1. SOFREGAZ LAGUNA-LBNO General Meeting PARIS 12-14 March 2012 LIQUID ARGON HANDLING Jérôme Sialelli / Didier Fernique

2. AGENDA 2LAGUNA-LBNO LAr-Process Facilities LIQUID ARGON TANK DESIGN CONDITIONS 1.LIQUID ARGON TANK DESIGN CONDITIONS 2.LIQUID ARGON SOURCING & PROCUREMENT 3.ABOVE GROUND RECEPTION FACILITIESLIQUID ARGON FILLING LINE BOIL OFF RECONDENSATION UNITS 4.LIQUID ARGON CIRCULATION & FILTRATION 5.AIR PURGE AND COOLING DOWN 6.CAVERN COOLING 7.POSSIBLE PROBLEMS WITH LEAKS 8.AIR PURGE AND COOLING DOWN

3. LIQUID ARGON TANK DESIGN CONDITIONS: Operating Pressure 3LAGUNA-LBNO LAr-Process Facilities The basic assumption is to operate a fixed absolute pressure in the LAr tank. So in order to have at any time an internal pressure above ambient pressure in the cavern we have to take into account the ambient pressure variation at ground level and the head of air column from ground to bottom. We use data giving pressure variation during three years at OULUSALO located 140 km north of PYHASALMI ( http://timetric.com/index/atmospheric-pressure-oulunsalo-oulu-province- efou-metar/ ) If we assume that the pressure in PYHASALMI is the same than in OULUSALO we can calculate the pressure variation in the bottom of the mine where the LAr tank is expected to be installed (either at -900 m or at -1,400 m depth from ground level). http://timetric.com/index/atmospheric-pressure-oulunsalo-oulu-province- efou-metar/ Depth below ground (m) Depth below sea level (m) Multiplying factor (ref. Sea level pressure) Minimum pressure (mbar) Maximum pressure (mbar) Pressure range (mbar) Sea level0967105790 Minus 900 Minus 750 1.0941058115698 Minus 1,400 Minus 1,250 1.16011221226104

4. LIQUID ARGON TANK DESIGN CONDITIONS: Operating Pressure 4LAGUNA-LBNO LAr-Process Facilities

5. 5 Maximum decrease of pressure over a fixed number of hours is summarized in the here below table The max rate, -3mbar/hour, corresponds to around minus 0.4°C / day in the equilibrium temperature, well more than the maximum variation of the temperature in the tank at constant pressure ( 0.010°C). So if all the liquid is concerned by the temperature drop, the vaporization rate will reach 0.32% of its mass. As boil off is 0.07% /day, this additional flow would be 5 times the boil off flow. In order to minimize effect of vaporization thus convection currents in the liquid and also the size of boil off condensation unit, a constant pressure in the tank is retained by scientific team. LIQUID ARGON TANK DESIGN CONDITIONS: Operating Pressure Depth below ground (m) Ambient pressure maximum variation range (mbar) 3 years72 hours48 hours24 hours12 hours6 hours Sea level903531252119 Minus 900983833272321 Minus 1,4001044136292422

6. 6LAGUNA-LBNO LAr-Process Facilities LIQUID ARGON TANK DESIGN CONDITIONS: Operating Pressure Depth below ground (m) Depth below sea level (m) Minimum ambient pressure (mbar) Maximum ambient pressure (mbar) Absolute operating pressure of LAr tank= Maximum ambient Pressure + 10 mbar (mbar) Maximum differential pressure Operating Range (mbarg) MeasuredDesignMeasuredDesign Minus 900 Minus 750 1058104811561166 118 Minus 1,400 Minus 1,250 1122111212261236 124 Taking 10 mbar security value for both maximum and minimum ambient pressure at LAr level, we obtain the following figures: So we propose following max operating differential pressure for LAr tank design : 118 mbarg for -900m and124 mbarg for -1400m

7. 7LAGUNA-LBNO LAr-Process Facilities LIQUID ARGON TANK DESIGN CONDITIONS: Boil Off rate The following LAr tank boil-off rates have been assumed: Tank capacity (in ktons) 2050100 Boil-Off rate (% vaporized / day) 0.090.070.06

