Radiation and Radiation Safety at the Australian Synchrotron · Radiation and Radiation Safety at...

Radiation and Radiation Safety at the

Australian Synchrotron (GERT Training)

Sergio Costantin

Radiation Safety Officer

Australian Synchrotron

Training Objectives (questions that will be answered)

• What is radiation and where does it come from?

• What are the different types of radiation present at the

synchrotron?

• What effect does exposure to radiation have on me?

• How is radiation monitored at the facility?

• How will people be stopped from going into radiation areas?

• How will people be warned about radiation and radiation areas?

• How do I minimise my radiation dose?

• To how much radiation will I be exposed and what is the risk?

What is radiation and where

does it come from?

What is Radiation?

The different types of particle

radiations are:

• alpha radiation

(alpha particles);

• beta radiation

(beta particles); and

• neutron radiation

(neutron particles).

Particulate Radiation

Radiation is the process of emitting

energy as waves or particles.

Diagram indicates the penetrating power of

the different types of radiations.

What is radiation and where does it come from?

Wave Radiations – Electromagnetic Spectrum

Radiation can be the

process of emitting

energy as waves.

The full

range of wave energies is

called the

electromagnetic

spectrum.


Types of Radiation

Ionising radiations are capable

of producing ionisation as they

pass through matter, i.e. radiation

energetic enough to strip atoms

of electrons.

Ionising Radiation

Non-ionising Radiation


Units for Measuring Ionising Radiation

Radiation Dose

• When something absorbs radiation, the energy of the

radiation is deposited (or absorbed) in that material.

• The amount of energy deposited in the material by an

exposure to ionising radiation is often referred to as a

radiation dose and can be expressed in joules per

kilogram (J/kg).

• The weighted radiation dose (taking into account the

type of radiation and the area of the body exposed)

is given the unit of sievert (Sv).

• One sievert (1 Sv) of radiation is a very large radiation dose.

Most often radiation doses are expressed as fractions of

sieverts, for example in micro (µSv) or milli (mSv).

[Swedish physicist

Rolf Sievert (1896-

1966), first professor

of the Dept. of

Medical Radiation

Physics in

Stockholm, did a lot

of work in radiation

protection.]


Radiation is everywhere, it is a natural part of our environment.

This radiation is often called Background Radiation.

Background radiation may be either from natural sources or

human-made sources.


Background Radiation Exposure to natural sources comes from: Cosmic rays,

ionising radiation

from the Sun and

outer space.

Naturally occurring

radioactive

materials found in

the earth such as

uranium, radium

and thorium.

Radon, a naturally

occurring

radioactive gas,

that comes from

radium present in

the soil.

Ingestion of naturally

occurring radioactive

elements in food,

such as potassium-40

(K-40), and water.


Background Radiation

Exposure to human-made sources comes from:

Medical X-rays and nuclear

medicine (i.e. medical procedures).

Consumer products such as

smoke detectors and lantern

mantles.

Fallout from nuclear weapons

testing present in the

environment.

Nuclear reactors for power

generation.


Background Radiation in Australia

Background Radiation

(Melbourne avg):

~2.2 mSv per year

(or 2,200 µSv/year)

(less than the World avg of 2.4 mSv).

Australian annual per capita

radiation dose (in mSv) from

natural and medical sources. (Source ARPANSA)

Medical Diagnostic

(35%)

0.8

Radon Progeny

(9%)

0.2

Potassium-40 in

the body (9%)

0.2

Terrestrial (26%)

0.6

Uranium/Thorium

in the body (8%)

0.2Cosmic Rays

(13%)

0.3

mSv

mSv mSv

mSv

mSv

mSv


What are the different types of

radiation present at the

Synchrotron?

There are three sources of ionising radiation present at the

Australian Synchrotron (when it is operating).

Bremsstrahlung radiation

(equivalent to gamma/X-ray radiation)

Neutron radiation

Synchrotron radiation (from ultra-violet to X-ray radiation)

Radiations Present at the Synchrotron

There is also non-ionising radiation present at the Australian

Synchrotron (when it is operating).

Radiofrequency radiation } present at most

Microwave radiation } accelerator facilities

Synchrotron radiation (from infra-red to ultra-violet)

What are the different types of radiation present at the Synchrotron?

non-ionising hazard

ionising hazard

Synchrotron Radiation (from Infrared radiation to X-ray radiation)

• Radiation emitted when electrons, travelling at close to the

speed of light, are forced to move in a circular orbit under the

action of a magnetic field.


