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F P Orsitto ENEA 1
Diagnostics for hybrid reactors
Francesco Paolo Orsitto ENEA FUSION Technical Unit
C R Frascati(Italy)
FUNFI VARENNA 2011
Outline
Hybrid reactor (HR) models considered and their characteristics: relation to ITER and relevance for DEMO
HR : a small,low power DEMO with a (more) complex blanket( fusion + fission) .
Criteria determining the diagnostic systems needed for HRClassification of Diagnostic systems:i) machine protection;ii)
basic plasma control (incl. DT reaction );iii)divertor control;iv) diagnostics for blanket (neutron source and transuranic burn)
Requirement on measurements Technology / R&D needed Conclusion and further work
F P Orsitto ENEA 2FUNFI Varenna 2011
References and contribution
W M Stacey Fus Sci & Tech 2007(SABR design)M Kotschenreuter Fus Eng Des 2009(ST design)M Wang Fus Eng Des 2010 ( Blanket FDS)Y Wu IAEA Conference Geneva 2008 (paper FT/P3-21)
Contributions M Angelone , M Pillon for diamond detectors detectors M Ciotti,J Manzano, F Crisanti, A Botrugno for useful and
lively discussions
F P Orsitto ENEA 3FUNFI Varenna 2011
Tokamak Hybrid reactor (HR) models
F P Orsitto ENEA 4FUNFI Varenna 2011
FDS-I China design
F P Orsitto ENEA 5FUNFI Varenna 2011
FDS-1 model
Georgia Model –SABR
F P Orsitto ENEA 6FUNFI Varenna 2011
Tokamak major radius R0=3.75-4 mTokamak high aspect ratio A=3.4-4 ( higher than ITER A=3)Medium magnetic field B=5-6T (like ITER)Medium-High current IP=6-8MA( 0.5*IP ITER)Relatively low norm beta N=2-2.8(like ITER)HIPB98 =1-1.1Main scenario : H-mode Pulsed mode Q=Pfus/Pheating=3 ( Q ITER =5-10)
Comparison between FEB/FDS-I (EM) and SABR
F P Orsitto ENEA 7FUNFI Varenna 2011
Comparison between Hybrid Reactor(HR) and ITER & relevance of HR to DEMO
The Q_HR factor is of the order of 5-7 times that possible on JET at present And about ½- 1/3 of Q-ITER.
Q_HR = 5-7 Q_JET
Q_HR = ½-1/3 Q_ITER
Q_HR is intermediate between JET and ITER
Difference of HR with respect to ITER is the availability : 75% is supposed for HR While for ITER presently it’s 4%.
The HR Tokamak can be considered a prototype at small scale of DEMO
The HR availability is that hypotesized for a small ( R0=3m) , LOW Q (low performance) DEMOWith a complex blanket: FUSION + FISSION
F P Orsitto ENEA 8FUNFI Varenna 2011
Criteria determining the diagnostics needed for Hybrid
F P Orsitto ENEA FUNFI VARENNA 2011
Tokamak as neutron source
The plasma scenario is supposed assessed : no measurements dedicated to physics /scenario evaluationThe engineering would permit the insertion of DIA for scenario ev.If needed.
The measurements ARE NEEDED for1. the CONTROL of the scenario ( including DT reactions and neutron production)2. the safety of the device ( including the divertor and PWI)3. Monitor the Blanket Modules dedicated to the tritium breeding
Criteria determining Diagnostics needed for Hybrid Reactor(HR)
F P Orsitto ENEA FUNFI VARENNA 2011
HR as neutron source for fission The measurements ARE NEEDED to monitor 1. the fission of Main transuranic(TRU) elements2. the secondary ( from fission) neutron production 3. energy production from fission
ITER assessed Diag Plan
F P Orsitto ENEA 11FUNFI Varenna 2011
An example of DIA set for tokamak : Diagnostics of JT-60SA
F P Orsitto ENEA 12FUNFI Varenna 2011
An example of control plan :Control plan JT-60SA
F P Orsitto ENEA 13FUNFI Varenna 2011
Tokamak/neutron source measurements and diagnostics
Tab I Tokamak Diagnostics
machine protectionBasic-plasma measurements basic plasma diagnostics
neutron monitors line average electron densityInterferometer/polarimeter
Neutron activation measurements fusion power neutron monitors
D emission monitors Zeff measurementsbrehmsstrahlung rad meas
Divertor Langmuir probes impurity and D,T influx Infrared TV camera(divertor) resistive wall mode magnetic loopsrunawys electrons Halo current magnetic loops nT/nD in plasma core divertor erosion monitors QMB/Monitor Tiles Gas pressure (divertor and ducts) electron temperature
ECE / Thomson scattering using Nd:YAG
Dust plasma radiation bolometers surface temperature( divertor and first wall) plasma shape and position
plasma current F P Orsitto ENEA 14FUNFI Varenna 2011
Tokamak/neutron source Control Plan
Tokamak/neutron source Control Plan quantity to be controlled actuators Sensors/diag systemsplasma position poloidal field coils magnetic pick-up coilsplasma shape in vessel coils flux loopsplasma current poloidal field coils Rogowsky coils
electron densitygas puff, pellet injector,divertor pumping Interferometer
