DBR40022
RADIATION SAFETY AND AWARENESS
JULY - DECEMBER 2022
KOLEJ KEMAHIRAN TINGGI MARA
LEDANG, JOHOR
JOB SHEET
COURSE/CLASS :
DIPLOMA IN BIOMEDICAL ELECTRONICS ENGINEERING
(RADIOLOGY AND IMAGING) / R4A & R4B
SESSION :
JULY – DECEMBER 2022
SEMESTER : 4
CODE/COURSE :
DBR40022 / RADIATION SAFETY
AND AWARENESS
SHEET NO : J.S 1.0
NO OF STUDENTS :
19
WEEK :
DURATION :
LECTURER :
MEDICAL
PHYSICS
LAB
AHMAD AZMEER BIN AZMAN (AAA), MUHAMAD NURHADI BIN
SALLEH (MNS)
2 HOURS
TOPIC :
Radiation Protection Principle
SUB-TOPIC :
Distance Concept
LEARNING
OUTCOME :
OBJECTIVES:
VENUE :
Perform dose measurement using survey meter
Verify inverse square law between distance and dose
rate
1. Understand relationship of distance and doserate
radiation protection principal.
2. Follow safe working procedures during radiology lab
practical.
Survey meter
1.
2.
Bleeper
TOOLS:
3
X-ray source
Ruler
Stand
Stopwatch
DBR40022
RADIATION SAFETY AND AWARENESS
JULY - DECEMBER 2022
1. SAFETY PRECAUTIONS:
Permissions
Before performing any of the tests in this workbook, ensure that all necessary
approvals to operate the x-ray source have been obtained from:

The regulatory authority

The equipment owner.
Radiation Protection
Persons carrying out testing must protect themselves from the radiation hazard
during all exposures. Where a protective screen is not available other protection such
as structural (a brick wall), lead gown, gloves and covered shoes must be used.
Persons carrying out testing may be required to wear an approved personal monitoring
device (film badge or TLD) to record their occupational radiation exposure.
Storage
The penetrating powers of the different types of radiation gives a clue to safe practice.
Pure alpha particles present little hazard when enclosed in a container; however,
since most alpha sources also emit gamma radiation, lead-lined containers are
needed. In general, keep all radioactive materials in lead containers when not
in use.
Food and Beverages
Do not eat or drink in any room labelled with “Caution : Radioactive Materials” sign
on the door. You may store your food, water bottles, beverages, medicines, coffee
mugs, eating utensils, etc. in your closed desk / designated locker in a radioisotope
use lab, but you are not permitted to have these items out on top of your desk or any
other surfaces.
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DBR40022
RADIATION SAFETY AND AWARENESS
JULY - DECEMBER 2022
2. JOB SHEET PROCEDURE:
a.
In group of maximum 4 students, perform area monitoring to get a
background reading.
b.
Each group is equipped with ruler, retort stand, stopwatch survey
meter and gloves.
c.
Capture the radiation dose at 10 seconds after the radiation source being
aligned with the detector.
d.
Perform measurement dose at 6 points with same intervals.
(𝑋2 , 𝑋3 , 𝑋4 , 𝑋5 𝑎𝑛𝑑 𝑋6 )
e.
Compare your measurement and calculations (based on the Inverse
Square Law). Use X1(5cm from x-ray source) as your reference point
for calculation.
b. EXPERIMENT SETUP:
X-ray source
X6
X5
X4
X3
Inverse Square Law:
𝑰𝟏 𝑫𝟐𝟏 = 𝑰𝟐 𝑫𝟐𝟐
where
I1 = dose/intensity at distance X1
D1=distance of X1
I2 = dose/intensity at distance X2
D2=distance of X2
3
X2
X1
DBR40022
RADIATION SAFETY AND AWARENESS
JULY - DECEMBER 2022
4. RESULT:
a. Attach pictures experiment setup and each radiation measurement taken
during laboratory session.
