THE "FUELCYCLE"
9.1

Design: ASN and IRSN Communications Departments - May 2022
Graphic design and production: www.kazoar.fr - Pictograms: Freepik, Kazoar - Photos: Lesage Philippe/Orano, Éric Larrayadieu/Orano
Reproduction prohibited without the agreement of ASN/IRSN. For further information: contact@irsn.fr

THE "FUELCYCLE"FROM THE MINE
TO WASTE

The fuel used in nuclear power plants is made fromuranium ore. In France, once it has been used,some of the fuel material becomes waste, while
the rest can be recycled.

THE "FUEL CYCLE"URANIUM
ENRICHMENT
Only uranium-235 is fissile and therefore
useful for the operation of nuclear power
plants.
Natural uranium contains less than 1%
uranium-235. For the French nuclear power
plants, uranium has to be converted to UF6
before it can be enriched to the 3 to 5% ofuranium-235 required for the final fuel.

MANUFACTURING
MOX FUEL
Plutonium is mixed with uranium andcompressed to form MOX fuel pellets.
The pellets are stacked in tubes assembled
in square bundles to form the final fuel.

ich
r
n
E

IN THE REACTOR
More than 200 fuel assemblies are arranged in
the reactor vessel to form the core.
One third of the assemblies are renewed every
year for 900 MWe reactors and every 18 months
for 1,300 MWe reactors.

ntem
1,000 t/year
Enriched uranium

uel
f
um n
i
n
Uraricatio
fab

110 t/year
Depleted uranium
8,500 t/year
Naturaluranium

URANIUM
MINES
Most of the time, uranium is
extracted from pitchblende.
From this raw ore, aconcentrated uranium powder
is produced, known as "yellow
cake". Tailings and waste rockremain on site.
Today, the French mines havebeen closed and uranium comesfrom abroad.

REPROCESSING
The fuel assemblies are
sheared and chemicallydissolved.
The uranium and plutoniumthat can be used to
manufacture new fuels are
extracted.
Plutonium is a componentof MOX fuel.

ionta
ric fuel
b
a
F OX
of M

7,390 t/year
Depleted uranium

2

nd

p

ss i necro1,000 t/year
Enriched uranium

g

ng
i
l
s
e
s
Fu rocerep

120 t/year
MOX fuel

10 t/year
Plutonium

f fu
o
se

el

U

1s p
t

sin
s
e
roc

1,000 t/year
Initial fuel residueg

940 t/year
Reprocesseduranium

50 t/year
Fission productsTechnologicalwaste

Oreracext

tion

COOLING
Nuclear reactions continue toheat the pellets even when theassemblies are spent andremoved from the reactor
vessel.
So they must be continuously
cooled in a pool connected toa water circulation system forseveral years before they canbe reprocessed.

ge
a
r
Sto

STORAGE OFREPROCESSEDURANIUM
Uranium from
reprocessed fuel is
no longer recycled in
France and is stored
at the Pierrelattesite.

120 t/year
Spent MOX fuel

ge
a
r
Sto

DISPOSAL
Fission products andactinides, radioactive wastefrom reprocessing, areincorporated into molten
glass, which is then poured
into hermetically sealed
stainless steel containers.
These containers are thenstored until a final disposalsite is found.

TRANSPORT
Once the spent fuel has
cooled sufficiently, it istransported in a speciallydesigned container to the
La Hague plant.

9.2

ge
a
r
Sto pentof sX fuelMO

Design: ASN and IRSN Communications Departments - May 2022
Graphic design and production: www.kazoar.fr - Pictograms: Freepik, Kazoar - Illustration: ASN
Photos: Petitot Nicolas/Orano, Éric Larrayadieu/Orano, EDF/mission communication Golfech, Orano, Philippe Lesage/Orano, Éric Larrayadieu/Interlinks Image, Philippe Dureuil/Médiathèque IRSN, Éric Larrayadieu/Orano
Reproduction prohibited without the agreement of ASN/IRSN. For further information: contact@irsn.fr

THE "FUELCYCLE"URANIUM

MINES

The uranium used in France today is sourced
exclusively from abroad. But France operated
mines for over 50 years, producing waste rockand tailings that still need to be managed.