Neutron emission rate P-NB (ECRH , LHCD) Neutron monitorPlasma stored energy P-NB (ECRH,LHCD) Diamagnetic loopDensity profile Pellet , gas puff InterferometerCurrent profile P-NB (ECRH,LHCD) PolarimeterRadiation power Impurity gas puff BolometerFusion power P-NB, gas-puff,pellet (ECRH,LHCD) Neutron monitorTemperature P-NB (ECRH,LHCD) ECE for Te
F P Orsitto ENEA 15FUNFI Varenna 2011
Blanket modules example from China FDS(*)
Y Wu Fusion Engineering Design 2006
FDS I Hybrid Blanket design General scheme of a blanket for hybrid
M Wang Fusion Engineering Design 2010
F P Orsitto ENEA 16FUNFI Varenna 2011
Proposed scheme of blanket
F P ORSITTO (ENEA) 17FUNFI VARENNA 2011
Isotopes and decays element Mass Nr
alpha decay(kev) gamma decay(keV) Half life
Am 2435233.3 74.6647370y 5275.5 43.533 5181.1 Pu 2424856.2 44.9153.733e5y 4900.5 Pu 2395105.5 24000y 5111.2 5144.3 5156.59
Np 2374788.0 29.37
2.144e6 y
4771.0 86.477 4766.0
Pa 2315013.8 27.36 32760y
5028.4 5058.6
F P ORSITTO (ENEA) 18FUNFI VARENNA 2011
Blanket diagnostics
The blanket diagnostics need for measuring :
i)The content of isotopes ( measurement alpha lines of various radionuclides)ii)The neutron multiplication ( neutron flux / neutron spectroscopy)iii)Tritium breeding ( monitors of tritium)
Sensors can be inserted in the :i)FUEL zoneii)Tritium breeding zone iii)Outside the vessel
F P ORSITTO (ENEA) 19FUNFI VARENNA 2011
Meaurement of Isotopes
The measurement of isotopes can be carried out both :i)Using alpha particle monitors inserted into the blanket very close to the containers of ling life isotopes to monitor on line the ‘transmutation’ of long lived isotopesii) Using off-line alpha particle spectroscopy
Sensors for alpha particle detection and spectroscopy in the range of4-5MeV can be syntetic diamond diodes with technology and electronics Well known and tested These diodes have also a very good resistence to the high neutron flux
F P ORSITTO (ENEA) 20FUNFI VARENNA 2011
Neutron and gamma ray measurements
Sensors for neutron can be inserted into the blanket in particular in the fuel zone As well as outside the vessel
The technology for this detection is well known
The gamma spectroscopy in particular made using high resolutionMeasurements by Ge detectors can be useful to characterize bothPlasma and secondary gamma derived from decay of radionuclides.
F P ORSITTO (ENEA) 21FUNFI VARENNA 2011
Parameters important for determining
the requirements on measurements Neutron flux Q=3 , Pheating =50MW , A=4 and R0=3m
2
218
1219
220
2
/7.2
)/(102.1*
)5/4(
150*
1024.2106.1*14
4.442
mMWPnLoadWallNeutron
smneutronsSEn
PfusNFluxNeutron
MWPheatingQPfusPowerFusion
JMeVEnEnergyNeutron
mA
RSsurfaceTokamak
F P ORSITTO (ENEA) 22FUNFI VARENNA 2011
Requirements on measurements
F P Orsitto ENEA FINFI VARENNA 2011
requirement on measurements for diagnostics of hybrid reactors Tokamak Neutron source
measurement range (keV)spatial resolution
time resolution
accuracy system
temperature 0.01-30 a/10 1Hz 10-20%
ECE & LIDAR Thomson scattering
density 1-20 10 E19 m-2 line integral 1Hz 10-20%
CO2 interferometer
neutron flux and emissivity
10 E14-10 E20 n/s integral 1Hz 10%
diamond detectors
neutron profile monitor
10 E14-10 E19 n/(m2 s)a/10 1Hz 10%
diamond detectors or scintillators
Zeff monitor line integral 1Hz 10%
vis bremmsthralung
escaping alpha <2MW/m3
a/10 along poloidal direction 100ms 10%
scintillator probe
Requirements on measurements
F P Orsitto ENEA FuNFI VARENNA 2011
divertor operational parameters divertor termography
200-3000 C 1Hz 10%
erosion rate 1-10E-6 m/s 10mm 1s 30%
Gas pressure 1E-4-20Pa
50ms 20%
blanket ( Fuel zone)
alpha particle 4-5MeV integral 1Hz 10%diamond detectors
(off line and inside measurements)
gamma ray 10-100keV integral 1Hz 10%
Ge detectors
(off line measurements)
DIA for Hybrids :R&D Needs
Tokamak /neutron source :
Erosion of divertor
Lost alpha probe
Blanket : Fuel Zone Test of Diamond detectors asAlpha particle diagnostic inside
F P ORSITTO (ENEA) 25FUNFI VARENNA 2011
conclusions
F P Orsitto ENEA
Tokamak for Hybrid concept is located between ITER and a low power proto-DEMOHR Tok :Q=3, availability 75%, long pulses (months?) ITER: Q=5-10, pulse duration 400s, availability 4%
Diagnostics for hybrid share some characteristics with a low power proto-DEMO Diagnostic system:• No scenario evaluation ,• monitor of main kinetic quantities,• control of MHD Stability and current profile via Current Drive• Diagnostics for the safety of the machine( Divertor erosion monitor)
Diag systems can be used also to monitor the FUEL zone of the blanketThrough the measurements of alpha decay of long term actinides