Panel Discussion ISLA-2011 April 27-29, 2011 Session VII. Panel Discussion “ Is lithium PFC viable in magnetic fusion reactors such as ITER?” [11:00 –

Panel Discussion ISLA-2011 April 27-29, 2011

Session VII. Panel Discussion

“ Is lithium PFC viable in magnetic fusion reactors such as ITER?” [11:00 – 12:30]

Panel Members: R. Goldston (ITER/Reactor), F. Groeschel (IFMIF), Y. Hirooka (IFE), S. Mirnov (Innovative Ideas), G. Mazzitelli (Tokamaks), M. Ono (Chair), D. Ruzic (LiMIT), F. L. Tabarés (non-tokamak), A. Ying (TBM)

11:00 – 11:45: Comments from Panel Members

11:45 – 12:30: Panel Discussion

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1. Handling Divertor High Heat Flux

2. Removal of D, T, Impurities

3. Divertor Steady-State Heat Removal

4. Liquid Lithium Flow in Magnetic Field

5. Long Term Lithium Corrosion

6. Flowing Liquid Lithium Safety

7. Compatibility with Hot Wall2

Issues for Lithium Reactor Applications


First Wall / BlanketAt 500°C – 700°C?Lithium is not likely to be on this surface.

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Core ReactingPlasma

Edge Plasma

Scrape Off Layer

Flowing Liquid Lithium Divertor Tray

(LLDT)200°C – 400°C LL

Circulation Pump

LLPurificati

onand

Cooling System

D, T, Impurities

Cooling line

Divertor Heat and

Particle Flux

~ 400°C

~ 200°C

Flowing Liquid Lithium System

LLDT

Flowing Liquid Lithium Divertor Tray an Ultimate Solution?Necessary “Ingredients” are Coming Together?!











Heat Flux Questions:

• Liquid lithium appears to handle high heat flux well. CDX-U, LiMIT, LLL, Goh

• Lithium reduces divertor heat flux? NSTX

• Can liquid lithium carry out necessary steady-state heat flux? IFMIF experience?

• Can liquid lithium divertor handle ultra high transient heat flux such as the ELM heat flux issue? Transient 100 MW/m2 Partial lithium vaporization.

• Vaporization necessary ultimately? (e.g., Nagayama)

Can Liquid Lithium Surface Handle High Heat Flux?Promising Properties of Liquid Lithium

Liquid Lithium Properties:

• Light 0.534 g / cc

• High heat capacity (4.22 J/g K)

• Low viscosity < 0.5 water above 400°C

• Low Melting Point of 180.4°C

• High Boiling Point of 1342°C

• Low vapor pressure at high T

• Very large vaporization energy ~ 23 kJ / g

(J.E. Selle, ORNL)

Flowing LLDT200°C - 600°C?

Divertor Heat and Particle

Flux











Can D, T, Impurities Removed via LLD SystemIFMIF Experience?

LLCirculation

Pump

LLPurification

andCooling System

D, T, Impurities

Cooling line


Flux

~ 600°C

~ 200°C

Flowing LLDT200°C - 600°C

D,T, Impurity RemovalQuestions and Issues:

• Argon bubble removal of hydrogen? M. Kondo

• IFMIF EVEDA – O,N, T <10 weppm in real time. Cold trap, nitrogen trap, hydrogen trap,

• IFMIF – local loop idea for impurity removal seems quite practical.











Can Liquid Lithium Remove Steady-State Divertor Power?IFMIF Experience?

LLCirculation

Pump

LLPurification

andCooling System

D, T, Impurities

Cooling line


Flux

~ 600°C

~ 200°C


Steady-State Heat RemovalQuestions and Issues:

• 130 l /s, 4.5 ton, 250 – 350°C, 10 MW, IFMIF EVEDA (F. Groeschel)

•

•

Liquid Lithium Properties:

• High heat capacity (4.22 J/g K)

• Low viscosity at high T











Can Liquid Lithium Circulated within Magnetic Field?Blanket Module Experience, Thermo-Electric Effect?

LLCirculation

Pump

LLPurification

andCooling System

D, T, Impurities

Cooling line


Flux

~ 600°C

~ 200°C


Liquid Lithium Circulation in B Questions and Issues:

• TBM - MHD forces dominate viscous and inertial forces for the PbLi flow in magnetic field. Modeling and Experiment (R&D) needed. A. Yoing

• T-E effect must be taken into account - could greatly help the flow (D. Ruzic)

• L. Zakharov ‘s comment on flow issues.












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Core ReactingPlasma

Edge Plasma

Scrape Off Layer


(LLDT)200°C – 400°C

Longer Term Lithium Corrosion

Lithium CorrosionQuestions and Issues:

• TBM material – corrosion rate – Er2O3 coationg is effecting against lithium. O, N impurities are corrosive. C impurity is OK. ( M. Kondo)

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•











Can Flowing Hot Liquid Lithium System Be Safe?IFMIF Experience? How to Avoid Contact with Water / Air?

LLCirculation

Pump

LLPurification

andCooling System

D, T, Impurities

Cooling line


Flux

~ 600°C

~ 200°C


Liquid Lithium Safety Questions and Issues:

•

•

•












000000000000000000000000

Core ReactingPlasma

Edge Plasma

Scrape Off Layer


(LLDT)200°C – 400°C

Is Lithium Utilization Compatible with Hot First Wall?

Hot Wall Questions and Issues:

• Avoid lithium contamination of first wall?

• Perhaps lithium dust, jet, evaporation etc., into the main chamber may be fine with hot wall?

• Would lithium and its compound eventually end up in the colder divertor area?

Documents

Panel Discussion ISLA-2011 April 27-29, 2011 Session VII. Panel Discussion “ Is lithium PFC viable in magnetic fusion reactors such as ITER?” [11:00 –