RADIOACTIVITY AND NUCLEAR HAZARD

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RISQUES NUCLEAIRES anglais_0411-0156A-DOC OKWith thecollaborationof the ANCLIRISQUES NUCLEAIRES anglais_0411-0156A-DOC OKThe major risk
formulaHAZARD

Dangerous and unpredictable+STAKES

Important and vulnerable=MAJOR RISKWhen an accident occurs, it is a disaster. The
damage will be very important and the rescue
teams will face many difficulties.

왘A power cut in a radiology clinic is nota major risk.

왘A long loss of heat removal while thenuclear power plant is in operation is amajor risk.

Answers :Major accidents :radioactive material transport accident (3), radioactive substances leakage into the environment (7).
Other situations :daily life hazards (1, 4, 5 and 6).
radiography incident (2).

7

1

2

3

4

5

6

Spot the major
accidents below.

RISQUES NUCLEAIRES anglais_0411-0156A-DOC OK

RISQUES NUCLEAIRES anglais_0411-0156A-DOC OK

Radioactivity
Matter is made of atoms. Someof these atoms are unstable anddisintegrate while emitting different
types of radiation : they areradioactive.
Alpha decay (α)

Beta decay (β)

ex : uranium-238 atom

ex : carbon-14 atom

helium nucleus

e- electronThis radiation can be accompanied by a gamma
decay (γ).

PARTICLES

Cosmic rays
Neutrons

ELECTOMAGNETIC
RADIATION

Alpha and beta rays
Gamma rays
X-raysUltraviolet rays

Human beings have always been exposed
to radiation in their environment.

왘In 4.5 billion years, natural
background radiation has been
divided by 4. As of today, it is still
significant.

the beginning of the왘 Since
20th century, human beings havecreated radioactive elementsfor various applications.
It is the artificial radioactivity.

RISQUES NUCLEAIRES anglais_0411-0156A-DOC OK

In the following
examples, does radiation
come from natural or
artificial radioactivity ?
Origins of radiation received
by the population in France.

1

Radon
This radioactive
gas is emitted bysome rocks(granite...) and bysome construction
materials.

2

Medicalexposure
Many x-ray
exams arecarried out
each year.

39 %

34 %

1%
19 %

7%

3

54

Technologicalactivity
Releases due tothe productionof electricity, scientificresearch or nuclear
military tests.

Cosmic rays andtelluric currents
Pilots and flightattendants dosimetry
is monitored.

Water, food andhuman bodyRadioactivity ispresent in minerals,vegetables
and animals.

왘 In 1903, Henri Becquerel along withPierre and Marie Curie share theNobel Prize in physics for their discovery of natural radioactivity.

radioactivity applies cumu왘 Artificial
latively with natural radioactivity.

Answers :Natural radioactivity : 1, 4 and 5
Artificial radioactivity : 2, 3 and 5 if foodhas been contaminated by radioactive
releases.

RISQUES NUCLEAIRES anglais_0411-0156A-DOC OK

From radioactivity
to nuclear energy
7% of the electricity in the world isproduced by 400 nuclear reactors.
80% of the electricity in France isproduced by 58 nuclear reactors
spread over 19 different sites.
alpha, beta andgamma raysfissionproduct

neutronimpactfreeneutronsHeat

fissionproduct
The nuclear fission reaction is induced by thebombardment of the atoms with neutrons.
It subsequently generates heat energy.

Fission products, such as cesium, iodine

strontium are highly radioactive
왘 andwaste which can contaminate the environment.They are stored temporarely,
waiting to be sent to final disposal facilities.
Containment building

Steam generator

Production of electricity

Secondary coolant closed loop
turbine alternator

core

condenser

Primary coolant closed loop왘

Coolingriver or seaor air cooling

Water pump circuit

In the nuclear reactor core, the fissionof uranium 235 is under control thanks
to control rods able to absorb the neutrons. The heat liberated by the fission
must be constantly removed by thecoolant loops.
A long loss of heat removal will lead toa major accident. The containmentbuilding must always remain leakproof.

RISQUES NUCLEAIRES anglais_0411-0156A-DOC OK

In the following examples,
how many neutrons will be
released at level 3 ?
Level 1

Level 3

Level 2

FIRST CASE : FISSION CHAIN REACTION

Heat

Heat

Heat> 9?
< 9?

Heat

SECOND CASE : CONTROLLEDCHAIN REACTION

Heat

Heat

1?
3?

One failure of the system and the coreis out of control !
In 1986, a reactor at theChernobyl nuclear power
plant exploded inUkraine.
A WHO* report from2006 stated that :• 30 people died in the15 days following thedisaster,• thousands of people(between 9 000 and16 000) will die in the 50 years following thedisaster. Diseases and deaths are caused by
the contamination of the soil, air and water.
Belarus, a neighbouring country, was particularly affected.
*WHO : World Health Organization

Answers :First case : more than 9 released neutrons
Second case : 1 released neutron

RISQUES NUCLEAIRES anglais_0411-0156A-DOC OK

Fukushima : Chaos
From a natural disaster ...
March 11, 2011,
the northeast coastof Japan is shaken
by an earthquakeof magnitude 9.
It causes a tsunamithat ravages theseafront with wavessometimes higher
than 10 meters.
Many aftershocks
follow for weeks.

