Radiation Protection for the
Beam Line 4 Schools project
Robert Froeschl (HSE/RP)
Goals
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Radiation Risks
Radiation Protection Rules
East Area – T9 Experimental Area specific
SIR course: Radiation Protection – Supervised Areas
Answer your questions
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BL4S – RP presentation
15/09/2016
Radiation at CERN
Accelerator in operation:
The interaction beam-matter
generates stray radiaton
Stray radiation
Accelerator stopped:
The interaction beam-matter
has made the matter
radioactive (activation)
Residual radioactivity (resulting)
Stable matter
Radioactive matter
Stray radiation
Beam
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No Beam
BL4S – RP presentation
15/09/2016
Ionising Radiation
in/around the Accelerators
Accelerator in operation
Beam tunnel:
Experimental hall:
Experimental area:
Primary beam
Secondary beam
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BL4S – RP presentation
15/09/2016
Ionising Radiation
in/around the Accelerators
Accelerator in shut down
Beam tunnel:
Experimental hall
Experimental area:
Radioactive accelerator
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BL4S – RP presentation
15/09/2016
Radiation Areas at CERN
Areas with risks due to ionizing radiation are classified as "Radiation Areas".
Radiation Areas at CERN are clearly marked with yellow panels.
Corresponding to the risk level, Radiation Areas are subdivided into:
"Supervised Radiation Areas“
(<15μSv/h - low risks)
"Controlled Radiation Areas“
(elevated risks)
East Hall is a Supervised Radiation Area
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BL4S – RP presentation
15/09/2016
East Hall – T9 Experimental Area
Pedestrian
Globally in the building:
Pathway
New Control
Room for T9
All material leaving
the East Hall must
be controlled by RP.
Experimental
area T9
Dismantling activities in this area
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BL4S – RP presentation
15/09/2016
CERN’s Personal Dosimeter (RADOS DIS)
The personal dosimeter at
CERN:
 Obligatory in Supervised
Radiation Area
 Registered to a person
 Non-transmittable
 Dosimeters will be
handed out after
successful SIR training
 Dosimeters can be read
out by yourself using
Dosimeter Readers
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RFID Chip : access system
Integration of the neutron dose
(track dosimeter)
Continuous measurement of the
β/γ dose (DIS system)
Dosimeter
Reader
e.g. in Restaurant 1
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BL4S – RP presentation
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Dosimetry - Reference Levels
Annual exposure in μSv
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99 % of the doses at CERN
are inferior to 1000 μSv/year
Whole body scan
10’000 μSv
Yearly effective dose due to
natural radiation in granite zones
3000 μSv
Yearly effective dose due to
natural radiation
2000 μSv
Lung x-ray
100 μSv
Plane trip Paris-New York
50 μSv
BL4S – RP presentation
15/09/2016
Radiation - How to protect yourself
DISTANCE
The further you move away
from the source, the more
the dose decreases.
TIME
If you reduce
the exposure time,
you reduce the dose.
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SHIELDING
Adequate shielding will reduce the
dose received. Specific material is
necessary against each type of
radiation. Concrete is effective against
all types.
BL4S – RP presentation
15/09/2016
Radiation Protection - General Principles
Do not start activities
which are not directly
relevant to the work
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BL4S – RP presentation
Respect markings and
the information given
on signs
15/09/2016
Radiation Protection - General Rules
In a Supervised Radiation Area it is forbidden to drink, eat or smoke.
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BL4S – RP presentation
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Alarms In Supervised Radiation Areas Two Types of Displays
Flashing light + ALARM
 Evacuate the area calmly
Flashing light
WARNING  Limit your stay
Flashing RED light + ALARM
 Evacuate the area calmly
Flashing ORANGE light + WARNING SOUND
 Limit your stay
Continuous green light = NORMAL situation
(low radiation levels, system OK)
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BL4S – RP presentation
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Summary
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Prompt and residual radiation
Time, Distance, Shielding
RP Rules for Supervised Radiation Area
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Personal Dosimeter
Forbidden to drink, eat or smoke
Material leaving the zone has to be controlled
Questions?
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BL4S – RP presentation
15/09/2016