Tritium Technology for ITER - Nucleus overview of fusion fuel cycle mass and energy flows IAEA DEMO Workshop, Karlsruhe, 15-18 Nov 2016 Page 8 ITER UID: THR7JS Current and planned

IAEA DEMO Workshop, Karlsruhe, 15-18 Nov 2016 Page 1

ITER UID: THR7JS

Disclaimer: The views and opinions expressed herein do not necessarily reflect those of the ITER Organization

Tritium Technology for ITER

Scott Willms

ITER Organization


ITER UID: THR7JS

Outline

• Fuel Cycle Overview

• Comparison of ITER Fuel cycle to DEMO

• Distinguishing Characteristics of the ITER Tritium Plant Systems

• Technologies for ITER Tritium Plant Systems

– TEP – Tokamak Exhaust Processing

– ISS – Isotope Separation Systems

– SDS – Storage and Delivery System

– DS – Detritiation System

– WDS – Water Detritiation System

– ANS – Analytical System

• Fuel Cycle Modeling

• Gap Analysis to DEMO

• Conclusions


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Fuel Cycle Overview


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ITER Fuel Cycle

• DT loop fuel tokamak with T2 and D2

• D2 loop supplies neutral beams with D2 (and some H2)

• Effluent detritiation oxidizes all hydrogen isotopes to

water, recovers tritium from the water and exhausts the

detritiated gases.

• TBM Stream recovers T and other gases from TBM


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Tritium Plant commissioning schedule


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Comparison of ITER Fuel Cycle to DEMO


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Generic overview of fusion fuel cycle mass and energy flows


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Current and planned key fusion tritium fuel

cycle development points

State-of-the-art

Fusion power: 10’s MW

Burn fraction: Nil

Pulse length: seconds

Annual duty cycle: ~5%

Breeding: None

ITER/ITER-TBM

Fusion power: 500 MW

Burn fraction: 0.3%

Pulse length: 3000 s

Annual duty cycle: 5%

Breeding: TBM testing

DEMO

DEMO

Fusion power: 2000 MW

Burn fraction: >3%?

Pulse length: Continuous

Annual duty cycle: 50%

Breeding: Self-sufficient


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Distinguishing characteristics of ITER Tritium Plant systems


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Unique capabilities of interest to ITER (1/2)


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Unique capabilities of interest to ITER (2/2)


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Technologies for ITER Tritium Plant systems

Note: Most design information is at the preliminary design phase.


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TEP – Tokamak Exhaust Processing


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TEP Functions

• Separate hydrogen isotopes from impurities

• Separate helium from hydrogen isotopes/impurities (proposed req.)

• Recover tritium from impurities (e.g. Q2O and CQ4)

• Retain gamma emitters (e.g. 41Ar) to provide time for radioactive decay

• Perform process evacuation of high-tritium gas mixtures


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TEP process diagram


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TEP Technologies

Function Core Technology

Separate Hydrogen isotopes from

impurities

Permeators, cryogenic molecular sieve,

oxidation/adsorption

Separate helium from Hydrogen

isotopes/impurities Cryogenic molecular sieve

Recover Tritium from impurities Palladium Membrane Reactor,

Oxidation/adsorption

Gamma (41Ar) decay Tanks

Process evacuation Vacuum pumps

Internal TEP gas management function Manifolds, tanks


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Palladium membrane reactor

• Without generating solid waste, recover hydrogen isotopes from:

– Water

– Hydrocarbons

– Ammonia

• Successfully tested at ITER scale in lab

• Considering tests at JET

HTO

(Tritiated Water)

CO

CO, CO2

HT

Catalyst

Pd/Ag Membrane Reactor Shell

HTO + CO HT + CO2

Seven tube PMR before and after loading catalyst


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Permeators

• Well-proven to separate hydrogen isotopes (infinite separation factor)

• Available pumps are well-suited to 1/10th ITER scale applications, but not

to full ITER scale. While feasible, new pump development would be

welcome.


