IRRSP STUDY GUIDE 2026 COMPREHENSIVE
RADIATION SAFETY QUESTIONS AND
SOLUTIONS
◉ Reddening of the skin, loss of hair, blistering.
Answer: Which of the following are symptoms of an acute extremity
overexposure?
a. Nausea, vomiting, diarrhea
b. Fatigue, nausea, reddening of the skin
c. Diarrhea, blistering, loss of hair
d. Reddening of the skin, loss of hair, blistering
◉ Higher gamma ray energy from the Co-60.
Answer: The reason the gamma radiation emitted from a Cobalt-60
source is more penetrating than the gamma radiation emitted from
Iridium-192 is due to the:
a. Higher output per Curie from the Co-60
b. Longer half life of the Co-60
c. Greater intensity from the Co-60
d. Higher gamma ray energy from the Co-60
,◉ 3/4.
Answer: A 0.400 inch piece of lead shielding will reduce the
radiation intensity from an Iridium-192 source by:
a. 3/4
b. 1/2
c. 1/4
d. 1/8
◉ Thick section of high atomic number material.
Answer: When shielding against high-energy gamma rays, which of
the following characteristics provide the most effective shield?
a. Thick section of material
b. Thick section of high atomic number material
c. Thick section of low atomic number material
d. Thick section of low density material
◉ 2.31 R/hr.
Answer: The radiation intensity at 1 foot from an Iridium-192
source is 452.4 R/hr. What is the radiation intensity at 14 feet?
a. 2.31 R/hr
b. 226.2 R/hr
c. 113.1 R/hr
, d. 32.3 R/hr
◉ C.
Answer: Gamma radiation can be defined as:
(Answer with A, B, C, or D)
a. Particles having the mass and charge of two protons and two
neutrons emitted from the nucleus of an unstable atom
b. Very light negatively charged particles emitted from the nucleus of
an unstable atom
c. Very short wavelength electromagnetic radiation emitted from the
nucleus of an unstable atom
d. Particles emitted from an unstable atom with an energy in the
range of 1 to 10 M.E.V.
◉ Attenuation.
Answer: The term that describes how gamma or x-rays are reduced
in intensity when passing through shielding material is:
a. Penetration
b. Scatter
c. Reflection
d. Attenuation
◉ 5 Rem to the whole body, 50 Rem to the extremities.
RADIATION SAFETY QUESTIONS AND
SOLUTIONS
◉ Reddening of the skin, loss of hair, blistering.
Answer: Which of the following are symptoms of an acute extremity
overexposure?
a. Nausea, vomiting, diarrhea
b. Fatigue, nausea, reddening of the skin
c. Diarrhea, blistering, loss of hair
d. Reddening of the skin, loss of hair, blistering
◉ Higher gamma ray energy from the Co-60.
Answer: The reason the gamma radiation emitted from a Cobalt-60
source is more penetrating than the gamma radiation emitted from
Iridium-192 is due to the:
a. Higher output per Curie from the Co-60
b. Longer half life of the Co-60
c. Greater intensity from the Co-60
d. Higher gamma ray energy from the Co-60
,◉ 3/4.
Answer: A 0.400 inch piece of lead shielding will reduce the
radiation intensity from an Iridium-192 source by:
a. 3/4
b. 1/2
c. 1/4
d. 1/8
◉ Thick section of high atomic number material.
Answer: When shielding against high-energy gamma rays, which of
the following characteristics provide the most effective shield?
a. Thick section of material
b. Thick section of high atomic number material
c. Thick section of low atomic number material
d. Thick section of low density material
◉ 2.31 R/hr.
Answer: The radiation intensity at 1 foot from an Iridium-192
source is 452.4 R/hr. What is the radiation intensity at 14 feet?
a. 2.31 R/hr
b. 226.2 R/hr
c. 113.1 R/hr
, d. 32.3 R/hr
◉ C.
Answer: Gamma radiation can be defined as:
(Answer with A, B, C, or D)
a. Particles having the mass and charge of two protons and two
neutrons emitted from the nucleus of an unstable atom
b. Very light negatively charged particles emitted from the nucleus of
an unstable atom
c. Very short wavelength electromagnetic radiation emitted from the
nucleus of an unstable atom
d. Particles emitted from an unstable atom with an energy in the
range of 1 to 10 M.E.V.
◉ Attenuation.
Answer: The term that describes how gamma or x-rays are reduced
in intensity when passing through shielding material is:
a. Penetration
b. Scatter
c. Reflection
d. Attenuation
◉ 5 Rem to the whole body, 50 Rem to the extremities.