URANIUM MINESAROUND THE WORLDFORMER MINES IN FRANCE

More details

Uranium was mined in France between 1948
and 2001, with production peaking in the 1980s.

on mines in France

There are around 250 former mining sites, spreadover 27 départements, which produced a total of
76,000 tonnes of uranium.

ORANO'S MINES ABROAD
Cogema, now Orano, has invested in high-gradeore mines abroad, for example in Niger andCanada.

CANADA
345.2 (13.1%)
RUSSIA131.7 (5.0%)

UNITED
STATES
102.0 (3.9%)SPAIN
2.5 (0.1%)
PORTUGAL
6.0 (0.2%)

UKRAINE
58.5 (2.2%)

THE MOTHER LODEKAZAKHSTAN
378.3 (14.3%)
UZBEKISTAN
59.7 (2.3%)

Uranium veins have formed over themillennia as a result of water flowing
through faults, cracks and the open
surfaces of granitic formations. The
water carried the uranium atoms with it,
depositing them where the chemical
conditions were favourable.

MONGOLIA
46.2 (1.7%)

ALGERIA
19.5 (0.7%)

NIGER
180.5 (6.8%)

BRAZIL157.7 (6.0%)

Unit:
thousands of tonnes
extracted per year.

NAMIBIA
151.3 (5.7%)
SOUTH AFRICA
177.1 (6.7%)

Total worldwide:
2,643.3 thousand tonnes
extracted per year.
Source: Energy
Observatory - IAEA/OECD

That's why there are so many old minesin the Massif Central and Brittany, where
the granite is rich in uranium.

AUSTRALIA
714.0 (27.0%)

OTHER
113.1 (4.3%)

How much does uranium cost?
Uranium is not a very expensive resource.
In 2017, 1 kg of raw uranium (excluding
processing) cost 80 euros.
For comparison, 1 kg of silver was worth around
500 euros and 1 kg of gold, 30,000 euros.
The price of uranium fluctuates in linewith market trends, but also with incidents
such as the flooding of the Cigar Lake minein Canada and the fire at the Olympic Dam minein Australia in 2007.
Uranium mining can present health risks forminers, and tailings left on site can pose risks
for the local population.

RISKS
FOR MINERS
Among other risks, miners extracting uranium can be
exposed to radon, a radioactive gas emanating from therocks and stagnating in the galleries. The Mining Coderegulates their work.

STUDIES ON MINERSIRSN carried out research on almost 5,000 miners todetermine the consequences of radon exposure, andcompared the results with numerous other studies.
Differences in lung cancer mortality rates as a functionof radon concentrations were quantified.
For example: exposure of around 1,000 Bq/m3 per yearfor 25 years doubles the risk of developing lung cancer.

Uranium mining in France has resulted in the
production of several million tonnes ofradioactive waste rock and tailings. At times,
they may have been used as fill or building
materials.

DEBATETHE ISSUE

Today, we cannot move tailings, so they haveto be monitored. Actions are taken to map
sites and assess risks.

OF MINETAILINGS

Regulations have changed: it is now forbidden to
use tailings for construction.

9.3

Design: ASN and IRSN Communications Departments - May 2022
Graphic design and production: www.kazoar.fr - Pictograms: Freepik, Kazoar - Maps: Kazoar - Photos: amixstudio/AdobeStock
Reproduction prohibited without the agreement of ASN/IRSN. For further information: contact@irsn.fr

THE "FUELCYCLE"FUELFABRICATION
Once out of the mine, the uranium undergoes anumber of physical-chemical treatments before
finally being converted into uranium dioxidepellets. The pellets are stacked in "rodcladdings" that make up the "assemblies".

