Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
5th International Workshop on the Utilization and Reliability of High Power Proton Accelerators (HPPA5)
Mol, 6.-9.5.2007
MEGAPIE IRRADIATION EXPERIENCE OF THE FIRST MEGAWATT LIQUID METAL
SPALLATION TARGET
F. Groeschel*, S. Dementjev, H. Heyck, W. Leung, K. Thomson, W. Wagner, L. Zaniniand on behalf of the MEGAPIE Initiative
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
Contents• Design of the target system• Integral test in MITS• Integration in SINQ• Startup• Beam history• Neutronics• Thermalhydraulic Aspects• EMP performance• Gas production• Conclusions
Presentation on conceptand design at HPPA4
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
ObjectivesMEGAPIE is an experiment to be carried out in the SINQ target location at the Paul Scherrer Institute and aims at demonstrating the safe operation of a liquid metal spallation target at a beam power in the region of 1 MW. It will be equipped to provide the largest possible amount of scientific and technical information without jeopardizing its safe operation.The minimum design service life will be 1 year (6000 mAh).Target material will be the PbBi eutectic mixture.The design beam power is 1 MW at 600 MeV.Existing facilities and equipment at PSI will be used to the largest possible extent.Cooling water loops of the target station will be left largely unchanged and will be ready for use with a solid target again within less than 1 month after termination of the MEGAPIE irradiation.
Contract of MEGAPIE Initiative, 2000
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
SINQ Spallation Neutron Source
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
MEGAPIE Target
Design parametersBeam energy: 575 MeVBeam current: 1.74 mADesign life: 1 year of operation
(6000 mAh)Target/coolant: Lead-bismuth eutecticLBE volume: 88 lWetted surface: 16 m2
Deposited Heat: 650 kWLBE T range: 230-380°C Max. flow velocity: ~1.2 m/sBeam window: T91 steel Window Temperature: 330-380°C Radiation Damage: 20-25 dpa
Target Head Feedthroughs
Target Shielding
Main EMP Flowmeter
Bypass EMP Flowmeter
Upper Target Enclosure
Main Guide Tube
Bypass FlowGuide Tube
LBE Leak Detector
Expansion Tank
12 Pin Heat Exchanger
Central Rod Heaters and Neutron Detectors
T91 Lower Liquid Metal Container
Lower Target Enclosure
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
Remote operated valve ( failsafe open)
Flow control valve(failsafe close)
Manual Valve
AA0XX: Flow control valveAA1XX: Remote operated valveAA2XX: Manual valve
AA7XX: auto controlled valveAA9XX: Safety valve
CTXXX: Temperature sensorCPXXX: Pressure sensor
CLXXX: Level sensorCFXXX: Flow sensor
CQ2XX: Conductivity sensor
ACXXX: Heatexchanger
BBXXX: Tank
APXXX: Pump
Flow control valvefailsafe open
Safety valve
auto controlled valve
Flowmonitor
Checkvalve
ATXXX: Filter/Ionexchanger
AA3XX: CheckvalveAA4XX: 3way valve
1KAC00AA201
1KAO01 AP001
1KAO10AC001
1KAO10 AA100
1KAO20 AA101
1KAO10 CF001
1KAO10CT001
1KAO10 AA001
1KAO30 CP001
1KAC20CT002
1KAO20 AA227
1KAO10 CT005
1KAO20 AA301
p
1KAO10 CT011
1KAO10 CP002
1KAO10 CP005
Oil Sampling
1KAC10CT001
1KAC00AP001
1KAC00CT201
1KAC00AA001
1KAC00AA202
1KAC00AA205
1KAC00AC002
1KAC00CP101
1KAC00AA203
1KAC00CT203
1KAC00CF101
1PRA51AA901
1PRA51CT201
1KAC40AT001
1KAC00AA208
1KAC40AT002
1KAC30BB001
1KAC40AA301
1KAC40AA202
1KAC30AA201
1KAC30AA203
1KAC30AA901
1KAC30AA701
1KAC00AA302
1KAC 00CT202
1KAC00CP501
1PRA52AA202
F
p
1PR A51CP101
1KAC30CL001
1KAC30CP001
1KAC30CL001
p
1KAO10 CT012
1KAO10 CT006
1KAO10 CT005
1KAO10 CT012
1KAO20 AA901
F
1KAO10 CF002
1KAO30BB001
1KAO30AA2201KAO30
CF003
1KAO30 CT007
1KAO20 BB002 1KAO20
AA205
p1KAO20 CP101
1KAO20AA213