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ISS – Isotope Separation System


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ISS Functions

• Recover T from WDS H2 and return H2 to WDS

• Recover T from neutral beam D2 and HD, and return D2 to neutral beams

(through SDS)

• Separate torus DT exhaust into T2 and D2 and return to SDS/Fueling for

torus fueling


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ISS process diagram


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ISS Technologies


Recover T from WDS H2 and return H2 to WDS Distillation

Recover T from neutral beam D2 and HD, and return D2 to

neutral beams (through SDS)

Distillation

Separate torus DT exhaust into T2 and D2 and return to

SDS/Fuelling for torus fuelling

Distillation

Support for ISS functions Pumps, equilibrators

Refrigeration

Rupture disks, expansion tank

Raman spectroscopy (gas analysis)


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Cryogenic distillation

• Demonstrated at laboratory-scale with dynamic ITER-type loads (10th

ITER) and routinely in industrial applications (tritium recovery from heavy

water)

• Issues for ITER

– Tritium inventory

– Control under various and changing loads

– Single system serving three duties simultaneously


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SDS – Storage and Delivery System


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SDS Functions

• Recycle DT for torus fueling

• Recycle D2 for neutral beams

• Recycle gases for glow discharge cleaning

• Medium-term storage of D and T

• Long-term storage of T

• Supply non-tritium gases to the Fuel Cycle

• Load-in/Load-out of T

• Q2 assay

• Collect 3He


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SDS process diagram


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SDS Technologies


Recycle gases for torus fuelling Transfer pumps, buffer tanks

Recycle Q2 for neutral beam

heating

Transfer pumps, buffer tanks, metal-hydride

beds

Recycle gases for glow discharge

cleaning

Transfer pumps, buffer tanks

Store Q2 (Medium term) Metal-hydride beds

Store Tritium in the Tritium-depot Tritium transport beds, secure facility

Supply non-Tritium gases Gas cylinders, lines with back-flow prevention

Load-in/Load-out Tritium Materials handling equipment, load in/load out

station

Measure Q2 inventory Calorimetry, PVT-c

Collect 3He Purifier, collection tank


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Uranium hydride beds

• Used successfully to store hydrogen isotopes including tritium

• Store tritium at room temperature with negligible gas pressure, deliver

hydrogen isotopes at 400 – 500 C.

• Generates gas pressure with no moving parts

• Tested with tritium at ITER scale


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DS – Detritiation System


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DS Functions

• Provide reduced pressure in rooms and enclosures (radioactivity

confinement-related )

• Perform detritiation of room atmospheres

• Perform detritiation of process gases

• Perform enclosure (incl. glovebox) atmosphere detritiation

• Perform torus detritiation


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DS process diagram

• Multiple oxidation/adsorption trains are used to serve an extensive list of

clients

– Processes

– Gloveboxes and other enclosures

– Port Cell and Neutral Beam Cell atmosphere

– Rooms

– Vacuum vessel over pressure venting

– Elephant trunks

Tritium Oxidation

Tritiated gases from sources (processes,

enclosures, rooms)

TM1

Tritium Collection

TM2

Detritiated gases to Stack

Oxidize all tritium to water

Collect tritium using molecular sieve or scrubber

columnTM = Tritium Monitors


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DS Technologies

Function Technology

Provide reduced pressure

Rooms Blowers

Enclosures Blowers

Perform gas detritiation

Room atmosphere Oxidation, Scrubber Column

Enclosure atmosphere Oxidation, molecular sieve (or scrubber column)

Elephant trunk Oxidation, molecular sieve (or scrubber column)

Process gas Oxidation, molecular sieve (or scrubber column)

Torus Oxidation, molecular sieve (or scrubber column)


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Scrubber Column technology is being deployed for tritiated water

collection

• Counter-current contactor between tritiated gas and clean water

• Completed pilot-scale technology validation

Two sections of “single” scrubber column (2.8 m combined length)

Perevezentsev, A., et al, Wet scrubber column for air

detritiation, Fusion Science and Technology, 56, 1455-1461

(2009).


