Transcript Document

Overview of LLCB TBM for ITER
Paritosh Chaudhuri
Institute for Plasma Research
Gandhinagar, INDIA
CBBI-16, 8- 10 Sept. 2011, Portland, USA
Intruduction
In India, development of Lead-Lithium Ceramic Breeder (LLCB)
blanket is being performed as the primary candidate of Test Blanket
Module (TBM) towards DEMO reactor.
The LLCB TBM will be tested from the first phase of ITER
operation (H-H phase) in one-half of a ITER port no-2.
The Indian TBM R&D program is focused on the development
and characterization of materials: structural (IN-RAFMS), breeding
materials (Pb–Li, Li2TiO3) and development of technologies for
Lead-Lithium Systems, Helium Cooling Systems, Tritium
Extraction Systems, TBM manufacturing and coatings.
Indian TBM Program
India is developing Lead-Lithium
cooled Ceramic Breeder (LLCB)
TBM for testing in ITER Port No-2
with position of TBM Leader.
Lead-Lithium cooled Ceramic Breeder (LLCB)
 Tritium Breeder: Lithium Titanate;
 Coolant: Pb-Li eutectic alloy (multiplier and breeder)
 FW coolant: Helium Gas;
 Structural Material : Reduced Activation FMS
 Helium purge gas for T extraction from CB
LLCB TBM Internal Arrangements
Dimensions
~1.66 m (P) x .484 m (T)x.496 m (R)
Structural
Material
FMS (IN-RAFMS) 28 mm thick
Breeder
PbLi, Li2TiO3
Total Power
Deposition
~ 0.857 MW
NWL
~ 0.78 MW/m2
Coolant
PbLi and Helium
TBM SYSTEM - Schematic
5
LLCB TBM Neutronic Analysis
Input parameters for LLCB TBM neutronic calculations
Fusion Power : 500 MW, Neutron Wall load : 0.78 MW/m^2
Pulse duration is 400 sec with pulse repetition time 1800 sec
Major and Minor radius of plasma: 6.3/ 2.1 m
Structural Material: IN-RAFMS (Eurofer as a reference material)
Shield Material:- SS-316 (65%) and water (35%)
Vacuum Vessel: Borated SS-316 cooled with water
Blanket materials:
-Pb-Li Eutectic (90 % Li-6) (Breeder, Multiplier and coolant)
-Li2TiO3 (60 % Li-6, Packing fraction 60%)(Breeder Material)
-He (Coolant for the First wall)
LLCB TBM in ITER sector model
A 15 degree sector of the ITER
machine has been constructed. The
shield and vacuum vessel has been
made using the intersection of
concentric tori and concentric
cylinders.
TBM dimensions are taken as
1.66 x0.484x0.518 m^3 (pol x tor x
rad ). TBM geometry has been
modeled using the parallel planes.
A 20 cm thick water jacket has
been placed around the TBM. 100
cm thick shield plug has been put
after the TBM.
Poloidal Radial view of ITER neutronic model (with LLCB TBM)
Power density profile & Total Power Deposition in LLCB TBM
Total Power deposited in LLCB
TBM is 0.62 MW
Preliminary LLCB TBM shield block design
Schematic
Frame
Assembly
LLCB TBM + Shield Block in Frame
assembly
LLCB TBM
Reference
Solid TBM
Sub-modules
Shield block
Shield Flange
with lip seal
The TBM in ITER will
attenuate the flux ~1 order
magnitude
To reduce dose rates this flux
should be further reduced (~106
n/cm2 /s) for safety and
maintenance purpose
 The shield block consists of
60 % SS 316 LN and 40 %
water (DM)
LLCB TBM Thermal Hydraulic
Thermal Hydraulics of ITER TBM
Main Objectives:
To optimize a suitable design of FW cooling w.r.t. Neutron wall
load and heat flux.
To estimate the temperature and thermal stresses of all
materials used in the blanket module and ensure these values
are within design limits.
To keep the temperatures of ceramic breeder zones within
the temperature window for effective Tritium release
To optimize the flow parameters (velocity, pressure)
LLCB First Wall Structure
480
568
20X11
20X20
R2.5
28
Circuit-1
Circuit-2
Total number of channels - 64
Number of circuits (counter flow) – 2
Number of passes per circuit – 4
Number of channels per passes – 8
Pitch: 25.5 mm (typical to all channels)
Rib thickness between channels = 5.5 mm
Power Deposition on LLCB TBM
Analytical Model
Input Parameters
- Total Heat Load: 0.616 MW
- He inlet Temp: 300 C
- He inlet pressure: 8 MPa
- He velocity : 45 m/s
- PbLi inlet Temp: 325 C
- PbLi inlet pressure: 1.2 MPa
- PbLi velocity: 0.1, - 0.5 m/s
Assumptions
- Flow is Steady and incompressible
- Flow is turbulent
Output:
- Radial temp. profile in all zones;
- PbLi velocity, Pressure Drop profile,
outlet temp.