8. LIQUID ARGON SOURCING & PROCUREMENT 8LAGUNA-LBNO LAr-Process Facilities LIQUID ARGON PRODUCTION CAPACITY IN GEOGRAPHIC EUROPE INCLUDING WEST RUSSIA:  220 AIR SEPARATION UNITS  4,000 TONS/DAY ARGON PEAK PRODUCTION  3,500 TONS /DAY TAKEN BY CUSTOMERS  AROUND 500 TONS/DAY AVAILABLE COST AROUND 0.6€/kg WITHOUT TRANSPORTATION

9. LIQUID ARGON SOURCING & PROCUREMENT: Transportation mode 9LAGUNA-LBNO LAr-Process Facilities Argon available in Europe only, seems enough to fill a LAr tank within a reasonable duration, with 500TPD it will be :  66 days for the 33,000 tons LAr for the 20kton  146 days for the 73,000 tons LAr for the 50kton  280 days for the 140,000 tons LAr for the 100kton Will come from part of the 220 sources of liquid argon in Europe, say 100 sources, with 500TPD each source will send 5TPD. This quantity is not enough for delivery by complete train, with minimum 500 tons argon. Only Russia which has the same rail width than Finland could supply by railway,if large quantity of argon are available on some large plant,such as VOLOGDA 800km from PYHASALMI and which will produce 3,000TPD oxygen thus around 150TPD argon.

10. LIQUID ARGON SOURCING & PROCUREMENT: Liquid Argon Transportation mode 10LAGUNA-LBNO LAr-Process Facilities Capacity of 6 m container is 26 tons of argon, capacity of semi trailer 18 tons of argon.

11. ABOVE GROUND RECEPTION FACILITIES 11LAGUNA-LBNO LAr-Process Facilities CONDITIONS OF ARGON ARRIVING IN PYHASALMI  Mean flow: 500TPD or 360m3/day  Mode of transportation : around 28 semi trailers or containers on trucks per day.  Unloading facilities working in 2 shifts of 8 hours.  Max pressure of container 3.8 barg corresponding to 11 days travel with 5% vapor space.

12. ABOVE GROUND RECEPTION FACILITIES: Sizing of Above ground Buffer Tank 12LAGUNA-LBNO LAr-Process Facilities Operating pressure of standard tanks are from 5.6barg to 10.7barg and 14 barg. 5.6 barg is 1.4 bar over maximum pressure of argon from truck. Temperature (at @5.6 barg) of liquid/vapor equilibrium of minus 163.4°C Arrival of heat at the rate of around 26 kW sufficient to take care of inflow of heat with the pumps, through the flexible hoses, the piping and the buffer tank itself (around 0.11% /day or 1kW). Capacity, to take care of the night without arrival of argon from trucks and some reserve will the max standard size close to 1 day or 300m3. Size of standard tank is diameter 3.6m length 38m.

13. ABOVE GROUND RECEPTION FACILITIES: Sizing of Above ground Buffer Tank 13LAGUNA-LBNO LAr-Process Facilities

14. LIQUID ARGON FILLING LINE 14LAGUNA-LBNO LAr-Process Facilities Mean flow of incoming argon is 500TPD, buffer tank at surface cater for flow variation with the irregularities with the arrival of trucks. Flow to the bottom cavern is constant, value is 15m3/h. With 100% pressure drop corresponding to a vertical pipe inner diameter of pipe is 31mm and full flow speed 5m/s So we take 1 ¼” Stainless Steel pipe ( 42.2mm external diameter ) with standard thickness 4.85mm ( schedule 80) and inner diameter 32.5mm.

15. LIQUID ARGON FILLING LINE 15LAGUNA-LBNO LAr-Process Facilities  Weight of the pipe is 5.61kg/m  Weight of 50mm half shells 80kg/m3 polyurethane insulation is 1.15kg/m  Weight of 1mm thick butyl aluminum sheet as vapor barrier on the insulation is 0.44kg/m 900m long vertical pipe, weight is 6.48tons for empty pipe and 7.52tons with pipe full of LAr: Stress of hanged pipeline is :  38% of yield strength at ambient.  27% of yield strength in operation. For 1,400 m long vertical pipe, results are also acceptable.

