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

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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)

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Stray radiation Residual radioactivity (resulting)

Beam Stray radiation

Radioactive matter

No Beam

Stable matter

Ionising Radiation in/around the Accelerators

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Primary beam

Experimental hall:

Secondary beam

Experimental area:Beam tunnel:

Accelerator in operation

Ionising Radiation in/around the Accelerators

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Radioactive accelerator

Accelerator in shut down

Experimental area:Beam tunnel:

Experimental hall

Radiation Areas at CERN

East Hall is a Supervised Radiation Area

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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

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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)

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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

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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

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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?

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