… to a nuclear accident ...
The protective dykeof the Fukushima
Daiichi nuclear power
plant is flooded.
Cooling systems ofreactors are destroyed.
3 out of 6 cores melt.
The population isevacuated up to 30 km
around the plant,
due to radioactive
releases.

…and to contamination
Assumptions,calculations and fieldmeasurements define :- the radioactive
plume,- contamination,- assessment of“received and future”
doses by thepopulation.

왘 ties and the population will have toThe Operator, the Japanese authori-manage long-term site, contaminationand health risks.

RISQUES NUCLEAIRES anglais_0411-0156A-DOC OK

Radiation is used for :Sterilising foodto improve its
preservation.
Food is irradiated withgamma rays.

Baggage screening.
X-ray device let you
see the content.

photos by CEA

Dating relics.
It involves the measurement of alpha andbeta rays from radioelements such ascarbon-14,
uranium/thorium...

Diagnosing andtreating somediseases of thehuman body.

out :왘 WatchDaily exposure to this radiation isdangerous. That is why workers areprotected by radiation shields.

RISQUES NUCLEAIRES anglais_0411-0156A-DOC OK

In the following examples,
which matter will protect
you from the radiation ?

α (alpha)β(alpha)γ (gamma) and X
neutrons

paper

aluminium

lead orconcretelarge
quantityof water

Case #1 :You are screening baggage in an airport.
You are shielded by an apron made of ?
Case #2 :You are working in a nuclear power plant.
You are protected from neutrons- emitted by fission products by ?
in the spent fuel pool.
Case #3 :In hospitals, α (alpha) and β (beta)
radiological sources are stored in boxes
made of ?
Case #4 :You are operating a food irradiation
device.You are protected by the irradiationchamber walls made of ?
Answers :Case #1 : lead
Case #2 : large quantity of water
Case #3 : lead
Case #4 : concreteRISQUES NUCLEAIRES anglais_0411-0156A-DOC OK

The 3 radioactivity
measurement units

1
1

2

3

ACTIVITY (illustrated by the number and size ofthe thrown stones)is the intensity of the radiation emitted by
the source. It is measured in becquerels.
2ABSORBED DOSE (illustrated by the number
and size of the stones hitting the boy)indicates the quantity of radiation
absorbed by the individual or the matter.
It is measured in grays.
3

DOSE EQUIVALENT (illustrated by the boy'sscrapes and bruises)indicates the biological effects on a body
exposed to radiation. It is measured
in sieverts.
Radioactivity can't be felt.
Special measurement
devices are needed toquantify radioactivity.
A dosimeter measures aworker's exposure to theradiation.

왘 The maximum exposure rate allo-wed is specified by specialists. Forinstance, as a precaution, theInternational Commission on
Radiological Protection considers
that the artificial radiation measured on any person should notexceed 1 millisievert per year.

RISQUES NUCLEAIRES anglais_0411-0156A-DOC OKKnowing is understanding themajor risks
countries inform the Public by :
왘 Most• Internet• Brochures• Posters• Public meetings• Documentation
E.g. in France : A local major risks fileis available for consultation at the local
authority. The city information document on the major risks (DICRIM).
The local information committees(CLI) communicate with the population over the nuclear installations
activities.

왘To learn more about nuclear hazards
and about the different keyplayers
involved surf on the IAEA website oron your national official websites e.g.
in France :www.prim.net
www.asn.fr
www.irsn.fr
www.ancli.fr
www.acro.eu.org
www.cea.fr

Spatial planning

Knowing
Information

Monitoring
Planning

Self protection

Education

Mitigation
Every effort to reduce the effects
of a disaster adds to sustainable
development of our territory.

RISQUES NUCLEAIRES anglais_0411-0156A-DOC OK

Where do proceduresapply ?
A release of radioactive elements
occurred at the power plant.
The alarm siren has been activated.
According to the contamination map :1 – What are the zones where people
should seek shelter ?
2 - In your opinion, why is village B
particularly contaminated ?

N

✦ESA

0.5 miBAnswers :1- In the immediate surroundings of the plant, all
the people must seek shelter.
2- Under some weather conditions, the wind cancarry the radioactive cloud in any particular direction. On the picture, the wind comes from thenorth-west and blows toward the south-east. So,
contamination is higher in village BW

RISQUES NUCLEAIRES anglais_0411-0156A-DOC OK

Emergency plansand procedures
to be prepared :Together, we are be better prepared to face a nuclear accident.
At school :The Specific School Safety Plan
explains students and staff membersof an educational institution how andwhen to shelter or to evacuate safely.
Parents are informed
about the emergency
plan and are toldthat they must never"pick up their children
from school"
throughout theduration of the alert.

