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ENEA Experience in PbLi Technologies
DCLL WORKSHOP- Tritium extraction technologies for EU DCLL
M. Utili (ENEA) [email protected]
14-15 November 2014
DCLL BB: Tritium extraction from Pb-16Li
D. Demage , BB Project KoM Tritium Extraction Technology & Tritium Control
Tritium Extraction System (TES), scope:
to extract tritium from the flowing lithium lead alloy in a dedicated sub-system called
Tritium Extraction Unit (TEU), to remove it from the resulting gas stream by Tritium
Removal System (TRS)
to route it to the Tritium Plant for final processing.
Development and Design of Tritium Extraction System, key factors:
SAFETY-WASTE: Tritium release, Inventory Tritium/Hydrogen
INTEGRATION: Physical size, complexity, synergy with tritium measurement and accountancy
system, volume of gas to be treated
PERFORMANCE: efficiency
OPERATION: Maintainability, Flexibility,
Reliability
ECONOMICS: Cost (R&D, capital, operation)
DCLL status 1995-2012
1st EU-US DCLL Workshop
PbLi Loops 1995
Heat
exchanger
PbLi Loops 2013
DCLL Breeder Blanket
TES
CPS
425°C
275°C
425°C
PMP pump
H2O
H2O
46.000kg/s
Heat exchanger
1. Solution
2. Diffusion
3. Transport of dissolved metal
4. Nucleation
5. Transport of crystallites
6. Crystal growth and sintering
(plug formation)
The issue of corrosion products precipitation in cold legs or near
megntic fields. Picture from OECD NEA Handbook of HLM V 1.0, Chap 6, in
publishing.
D2Storage tank
He Line
25% of mass flow rate
Preliminary PFD PbLi loop
T production 360 g/day 16 toroidal segment: 3 OB per sector, 2 IB per
sector n. recirculation x day: 100 Total PbLi mass fow rate: ~ 46.000kg/s N. PbLi loop: 16 PbLi mass flow rate x Segment: ~ 2875kg/s
Operative Conditions:
Vacuum Permeators
CT,l,in CT,l,out
PbLi, T
T2
PbLi, T
permeable membrane Permeated
side
Liquid Boundary Layer Membrane Gas Boundary Layer
CT,l
C*T,l
C*T,M
C*T,g
)cc(hJ *l,Tl,Tll,T
Mass Transport
typologies: tube&shell
helicoidal tube
2*g,Trg,T ckJ
0.3460.913
17LiPbT,
tubel Sc Re 0.0096 D
Dh
correlation for the mass transfer coefficient in the liquid
boundary taken from literature for fluids different from PbLi
PROS and CONS for Vacuum Permeators
• High compactness, especially in the helicoidal tube configuration
• Being the overall tritium mass transfer strongly sensitive to hl, the tritium mass
transfer coefficient in the liquid boundary layer, its value needs to beexperimentally determined under relevant conditions. Present data fromliterature refer to fluids different from PbLi
• The metallic membrane needs to have significant tritium permeability and highcompatibility with PbLi under relevant operating conditions
• The metallic membrane needs to be resistant to oxidation in case of incidentalreduction or loss of vacuum (killing issue for Nb). Possible need of a coatinglayer (Pd?) on the vacuum side to keep the membrane oxidationunder control
• Never experimentally tested, even at small scale
)( 2,2, TiTggT PPkJ
iTaTrrT PkckJ ,22*
,
IF Liquid
Bulk
Liquid
Boundary
Layer
Gas
Boundary
Layer
Gas
Bulk
CT,l CT,l* Ks(PT2,i)0.5 RT
PT 2
Gas Liquid Contactors
Different typologies:
)cc(hJ *l,Tl,Tll,T
])Pkc
4
1(
2
1c[ha 5.0
2T2S
l,T
2l,TlvT
= kr/h l
Mass Transport
packed columns
bubble columns droplet spray columns
Net Tritium flow-rate
from PbLi into gas phase per unit volume
PROS and CONS for Gas Liquid Contactors
•Need to have low value of γ (high hl) and high value of av: this last point is verydifficult to be achieved by bubble columns and droplet stray column. With packed
columnsa reasonable value of av is assured by the packing itself
• GLCs need a downstream process for tritium concentration in He before routingtritium to the further tritium processingsystems upstreamthe refuelling stage
• Packed columns are large systems especially when large liquid flow-rates have tobe processed and high extractionefficiency is required
• Robust technology with much industrial experience
• Already tested at CEA (F) on Melodie loop, with 30% of extraction efficiencyachieved
Tritium fluxes in the different
liquid and gas regions
Tritium fluxes in the different
liquid and solid regions
η=𝑐𝐻 −𝑃𝑏𝐿𝑖