(5 marks)
b. Dose measurement
Distance
Dose measurement (µSv/hr)
Average
(cm)
Reading 1 Reading 2 Reading 3
Measurement
(µSv/hr)
X1
5
X2
X3
X4
X5
X6
(10 marks)
c. Dose calculation
(Attach working calculation with report.)
Distance
(cm)
X1
Calculation (µSv/hr)
5
Percentage
Difference (%)
Reference point
X2
X3
X4
X5
X6
(10 marks)
d. Plot Measured Dose Vs Distance graph
(Use graph paper and attach with report.)
(10 marks)
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DBR40022
RADIATION SAFETY AND AWARENESS
JULY - DECEMBER 2022
5. Discussion
a. Brief about radioactive material used in the experiment.
Ra-226 is produced by the radioactive decay of uranium-238. Radioactive decay
occurs because certain atoms are unstable and need to release energy in an attempt
to become stable. When Ra-226 decays, it releases energy in the form of particles
and rays. This energy, called “radiation,” cannot be detected by our senses. Radium226 decays by alpha particle radiation to an inert gas, radon-222, which also decays
by alpha particle radiation. Due to the short half-life of radon -222, 3.8 days, there is a
high probability it will decay in the body when breathed in, emitting alpha particle
radiation in the body and aktivitat for radium 226 is 5kBq.Radium 226 in nature is found
in varying concentrations in virtually all kinds of rocks and soils that contain natural
uranium, occurring in the greatest amounts in the mineral uraninite.Radium-226 was
also mixed with fluorescent zinc sulfide to make a luminous paint. This luminous
material was used to paint timepieces, compasses and other devices. However,
exposure to higher levels of radium over a long period of time may result in harmful
effects including anemia, cataracts, fractured teeth, cancer (especially bone cancer),
and death. Some of these effects may take years to develop and are mostly due to
gamma radiation.
b. Explain about Inverse Square Law.
The intensity of the light to an observer from a source is inversely proportional to
the square of the distance from the observer to the source. Hence, from the law,
light losses its brightness or luminosity as it moves away from the source.
c. Discuss about the possible factors causing the difference of measured and
calculated dose.
The possible factors causing the difference of measured and calculated dose are the
error in test lab is caused primarily by laboratory instrument inaccuracy. If the meter
dial or the zero point is inaccurate, for instance ,the measurement result would be too
small or too big. Unless the adjustment is not done for too long, the weighing error will
eventually occur. The glass gauge has not undergone standard and scale testing; so
it is used after purchasing from the manufacturer, which will allow the instrument error
to occur.Sometimes, human error will cause differences in measured and calculated
dose. For example, the time taken is not accurate, there is a tremor occur when
holding instrument. Beside that, placing the instrument is not at the correct
measurement. Therefore, the accuracy of the measurement, the time taken and selfstability in making a lab test are very important to there is no difference of measures
and calculate dose.
d. Discuss about other 2 principles to protect against external exposure.
Excessive exposure to radiation which is high doses of radiation can cause Acute
Radiation Syndrome (ARS) or Cutaneous Radiation Injuries (CRI).
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DBR40022
RADIATION SAFETY AND AWARENESS
JULY - DECEMBER 2022
e. Explain about possible hazards when being exposed to excessive external
radiation.
The possible hazards when being exposed to excessive external radiation is exposure
to very high levels of radiation, such as being close to an atomic blast, can cause acute
health effects such as skin burns and acute radiation syndrome (“radiation sickness").
It can also result in long-term health effects such as cancer and cardiovascular disease.
(10 marks)
6. Conclusion
In conclusion , the goal of radiation protection is to limit human exposure to ionizing
radiation to a degree that is reasonable and acceptable in relation to the benefit gained
from the activities that involved the exposure, thereby reducing the likelihood of
occurrence of somatic and genetic effects. After that , we know to perform dose
measurement using survey meter and then we learn verify inverse square law between
distance and dose rate .Lastly , we understand relationship of distance and doserate
radiation protectiom principal and we follow safe working procedures during radiologi
lab practical sucessfully.
(3 marks)
7. References with correct format.
(2 marks)
Prepared by:
Approved by:
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