In the city
A city emergency plan reviews themeans of protection and activatesthem in the case of a major emergency.
In the area around a high-risk
industry
A specific intervention plan is triggered by the local authority at department level in order to protect thepopulation. It rallies and coordinates
the State services and the emergency rescue teams.
exercises are왘 Simulation-basednecessary to test the efficiency ofthese plans. They also teach you how
to react in case of an accident.

RISQUES NUCLEAIRES anglais_0411-0156A-DOC OK

You are hearing thenational alert siren...
What will you do next ?
1

I open the window totake photos.

2

I quickly stock up withbottled and tap water
pending a potential
contamination.

3

I ensure that allwindows in the house
are well closed andI listen to the radio.

4

I call my friends totell them about theaccident.

5

I look for the iodine
pills or syrop to havethem at hand in casethe officials tell me totake them.
Answers : Yes, you should : 2, 3 and 5
No, you must not : 1 and 4

RISQUES NUCLEAIRES anglais_0411-0156A-DOC OK

Safe and sheltered
When there is a radioactive cloud,the National Alert System (NAS) will
warn you. It means that you have totake shelter inside a building.

ALERT

END OF ALERT

discontinuous soundcontinuous sound3 X 1 MINUTE 41 SECONDS

France you can listen to the왘 In
NAS sound on this website :www.iffo-rme.fr

Vehicles equippedwith a siren relay
the alert.

By a nuclear accident always listen
to the instructions given by theauthorities on the Radio.
Use a battery-powered radio in caseof a blackout.
local authority at department
왘 Thelevel decides when the iodine pills
or syrop are to be taken. He canalso issue an evacuation order forthe population or keep them athome and give them specificinstructions.

RISQUES NUCLEAIRES anglais_0411-0156A-DOC OK

Spot the misplaced
pictures.
ABEFORE

B

Nuclear plant workers are regularlytrained.
3 safety barriers
protect each nuclear
reactor to avoid any
risk of radioactive
leakage :the fuel cladding, thereactor vessel andthe containment
structure.

DDURINGC

A warning system towarn the population
if a major accident
occurs.

The population isevacuated from ahighly contaminatedsite.

AFTERE

Living in acontaminatedenvironment implies
changing habits :not consuming
certain products...

Answers :Pictures A, C and D are misplaced.
The correct order is : C, B, D, A, E

RISQUES NUCLEAIRES anglais_0411-0156A-DOC OK

Taking action to :PREVENTION• avoid a major accident,• manage emergencies to immediately
limit their consequences,• allow the society to progressively goback to a normal life.

Laws regulate theoperation andthe storage ofradioactive materials.

A regular monitoringof the radioactivity
is performed in andaround nuclear
installations.

AFTERDURING

On a contaminatedsite, an emergency
team dressed in protective gear brings
assistance to thepopulation.
Following official
instructions, each
person must take aan iodine pill to diminish the impactof a radioactive cloudon Public Health.
Certain countries evenhave Iodine syrop forchildrens.
Cleanup of thecontaminated soil
can facilitate thereturn of an evacuatedpopulation. Highly
polluted soils andobjects will be considered as radioactivewaste.

RISQUES NUCLEAIRES anglais_0411-0156A-DOC OKFukushima :Consequences
Human
Thousands of people
were evacuated andrelocated. Others areforced to adapt to live
in contaminated areas.
Health effects will berevealed in the future.

Environment
Soils and marine
ecosystems arecontaminated.
Vegetables, fruits andanimals are unfit forhuman consumption.

EconomyThe local economy
disappears aroundthe nuclear power
plant.The country’s
financial growth stops
for several months.

Politics
Nuclear energy, safety,
emergency responsemanagement, risk
prevention and public
information aresubject to debate inmany nuclear nations.

왘 to alert the population in case of

Air is monitored on all continents
significant radioactivity.

RISQUES NUCLEAIRES anglais_0411-0156A-DOC OKInternal or externalcontamination ?
In a contaminated zone...
1

I eat mushrooms
picked by myneighbour.

2

I roll on the lawn.

3

A cow grazes inthe field nearby.
I drink the milk fromthe cow.

4

I play ball in the street.

Answers :Internal contamination :Cases #1 and 3
External contamination :Cases #2 and 4. If the air is also contaminated, there
will be internal contamination as well in these cases.

RISQUES NUCLEAIRES anglais_0411-0156A-DOC OK

Irradiation andcontamination

By a major nuclear accident, fission
products are released and spread in
the air.They form a radioactive cloudcomposed of gas, drops and dust.

When the radioactive
cloud, caused by the nuclear
accident, is above me,
I’m irradiated by ionisingradiation.

When the radioactive
cloud is gone, the fallout(dust and drops) remains
and fission products are
all over my body, myclothes and theenvironment.
Everything iscontaminated.

왘Contamination occurs throughinhalation, ingestion or contact.

Conception graphique : Isabelle Cochereau, conception éditoriale : IFFO-RME / 2011

RADIOACTIVITY AND NUCLEAR HAZARD

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RISQUES NUCLEAIRES anglais_0411-0156A-DOC OKWith thecollaborationof the ANCLI