𝑖𝑛 −𝑐𝐻−𝑃𝑏𝐿𝑖𝑜𝑢𝑡
𝑐𝐻−𝑃𝑏𝐿𝑖𝑖𝑛
5
Tritium extraction from Pb-16Li
Gas Liquid Contactor:
Vacuum Permeator:
Tritium Extraction System Technologies:
- Bubble columns
- Packed columns
- Spray tower
Regenerable getters: This technology uses a tritium gettering
bed of metal in which the solubility of
tritium is higher than in lead lithium
A gas and a liquid phase are brought into contact for the purpose of a
diffusion interchange between them. Facilities: Melodie loop (CEA),
TRIEX (ENEA)
based on the phenomenon of tritium
permeation through a membrane Vacuum Permeators
CT,l,in CT,l,out
PbLi, T
T2
PbLi, T
permeable membrane Permeated
side
Liquid Boundary Layer Membrane Gas Boundary Layer
CT,l
C*T,l
C*T,M
C*T,g
)cc(hJ *l,Tl,Tll,T
Mass Transport
typologies: tube&shell
helicoidal tube
2*g,Trg,T ckJ
0.3460.913
17LiPbT,
tubel Sc Re 0.0096 D
Dh
correlation for the mass transfer coefficient in the liquid
boundary taken from literature for fluids different from PbLi
PROS and CONS for Vacuum Permeators
• High compactness, especially in the helicoidal tube configuration
• Being the overall tritium mass transfer strongly sensitive to hl, the tritium mass
transfer coefficient in the liquid boundary layer, its value needs to beexperimentally determined under relevant conditions. Present data fromliterature refer to fluids different from PbLi
• The metallic membrane needs to have significant tritium permeability and highcompatibility with PbLi under relevant operating conditions
• The metallic membrane needs to be resistant to oxidation in case of incidentalreduction or loss of vacuum (killing issue for Nb). Possible need of a coatinglayer (Pd?) on the vacuum side to keep the membrane oxidationunder control
• Never experimentally tested, even at small scale
)( 2,2, TiTggT PPkJ
iTaTrrT PkckJ ,22*
,
IF Liquid
Bulk
Liquid
Boundary
Layer
Gas
Boundary
Layer
Gas
Bulk
CT,l CT,l* Ks(PT2,i)0.5 RT
PT 2
Gas Liquid Contactors
Different typologies:
)cc(hJ *l,Tl,Tll,T
])Pkc
4
1(
2
1c[ha 5.0
2T2S
l,T
2l,TlvT
= kr/h l
Mass Transport
packed columns
bubble columns droplet spray columns
Net Tritium flow-rate
from PbLi into gas phase per unit volume
PROS and CONS for Gas Liquid Contactors
•Need to have low value of γ (high hl) and high value of av: this last point is verydifficult to be achieved by bubble columns and droplet stray column. With packed
columnsa reasonable value of av is assured by the packing itself
• GLCs need a downstream process for tritium concentration in He before routingtritium to the further tritium processingsystems upstreamthe refuelling stage
• Packed columns are large systems especially when large liquid flow-rates have tobe processed and high extractionefficiency is required
• Robust technology with much industrial experience
• Already tested at CEA (F) on Melodie loop, with 30% of extraction efficiencyachieved
Tritium fluxes in the different
liquid and gas regions
Tritium fluxes in the different
liquid and solid regions
Parameters Value
T production [g/day]
360
T PbLi [°C] 475
M PbLi [kg/s] 1.000÷3.000
Droplets tower: making small droplets in the vacuum,
tritium is released and collected by
vacuum line. Kyoto University
PAV: Permeators Against Vacuum
PAV technologies is based on the phenomenon of tritium permeation through a membrane in
contact with Pb-15.7Li toward a secondary side where vacuum or a carrier gas is present.
PAV is a first choice process candidate due to its simplicity and reliability.
2
11
2
1212 P
mdesadsp (upstream) (2.14)
11111
1 Cdsbabsp
(upstream) (2.15)
x
CCDdp
21
(bulk) (2.16)
22222
1 Cabsdsbp
(downstream) (2.17)
2
222
desp (downstream) (2.18)
KS,M and KS,LM are the Sieverts’
constants of tritium in the membrane
and liquid metal
the pipe length is strongly depending
on the tritium mass transfer
coefficient through LBL
I. Ricapitoa, A. Ciampichetti, R. Lässer, Y. Poitevin, M. Utili, FUSION SCIENCE AND TECHNOLOGY VOL. 60 OCT. 2011
drawback when using Nb/pure iron is that at high temperature it has a strong tendency to
oxidation, requiring a very high vacuum during operation and/or a surface layer of Pd
which is more oxidation resistant. This is a point of great importance, strongly impacting
PAV design.
