sources of radiation

SOURCES OF RADIATION

TO THE GENERAL PUBLIC

Upon completion of this course, the participants will demonstrate their knowledge and understanding of the information presented during RADCON Technician training by obtaining a score of greater than or equal to 80% on a written examination. The information presented in this lesson plan may be part of an overall exam or be the only information for which the student is examined.

Terminal Objective

☼ Identify the types of ionizing radiation providing exposure to the general public – natural background sources and man-made radiation sources.

☼ Define natural background sources and each of its types.

☼ Provide an explanation of cosmic radiation sources.

Enabling ObjectivesStandards and conditions apply to all enabling objectives. They include: under the examination ground rules, without the use of training materials or outside assistance, and utilizing information presented in this lesson plan. Upon completion of this each participant will be able to:

☼ Provide an explanation of terrestrial radiation sources.

☼ Identify the source of radon and its daughter products.

☼ Provide an explanation of internal radiation sources.

☼ Define the types of man-made radiation sources and provide examples of each.

Enabling Objective cont.

Categories of types of Sources of Ionizing Radiation to the General

Public

Natural Background Radiation Sources

Man-made Radiation Sources

Types of Natural Background Radiation Sources

Cosmic Radiation

Terrestrial RadiationInternal Radiation

Origin of Cosmic Radiation

Cosmic RaysCosmic Rays

Protons - p

Alpha particles - a


COSMIC RAY SHOWERInteraction of “Primary” cosmic ray with atmospheric nuclei.

Results in dissipation of “Primary” cosmic ray and nuclei.

Creates “Secondary” cosmic rays.

Interactions of “Secondary” cosmic rays creates…

COSMIC RAY SHOWER.

“Secondary” cosmic rays are the source of Cosmic Radiation exposure to the general public.

Altitude

The greater your altitude, the higher

your exposure


Exposure Variance with Altitude

Cosmic Radiation ExposureCalculated average radiation dose

equivalent at ground level from Cosmic Rays

26 mrem/yr or 0.26 mSv/yr

Calculated average radiation dose equivalent for Air Travel


Other sources add an additional


Terrestrial Radiation Sources

Primordial Radionuclides

Naturally occurring radionuclides

Created when Earth was formed

Long-lived half-lives

Terrestrial Radiation Sources– external

Inhaled Radiation Sources– internal (radon)


