IRRADIATION EXPERIENCE OF THE FIRST MEGAWATT ......AA111 1KGA20 AA110 Small Box BB004 1KGA10 AA201 p 1KGA10 CP002, 1KGA10 AA201 1KGA10 AT002 1KGA10 AT001 1KGA10 AA105 1KGA10 AA107

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


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


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


SINQ Spallation Neutron Source


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


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


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


System Integration in SINQ

January - June 2006D2O Lines

Fillingvessel

HRS skidIGS condenser

Cover gas decay vessel


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


Upgrade of ventilation system

Active carbon filtersEarthquake strengthened shut-off dampersAutonomous filter unitLowOx-System (<13% oxygen) to mitigate fire hazard


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


First beam on Target on 14 Aug. 2006

40µA / ∼25 kW

stable forca. 1.5 h

Accelerator Control Room

SINQ Control Room


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


Regular operation August 21

1000 μA

Manned operation

Unmanned operation from August 24 onwards


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


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


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


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


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


LBE and Oil Temperatures

Proton current

Guide tube

THX inlet

THX LBE outlet

THX oil outlet

Target temperatures as predicted


LBE: THX inlet

LBE: in main guide

LBE: THX outlet

Oil: THX inlet

Proton beam

LBE: lower main guide

Temperature Transients with Beam Drops


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


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


☺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


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


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


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.


Gamma and mass spectroscopyGas samples taken afterphase 2 of start-up

Second sample with Ar flushing did not showHg and Au isotopes

Kr

Xe


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


Isolation Gas Pressure during Irradiation

Gas releaseTotal Gas Volume: 300 Nl


Temporary installation of isolation gas decay tanks in the SINQ cooling plant room


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


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

Documents

IRRADIATION EXPERIENCE OF THE FIRST MEGAWATT ......AA111 1KGA20 AA110 Small Box BB004 1KGA10 AA201 p 1KGA10 CP002, 1KGA10 AA201 1KGA10 AT002 1KGA10 AT001 1KGA10 AA105 1KGA10 AA107