[A. Ibarra, 1st EU–US DCLL Workshop Fuskite PbLi loop
Karlsruhe, April 23-24th 2013]
Fuskite loop (CIEMAT):
• New size of the test section
• Scale testing of permeation against
vacuum
• Perform measurements of permeation
in gas-phase and flowing PbLi
• Analyze permeation under a number of
controlled variables (T, P, velocity,
species)
Vacuum Permeators
CT,l,in CT,l,out
PbLi, T
T2
PbLi, T
permeable membrane Permeated
side
Liquid Boundary Layer Membrane Gas Boundary Layer
CT,l
C*T,l
C*T,M
C*T,g
)cc(hJ *l,Tl,Tll,T
Mass Transport
typologies: tube&shell
helicoidal tube
2*g,Trg,T ckJ
0.3460.913
17LiPbT,
tubel Sc Re 0.0096 D
Dh
correlation for the mass transfer coefficient in the liquid
boundary taken from literature for fluids different from PbLi
PROS and CONS for Vacuum Permeators
• High compactness, especially in the helicoidal tube configuration
• Being the overall tritium mass transfer strongly sensitive to hl, the tritium mass
transfer coefficient in the liquid boundary layer, its value needs to beexperimentally determined under relevant conditions. Present data fromliterature refer to fluids different from PbLi
• The metallic membrane needs to have significant tritium permeability and highcompatibility with PbLi under relevant operating conditions
• The metallic membrane needs to be resistant to oxidation in case of incidentalreduction or loss of vacuum (killing issue for Nb). Possible need of a coatinglayer (Pd?) on the vacuum side to keep the membrane oxidationunder control
• Never experimentally tested, even at small scale
)( 2,2, TiTggT PPkJ
iTaTrrT PkckJ ,22*
,
IF Liquid
Bulk
Liquid
Boundary
Layer
Gas
Boundary
Layer
Gas
Bulk
CT,l CT,l* Ks(PT2,i)0.5 RT
PT 2
Gas Liquid Contactors
Different typologies:
)cc(hJ *l,Tl,Tll,T
])Pkc
4
1(
2
1c[ha 5.0
2T2S
l,T
2l,TlvT
= kr/h l
Mass Transport
packed columns
bubble columns droplet spray columns
Net Tritium flow-rate
from PbLi into gas phase per unit volume
PROS and CONS for Gas Liquid Contactors
•Need to have low value of γ (high hl) and high value of av: this last point is verydifficult to be achieved by bubble columns and droplet stray column. With packed
columnsa reasonable value of av is assured by the packing itself
• GLCs need a downstream process for tritium concentration in He before routingtritium to the further tritium processingsystems upstreamthe refuelling stage
• Packed columns are large systems especially when large liquid flow-rates have tobe processed and high extractionefficiency is required
• Robust technology with much industrial experience
• Already tested at CEA (F) on Melodie loop, with 30% of extraction efficiencyachieved
Tritium fluxes in the different
liquid and gas regions
Tritium fluxes in the different
liquid and solid regions
preliminary sizing of a tube and shell PAV in niobium was carried
out in the frame of the design of the DCLL (Dual Coolant Lithium
Lead) BB for Aries-CS reactor, having a tritium generation rate of
340 g/d.
GLC: Packed Columns
The packed columns are vertical columns filled with packing or other device providing a large interfacial surface between liquid and gas phase in both counter-current and cocurrent flow.
There are two groups of packing: • the random packing like rings • the regular or structured packing like layered sheets
The main characteristics of packed columns are:
Packed Column
Liquid in Lin , xin
Liquid out Lout , xout
Gas in Gin , yin
Gas out Gout , yout
Advantages: • reliable injection system, because it is not necessary to inject small size bubbles • reliability of the functional answer because of the kinetics of mass transfer • the packing material could be manufactured with high corrosion resistance materials to
Pb-15.7Li • the Packed columns, used as tritium extraction from lead lithium, have been tested
extensively in the past in Melodie loop at CEA
𝐽𝑇 = 𝐾𝐷 𝑐𝑇,𝑙 − 𝑐𝑇,𝑒𝑞
experimental results on Melodie loop - 800 mm height, 54 mm diameter, packing area: 750 m2/m3, T:673 K
Disadvantages: Lower rate size/η (tritium extraction efficiency for one column is 25-30%) than permeators. In any case the size of the columns is a consequence of its efficiency, and the design of the columns can be optimised.
