Why recycling the actinides? A sustainable approach of nuclear fuel … · 2015-05-11 · Why...

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Why recycling the actinides? A sustainable approach of nuclear fuel

cycles

| PAGE 1

Prof. Christophe POINSSOT (*), Stéphane BOURGCEA Marcoule / Nuclear Energy Division,

RadioChemistry & Processes Department,

(*) Head of the DepartmentProfessor at the National Institute of Nuclear Science and Technology

Nuclear Energy Division – Marcoule -RadioChemistry & Processes Department

SACSESS Int' Meeting - PoinssotWarsaw, April 2015

Future energy systems will have to meetsustainability criteria

• GHG-free energy• Low environmental footprint• Preservation of natural resource

• Predictable, stable and affordable energy cost

• Economic stability throughenergetic independence

Sustainability = global approach:

2

• Highest level of safety and reliability• Democratic choice of the society• Promote the international stability• Inter/intra-generational equity

How actinides recycling could contribute to improve the nuclear energy sustainability?

- Energy needs (population, development)- GHG emissions (Limit climate change)

Sustainable energy portfolio based on low-carbon energies

Energy transition



Evolutions to improve the environmentalcriteria

Low GHG emissions

Environmental footprintCan be addressed thanks to Life Cycle Assessment (LCA) calculationsNELCAS: CEA home-made tool based on the actual release/withdrawal of each fuel cycle plant

Considering every fuel cycle plants + transportations.From craddle to grave: considering the whole lifetime of each plantNormalized to the annual electricity production (ref.year 2010, 410 TWh)

Poinssot et al., 2014

3



The current environmental footprint of nuclear energy

Nuclear: already a beneficialfootprintDominated by front-endImproving the overall footprint:

Improve the front-end processes to reduce theirfootprint R&D !!Reduce the front-end activities: Recycling !!

4



What is the current status on the efficiency in using natural resource?

Global efficiency is currentlyvery low: ~0.6%

France: ~70t from the initial ~9500t of U is effectively used

Uranium resources limited:Limited for the far-future at a reasonable price (130$/kg U)

Sustainability saving naturalresource recycling valuableactinides

First recycling step alreadyimplementable thanks to PUREX

Uranium ore

~9500t

depleted U(0.2 – 0.5% 235U)

8300t

1200t 1200t

430 TWhe

Spentfuel

~9t 235U~1122t 236+238U~14t Pu~55t FP+AM

56t 235U1144t 238U

(Once-through)

Rough estimates derived from French Fuel cycle assuming no recycling

U~70tEfficiency~0.6%

0

100

200

300

coal gas oil uranium

Estim

ated

lifespan

(years)

PAGE 5

99,9% of Pu

1200t

10t

8000t Twice-Through Cycle

Resource preservation



1971 1980 1989 1998 2004 2012

MOXURE

0

2000

4000

6000

8000

10000

12000

14000

A very positive industrial feedback on recycling activities

~2 000tHM of MOX fuel produced (2012)

La Hague

>30 000 tHM reprocessed

MELOX

0

5000

10000

15000

20000

25000

30000

1976 1981 1986 1991 1996 2001 2006 2011

UP3

UP2

Source : AREVA

- 15 to 20% of French electricity yearly supplied by recycling materials- ~1500t uranium ore yearly preserved- No significant SNF interim storage risk reduced

PAGE 6



A beneficial effect of recycling on wasteconditioning

0,1

1

10

100

1000

10000

10 100 1000 10000 100000 1000000Temps (années)

Rad

ioto

xici

té re

lativ

e

102 105 1061041030,1

1

103

104

Time

Relative radiotoxicity

10

102

10

U-ore

Without recycling:Spent nuclear fuel (SNF)

With recycling:Taylored nuclear glass

Time (years)

Dose (Sv/year)

-2

-3

-4

-5

-6

-7

-8

Log

frac

tiona

l rel

ease

rate

(day

-1)

Log time (days)0 1 2 3 4 5 6 7

Gap

Grains

Grain boundaries

Labile = IRF

Log time (days)Lo

g. fr

actio

nal

rele

ase

rate

(day

-1)