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Scrubber Technology Validation Completed

• Completed R&D at three sites including pilot-scale testing with tritium

• Developed mathematical model and correlated results

• Used model to predict performance of

ITER-scale scrubber column and show

that requirements are met

• ITER system can produce tritiated

less water than traditional system

with same detritiation performance

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

0 200 400 600 800 1000 1200 1400 1600

DF

G (Nm3/h)

l=1.0

l=0.95

l=0.90

In the low flow region, L is not reduced below a minimum level to maintain sufficient DF

Gas Feed Rate (Nm3/h)

Detr

itia

tio

n F

acto

r

l = Clean water feed rate

Tritiated water vapor feed rate


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The Tokamak Complex DS is a large industrial system

Scrubber columns, 8 each (11 m tall)


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WDS – Water Detritiation System


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WDS Functions

• Recover tritium from moderately tritiated water

• Release protium (and deuterium) to the environment


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WDS process diagram


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WDS Technologies

Function Core technology

Admission and storage of

tritiated water Water holding tanks

Chemical purification of feed-

waters

Filtration, ion-exchange resin, adsorption of

impurities by solid adsorbent

Production of gaseous Hydrogen Electrolysis of water

Chemical purification of gaseous

Hydrogen for delivery to ISS

Hydrogen permeation through palladium-alloy

membranes

Detritiation of gaseous

Hydrogen

Liquid phase catalytic exchange between

gaseous Hydrogen and liquid water

Hydrogen discharge to the

atmosphere1

Mixing with air to Hydrogen concentration below

4vol.%, prevention of fire backwards

propagation


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WDS water storage tanks are the first processing components

installed in the Tokamak Complex

20 m3 tank installed with tokamak

ring in background

100 m3 tank swinging into position


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ANS – Analytical System


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ANS Functions

• Perform gas chemical analysis for hydrogen isotope inventory

determination

• Perform gas chemical analysis for process gas characterization

• Support analytical capabilities included within Tritium Plant systems

• Determine tritium content of liquids

• Determine tritium content of solids

• Perform chemical analysis for special samples


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ANS process diagram


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ANS Technologies

Functions Analytical technologies

Security Laser Raman Spectrometer (LRS), Gas Chromatograph (GC)

Safety LRS, GC (micro Gas Chromatograph)

Operations LRS with fiber connection to KMPs

Gas acceptance testing GC including GC

Operational

monitoring/diagnosis

GC including GC, QMS

Verification LRS, GC including GC, Quadrupole Mass Spectrometer (QMS)

Calibration (Calibration strategies)

HDO and D2O Fourier Transform- Infrared spectrometer (FT-IR), Liquid Scintillation

Counter (LSC)

Solids Thermal Desorption Spectrometer (TDS), LSC, Open-wall ionization

chamber, Tritium contamination detectors like open-wall ionization

chamber

Special samples Instruments in current plant, future instruments


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Fuel Cycle Modeling


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0

0.2

0.4

0.6

0.8

1

83736353433323133

Mo

le F

racti

on

Stage number from bottom to top

HH1

HD2

HT3

DD4

DT5

TT6

HH exp

HD exp

HT exp

DD ext

DT exp

TT exp

Feed Tray

Time-dependent Fuel Cycle system modeling

• Commercially available chemical engineering software (Aspen)

adapted to tritium system modeling. Highlights include:

– Cryogenic distillation

– Flow and composition determination throughout cycle

0

50

100

150

200

250

0 10 20 30 40 50 60 70 80 90 100

D2

, D

T a

nd

T2

flo

wra

tes

(Pa

m3

/s)

Time (min)

Torus Feed (Flat)

TEP Feed (waves)

DT

T2, D2(lines on top ofeach other)

DT

D2

T2

Torus feed (ramp up/flat top/ramp down) becomes

highly variable feed following cryogenic pumping

and regeneration Cryogenic distillation column concentration profile

matches favorably with experiments


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Gap analysis to DEMO


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Tritium technology gap analysis major themes

• Tritium purification and recycle

– Proof-of-concept work has been performed, but now this must progress to the

next level. ITER will make significant contributions.