L/G =7
Test n. LM flow-rate
(lh-1)
Ar flow-rate
(N lh-1)
PH2,in
(Pa)
(%)
10 70-90 6 1200-1350 20-22
11 30-50 6 1000-1100 29-31
12 30-50 30 975-1000 29-31
13 30-50 6 450-475 23-25
14 30-50 6 220-230 23-25
GLC: Packed Columns
GLC – Packed column
The extractor column, used for the stripping of the hydrogen contained in the eutectic alloy Pb–16Li, is of the filled type, in counter flow. The liquid phase, represented by the Pb–16Li alloy, enters in the column from the top, passing through the filler, in hydrogen saturated conditions. The real hydrogen content is read by a hydrogen sensor in liquid metal. The gaseous phase, represented by pure argon, is injected in the column from the bottom through an appropriate system of distribution that has the function to uniform and fragment the gas bubbles.
Barelli B1 350
Material AISI 304
Tipe B1-350
Spec. surface [m2/m3] 350
Loading specific volumetric
flow[m3/m2h)] 250
Extractor:
C
B
C
B
D D
L.T.
L.S.
L.T.
L.S.
𝜼 =𝟏
𝑳𝒗𝒐𝒍 ∗𝟏
𝑺𝑲𝑫+
𝟏𝟐𝑮𝒎𝒐𝒍𝑽𝑴𝑨𝒓
Determination of the efficiency with the partial pressures: 𝒄𝑯 = 𝒌𝑺 𝑷𝑯
𝜼 =𝒌𝑺 𝑷𝒊𝒏 − 𝒌𝑺 𝑷𝒐𝒖𝒕
𝒌𝑺 𝑷𝒊𝒏
=𝑷𝒊𝒏 − 𝑷𝒐𝒖𝒕
𝑷𝒊𝒏
0
0,02
0,04
0,06
0,08
0,1
0,12
0,14
0,16
0
5
10
15
20
25
30
35
40
11
:50
:00
10
:15
:00
08
:40
:00
07
:05
:00
05
:30
:00
03
:55
:00
02
:20
:00
00
:45
:00
23
:10
:00
21
:35
:00
20
:00
:00
18
:25
:00
16
:50
:00
15
:15
:00
13
:40
:00
12
:05
:00
10
:30
:00
08
:55
:00
07
:20
:00
05
:45
:00
04
:10
:00
02
:35
:00
Hyd
roge
n p
arti
al p
ress
ure
[b
ar]
Extr
acti
on
eff
icie
ncy
[%
]
Efficiency
TheoreticalEfficiency
GLC: Packed Columns
Droplets and Gas-liquid counter-current extraction tower or vacuum sieve tray
By making small droplets in the vacuum, tritium released from droplets is collected by
vacuum pumping system.
A recent study at Kyoto University indicated interesting results on the vacuum sieve tray
approach
tritium release from LiPb is governed by diffusion-limited process
Fusion Engineering and
Design (2012), 87(7-8):
1014-1018
Parameters Value
Temperature [°C] 400
P H2 [Pa] 2.5x104
Nozle radius [mm] 1
Extraction environment Vacuum
Droplet radius Rd
Experimentally obtained
values:
Rd = 0.9mm
l0 = ~20mm
Multi-stage
Mass Flow rate: 0,724 m3/s
(6.440kg/s)
Diameter: 2,1m
h= 1m
Efficiency: 45%
One - stage
Mass Flow rate:
0,724 m3/s
(6.440kg/s)
Diameter: 4,6m
h= 6-7 m
Efficiency: 90%
Droplets and Gas-liquid counter-current extraction tower or vacuum sieve tray
Fusion Engineering and Design
(2012), 87(7-8): 1014-1018
SAFETY-WASTE: Tritium release, Inventory Tritium/Hydrogen
INTEGRATION: Physical size, complexity, synergy with tritium measurement and
accountancy system, volume of gas to be treated
PERFORMANCE: efficiency
OPERATION: Maintainability, Flexibility, Reliability
ECONOMICS: Cost (R&D, capital, operation, power required)
GLC – Packed Tower
PAV GLC- Droples
SAFETY-WASTE
INTEGRATION Volume of gas to be treated, physical size
Physical size
PERFORMANCE 30% 69%-90% 45-90%
OPERATION
• Reliability
• Maintainability
• Flexibility: floading loading condition
• Reliability
• Maintainability
• Flexibility
• Reliability
• Maintainability
• Flexibility
ECONOMICS