Primordial Radionuclides

Non Series

and

Series


Non-Series Primordial Radionuclides

These decay directly to a stable nuclide

*K-40*V-50, Rb-87, Cd-113, In-115, Te-123, La-138, Ce-142, Nd-144, Sm-

147, Gd-152, Hf-174, Lu-176, Re-187, Pt-190, Pt-192, Bi-209


Uranium Series U-238

Terrestrial Radiation SourcesPrimordial Radionuclide Concentration

Dose Dependency


Primordial Radionuclide Concentration

High Background Areas

Nile Delta Egypt – 350 mrem/year

Paris, France – 350 mrem/year

Kerala, India – 400 mrem/year

McAlpe, Brazil – 2448 mrem/year

*Pocos de Caldas, Brazil*

*7000 mrem/year*


Total Radiation Dose Equivalent

28 mrem/year or

0.28 mSv/year

Inhaled Radiation Sources - Radon


Gas with progeny of particulates

From ground to air

Poor ventilation greater hazard

Highest exposure to general public


Dose depend on

Geographical area

Type structure

Type ventilation

Ramas, Iran

Individual exposure

to 26000 mrem/year

Radiation Dose Equivalent

Inhaled Radon Radiation Sources

200 mrem/year

Internal Radiation Sources

Radionuclides in Body

Inhalation

Ingestion

Absorption

Present at birth

14C3H

22Na

40K

87Rb

230Th232Th

232Th226Ra

228Ra

238U 210Pb

Internal Radiation Sources

Food

Possible pathway for all

K40 primary with food

Ra226 – brazil nuts and salmon

Pb210 - muscle meats and seafood

Ra228 through food

Drinking water

Ra226 & U238 ingested from drink

Ra226 level : water intake & water levels

Pb210 atmospheric aerosols & cigarette smoke

Air

Internal Radiation SourcesDose

agesex

body mass

dietary habits

smoking

Radiation Dose Equivalent Internal Radiation Sources

40 mrem/year or 0.4 mSv/year

Radiation Dose Equivalent Total

Natural Background Radiation Sources

296 mrem/year or2.96mSv/year


Medical Procedures

x-rays

nuclear medicine

Nuclear Power Production

Consumer Products

Radioactive Materialfrom

Fallout

Man-made Radiation SourcesX-ray

♥Provides most exposure

♥Minimum 6 mrem/x-ray

♥Average 200 mrem

Radiography x-rays

CT

Mammography

Average Radiation Dose Equivalent – X-rays

39 mrem/hr or 0.39 mSv

Man-made Radiation SourcesNuclear medicine

Radiopharmaceuticals used

Diagnostic and therapeutic

Thallium heart stress tests

Tumor irradiation therapies

I131, Tc99m, Co60, Ir192, Cs137

Average Radiation Dose Equivalent

Nuclear medicine


Man-made Radiation SourcesMedical Radiation Sources

Total


Medical Radiation SourcesX-ray & Nuclear Medicine


Man-made Radiation SourcesConsumer Product Radiation Sources

Electronic Products

Products of Radioactive Material


Electronic Products

Examples TelevisionsVideo display terminalsAirport luggage inspection systemsPersonnel scanning systems

Produce x-rays

Designed to eliminate general public exposure

Radiation Dose Equivalent Electronic Products

<1 mrem/yr

Man-made Radiation SourcesConsumer Products with Radioactive Material

Radioluminous products – Ra-226, H-3, Pm-147

Spark gap indicators & electron tubes-Co-60, H-3, Kr-85, Cs-137, Ni-63, Pb-210

Smoke detectors – Ra-226 Cardiac pacemakers – Pu-238

Check sources-Co-60Ra-226Sr-90Kr-85

Lighting rods – Ra-226, Am-241

Ra226 watches – 3 mrem/yr Tritium watches – 0.6 mrem/yr

Pacemaker – 100 mrem/yr Smoke detectors – 1 mrem/yr


Products of Radioactive MaterialNatural Radioactive Material Products

♣ Highway and road construction material

♣ Fertilizer Products

♣ Opthalmic glass – 400 mrem♣ Combustible coal – 4 mrem♣ Combustible oil♣ Combustible natural gas – 6-9 mrem

♣ Glass & ceramics – 2400 mrem

♣ Dental Products – 60000 mrem ♣Gas mantles – 0.1-0.4 mrem

♣ Camera lenses♣ Thoriated tungsten welding rods



Consumer Product Radiation Sources


Man-made Radiation SourcesRadioactive Material from Fallout

Atmospheric testing to 1960’sUnderground testing after 1960’s

Example Isotopes releasedC-14, Na-22, Sr-89, Pl-239, Ar-39, Cs-137, Sr-90, I-131

Isotopes decayed or bottom of oceanExposure depleted over time


<1 mrem/year or <0.01 mSv/year

Man-made Radiation Sources Nuclear Power Production

►Mining

►Milling and Refinement

►Enrichment

►Fabrication of pellets, fuel rods and bundles for use in the reactor

►Power generation

►Storage

►Transportation

►Burial

Man-made Radiation Sources Nuclear Power Production

Power Plant Operation

Exposure Direct – radiation produced in processEffluents – gas & liquid released

Regulations for exposure and effluent release control

Maximum Exposure - <1 mrem/year

Radiation Dose Equivalent Total


64 mrem/year0.64 mSv/year

Exposure from Sources of Radiation General Public

Natural Background Radiation296 mrem/yr 2.96 mSv/yr

Man-Made Radiation –64 mrem/yr 0.64 mSv/yr

Cosmic Radiation – 28 mrem/yr 0.28 mSv/yr

Terrestrial Radiation28 mrem or 0.28 mSv/yr

Inhaled (radon)200 mrem/yr or 2.0 mSv/yr

Internal Radiation40 mrem/yr or 0.4 mSv/yr

Medical processes –53 mrem/yr 0.53 mSv/yr

X-ray- 39 mrem/yrNuclear medicine – 14 mrem/yr

Consumer products11 mrem/yr or 0.11 mSv/yr

Fallout<1 mrem/yr or <0.01 mSv/yr

Nuclear power production<1 mrem/yr or <0.01 mSv/yr

Average Total 360 mrem/yr 3.6 mSv/yr

Controlling General Public Dose

Controllable

Man-made exposure in workplaceOperations releasing man-made/naturally

occurringRadiation producing machinesLocalized area of environmental releasesTechnologically enhancedMedical exposures to non-patientsIndoor Radon

Non-controllable

Natural terrestrial Cosmic radiation Natural inside body Medical to patient Fallout Regional from accidents

Ways to limit exposure

Test the home for Radon and reduce levels if necessary Evaluate medical uses and weigh the benefits versus the risk Participate in public decisions-making

sources of radiation

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