Radial Temperature Plot for LLCB TBM
Temperature Distribution of LLCB TBM (for different V= 0.1, 0.2, 0.3, 0.5 m/s)
Radial temperature profile in different CB zones
Radial temperature profile in different CB zones for PbLi velocity of 0.1 m/s
Peak Temperature at different zones in LLCB TBM
Peak Temperature at different zones in TBM (for PbLi velocity = 0.1 m/s)
Zone Name
Temperature (C)
Analytical
Analysis)
CFD Analysis
Be Surface
422.21
462.57
Be-FMS Interface
414.53
453.95
FMS-Insulator Interface
441.69
455.01
Insulator-PbLi Interface
439.49
449.37
Insulator-FMS Interface
442.85
458.30
FMS-CB Interface
438.99
459
CB zone
(5th
489
Breeder)
(5th
491
Breeder)
Alternative Concept
Exploded views of LLCB
Top plate assembly
Breeder assembly
Outer & Inner back plates
Manifold
First-Wall
Pipes
Bottom plate assembly
Housings & keys
R&D Activities under progress (1/2)
Indian RAFMS Development:
- Composition Achieved
- Melts are under characterization (Microstructure &
Mechanical properties)
Lead-Lithium Technologies development:
- Lead-Lithium production
- Pb-Li Corrosion experiments
- Full scale Pb-Li loop development
Ceramic Pebbles Fabrication:
-Lab scale pebbles (Lithium Titanate)
successfully fabricated
- Pebble bed characteristics are under investigation
-Large scale production plans are under progress
R&D Activities under progress (2/2)
Helium Loop development
- ¼ the size loop development plan
- Small scale TBM testing
Tritium Extraction Systems development
- H/D extraction from Helium purge gas
- H/D extraction from Pb-Li
- Permeation Analysis
Work under Progress
RAFM steel is a structural material under development for fusion
reactor applications.
Several fabrication processes for the production of TBM subcomponents and assembly need to be investigated in the
developmental program.
For the fabrication of sub-components (first wall, stiffening plates,
cooling plates and caps) using the Indian RAFMS different options
are being considered to investigate its fabricability: HIP process, EB
welding, Laser and Narrow Gap TIG welding.
Initial trials for First wall
small scale mock-up by
HIP process
were carried out using
stainless steel discs with
pre-machined slots for
making internal channels.
Fig.6 shows the hipped
part.
EB welding on 6 mm thick austenitic
stainless steel plates. Welds of this
structure cleared both ultrasonic
examination and radiography. Virtually
no distortion was observed in this
structure. It is planned to make similar
structures using RAFM steel plates to
gain experience in fabrication.
Alternative approach for FW fabrication
Cutting of straight square channel
by wire EDM followed by hot
bending. advantage of this
approach is that there will be no
mating surface and therefore, no
lack of bonding. However,
challenges remain in cutting such
a long square channel by wire
EDM.
Summary
 Institute for Plasma Research (IPR), collaboration with Bhaba
Atomic Research Centre (BARC), Indira Gandhi Centre for
Atomic Research (IGCAR) and other research institutions and
universities within India involve the R&D activities focusing on
ITER-TBM systems development .
 The major areas of R&D activities are:
- Development of technologies of circulators, heat exchangers
and diagnostics for Lead-Lithium Systems, HCS, LL, TES
- Lead-Lithium Loop developments:
- MHD studies:
- Li2TiO3 Ceramic Pebbles development
 The RpRs report on safety analysis have been submitted,
further detail work is in progress.
Thank you
26
MHD pressure drop in LLCB TBM
The MHD pressure drop is calculated with an analytical expression for fully
developed laminar flow in a rectangular duct.
Channel Parameters
Channel Height (2a)
= 50 mm
Channel Width (2b)
= 484 mm
Insulation layer (A2B2) thickness = 0.2 mm
Outer wall (A1B1) thickness
= 5 mm
Channel length = 10 m
Electrical conductivity :
With Flow dividers
Pb-Li ~ 0.7e6, Fe wall ~1.4e6, Alumina ~ 1e-9
Hartmann number ~ 25000
Case
Mean velocity is 0.1 m/s
MHD Pressure Drop
(1)Without coating : 122.5 kPa
(2)With Alumina coating : 0.432 kPa
1
2
3
2b
mm
484
242
161
Ha
25652
12826
8551
Dp(Al2O3)
kPa
0.432
0.853
1.273
Considerably small MHD pressure drop inside TBM
Dp(Fe)
kPa
123
250
623
2D MHD Code:
Velocity & induced field
With alumina
Without alumina
Surface plot velocity profile
More details in Poster
NO:
PO1-10, K.S. Goswami
Velocity profile
Further work:
MHD effects in Manifolds &
in fringe field
Heat Transfer with MHD
effects
Crack analysis
contour plot of induced magnetic field
Analysis with 2-D MHD code
• Fully developed MHD flow in a rectangular
channel
• Surrounded by various layers with different
electrical properties
• Similar to S.Smolentsev et al. (FED, 2005)
• Velocity and induced magnetic field are calculated
self consistently
• No-slip condition at the liquid-solid interface
• No induced magnetic field at the outer boundary
of the computational domain
Validation of 2-D MHD
code
Comparison with
analytical results
Ha & grid size
J.R Hunt (1965)
MHD code
100 (81x81,12)
0.1600 x 10-2
0.1588 x 10-2
1000 (81x81,12)
0.4195x10-4
0.430x10-4
10000
(81x81,12)
0.1240x10-5
0.1286 x 10-5
10000
(161x161,24)
0.1240x10-5
0.1258 x 10-5
25000
(81x81,12)
0.310x10-7
0.323 x 10-7
Velocity profile for higher Ha