Radiation Protection for the Beam Line 4 Schools project Robert Froeschl (DGS/RP)
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Transcript of Radiation Protection for the Beam Line 4 Schools project Robert Froeschl (DGS/RP)
Radiation Protection for the Beam Line 4 Schools project
Robert Froeschl (DGS/RP)
Goals Radiation Risks Radiation Protection Rules East Area – T9 Experimental Area specific SIR course: Radiation Protection – Supervised Areas Answer your questions
2 11/09/2015BL4S – RP presentation
Radiation at CERN
Accelerator in operation:The interaction beam-matter generates stray radiaton
Accelerator stopped:The interaction beam-matter has made the matter radioactive (activation)
11/09/2015BL4S – RP presentation3
Stray radiation Residual radioactivity (resulting)
Beam Stray radiation
Radioactive matter
No Beam
Stable matter
Ionising Radiation in/around the Accelerators
4 11/09/2015BL4S – RP presentation
Primary beam
Experimental hall:
Secondary beam
Experimental area:Beam tunnel:
Accelerator in operation
Ionising Radiation in/around the Accelerators
5 11/09/2015BL4S – RP presentation
Radioactive accelerator
Accelerator in shut down
Experimental area:Beam tunnel:
Experimental hall
Radiation Areas at CERN
East Hall is a Supervised Radiation Area
6 11/09/2015BL4S – RP presentation
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 – T9 Experimental Area
7 11/09/2015BL4S – RP presentation
Globally in the building:New ControlRoom for T9
Experimentalarea T9
Dismantling activities in this area
Pedestrian Pathway
All material leaving the East Hall must be controlled by RP.
CERN’s Personal Dosimeter (RADOS DIS)
11/09/2015BL4S – RP presentation8
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 e.g. in Restaurant 1
Continuous measurement of the β/γ dose (DIS system)
Integration of the neutron dose (track dosimeter)
RFID Chip : access system
Dosimeter Reader
Dosimetry - Reference Levels
9 11/09/2015BL4S – RP presentation
99 % of the doses at CERNare inferior to 1000 μSv/year
Plane trip Paris-New York 50 μSv
Lung x-ray 100 μSv
Yearly effective dose due to natural radiation
2000 μSv
3000 μSvYearly effective dose due to
natural radiation in granite zones
10’000 μSvWhole body scan
Annual exposure in μSv
Radiation - How to protect yourself
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TIMEIf you reduce
the exposure time,you reduce the dose.
SHIELDINGAdequate shielding will reduce the dose received. Specific material is necessary against each type of radiation. Concrete is effective against all types.
DISTANCEThe further you move away from the source, the more
the dose decreases.
Radiation Protection - General Principles
11 11/09/2015BL4S – RP presentation
Do not start activities which are not directly relevant to the work
Respect markings and the information given on signs
Radiation Protection - General Rules
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In a Supervised Radiation Area it is forbidden to drink, eat or smoke.
Alarms In Supervised Radiation Areas - Two Types of Displays
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Continuous green light = NORMAL situation(low radiation levels, system OK)
Flashing ORANGE light + WARNING SOUND Limit your stay
Flashing RED light + ALARM Evacuate the area calmly
Flashing lightWARNING Limit your stay
Flashing light + ALARM Evacuate the area calmly
Summary Prompt and residual radiation Time, Distance, Shielding RP Rules for Supervised Radiation Area
Personal Dosimeter Forbidden to drink, eat or smoke Material leaving the zone has to be controlled
Questions?
14 11/09/2015BL4S – RP presentation