a demonstrator of a pav for tritium recovery from …3 rationale of developments of pav iea...

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A demonstrator of a PAV for tritium

recovery from LLE at HCLL TBM

loop operational ranges

Ismael Martínez, B. Herrazti, G. Veredas, J. Fradera,

I. Fernández, L. Batet, I. Peñalva, L. Mesquida,

J. Abellà, J. Sempere, L. A. Sedano

IEA International Workshop on Liquid Metal Breeder Blankets, 23-24 September, 2010 (Madrid), Spain.

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Summary

• Rationale of development of a Permeator Against

Vacuum (PAV) as Tritium recovery Technology (in

front of: gas-liquid contactors, bubblers and getters)

• Optimized design option for PAV [Fuskite®]

• Fuskite ®: Numeric efficiency assessment

• Experimental lay-out of an in-prototype

demonstration project

• Conclusions

IEA International Workshop on Liquid Metal Breeder Blanket, 23-24 September, 2010 (Madrid), Spain.

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Rationale of developments of PAV

IEA International Workshop on Liquid Metal Breeder Blankets, 23-24 September, 2010 (Madrid), Spain.

• Tritium (T) supply for DEMO is a serious concern after ITER

(27kg available in the second decade of XXI century and

ITER consumption is about ~15kg)

• External production of T is known as non economical (In

Fusion we should produce our own T). Reliable breeding

blanket technology is a must.

• At present plasma low T burn-up scenarios Fuel self-

sufficiency depends strongly on T residence time in Plant

Systems

• Considering present T residence times in ITER Plant

Systems (hours) [TRIMO modelling], the design of T plant for

DEMO is expected to differ strongly from that of ITER.

• T residence time in blanket systems and T recovery times in

T Extraction Systems (TES) should be comparable to T

residence time in Plant Systems.

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)()1()(0 PRRPR tt

b

cbt

b

cttHI

)()( PRPRP ttcTBRt

b

cttH


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Tritium extraction techniques


TES Technique tR Weaknesses

PB Sweepers +

TRS (CTs, MSBs,

getters)

Hours •Low efficiency, large systems

•Parallel batch systems (TRS)Dynamic

inventories

•Sizing at DEMO scale (TRS)

•Power consumption

PB Strippers

+TRS (CTs, MSBs,

getters)

Hours •Injectors for sub-mm bubbles

•Size of Packed Beds

•Parallel batch systems (TRS)

•Sizing at DEMO scale

•Power consumption

Inmersed getters Hours •Poor and non validated database for

breakthrough

•Parallel batch systems

Inmersed PAV Tens of seconds •In-prototype demonstration pending

TRS: Tritium Recovery System

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• Conceptually minimizes the T recovery time in blanket systems

• Tritium can be directly transferred to fueling systems in T-plant (minimum purification requirements and direct re-fueling)

• High potential efficiency and compactness by design

– High contact surface by geometrical design

– Optimized hydrodynamics for LLE (channels)

– Materials with a high Ks factor (a-Fe, steel or Nb)

• Simple/natural integration in a piping loop system

– Huge space and weight savings

• Easy manufacturing low cost

• Passive

– Only a vacuum pump is needed

– Efficiency can be thermally driven

• Potentially T breeding and recovery systems inside Bioshield (safety! & also environmental impact)

Strengths of Permeators Against Vacuum for TES


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)),,,(exp(1)( * LzhRvAL m

FeS

LiPbS

T

m

m

K

K

D

zh

vR

h

A

,

,

*

1

2

PAV conceptual efficiency

mh Re,Sc

HydrodynamicsWe need turbulent flow

TS DK , chemistry

Rz, geometry

Higher A and L is

better


L

How would it be the most compact and efficient permeator?

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Towards a highly efficient and

compact PAV


FUSKITE ®

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• Assuming steady-state, the microscopic

mass balance in a differential radial volume

of the membrane is, and the boundary

conditions:

• After integration the concentration profile is

found.

• The molar flux through the membrane wall

facing the LM can be expressed as follows

• and the molar rate reads,

• With the continuity conditions


PAV concept: numerical qualification

01

dr

dCr

dr

d

r

)()(

)()(

22

11

rCrCrr

rCrCrr

)/ln(

)/ln(

)()(

)()(

21

2

21

2

rr

rr

rCrC

rCrC

dr

dCDJ T

dr

dCrLDS T2

LMsSMTSMsLMT kCkC ,,,,

• The overall mass transfer coefficient (kt) is

computed from that in the boundary layer

(hm) and transfer from the bulk in LL

• Therefore:

)/ln(

)()(

221

2

,

,

1

rr

rCk

krC

LDSSMTs

LMTs

T

TmT LD

rr

hk 2

)/ln(11 21

Tm

SMTs

LMTs

T

LD

rr

h

rCk

krC

LDS

2

)/ln(1

)()(

221

2

,

,

1

dDSch Tm /Re0096.0 346.0913.0

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PAV concept: numerical qualification• A simplified axis-symmetric 3D domain is

needed in order to save computational time.

• Due to the spiral cross section, the domain

is represented by a sector consisting of

series of concentric annular channels.

• Two cases assessed:

– inlet v of 1 mm/s (laminar case)

– Inlet v of 10cm/s (turbulent case)

a channel height of 5mm and a tube length

of 2m. In the present work a 2m long

permeator with 45 concentric channels

Membrane thickness is set to 1mm with a

vacuum space of 1mm.

Channels are 5mm thick.

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PAV concept: numerical qualification

• DEMO HCLL

– Low velocity ~1mm/s

– Laminar regime hm=10-5 m/s,

Re=65

– High efficiency at small

diameters

– Very compact

– Surface rugosity not optimized


• DEMO DCLL

– High velocity ~ tens of cm/s

– Turbulent regime hm ~ 10-3 m/s,

Re>500

– High efficiency at medium

diameters

– Surface rugosity not optimized

HCLL

DCLL

• In the present work a k- SST for low

Reynolds numbers has been used (see

Gordeev et al. )

• TMBF (Lefhalm et al.) give better results

for LM (Carteciano et al.)

• Laminar solver does not reach the steady

state, but an oscillatory regime. On the

contrary, turbulent solver reaches the

steady state.

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PAV demonstrator prototyping


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PAV demonstrator prototyping


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Conclusions

• PAV appears as the most simple, economical, system

integrable and reliable TES solution for ITER and

DEMO LM blankets

• A PAV optimized design (Fuskite ®) has been

proposed: potentially for ITER and DEMO

• Numerical efficiency qualification anticipates

promising performances

• Prototype demonstrator is under construction


15IEA International Workshop on Liquid Metal Breeder Blanket, 23-24 September, 2010 (Madrid), Spain.

16IEA International Workshop on Liquid Metal Breeder Blanket, 23-24 September, 2010 (Madrid), Spain.

Thank you!!!! Gracias!!!!

a demonstrator of a pav for tritium recovery from …3 rationale of developments of pav iea...

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