Institut de Physique Nucléaire de Lyon

Research group: “Aval du cycle Electronucléaire”

French-German seminar, Strasbourg, 22-23 February 2012

IPNL: CNRS + University

~ 200 persons (including PhD students)

- Particle physics, astroparticle, nuclear matter

- Pluri-disciplinary researches:

→ “Aval du Cycle Electronucléaire”

The “ACE” team: 7 researchers + 5 Ph-D students

N. Moncoffre C. Gaillard

N. Millard-Pinard

S. GavariniN. Bererd

Y. Pipon N. Toulhoat

G. Silbermann M. Le Guillou

A. BlondelB. Marchand

M. Gherrab

Nuclear materials

- Fuel

- Cladding materials

- For storage and disposal

- For fuel reprocessing

Radiolytic corrosion at solid/gas

or solid/liquid interfaces

Ab-initio

calculations

Migration of radioelements in

nuclear material at high

temperature and under

irradiation

Radioelements behaviour

in ionic liquids

Fundings:

CNRS/IN2P3

Rhône-Alpes region

French CNRS program “PACEN” (GnR MATINEX, PARIS)

ANR

French nuclear industry: EDF, AREVA, ANDRA

European program 7th PCRD: F-Bridge, Carbowaste

IPNL facilities: “ANAFIRE” platform

- For sample preparation / treatment

400 kV ionic implantor « IMIO-400 »

Introduction of any elements (from H to Au) in

any solid matrix, at depth ranging from few nm

to several 10 µm

High-temperature furnaces

- Up to 2000°C, under vacuum or controlled

atmosphere

Thermo-Gravimetric Analysis

- For sample analysis and in-situ sample treatment

4 MV Van de Graaff accelerator: 5 beamlines

Extracted beamline for irradiation of solids, liquids and gas

For elementary analysis of poly- and mono-

crystalline materials by ion beam analysis: RBS,

NRA, ERDA, PIXE…

Irradiation of solids

at high T (1500°C)

On-line µGC-MS:

analysis of radiolytic gas

Under development:

Ion Beam Induced

Luminescence (IBIL)

in collaboration with

LPCML (univ. Lyon)

Migration of radioelements in nuclear materials

at high temperature and under irradiation

-Behaviour of volatile species (Xe, Kr, Cl) at high temperature and under irradiation in

nuclear materials (ceramics for Gen IV, UO2, graphite)

- Experimental + theoretical (ab-initio) studies

� Studied species introduced in material by ion implantation at various concentrations

� Simulation of reactor conditions: effect of high T or/and irradiation

o irradiation by heavy or light ions to simulate ballistic effects (~neutrons) or

electronic effects: Ar of 9 MeV (IPNL), W of 3 MeV (JANNUS-Saclay), I of 63/200 MeVelectronic effects: Ar of 9 MeV (IPNL), W of 3 MeV (JANNUS-Saclay), I of 63/200 MeV

(TANDEM Orsay)

• Concentration profiles followed by RBS, NRA, SIMS , ERDA

• Physical state/speciation by EXAFS, XPS

• Material characterization by TEM, positron annihilation spectroscopy, RAMAN

• Determination of species migration mechanism

• Evaluation of retention properties of materials

Ceramic materials for Gen IV reactors

- Fuel cladding of GFR reactors: retention of fission products, good thermal

conductivity, resistance to irradiation and high temperature

- Carbides and nitrides: TiN, TiC, ZrC

- Behaviour of gaseous fission products (Xe, Kr) at high temperature and

under irradiation

Inert matrix

Metallic liner fuelAb initio calculations:

In which crystallographic site does Xe incorporate in TiN?

• Very low solubility of Xe in TiN

• Xe mobility related to

movement of bi-vacancies Ti+N

R. Bès PhD (2010)

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0 50 100 150 200 250 300 350 400X

e a

t. %

as implanted

10h 1000°C

3h 1300°C

3h 1400°C

1h 1500°C

Effect of high temperature (up to 1800°C)

� bubble formation and coalescence

0 50 100 150 200 250 300 350 400

depth (nm)

Xe in TiN, RBS, (R. Bès PhD)

EXAFS, Xe K edge, 15 K

SiO2

TEM

Behaviour of Xe in polycristalline UO2 at high T and under irradiation

Determination of Xe concentration profiles by SIMS (Secondary Ion Mass Spectrometry)

� Sputtering of sample surface followed by mass analysis of ejected ions

→ Quantitative elementary analysis as a function of sample depth

Problem with poly-crystalline material, several grains are analyzed at the same time and the sputtering

velocity depends on grain orientation → non reproducible measurements

Solution: Development of a new data treatment taking into account ≠ velocities

Before

Xe release during annealing

After

No Xe release during annealing

• Nuclear graphite = moderator in graphite-gas reactors, now under dismantling

→ Disposal of 23000 tons of irradiated graphite (2006 French law)

→ What is the “history” of graphite?

Radiolytic corrosion at solid/gas interfaces

→ In-situ radiolytic corrosion of nuclear graphite, coupled effect of T + gas irradiation

� 200°C < Tcooling gas < 400°C, 100°C < Tnuclear graphite< 500°C

� irradiation of gas + heating of graphite 500°C

Cooling gas = CO2 + impurities (CO, CH4, O2, H2)

Radiolysis

CH4 not detected

CH44 MGy

Plateau

H2

4 MGy

C-E. Vaudey (PhD, 2010)

gas radiolysisRadiolytic corrosion of graphite: CO2 + Cgraphite → 2 CO

Effect on radioelements embedded in graphite? 36Cl, 14C, 3H

Radioelements in ionic liquids

Possible use in the nuclear cycle:

� in replacement of organic solvents for fuel reprocessing

� for electrodeposition

With IPHC, MSM lab (Strasbourg)

- Basic chemistry of An/Ln in IL: solvatation, complexation

C4mim+ Tf2N-

IL are composed of anions/cations pairs, liquid at T< 100°C

Under development: irradiation cell for IL radiolysis

� Coupling of spectroscopic techniques (UV-vis, EXAFS, TRLFS) and MD calculations

UO2(ReO4)42-

- Basic chemistry of An/Ln in IL: solvatation, complexation

- Liquid-liquid extraction mechanisms: U(VI) by TBP

U(VI) + Tc(VII) by TBP

Collaborations

Studies made in collaboration with:

- INSA-Lyon, LPCML (Univ. Lyon),

- SPCTS Limoges

- ENS-Paris

- IPHC, MSM lab (Strasbourg)

- SIMS, Ecole des Mines de Paris

- University of Sofia (Bulgaria)

- CEA

-….-….