• The synchrotron radiation

is emitted in a narrow cone

in the forward direction, at

a tangent to the orbit.


Important to Remember

• Ionising radiations, as a result of the electron beam, are

present only when the beam is operating or being

accelerated.

• No different to turning off a light

– there is no ‘residual light’ left

in the darkened room.


• NOTE: Non-ionising radiations

are normally present when

power is provided to equipment.


• Materials in close contact to the

electron beam (i.e. inside the tunnels)

may become activated, that is,

become radioactive.

• If you are working close to activated

material you may be exposed to

radiation levels slightly higher than

background.

• Activated components will be

labelled.



What effect does exposure to

radiation have on me?

What effect does exposure to radiation have on me?

Non-ionising radiations

Under normal conditions

there are no effects.

When exposed to high

radiation levels the main

effect of non-ionising

radiation is to heat the

body.

The body has many defence

mechanisms to dissipate heat.

What effect does exposure to radiation have on me?

Ionising radiations:

Under normal conditions

there are no effects.

Exposure to high levels of

ionising radiation gives

rise to an increased risk

of cancer.

At the Australian Synchrotron

any increased risk is small and

comparable to other everyday

risks.

Radiation controls at the facility

How is radiation

monitored at the facility?

Radiation Monitoring Equipment.

Radiation levels around the facility are

monitored using radiation detection equipment.

Radiation Monitoring (Ionising Radiation)

How is radiation monitored at the facility?

gamma radiation

monitors

neutron

radiation

Monitor

Monitoring Equipment

(non-ionising)

• Narda EMR-300 with type 8C

E-Field probe (100 kHz to 3 GHz)

Radiation Monitoring (Non-ionising radiation)


Personal Monitoring (TLD/neutron & Luxel badges)

The Australian Synchrotron has been given

an exemption from personal monitoring for

Users by its radiation Regulator (ARPANSA).

This exemption was given based on seven

years of data showing that the facility has

maintained radiation doses to personnel at

less than 1 milliSv/year.

A personal radiation monitor WILL NOT

normally be provided to you unless a specific

request is made.

This request must be made at least one

week prior to your allocated beam time.



Personal monitors will continue to be used by

Staff, other specific personnel and under

some special circumstances.

The special circumstances are:

o Where explicitly required by the Safety

Office.

o Where a person declares pregnancy.

The Safety Team is to be consulted regarding

availability and accessing a personal radiation

monitor.



IF YOU ARE PROVIDED WITH A

PERSONAL RADIATION MONITOR

THE FOLLOWING APPLY:


Worn by individuals to assess their personal radiation dose.

Provided by (independent) external service providers.

Preferred wearing location: upper torso.

NOTE: DO NOT HANG BADGE ON YOUR LANYARD.

Approximate ten week wearing period (hence same badge

available for approximately ten weeks).

Note: No instantaneous reading; must be sent away to the

service provider to determine radiation doses.

Users’ badges are placed in the foyer.

Radiation dose results are available from the Radiation Safety Officer upon request.

Must be worn at all times while at the synchrotron facility.

Lost or damaged badges must be reported to the Radiation

Safety Officer / Safety Office immediately.

Must not leave the Synchrotron facility.

Must not be left in a Radiation Area.

Must not be intentionally tampered or interfered with.

Must not be worn during non-occupational activities, such

as when undergoing medical or dental X-rays, nuclear

medicine procedures or during air travel.



IF YOU ARE PROVIDED WITH A PERSONAL MONITOR

THE FOLLOWING REQUIREMENTS APPLY:

MUST

MUST NOT

Pocket dosimeters can be used to give an

instantaneous reading of radiation dose

levels to individuals.

May be required (as part of a procedure)

to wear a pocket dosimeter while working

in a particular area.

Available from Control Room.

Must complete log book when taken:

Date, Name;

Serial number of dosimeter;

Time Out, Dose Out;

Dose In, Time In.

Radiation Monitoring (Ionising Radiation)



How will people be

stopped from going into

radiation areas?

How will people be stopped from going into radiation areas?

The facility has a Machine Personnel Safety

System and Beamline Personnel Safety

System to stop entry into radiation areas.

Personnel Safety System (PSS)

The function of the PSS is to prevent

personnel from being harmed from

exposure to ionising radiation

generated by the electron beam.