16. LIQUID ARGON FILLING LINE 16LAGUNA-LBNO LAr-Process Facilities Stop of flow in the pipeline will be done using a valve at surface,in this case liquid argon in the pipe will go to the available volume in the tank at bottom. Flow reduction will be by a valve at surface buffer tank outlet, flow in the pipe will be torrential when flow is reduced below maximum capacity. With thickness 50mm polyurethane, heat inflow is 27kW for the pipeline. Energy of descending argon is converted into heat content, for max flow 15m3/h this correspond to power: 15 x 1380 x 9.81 x 900=182 MJ/h or 51kW. Total power for maximum flow : 78kW The orresponding temperature increase : +11.4°C Liquid /vapor pressure supposing 5.6 barg at surface : 12 barg.

17. BOIL OFF RECONDENSATION UNIT 17LAGUNA-LBNO LAr-Process Facilities SIZING OF UNITS: Two sizing cases shall be considered :  During filling of LAr tank  During normal operation

18. BOIL OFF RECONDENSATION UNITS: Sizing for a 50 ktons LAr tank. 18LAGUNA-LBNO LAr-Process Facilities A - Heat to be removed during filling of tank: Source of HeatkW Heat coming into argon during transportation to site : 7 days mean 2 ways travel duration, 0.4% /day boil off for 18 m3 container, 500TPD : 7 x 0.004 x 500=14TPD 26 Heat in pumping at surface, assumed 30m LAr efficiency 60% : 500 000*9.81*30/(0.6*3 600 000*24) 2.8 Heat in vertical pipe 78 Re-condensation of volume of displaced gas by incoming liquid 4 Heat coming in the tank through insulation : 0.07% /day or 51ton/day 95 Heat with recirculation for purification : assumed 100m/h, 2 bar, efficiency 50% (including heat from motor) 11 Heat coming in the piping and equipment for on surface piping and equipment, argon condensation, argon recirculation, nitrogen piping 20 Total 1 to 7 heat during filling of tank 236

19. 19LAGUNA-LBNO LAr-Process Facilities B - Heat to be removed in normal operation : BOIL OFF RECONDENSATION UNITS: Sizing for a 50 ktons LAr tank. Source of HeatkW Heat coming in the tank through insulation : 0.07% /day or 51ton/day 95 Heat from scientific instrument in the tank ~0 Heat due to high voltage electric field: ~0 Heat with recirculation for purification : assumed 300m/h, 2 bar, efficiency 80%, 21 Heat coming in the piping and equipment for argon condensation, argon recirculation, nitrogen piping: 15 Total 1 to 5 heat during normal operation of tank 131

20. 20LAGUNA-LBNO LAr-Process Facilities Heat during filling. 236kW Heat during normal operation 131kW So we propose to install two units each sized for 131 kW: i.=> one spare, one in operation during normal operation period, ii.=> Two units in operation in parallel during the filling operation period. BOIL OFF RECONDENSATION UNITS: Sizing for a 50 ktons LAr tank. == ~ 2 Each unit is based on a nitrogen refrigeration loop (compression – expansion). The two units share the Ar / Nitrogen heat exchanger. Performance of each unit is 880kW mechanical power (with 36°C heat source, 75% efficiency of compressors, 88% efficiency of expander, minimum delta T in exchangers 3°C.

21. BOIL OFF RECONDENSATION UNITS: PERFORMANCE OF HEAT EXTRACTION UNIT(for 50kton tank ) 21 LAGUNA-LBNO LAr-Process Facilities We need 6.7kW mechanical for each kW heat extracted. Thermodynamic maximum efficiency with cold source produced at - 184.5°C and heat rejected at +36°C is: T/Hc= (273+36)/(273-184.5)-1=2.49kW/kW Minimum Thermodynamic power would be 326kW. So efficiency versus max thermodynamic efficiency is rather poor: 37%. Except rotating machine, there is a large loss with irreversibility in the LP N2/HP N2 exchanger. Large delta t at low temperature, 24°C at cold part with 3°C at warm part. Addition of 117kW thermodynamic power (+35%) is done by this exchanger only!

22. BOIL OFF RECONDENSATION UNITS: Brazed Aluminum Plate Fin Heat Exchanger 22 LAGUNA-LBNO LAr-Process Facilities

23. 23LAGUNA-LBNO LAr-Process Facilities Tank nominal size Heat during filling Heat during operationRatio units running for filling units running for operation power of unit (kW) kW kW on shafts 20 kton211722,9321485 50 kton2371311,8121880 100 kton3242491,3032840 BOIL OFF RECONDENSATION UNITS: Sizing summary for 20 / 50 & 100 ktons LAr tank.