A CASCADEOF CHEMICAL TRANSFORMATIONS...
Uranium extracted from mines, concentrated in the formof "yellow cake",cannot be used in French nuclear reactors.
To become fuel, it has to undergo a number of operations.
First, the yellow cake is dissolved in acid and then purified.
Calcination produces uranium trioxide powder (UO3),
which is then transformed into uranium tetrafluoride (UF4).
These operations are carried out at Orano's Malvési plant near
Narbonne.
At the Philippe Coste plant at Tricastin in the Drôme, UF4 is thenconverted into uranium hexafluoride (UF6), which is thentransformed from a solid into a gas to enrich it in isotope 235.
Uranium oxide (UO2) pellets are then produced from enricheduranium powder.

ASSEMBLY
Over 200 rods are assembled ingrids into which a control bar isinserted to control the chain
reaction.

...TO MANUFACTURE
URANIUM OXIDE PELLETS...

...AND RODS CLADDED 
WITH ZIRCALOY...
Zircaloy is an alloy that allows neutrons to pass through,but unfortunately it can oxidise at high temperature toform hydrogen.
In the event of an accident, the quantity of hydrogenproduced is such that it could lead to a risk of explosion.

Actual size:
1 × 1 cm.

URANIUM CHEMISTRYIS NOT WITHOUT RISKUranium hexafluoride is radioactive.
What's more, it's a highly toxic
product: it reacts with water toform uranyl fluoride (UO2F2) andhydrofluoric acid (HF).
This reaction is rapid and strong,
and is accompanied by the emissionof irritating and suffocatinghydrofluoric acid fumes. These risks
also need to be managed.

9.4

Design: ASN and IRSN Communications Departments - May 2022
Graphic design and production: www.kazoar.fr - Pictograms: Freepik, Kazoar - Illustrations: B2 infographie – Photos: Orano/ Adeline Justamon
Reproduction prohibited without the agreement of ASN/IRSN. For further information: contact@irsn.fr

THE "FUELCYCLE"FUELREPROCESSINGIn France, only part of the spent fuelfrom nuclear power plants becomes waste.
The rest can be recycled to make new fuel.

1. REACTOR:
SPENT FUEL

2. THE POOL:
HOT! HOT! HOT!

The uranium-235 concentration in fuel pellets
decreases as they are irradiated. These isotopes
are transformed into artificial radioactive
elements. Each fission reaction breaks up an
atom, replacing it with two atoms known asfission products.

Radiation from the artificial radioactive
elements in the spent nuclear fuelcause it to heat up intensely.
At end of life, the fuelassemblies are removed
from the reactor using
automated equipment
and stored on site in apool to be cooled down.

When a neutron strikes a uranium-238 atom,
the atom can absorb the neutrons, forming
heavy actinides such as americium, neptuniumor plutonium.

The heat will then gradually
decrease.

Plutonium is also fissile and, in France, it can beused to make MOX fuel. The plutonium content
of spent fuel is around 1%. Reprocessing
separates these different products.

97%

3%

94%

1%

1%

4%

0.1%

Decay curve for the power ofspent fuel assemblies over time
25,000

1 day
20,000

2 days

15,000The
uranium
enters thereactor...

...and four
years later

4 days8 days15 days
1 month
3 months
That leaves 1,000 kW which
6 months
1 year will decrease very, very slowly

Power in kW

10,0005,000
0Time (logarithmic scale)

URANIUM-238(recyclable for
future use)
URANIUM-235(recyclable for
future use)

MINOR ACTINIDES(ultimate waste)
FISSION PRODUCTS(ultimate waste)
PLUTONIUM(recyclable as MOX)

3. TRANSPORTAND STORAGE
When the fuel has cooled sufficiently, it is removed from the pool of
the reactor, placed in specially designed packages and transported
to the La Hague plant, where it is stored again in a pool before
potential reprocessing.
One of the pools at La Hague contains the equivalent of 40 nuclear
reactor cores. A height of 20 metres of water protects workers fromionising radiation.

4. RECYCLING:
THE SECOND LIFE OF FUEL
Uranium remains in the spent fuel and is extracted to be reused andre-enriched.
Spent fuel also contains fissile plutonium, which can be used in a nuclear
reactor. It is mixed with uranium to make a "recovered" fuel called MOX(mixed oxide).
The fuel most commonly used in France, made with uranium alone,
is called UOX (uranium oxide).

