Transcript Module 1. Radiation Safety at LSU

Louisiana State University
Radiation Safety Office
Module 1
Radiation Safety At LSU
1
David Banner
Incredible Hulk
Became the incredible hulk after being
exposed to gamma radiation
2
Peter Parker
Spider Man
He became the Spider Man after being
bitten by a radioactive spider.
3
The Reality of Radioactivity
Chernobyl
(for more information click here)
Mushroom Cloud
4
Our Radioactive Environment
5
Natural Sources
• Cosmic
• Terrestrial
• Internal
• Inhaled
6
Cosmic Radiation
• High energy particles and photons from the sun and other
sources outside the earth's atmosphere
– Our atmosphere provides
shielding from cosmic radiation
– An increase in altitude results
in an increase in exposure
Sea Level:
Denver, CO:
26 mrem/yr
50 mrem/yr
This picture of the Sun was taken on January 24, 1992. The image
shows the Sun at x-ray wavelengths. It was recorded by the Soft X-ray
Telescope on board the Yohkoh satellite.
7
Terrestrial Radiation
Radiation from radioactive materials occurring naturally in the earth’s crust
Highest on eastern slopes of the Rockies
Lowest on the Atlantic coast
8
Inhaled Radiation
• Primarily from Radon (222Rn) and its
daughters
–
222Rn
is released from the soil as Radium-226
(226Ra) and then it decays to Radon
• Radium is part of the Uranium-238 (238U) decay chain
– Levels vary widely from area to area
• Average dose is 200 mrem/yr
– Dose may be enhanced by poor ventilation or the
use of Uranium-containing building materials
9
Internal Radiation
Radiation from radioactive materials incorporated in the human body
Carbon-14 (14C)
Potassium-40 (40K)
Total dose of 39 mrem/yr
(due mostly to 40K)
10
Man-Made Sources
• Medical Uses
• Consumers Products
• Industrial Uses
• Nuclear Power
Cerenkov Glow : gamma rays through water
11
Medical Sources
Diagnostic X-ray
Nuclear Medicine
39 mrem/yr – U.S. average
–
–
–
–
General Radiography
Dental Radiography
Fluoroscopy
CT
14 mrem/yr – U.S. average
–
–
Imaging using 131I, 99mTc, 201Tl
Therapy using 131I
Radiation Therapy
2.3 mrem/yr – U.S. average
– External beams
– Sealed Sources implanted
into body
12
Industrial Sources
Industrial Radiography
•
Use of X-rays or sealed gamma-ray
sources for imaging of structures
and components
Level Gauges
•
Use sealed sources to
check the level of materials in a
tank or vat.
Well Logging
•
Use of sealed sources to
measure soil porosity, soil
density, or underground
structure and composition
Static Elimination
•
Use of radiation to remove
static electricity
13
Nuclear Power
Components of the Nuclear Power Industry
•
•
•
•
•
Uranium Mines - source of natural uranium (26-61 mrem/yr)
Processing - ”purifying” natural uranium into efficient nuclear fuel (1-8 mrem/yr)
Nuclear Power Plants - power production (< 1 mrem/yr)
Waste Storage - spent nuclear fuel storage (< 1 mrem/yr)
Transportation - to and from power plants (20 mrem/yr)
(Doses are calculated for maximally exposed member of the general public)
14
Consumer Products
•
•
•
•
•
•
•
•
Smoke Detectors (241Am)
Tobacco Products (210Pb & 210Po)
Building Materials (Sheetrock; gypsum board)
Airport Baggage Inspection (x-rays)
Welding Rods (Thorium)
Luminous Paints (3H, 226Ra, 147Pm)
Television (Low energy x-rays)
Radium Hot Springs (226Ra, 222Rn)
15
Contributions to the Public Dose*
Terrestrial
5%
CT
23%
Nuclear
Medicine
12%
Internal
5%
Cosmic
5%
Radon/Thoron
36%
Interventional
7%
Diagnostic
5%
Consumer
2%
from NCRP 160, 2006
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