24. LIQUID ARGON CIRCULATION & FILTRATION: Impurities to be removed 24LAGUNA-LBNO LAr-Process Facilities Impurities in commercial argon or coming from matter in contact with argon ( steel envelope, aluminum on roof, steel roof reinforcement, instrument cables, connectors in the roof, detectors of light and electrons, electric field generator, pumps ) are mainly : Water, Oxygen, Hydrocarbons. Filtration is done on liquid argon at -185°C using 3 specific filters in series (or a mixed solid adsorbent common one): Molecular sieves for water, [regenerated on site] Active carbon for hydrocarbons, [regenerated ouside] Copper powder for oxygen. [regenerated either on site or outside]

25. LIQUID ARGON CIRCULATION & FILTRATION 25LAGUNA-LBNO LAr-Process Facilities Four filtration functions are foreseen for the LAr, the flows and impurity content at inlet varies and the impurity content at outlet is maybe to be optimized knowing the filters characteristics and cost. 1 - Filtration of commercial argon coming from surface Flow= 15m3/h 4ppmv oxygen 1ppmv water Outlet : 10ppb? Flow to be extracted O2 = 63g/h, H2O= 10g/h Pump power : 1.6 kW ( 2 horizontal pumps )

26. LIQUID ARGON CIRCULATION & FILTRATION 26LAGUNA-LBNO LAr-Process Facilities 2 - Filtration with recirculation during filling period Flow = 60m3 /h Starting O2 content = 10ppb Content outlet = 1ppb Flow O2 to be extracted =1g/h Pump power (1 vertical in tank : 10 kW ) Total to be extracted: O2=530g 3 - Filtration on condensed boil of in normal operation Flow = 1.77m3 / h Starting O2 content = 10ppb? Content outlet = 0.05ppb Flow O2 to be extracted = 0.019g/h Power : 150W (2 horizontal) Duration of purification =? Or all life of detector

27. LIQUID ARGON CIRCULATION & FILTRATION 27LAGUNA-LBNO LAr-Process Facilities 4 - Filtration with recirculation of liquid argon Rate is 1 recirculation of volume /week (assuming that it remains at the O2 0.1ppb ) Flow = 400m3/h Starting O2 content = 0.1ppb Content outlet = 0.05ppb Flow O2 to be extracted = 0.021g/h Pump power : 40 kW ( 2 vertical in tank) Duration of purification = all life of detector

28. 28LAGUNA-LBNO LAr-Process Facilities LIQUID ARGON CIRCULATION & FILTRATION: In-tank pumps Ebara pumps Carter pumps

29. 29LAGUNA-LBNO LAr-Process Facilities LIQUID ARGON CIRCULATION & FILTRATION: Filtration

30. LIQUID ARGON CIRCULATION & FILTRATION 30LAGUNA-LBNO LAr-Process Facilities Larger purification in matter of quantity of impurities is purification of commercial argon, for the main impurity, oxygen: Flow O2 to be extracted = 63 g/h, H2O = 10g/h Total to be extracted: O2=233kg H20=33kg Cu O2 getter takes 1.5% mass at ambient ( 20% of stoechiometric ) Cu +1/2O2 > CuO and 38% Cu on the Al2O3 support) and unknown at -185°C (as we didn’t found results from ICARUS T600, LAPD in Fermilab). Assuming 1% mass at -185°C, mass of O2 getter would be 23 tons and 30m3. It unnecessary to buy all that quantity and the tanks coming with, as O2 getter can be regenerated with H2, Ar mixture at 200°C.

31. LIQUID ARGON CIRCULATION & FILTRATION 31LAGUNA-LBNO LAr-Process Facilities For instance 3m3 O2 getter can be used 2 x 1.5m3 tanks in operation, 1 in regeneration, with 20 regenerations, around 1 regeneration each week. Regeneration could be done without dismantling of tanks, with specific circuit re circulating with compressor hot H2 mixture in the tank rather. Quantity of H2 required, with condensation of produced water than reheating is 40kg, thus 13 x 200 liters 200bar bottles or a little laboratory water electrolyser.