Matrix

Alte

red

thic

knes

s

Time

Initial rate vdisso

A decreased radiotoxicity A dedicated long-term matrix

Improved performance



A beneficial effect of recycling on wasteconditioning

-2

-3

-4

-5

-6

-7

-8

Log

frac

tiona

l rel

ease

rate

(day

-1)

Log time (days)0 1 2 3 4 5 6 7

Gap

Grains

Grain boundaries

Labile = IRF

Log time (days)

Log.

frac

tiona

lre

leas

e ra

te (d

ay-1

)

Matrix Adap

ted fr

om

John

son e

t al.,

1988

Without recycling: spent nuclear fuel (SNF)

Rim

Matrix

Altered nuclear glass

With recycling: taylored nuclear glass

gel

glass

PAGE 8

Alte

red

thic

knes

s

Time

Initial rate vdisso

Glass

Gel3 – Gel dissolution

2 – Diffusion

4 – Secondary phase precipitation

Solution

H2O

Na+, B1 - Hydration

Glass

H2O

H2O2, OH°, HO2°, H2, O2, UIV

UVI

generation of oxidants by water radiolysis

Fuel oxidation by radiolytic oxidants

dissolution

precipitation of secondaryphases

Aqueous species (HCO3-,

OH- , Fe2+, H2…)UVI + RN

UIV

UIVaq Chemical dissolution

Modif

ied fr

om B

runo

et al

. (20

03),

Poins

sot e

t al.

(200

6)

UVIaq Corrosion by aqueous species

ECORR

Wasteform

Kinetics

Mechanisms

8



A beneficial effect of recycling on waste long-term performances

Radiotoxicity glass << SNF Relative performance of

nuclear glass vs. SNFNormal scenario: a significantpenality for SNF coming from IRF

highly mobile anionic FPs.Incidental scenario: important role of matrix performance.

SNF very sensitive to redox conditions ≠ nuclear glass.Impact much higher for SNF

9

Normal scenario

0,1

1

10

100

1000

10000

10 100 1000 10000 100000 1000000Temps (années)

Rad

ioto

xici

té re

lativ

e

102 105 1061041030,1

1

103

104

Time


10

102

10

U-ore

- - - - -: SNF_____: nuclear glas

Time (years)

Dose (Sv/year)



How can we recycle more efficiently?

Current LWR reactors do not allow an efficient Pu multi-recycling

Increase of non-fissile even Pu isotopes, Low consumption of 238U through neutrons captures

Neutrons with higher energies allow a betteruse of U and Pu neutron capture by 238U 239Pu fission of every Pu isotopes MA inventory

fission/capture

LWRFNR

PAGE 10

Possibility of Pu-multirecycling

(MTC)

Spent FR MOx(450 t)

Plutonium (# 90 t)

Uranium (RepU# 320 t)

FR MOx (450 t)

FNR

Depleteduranium(# 50 t)

FuelFabrication

SNFTreatment

PF / MA(*)

Wastes(50 t)

Large stockpiles (e.g. France: ~450 000 t in 2035).

www.cea.fr



Beneficial effect of recycling on the overallenvironmental footprint

Poinssot et al., 2014

12

Recycling

Environmentalfootprint



Evolutions to improve the social acceptability

Improve waste issueWaste long-term management is severelyquestioned by the public opinion

Nuclear waste = Achille's heel of nuclearDecreasing the waste lifetime may improvethe social acceptance … can we move the waste issue back within Human history?

13

239Pu

109 106 100103

109 106 100103

PastEarth

formationDinosaurs

1st Humanbeings

Cro-MagnonCharlemagne

WWII

129I 135Cs 79Se 14C 241Am 137Cs235U40K

Billions... Millions... Thousands... YearsFuture

Opinion survey

Ensure safety! Permanent priority …



Recycling the minor actinides, a potential contribution for decreasing the waste burden

14

Below plutonium, waste toxicity dominated by minor actinides MA (Am+Cm)

Recycling MA waste lifetime waste toxicity gain in incidental scenario activity heatpowerdenser repository repository lifespan preservation of the repository resource!

