVIER / JP THERMEAU LUND June 9, 2016 18

SAFETY DEVICES OPERATING RANGE ABSOLUTE PRESSURE Pmax = 2. 14 bar 2. 04 bar Bursting area of the rupture disk GAUGE PRESSURE Maximum pressure = 1. 1 PS = 1. 14 barg PS = MAWP = 1. 04 barg Rupture disk outlet to the atmosphere at 1 bara Bursting pressure = 0. 99 barg ± 0. 05 bar 1. 94 bar 0. 94 barg Pressure margin ~ 0. 2 bar 1. 74 bar Set pressure = 0. 64 barg ± 5% of the 0. 95 Pset ~ 0. 61 barg relief valve 1. 55 bar 1. 5 bar Min. pressure to allow the closing of the relief valve: 0. 9 x 0. 61 ~ 0. 55 barg PLC Control valve ~ 0. 5 barg 1. 43 bar Min. /Max. operating pressure of the cryogenic plant: ~ 0. 43 barg (cooling down phase) 30 mbar Pressure operation at 2 K Operating G OLIVIER / JP THERMEAU Safety valve outlet to SV relief line at 1 bara 1. 05 Pset ~ 0. 67 barg Opening area pressure area Max. pressure when the relief valve is open: 1. 1 x 0. 67 ~ 0. 74 barg LUND June 9, 2016 19

SAFETY DEVICES OPERATING RANGE ABSOLUTE PRESSURE Pmax = 2. 14 bar 2. 04 bar Bursting area of the rupture disk 1. 94 bar 1. 84 bar PS = MAWP = 1. 04 barg Rupture disk outlet to the atmosphere at 1 bara 0. 94 barg Max. pressure when the relief valve is open: 1. 1 x 0. 67 ~ 0. 74 barg (% outlet circuit) 1. 05 Pset ~ 0. 67 barg (% outlet circuit) Opening area Set pressure = 0. 64 barg ± 5% (% outlet circuit) of the 0. 95 Pset ~ 0. 61 barg (% outlet circuit) relief valve 1. 65 bar 1. 5 bar Safety valve outlet to SV relief line at 1. 1 bara Min. pressure to allow the closing of the relief valve: 0. 9 x 0. 61 ~ 0. 55 barg (% outlet circuit) PLC Control valve ~ 0. 5 barg 1. 43 bar Min. /Max. operating pressure of the cryogenic plant: ~ 0. 43 barg 30 mbar Pressure operation at 2 K Operating G OLIVIER / JP THERMEAU Maximum pressure = 1. 1 PS = 1. 14 barg Bursting pressure = 0. 99 barg ± 0. 05 bar Pressure margin ~ 0. 1 bar pressure area GAUGE PRESSURE LUND June 9, 2016 20

SAFETY DEVICES OPERATING RANGE ABSOLUTE PRESSURE Pmax > 2. 14 bar >2. 04 bar Bursting area of the rupture disk GAUGE PRESSURE Increase of the Ps value, if exhaust line > Patm Maximum pressure = 1. 1 PS PS = MAWP > 1. 04 barg (% outlet circuit) Bursting pressure = 0. 99 barg ± 0. 05 bar (% outlet circuit) >1. 94 bar 0. 94 barg (% outlet circuit) Rupture disk outlet to exhaust line > 1 bara Pressure margin > 0. 1 bar 1. 84 bar 1. 05 Pset ~ 0. 67 barg (% outlet circuit) Opening area Set pressure = 0. 64 barg ± 5% (% outlet circuit) of the 0. 95 Pset ~ 0. 61 barg (% outlet circuit) relief valve 1. 65 bar 1. 5 bar G OLIVIER / JP THERMEAU Safety valve outlet to SV relief line at 1. 1 bara Min. pressure to allow the closing of the relief valve: 0. 9 x 0. 61 ~ 0. 55 barg (% outlet circuit) PLC Control valve ~ 0. 5 barg 1. 43 bar Min. /Max. operating pressure of the cryogenic plant: ~ 0. 43 barg 30 mbar Pressure operation at 2 K Operating pressure area Max. pressure when the relief valve is open: 1. 1 x 0. 67 ~ 0. 74 barg (% outlet circuit) LUND June 9, 2016 21

REMAINING ISSUES - Value of Ps to remain in PED 3. 3 category - Value of Ps to avoid any yielding of the cavities - Impact of the helium discharge of one cryomodule on the other disks: increase of the bursting pressure Exhaust line at atmospheric pressure? (lost of the helium? ) G OLIVIER / JP THERMEAU LUND June 9, 2016 22

ESS ELLIPTICAL CRYOMODULE THANK YOU FOR YOUR ATTENTION G OLIVIER / JP THERMEAU LUND June 9, 2016 23