32. 32LAGUNA-LBNO LAr-Process Facilities N2 to & from cooling loops To & from filtration units To relief & vacuum valves To filtration unit In-tank pump for filling period In-tank pumps for normal operation TANK PROCESS EQUIPMENT & NOZZLES c

33. 33 LAGUNA-LBNO LAr-Process Facilities TANK PROCESS EQUIPMENT & NOZZLES Nitrogen refrigeration loop Filtration unit A Filtration unit B Relief & vaccum valves Filling line

34. 34 LAGUNA-LBNO LAr-Process Facilities TANK PROCESS EQUIPMENT: Process & electrical excavated room 64 m 25 / 30 m 12 /15 m 7 m Process area Electrical area Shaft for filling line Ventilation Shaft Lar Tank

35. AIR PURGE AND COOLING DOWN 35LAGUNA-LBNO LAr-Process Facilities If liquid argon is introduced in the tank, with the effect of heat brought by envelope the reduction of the volume of air with the temperature reduction is less than volume taken by vaporized argon so air goes out the tank. For each ton of liquid argon temperature would decrease by 1°C When dew point of water will be reached, rain or snow will fall in the tank, quantity with saturation at 20°C will be 900kg water. That not finished, at -90°C a snow of CO 2 will fall from remaining air. Initial quantity of CO2 in air in tank is 38kg. AIR PURGING

36. AIR PURGE AND COOLING DOWN 36LAGUNA-LBNO LAr-Process Facilities Quantity of argon is 2 x 61700m3x 1.9=234tons. Commercial used argon will come from the 300m3 buffer tank at surface and will be vaporized at bottom with mobile air vaporizer. Heat required is 16 000kWh, with 2 days duration vaporizer is 333kW. Air then argon is vented on top flow of argon is 4.87tons/hour, or 0.7m3/s, with ventilation rate of 30m3/s, argon content in air is 3.2%. AIR PURGE

37. AIR PURGE AND COOLING DOWN 37LAGUNA-LBNO LAr-Process Facilities Cooling down is done by introducing liquid argon at bottom and extracting some exceeding argon gas on top. With following hypothesis: Tank full of gaseous argon at 10°C and around 1.12bara after air purge. 800 tons steel equivalent heat capacity of tank including instruments and half insulation heat capacity. No use of argon re-condensation during cooling down cool COOLING DOWN OF TANK

38. AIR PURGE AND COOLING DOWN 38LAGUNA-LBNO LAr-Process Facilities cool COOLING DOWN OF TANK Cooling down requires around 400tons LAr. With temperature variation of 5°C /hour: Duration is 80 hours with flow 5t/h. Max % flow to be vented versus inlet flow is 72% at beginning, 3.5 tons /hour less than flow for air purging.

39. AIR PURGE AND COOLING DOWN 39LAGUNA-LBNO LAr-Process Facilities cool COOLING DOWN OF TANK Around 150 tons are vented (90k€) It’s possible to reduce that using simultaneously introduction of LAr and use of gas condensation units. With 2 units running and 262kWh removed and LAr mass 1.36ton/h. Temperature decrease is 3.3°C /hour and vented argon 0. To reach -3.3°C without condensation units requires 5 tons, so for 262kWh or 13€, 3.64 tons LAr, worth 2200€, is saved each hour Using condensation units can reduce to 0 vented argon during cooling down, but be cautious to avoid air inlet. At the end of cooling-down, below -160°C heat as to be added or liquid flow reduced in order to avoid air inlet!

40. CAVERN AMBIENT AIR TEMPERATURE CONTROL 40LAGUNA-LBNO LAr-Process Facilities cool c I.Heat from coolers of condensation unit : 1,030kW II.Heat from losses motor of compressor of condensation unit: 50kW III.Heat removed from cavern by tank and piping: -110kW Net heat 970kW With 2 units running during filling period With lighting, HVAC, instrumentation, control, electricity, motors of pumps loss ( water, argon ) : Around 2,200kW

41. CAVERN COOLING 41LAGUNA-LBNO LAr-Process Facilities cool c 2200kW removal with air ventilation and 10°C requires 170m3/s air, 30m3/s available from mine system. With water and 10°C flow 189m3/h 2 vertical pipes 6 inches. Pressure drop 4.5%, loss 80m for 2*900m. Pumps on surface, 189m3/h 90m 66kW. Water/water from lake or air cooler on surface.

42. THANK YOU FOR YOUR ATTENTION 42LAGUNA-LBNO LAr-Process Facilities