ESOF 2010, Turin, 3rd July 2010 1

Properties and Behaviour of Advanced Nuclear FuelsJ. Somers

Joint Research Centre (JRC)

ITU - Institute for Transuranium ElementsKarlsruhe - Germany

http://itu.jrc.ec.europa.eu/http://www.jrc.ec.europa.eu/

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A European vision of nuclear energy development

First First ReactorsReactors

Current Current ReactorsReactors

Future Future SystemsSystems

Generation I

Generation II

1950 1970 1990 2010 2030 2050 2070 2090

Generation III

Dismantling& clean-up

Generation IV

Produces 31% of Europe’s electricity

New build in Finland and France (EPR), other countries… Start of industrial deployment in 2040-

2050

Advanced Advanced ReactorsReactors

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The Sustainable Nuclear Energy Technology Platform (SNE-TP)

• Research to improve sustainability of nuclear energy● Conservation / recycling of resources● minimisation of radioactive waste (volume, lifetime, radio-toxicity)● maintaining high level of safety and favourable economics

• Gather all EU stakeholders involved in the nuclear sector and structure and finance nuclear fission R&D

• Develop knowledge and competence through education and training linked with a network of research infrastructures

• Maintain Europe’s leadership in nuclear technology in the longer term by building demonstrators and prototypes for a future generation of reactors

• Develop international cooperation on a basis of mutual interest and benefit

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Strategic Research Agenda: 3 pillars

Over 180 researchers, scientists and engineers have contributed to the SRA

www.snetp.eu

Vision document

Strategic Research Agenda (SRA)

Deployment StrategySustainable FuelsMinimising Waste Issues

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The Nuclear Fuel Cycle

EnrichmentEnrichment

FuelFuelFabricationFabrication

Reactor

SNFSNFStorageStorage

ProcessingProcessing

High LevelHigh LevelWasteWaste

SpentSpentNuclearNuclear

FuelFuel

RepositoryRepository

UraniumUraniumStorageStorage

DepletedDepletedUraniumUranium

NaturalNaturalUraniumUranium

reprocessing plant U mining

nuclear reactor

spent fuel storage

repository

Fissile andFissile andFertileFertile((U,Pu,MAU,Pu,MA))

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Evolution of radiotoxicity as a function of time:Evolution of radiotoxicity as a function of time:evaluation by CEA, FZK and ITUevaluation by CEA, FZK and ITU

Waste Radiotoxicity EvolutionWaste Radiotoxicity Evolution

time (y)10 1 10 2 10 3 10 4 10 5 1010 2

10 3

10 4

10 5

10 6

10 7

10 8

10 9

with P&T

1000 y [99% Pu, 98% MA removal]

270 y

500 y [99.5% Pu, 99% MA removal]

130,000 y

results based on ICRP72

Inge

stio

n ra

diot

oxic

ity (S

v pe

r ton

spe

nt fu

el)

Totalactinides

fission products

ref. 7.83 t U in equilibriumwith P&T

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ActinideActinide--RecyclingRecycling--SchemesSchemes

Homogeneous recycling

R T

U

FP

U Pu MA

R T

U

MAU Pu

FPFP&MA

Heterogeneous MArecycling

R T

U

UU & Pu recycling,

PUREX

Pu

R T

U

U Pu

U & Pu recycling, COEX

FP&MA R T

U

U Pu

FP

TADS

« double strata »

MA (Pu)

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Fuel requirements for MA Fuel Recycling

• Neutronics and core physics– Safe operation, Conversion ratio =1

• Material properties– Fabrication feasibility– Margin to melt (Tf, λ, Cp)– Mechanical properties– Interaction with coolant– Interaction with cladding (chemical and mechanical)

• Irradiation Performance– High burnup– Swelling behaviour– Relocation/vaporisation behaviour– FP retention– Reprocessability (or not)

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Candidate fuels for transmutation

Fuel properties (U,Pu)

Metal Oxide Nitride Carbide

Heavy metal density (g.cm-3) 14.1 9.3 13.1 12.4

Melting point (K) 1350 3000 3035 2575

λ (W.m-1K-1) 16 2.3 26 20

T centreline (K) 1050 2350 1000 1000

Cp (J.g-1.K-1) 17 34 26 26

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Fabrication Feasibility

Additional Shielding (γ,n) compared to UO2 or MOX FacilitiesMinor Actinide Laboratory at JRC-ITU

(a) Shielded installations → remote handling(b) Automation → use of robots(c) dust free(c) process simplification : minimises the (active) fabrication steps

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Uranyl Nitrate Solution Plutonium Nitrate Solution

Ammonia Precipitation Oxalate Precipitation

Drying/ Calcination Drying/ Calcination

Powder Blending / Milling

Compaction

Sintering

Extension of Traditional Fabrication Technology

MA Nitrate Solution

Oxalate Precipitation

Drying/ Calcination

Advantages: Blend for individuals fuel pins or assemblies Commercially use

Disadvantages: Dust with particle sizes 2-3µm or less

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Liquid to solid conversion

U, Pu, Np , Am,( Cm)nitrate solution

Addition of polymers

Atomisation

Gelation in ammonia bath

Drying/ Calcination

Compaction

Sintering

U depO2 (NO3 )2

Sol gel route for group conversion of Gen V fuels

No fine powder but BEADS(Important for plant operation)

Beads diameter : 20 -600µm(depending droplet dispersion device)

Solid solution

However,

MA in all production steps

Extensive shielding, remote operation

and automation

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(U0.74Pu0.24Np0.02)O2

1mm 1mm

100µmm

Sol-gel beads

Fabrication ⇒sol gel method

Oxide fuel: SUPERFACT

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• Fuel Restructuring similar to standard MOX • Pore migration and central hole formation• Oxide layer (10 µm) on cladding• Reprocessing demonstrated

Typical observations for(U0.74Pu0.24Am00.2)O2 Fuel

SUPERFACT – a milestone irradiation test (CEA/ITU)Homogeneous MA Recycle in FR

Post Irradiation Examination (PIE)

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Before irradiation After irradiation

50 µm 50 µm

AmAlO3

HELIUM is an issue in MA fuelsRelease or swelling

241Am242mAm

242Cm

239Pu238Pu

242Am

243Cm

242Pu

10%

90%17%

83%

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matrix

Inclusion

iv

i

iii ii

i. The actinide particle with very high displacement damageii. Matrix damaged by recoil of fission products and energetic alpha

particles (5 µm) iii. Matrix damaged alpha particles (13 µm)iv. Matrix (neutron damage only) TAILOR PROPERTIES of the FUEL

Composite fuels for Accelerator Driven Systems

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CERMET Fuels

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CONCLUSIONS AND OUTLOOK

• Capitalise on past programmes

• Dedicated sample fabrication and property measurement

• Separate effect studies (in and out of pile)

• Integral irradiation testing

•Improve modelling at all time and distance scalesA NEW APPROACH NOW BECOMING POSSIBLE

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Thank you for your attention