1KAO30AA214
1KAO30AA102
1KAO30AA102
1KAO30BP001
1KAO20 CP103
1KAC40 CT201
1KAC40AA201
1KAC40 CQ201
1KAC40 AA901
Heat Removal System (HRS) 1KAO
Intermediate Water Cooling Loop (WCL) 1KAC² p
1KAC00AA301
1KAC00AA901
1KAC40BP001
Cooling Water Loop 6
Orifice
PBXXX: Orifice
CWXXX: Weight sensor
BHXXX: Heater
L
L
p
p
Rupture disk
Pump
Filter
1KAO30AA231
Remote operated valve ( failsafe close)
MEGAPIETarget
1KAO30AA232
1KAO30BB003
1KAO30AA211
Offgas
Gas Sampling
1KGH71AA901
1KGH71BP901
p
p
1KGH71CP002
1KGH71CP001
1KGH71 AA207
1KGH71 AA205
1KGH71AA204
1KGH71 AA203
1KGH71 AA201
kontrollierteFortluft
Abgas-strang2
1KGH71 AA301
He
p
p 1KGH71CP003
L1KGH71CL001
1KGH71BB001
Blank Flange
Insulation Gas System 1KGH71
1JER34AC001
F1JER20 BB001
p
1JER20CP002
1JER20CT201
1JER20CT922
1JER20AA101
1JER10AA901
F
1JER11CT922
1JER10AA101
1JER10CF001
1JER10AA001
1JER10AA102
1JER10CP902
1JER01 AP001
1JER02 AP001
1JER01 CF001
1JER02 CF001
1JER34AA101
p F
1JER11AA001
1JER11CP001
1KBL65AT001
1KBL65AT001Q
1KBL60CQ201
1JER33CF902
Drainsystem Drainsystem Drainsystem
1JER11CF001
Target Window Cooling System1JER
Kreislauf 6 1PRA22
1PRA34AA001
1PRA34AA101
p1PRA33CP001
1PRAAA901
1JER33BB001
Δp1KBL68CP501
1KGA20AA102
1KGA20AA101
1KGA10CP001
1KGA20AA111
1KGA20AA110
Small BoxBB004
1KGA10AA201 p p
1KGA10CP002,
1KGA10AA201
1KGA10AT002
1KGA10AT001
1KGA10AA105
1KGA10AA107
1KGA10BB002
1KGA10BB001
p1KGA10CP005
1KGA10AA3031KGA10BP901
1KGA10AP001
1KGA10AA202
Gas Sampling
1KGA10AA106
1KGA10AA103
1KGA10AA104
p
p
1KGA10CP003
1KGA10CP004
1KGA20AA109
1KGA20AA205
1KGA20AA301
Offgas
1KGA10AA204
ArgonSupply
ArgonSupply
1KGA20AA206
1KGA20AA2071KGA20
AA208
Fill&Drain
System
ArgonSupply
ArgonSupply
SecondaryContainment
1KGA10AA203
Labels and Symbols:
1PR A51AA701
1PRA52AA201
p1PR A52CP101
1PR A51AA101
1PRA51AA201
1PRA51AA202
1PR A52CT301
1PRA52CF001
1PRA52CT201
pp1JER10CP001
Cover Gas System 1KGA
MEGAPIE Target System
in SINQ
Cover Gas System Ar
Isolation Gas System (IGS)
He, Ar
Heat Removal System (HRS)
Diphyl THT
Target WindowCooling System
(D2O)
Intermediate Water Cooling Loop (WCL)
CirculatingCoopling Water
Loop
Target
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
MEGAPIE Integral Test
September – Dezember 2005• 133 hours of operation with LBE• EMP/EMF performance• Thermal hydraulic test, 200 kW heater• Beam window coolig tests
THX heat transfer (oil side) better than anticipated
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
System Integration in SINQ
January - June 2006D2O Lines
Fillingvessel
HRS skidIGS condenser
Cover gas decay vessel
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
SINQ Beam Trip Logic during MEGAPIE
MEGAPIEFast shut
down system
MEGAPIE-Slow shut down
system(PLC)
LBE Temp. 1 bottom too high (>400°C)
LBE Temp. 2 bottom too high (>400°C)
LBE Temp. 1 middle too high (>400°C)
LBE Temp. 2 middle too high (>400°C)
EMP1 Current Phase 2 <20A >35A
EMP1 Current Phase 3 <20A >35A
EMP2 Current Phase 1 <20>35AEMP2 Current Phase 2 <20A >35AEMP2 Current Phase 3 <20A >35A
MEGAPIE CS not ok
Vakuum valve
SINQ Magnet
Kickermagnet
Beam shutterclose Shutter
Powersupply Kicker
Monitor Kickermagnet
Beam Transmission Monitor
MEGAPIEControl-system(PLC)
H+ Ion Source out
Voter -electronic
Permanent SINQ Beam Trip Logic
Temporary MEGAPIE Beam Trip Logic
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
Upgrade of ventilation system
Active carbon filtersEarthquake strengthened shut-off dampersAutonomous filter unitLowOx-System (<13% oxygen) to mitigate fire hazard
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
Preheating, Filling and Off-beam Operation
LBE weight
F&D Temp
MFGT bottom Temp
Target Pressure
Level L
Filling
P Adjustment
LBE Adjustment
