1. magnetic confinement - ENEA - Fusione

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3. FUSION TECHNOLOGY
3.9 Thermal-Fluidodynamics
2001, the first experimental campaign started on four of the EDA mockups mounted
inside EDA-BETA [3.44, 3.45].
3.9.2 HE-FUS3 experimental cassette of lithium-beryllium pebble
beds
During 2001, a new thermal test campaign was started on the HELICHETTA solidbreeder
mockup. The objective of the tests on a single prismatic cell filled with the
reference breeder Li 4 SiO 4 and Li 2 TiO 3 pebble beds was to determine the influence
of the filling factor on the thermal-mechanical parameters and the behaviour of the
ceramic bed after mechanical pre-cycling and application of the spring-system lateral
load. From July 2001 to the end of the year, 60 tests were carried out in air on the
HEFUS-3 facility at ENEA Brasimone on both the reference materials. The measured
Li 4 SiO 4 and Li 2 TiO 3 pebble packing factors were, respectively, 0.65 and 0.64. The
results of the first HELICHETTA test campaigns are:
i) the displacement of the beds is as large as 0.2 mm towards the cooling plates and
ranges from 0.5 to 1 mm for L i 2TiO 3 and up to 1.5 mm for Li 4 SiO 4 towards the
sliding plug;
ii) the washer springs and sliding plug systems prevent larger stresses on the
containment structure;
iii) the pebble bed thermal conductivities in air show good agreement with previous
FZK experiments;
iv) the pebble thermal mechanical hysteresis, well evident during the cyclic ramp
up/down tests, affects the thermal-mechanical bed behaviour.
The tender for construction of both HELICA and HEXCALIBER was launched in
December 2001 and their fabrication will be finished, respectively, by June 2002 and
December 2002 [3.46, 3.47].
3.10 International Fusion Material
Irradiation Facility (IFMIF)
3.10.1 Design and mockup tests of lithium jet target
One of the main tasks of the lithium target design is to guarantee the jet stability
against overheating by the powerful deuteron beam. This is achieved with the use
of a curved plate (backplate) on which lithium flows. A computer code (RIGEL)
developed ad hoc by ENEA Bologna was used to determine the best working
conditions (table 3.V) for the new IFMIF design parameters (Reduced Cost Design).
[3.44] G. Dell’Orco et al.,
Status of the Contracts
EFDA 00/529 and
00/533 for the thermal
fatigue tests of Be
protected EDA – PFW
mock-ups, ENEA-EFDA
Meeting (Brasimone
2001)
[3.45] G. Dell’Orco et al.,
Report for the Task
T216+, subtask E1, on the
thermal fatigue tests of
Be protected first wall
mock-ups, ENEA Internal
Report, SB-G-R-0051
(2001)
[3.46] G. Dell’Orco et al.,
TAZZA mock-up pebble
beds - Experimental and
theoretical investigations,
presented at the
10th Int. Workshop on
Ceramic Breeder Blanket
Interactions (CCBI-10)
(Karlsruhe 2001)
[3.47] G. Dell’Orco et al.,
Progress on pebble bed
experimental activity for
the HE-FUS3 mock-ups,
presented at the 10th
Int. Workshop on
Ceramic Breeder Blanket
Interactions (CCBI-10)
(Karlsruhe 2001)
Tab 3.V - IFMIF target input data and Li jet stability results
Main input data
r
Main results
Beam footprint 5×20 [cm×cm] Reynolds number 694417 [-]
Jet thickness 0.025 [m] Max. pressure 12493 [Pa]
Jet width 0.26 [m] Max. surface temperature 297 [°C]
Jet velocity 15 [m/s] Max. temperature in the 441 [°C]
bulk
Backplate curvature 0.25 [m] Min. free surface boiling 35 [°C]
radius
margin
Inlet temperature 250 [°C] Min. bulk boiling margin 403 [°C]
Jet power deposition 10 [MW] Free surface evaporation 16 [g/year]