Machine Access Modes

Open access: Allows unlimited, open access

to authorised personnel.

Authorised access: Limited, controlled

access to a specific zone for a specific

purpose. Radiation hazards interlocked off.

Electrical hazards may be present. SOP must

be followed

The design of the PSS allows three access modes into

the tunnel areas:


No access: Radiation and electrical hazards present; no personnel

allowed. Blue lighting in tunnels indicates no access mode.

NOTE: Entry into the tunnels is to authorised personnel ONLY.

Beamline Access Modes

Open access: Allows unlimited, open access to authorised

personnel. (green light)

The design of the PSS allows three access modes

into the beamline enclosures:


Search and secure mode: enclosure has

been searched and secured and is ready

for beam. (orange light)

No access: Radiation hazard present; no

personnel allowed. (red light)


How will people be

warned about radiation

and radiation areas?

Radiation Warning Signs

Radiation areas display

radiation warning signs.

How will people be warned about radiation and radiation areas?


Area Radiation Monitoring

TLDs and small radiation

dosimeters are placed at

various locations throughout

the facility to assess radiation

doses at specific locations.


Red Lights (normally) indicate that radiation is present,

e.g. inside the accelerator tunnels

or inside a beamline enclosure.

Warning Lights


During the injection process of the

electron beam (electron beam transferred from

Booster Ring to Storage Ring) orange lights will

flash at locations on and within the

Storage Ring. (Not to be confused with forklift warning lights which are

located under the mezzanine level.)

During this period radiation levels within

the facility are slightly higher than

during normal operation.

(Use distance to help minimise radiation dose.)

Warning Lights


Other Radiation Controls

within the Facility

• Sign / label to indicate important

configuration items.

• Item NOT to be

modified or removed

without proper (written)

authorisation.

Other Radiation

Warning Signs / Labels

Other radiation controls within the facility.

• All shielding panels of

beamline enclosures are

painted blue (aqua).

(Note, two shades – inside

lighter than outside.)

• Any item in this colour must

not be interfered with

(modified or removed) in any

way, without (written)

authorisation.

Warning Indicator (Paint Colour of Beamline Enclosures)


Permission must be granted to

access the facility beyond the foyer

and viewing gallery.

The Technical/Beamlines floor

area is a Controlled Area.

Only persons who have completed

safety induction training may work in

this area.

Visitors to a Controlled Area must be

escorted by a staff member at all

times.

Facility Access


How do I minimise my

radiation dose?

There are three basic principles to protection from radiation.

(3) TIME

Three Principles of Radiation Protection

(1) SHIELDING (2) DISTANCE

How do I minimise my radiation dose?

Placing adequate

shielding between

you and the

radiation source will

minimise the amount

of radiation you

receive.

Three Principles of

Radiation Protection - Shielding


Radiation Shielding

Photon radiation (gamma & X-ray radiation)

Normally requires significant thicknesses of dense

material, such as lead or tungsten.

Neutron radiation

Best shielded by materials with a lot of ‘light’

atoms, eg materials that contain hydrogen, such

as paraffin, water and concrete.


Maximising the

distance from a

radiation source will

minimise the amount

of radiation you

receive.

Three Principles of

Radiation Protection - Distance


Minimising the

time you spend

near a radiation

source will

minimise the

amount of radiation

you receive.

Three Principles of

Radiation Protection - Time


To how much radiation may I be exposed?

The radiation Regulations set the

Occupationally Exposed Persons limit at 20,000 µSv/year

and the Public Exposure limit at 1,000 µSv/year.

Regulatory Requirements – Exposure Limits

The facility has systems and controls in

place to help minimize exposure to

radiation. The dose constraint at the

facility is to keep all radiation doses to

less than 1,000 µSv/year.

Our goal, however, is to always keep all

radiation doses As Low As Reasonably

Achievable (ALARA principle).

To how much radiation may I be exposed?

• Radiation is a natural part of the environment.

• At the Australian Synchrotron you will not be exposed to

any significant levels of radiation (both ionising

and non-ionising).

• Signs and barriers are used to advise where radiation is

present and to control access to those areas.

• SHIELDING, DISTANCE & TIME will minimise the amount of

radiation you will receive.

• Our aim is to ensure that all radiation doses are as low as

reasonably achievable (ALARA principle).

• The risk from a low level of radiation exposure is no

different to other risks faced everyday.

Summary (the facts)

Date post:	02-Apr-2018
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