Level LL
EMP Start926 kg LBE
July - August 2006
• Failure of 4 of 6 heater circuits• Heater power 22 kW 8.9 kW
Operation in Hot Standby over 17 days• EMP performance assessment• EMF/AFBM setup• TH control adjustment• Safety systems check
BAG permission for irradiation, August 11• 4 milestones• 52 additional requirementsfulfilled
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
First beam on Target on 14 Aug. 2006
40µA / ∼25 kW
stable forca. 1.5 h
Accelerator Control Room
SINQ Control Room
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
18:0016:0014:0012:00
100 μA200 μA
Phase 2: Tue., Aug 15, 2006 Phase 3: Thu., Aug 17, 2006
MEGAPIE Operation Start-Up
Check of proper functioning, safety systems and gas sampling
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
Regular operation August 21
1000 μA
Manned operation
Unmanned operation from August 24 onwards
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
MEGAPIE Target Operation
First protons on target, August 14
First protons on targetAugust 14, 2006
On beam: August 14 – December 21, 2006• Accumulated charge: 2.8 Ah• Peak Current: 1400 μA• Beam trips (< 1 min): 5500• Interrupts (< 8 h): 570
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
Target temperatures at full beam
Cover gas: 226ºC
THX inlet: 315ºC
Spallation zoneoutlet: 340ºC
Oil outlet: 210ºC
THX outlet:229ºC
Spallation zoneinlet: 280ºC
Beam current: 1274 mA
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
Neutronic Measurements
• Task 1: delayed neutron measurements• Task 2: micro fission chambers• Task 3: bonner spheres flux measurement
(+ monitoring with fission chamber)
• Task 4: gas production• Task 5: gold foil activation• Task 6: activation foils at PNA/NAA• Task 7: flux at ICON
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
Gold Foil Measurements at ICON, NEUTRA and EIGER beam lines and NAA station
NAANEUTRA
ICON
EIGER
1.79
1.81
1.85
1.61
Ratio of MEGAPIE/SINQ thermal flux.
Results
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
SINQ target 6 (2005) MEGAPIE (2006) RATIO
EXP CALC (E<1eV) EXP CALC (E<1eV) EXP CALC(E<1eV)
NEUTRA (30) 2.59 107 (5%) 2.42 107 (1%) 4.80 107 (5%) 3.85 107 (.5%) 1.85 1.59
ICON (50) 3.80 108 (5%) 4.57 108 (1%) 6.89 108 (7%) 7.70 108 (.5%) 1.81 1.68
EIGER (82) 6.46 108 (5%) 7.49 108 (1%) 1.04 109 (5%) 1.51 109 (.5%) 1.60 2.02
NAA 5.82 1012 (5%) 6.31 1012 (1%) 1.05 1012 (9%) 1.12 1013 (.1%) 1.80 1.77
Comparison of flux measurements and calculations
( fluxes in n/cm2/s/mA)
MCNPX 2.5.0F5 talliesMEGAPIE nps=1000000SINQ nps = 300000
Factor 1.77 increase vs. SINQ target 6 good agreement between measurements and calculations
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
LBE and Oil Temperatures
Proton current
Guide tube
THX inlet
THX LBE outlet
THX oil outlet
Target temperatures as predicted
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
LBE: THX inlet
LBE: in main guide
LBE: THX outlet
Oil: THX inlet
Proton beam
LBE: lower main guide
Temperature Transients with Beam Drops
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
The Proton Beam Heating
0
100
200
300
400
500
600
0 100 200 300 400 500 600
Proton Beam Heat, kW
THX_
2 H
eat,
kW
0
100
200
300
400
500
600
0 100 200 300 400 500 600
Proton Beam Heat, kW
IHX-
2 H
eat T
rans
fere
d
Secondary side of the IHX Secondary side of the THX
The average errors are:+1.9%, -2.% and max: 5.71%
The average errors are -13.6 % and max: -22.4 %
The Monte Carle codes predicted the heat deposition quite well in this range, but it seemed that the error would be larger at high current.
~6 kW of EMPs and 18 kW ICL Pump so as the heat losses were not included in evaluating the reference power.