– New technologies will be needed due to impractical scale-ups and to

accommodate tritium breeding.

• Safety

– Scaling containment/detritiation systems to the next level is proving difficult

and expensive.

– Containment in the extreme DT fusion environment will reveal issues that

must be addressed.

• Tritium breeding and extraction

– Fundamental experiments are needed.

– No proof-of-concept experiments have been performed. Full experiments will

require neutron irradiation.

– ITER TBM is planned and complimentary work is needed

– A large body of work will be required to field a functioning, full breeder blanket

on DEMO or pre-DEMO experiments


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ITER TBM

Mission:

Test, understand and develop prototype blanket systems (tritium

breeder/tritium extraction) in a realistic fusion environment. Together with

TBEF, qualify blanket systems for FNSF.

Approach:

Neutron irradiate multiple, inexpensive (“suitcase”) sized blanket modules

and extract resulting tritium in realistic fusion environment

49


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ITER Test Blanket Module (ITER-TBM)

System characteristics

• Operate in extended burn and dwell with daily interruptions for 6 days

• Include tritium containment systems

• Large ITER tritium inventory and small TBM inventory

Sub-system characteristics

• 14 MeV source • Varying neutron flux

• Small modules (~1 m2) • Realistic fusion

environment • Must consider non-TBM

interactions

• Modules changeable during maintenance periods

• Include tritium

extraction and heat extraction technology

• Technology changeable during maintenance periods


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Tritium Breeding and Extraction Facility (TBEF)

Mission:

Test, understand and develop prototype integrated blanket systems

(neutrons/breeding/tritium extraction) in a controlled, scalable, easily-

configured environment. Together with ITER-TBM, qualify blanket systems

for FNSF.

Approach:

Neutron irradiate multiple, inexpensive (“suitcase”) sized blanket modules

and extract resulting tritium in controlled, easily-configurable environment


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Tritium Breeding and Extraction Facility (TBEF)


• Operate continuously until steady state achieved (1-4 wks)

• Include tritium containment systems

• Relatively small tritium inventory

Sub-system characteristics

• Not necessary to be 14 MeV source

• Controlled neutron flux

• Small modules, but large enough to display system behavior (~1 m2)

• Modules readily

changeable • Controlled

temperature/heat input

• Include tritium

extraction and heat extraction technology

• Technology readily changeable


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Fuel Cycle Development Facility (FCDF)

Mission:

Test and develop technologies in an integrated fusion fuel cycle configuration

in support of TBEF, FNSF and ITER as well as meet other needs such staff

development.

Approach:

Test new technologies and new configurations in an H and D (not T)

integrated fusion fuel cycle facility. Develop, demonstrate and optimize

system performance.


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Fuel Cycle Development Facility (FCDF)


• Include all purification/recycle and extraction sub-systems

• Constructed at approximate 1/5th DEMO scale

• Used to develop sub-systems as well as the overall system

• Conducive to low-cost technology development since

• Not directly tied to support machine operations (ITER or FNSF)

• Not operating with tritium

• Test safety systems without risking actual tritium release

• Can test beyond performance extremes (not tied to operating machine)

• Generate reliability

• Use for staff training


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Conclusions

• The ITER Tritium Plant design and construction is a major undertaking

• Feasible technologies for each function have been identified

• Lessons being learned on ITER will be valuable for DEMO

• There is still tritium technology work beyond ITER that is needed to

advance to DEMO.

Documents

Tritium Technology for ITER - Nucleus overview of fusion fuel cycle mass and energy flows IAEA DEMO Workshop, Karlsruhe, 15-18 Nov 2016 Page 8 ITER UID: THR7JS Current and planned