To make MOX fuel, plutonium containedin spent fuel is reused. This avoids disposingof it as waste and saves uranium resources.
In the event of an accident, the fission products
from MOX fuel are more dangerous than thosefrom UOX.

DEBATE
DOES MOXHAVE ANYDISADVANTAGES?

9.5

Chemically, plutonium is also highly toxic for workers,
requiring additional protective measures.
From a security point of view, plutonium in purified
form can be the target of theft in order to be usedin weapons.

Design: ASN and IRSN Communications Departments - May 2022
Graphic design and production: www.kazoar.fr - Pictograms: Freepik, Kazoar - Photos: Interlinks Image/Éric Larrayadieu, Laurent Zylberman/Graphix-Images/Médiathèque IRSN
Reproduction prohibited without the agreement of ASN/IRSN. For further information: contact@irsn.fr

THE "FUELCYCLE"

TRANSPORTOF RADIOACTIVE
SUBSTANCESIn France, around one million packages of radioactive
substances are transported every year. Transport relating
to the "fuel cycle" accounts for only a small proportionof this (around 10% of the packages transported) but
presents the greatest safety challenges (particularly
for the transport of spent fuel).

PACKAGESDESIGNED FOR STRENGTH
There are several categories of package for transporting radioactive substances, definedaccording to the quantity of radioactive substances to be transported (the activity of thecontents) or their dilution in the totality of the materials to be transported (the mass
activity of the contents).
Of these different categories of radioactive substance packages, category A covers
substances of intermediate radioactivity and category B covers those of highradioactivity, such as spent fuel.
Engineers have designed packaging that can withstand different types of incidents
and accidents.
Examples of regulatory tests
9m

Drop resistancetest

Category A(intermediate level
radioactivity)

Resistant to water
spraying to simulate
a severe storm

Resistant to penetration
by a 6 kg bar dropped
from a height of 1 m

Resistant to free fallof the package froma height of up to 1.2 m

Category B(high level
radioactivity)

Can withstandsubmersion toa depth of 200 m

Resistant to free fall of
9 m and a drop of 1 m
onto a punch

Resistant to a fire test of
800°C for 30 minutes

WHAT ABOUT
LOW-LEVEL PACKAGES?
Even if they were to be completely
destroyed in an accident, exposureof the public and responders
would remain limited.
1m

Punch resistance
test

200 m

Fire resistancetest

Submersion
resistance test

TRANSPORT SAFETYOF RADIOACTIVE SUBSTANCESThe company responsible for transport must comply with international regulations concerning therobustness of packaging containing radioactive substances, the reliability of transport operations andemergency preparedness.
Packages representing significant safety concerns must be approved by ASN, following technicalassessment by IRSN.
In addition, it is important to make sure that:•T he operators and staff concerned are organised and trained to deal with any event that could occur;•T he traceability of transported radioactive materials is ensured and labelling is precise and standardised,providing clear information and instructions for those who would intervene in the event of an accident;• Inspections and checks on compliance with these rules are carried out by ASN.

Even if the packaging provides a high degree of radiation
protection, the packages continue to emit radiation.
Packages can be transported by all modes of transport (road,rail, air, sea) and on public routes.

DEBATERISKS ASSOCIATED

WITH TRANSPORT

Some elected officials and non-governmental organisations
denounce the risks of exposure for local populations, as wellas the lack of information about the routes taken.

The risk of public exposure is low.
A person would have to spend ten hours, within two metresfrom a vehicle carrying high-level radioactive substances
to be exposed to 1 millisievert, the annual regulatory limit
for the public.
To prevent malicious acts, the most sensitive transport routes
must remain confidential.

9.6

Design: ASN and IRSN Communications Departments - May 2022
Design and production: www.kazoar.fr - Pictograms: Freepik, Kazoar - Illustrations: La-fabrique-créative/Bruno Bourgeois
Reproduction prohibited without the agreement of ASN/IRSN. For further information: contact@irsn.fr