415 kW/mA
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
MEGAPIE - THX behaviour
210
215
220
225
230
235
240
210,00 215,00 220,00 225,00 230,00 235,00 240,00
Outlet Temperature Diphyl calculated (°C)
Out
let t
empe
ratu
re D
iphy
l mea
sure
d (°
C)
Outlet Outlet DiphylDiphyl temperaturetemperature
Error : mean 3%, Max 5%
210
215
220
225
230
235
240
210,00 215,00 220,00 225,00 230,00 235,00 240,00
Outlet Temperature Diphyl calculated (°C)
Out
let t
empe
ratu
re D
iphy
l mea
sure
d (°
C)
Flow rateFlow rate Correction of the two fluids:Diphyl : +25%
LBE: 26 – 41,5 kg/s TCQm
p Δ⋅=•
Error : Mean 0,4%, Max 4,5%
Comparison of ε-NUT modelwith experimental data
Good agreement if flow rates are adjustedKnown uncertainty in flow rates in LBE and Oil loop
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
☺Resistance of electrical insulation is >1MΩ
☺No change in the coils el resistances
Main flow EMP
Ivanov calculations based on EMP1 current, taking into account LBE path hydraulic resistance and actual LBE temperatures distribution: 4.2-4.9 l/s
DS evaluation from the LMT thermal balance
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
By-pass flow EMPThe pump temperature very slowly goes down (approx. 0.5K/month)
evidently because of decomposition of green stuff. There are correlations between IG pressure and EMP2 temperature as well
LBE flowrate through by-pass nozzle calculated from EMP2 current, taking into account LBE path hydraulic resistance and LBE temperature distribution: 0.26…0.34 l/s
The pump U-I characteristic corresponds to prediction. Resistance of electrical insulation is >1MΩ
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
Gas production measurements
• Measurement of the radionuclide inventory: samples taken at the start up (few mA h on target)
• Measurement of stable light nuclei (mainly 4He): samples taken later.
• Important for safety reasons• Information on the release process of
gases in a real molten metal target.• Benchmark of Monte Carlo models
protons
gas
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
Pressure increase in expansion volumeAverage expansion tank pressure vs integrated charge on target
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0 50 100 150 200 250 300 350 400 450 500
Integrated charge (mA h)
Ave
rage
(CP0
01,C
P002
) pre
ssur
e (b
ar)
X9 estimates: 1 l NTP after 1 month at 1.74 mA (=1253 mA·h) , that is about 0.4 lafter 500 mA h.
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
Gamma and mass spectroscopyGas samples taken afterphase 2 of start-up
Second sample with Ar flushing did not showHg and Au isotopes
Kr
Xe
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
IsotopActivity
calculatedActivity
measured UDAKDose topublic
[Bq] [Bq] [Sv/Bq] [Sv]H-3 1.34E+11 1.33E+11 5.83E-18 7.75E-07Kr-79 1.77E+12 7.76E-03 7.06E-19 5.48E-21Kr-85 1.93E+08 1.91E+08 6.11E-21 1.17E-12Xe-122 2.27E+10 3.59E-15 3.29E-19 1.18E-33Xe-125 8.54E+11 2.72E-18 6.70E-19 1.82E-36Xe-127 5.20E+11 1.40E+11 7.85E-19 1.10E-07Xe-129m 8.26E+10 3.80E+08 2.03E-19 7.72E-11Xe-131m 1.09E+07 1.97E+05 9.80E-21 1.93E-15Xe-133 2.45E+10 2.71E+06 9.80E-20 2.66E-13Xe-133m 5.70E+07 1.82E-02 2.05E-19 3.74E-21
Release Measurements of Cover GasRelease from decay tank on 6.12.06
Excellent agreement between measurements and calculation
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
Isolation Gas Pressure during Irradiation
Gas releaseTotal Gas Volume: 300 Nl
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
Temporary installation of isolation gas decay tanks in the SINQ cooling plant room
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
Conclusions• The MEGAPIE target operation was successful
• The neutronic performance yielded the expected flux increase
• The thermalhydraulic behaviour was stable and beam trips could be well controlled
• The release of radioactive noble gases in liquid targets is much more important than in solid targets. Careful design of the handling system is needed. We experienced some unexpected leaks and could manage them successfully
• The large amount of data collected and experience gained needs further evaluation and documentation
• The experience gained is extremely important for future LM target design and operation
Paul Scherrer Institut • 5232 Villigen PSI HPPA5, 6.-9.5.2007/GF34
Acknowledgement
This presentation was prepared on behalf of the MEGAPIE team
H. Heyck, S. Dementjev, L. Zanini, K. Berg, W. Leung, L. Cachonand G. Hauswirth are especially acknowledged for their contribution
MEGAPIE-TESTMEGAPIE-TEST
Departmentof Energy
Departmentof Energy