Surface reduced up to a factor of 8

0,1

1

10

100

1000

10000

10 100 1000 10000 100000 1000000Temps (années)

Rad

ioto

xici

té re

lativ

e

102 105 106104103 10 0,1

1

103

104

Time


10

102

U-ore

Spent nuclearfuel

Residual heat power (W/tHM)



Two main MA recycling options

TU

U Pu AM

FP

Grouped recycling

TMA

U Pu

FP

Heterogeneous recycling

U

Homogeneous recycling grouped recycling

GANEX processes

Heterogeneous recycling enhanced partitioningDIAMEX/SANEX processes

Moderated core target or blanket in periphery of the core with MA content up to

20%

MA diluted in standard fuel,

concentration up to ~2%,

Impossible d’afficher l’image.

15

1. In

trod

uctio

n



The rationale of the various separation processes developed in CEA

GANEX 1

GANEX 2

U

Pu Np Am Cm

Am,CmAmAmAm Am CmAn(III) selective

Stripping (innovative SANEX)

Am selective Stripping(EXAm)

AmAm

An(III) + Ln(III)-

An(III)/Ln(III)separation

An(III) + Ln(III)-


An(III) + Ln(III)- coextraction


An(III) + Ln(III)-


(DIAMEX) (SANEX)Am Cm

Heterogeneous recycling= enhanced partitioning

DIAMEX/SANEX

TMA

U Pu

FP

U

Homogeneous recycling= grouped separation

GANEX

T

U Pu MA

FP

U

2. M

A pa

rtiti

onin

g

16

U Product

Pu Product

U Product

Pu Product

U Product

Pu Product

U Product

UPu Product

U

U,Pu

U/Pu separation



A significant Improvement of the nuclear waste issues

PAGE 17

• Relative of HLW vs. ILW while total volume of waste ~ constant +/- 20%• of thermal power due to Pu-recycling significant gain for the

repository surface and volume

OTCSNF = waste

TTCMOX in LWR

2/3 EPR1/3 SFR SFR

SFRAm recycling



The rationale of future nuclear fuel cycles in view of sustainability

Gen. II & III

1980 2000 2200 2040 2060 2080 2100

Gen. IV

…+ MA recycling

Pu-monorecycling

Pu-multi-recyclingPu-mono-recycling- Twice-Through Cycle- LWR reactors- Pu-recycling in MOX fuel

Pu multi-recycling- Multi-Through Cycle- Fast-Reactors (FR)- Pu multi-recycling

Pu+MA multi-recycling- Fast Reactors (FR)- Pu multi-recycling- MA burning: (i) Am, (ii) Cm

Gen. IV

Main incentives- 1st step towards U

resource saving- Efficient waste

conditioning

Main incentives- Major resource saving- Energetic independence- Economic stability

Main incentives- Decrease of waste burden, - Preservation of the repository- Enhanced public acceptance

TOWARDS INCREASING SUSTAINABILITYDates are purely indicative

Breakthrough = reactors

Evolution = cycle

Onc

e-th

roug

hcy

cle

18



Conclusion: on the sustainability of fuel cycles …

Actinides recycling improvement of the nuclear global sustainability

Preservation of U resource for future generationsImprovement of the environmental footprintimprovement of the waste issues (lifetime, volume, toxicity…)Accessible economic overcost: 2 to 5 %

Roadmap for a stepwise deploymentTwice-through cycle is a beneficial first step

already allows saving 17% natural uraniumWith a beneficial impact

Next step requires FNR to better use natural UPu-multi-recycling in FNR, Multi-Through CycleReduced need for any U-mining activities

Final step could be decreasing waste burdentowards future generations if needed

Minor actinides transmutation

3rd step: MA recycling to decrease burden to

future generations and increase acceptance

1st and 2nd step: Pu recyclingto increase natural resourcesaving and promote stable

and predictable energy costs

Recycling the actinides is the cornerstone of any sustainable fuel cycle!PAGE 19

Christophe POINSSOT, CEA Marcoule / Nuclear Energy Division (DEN)

Head of the RadioChemistry & Processes Department (DRCP)Professor in Nuclear Chemistry, National Institute of Nuclear Science &

Technology (INSTN)

20

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Why recycling the actinides? A sustainable approach of nuclear fuel … · 2015-05-11 · Why...

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