40 HOUR RADIATION SAFETY EXAM 2 2025/2026
QUESTIONS WITH ANSWERS GRADED A+
✔✔Shallow dose - ✔✔dose equivalent computed for a tissue depth of 0.007 cm (skin
dose)
✔✔Deep dose - ✔✔dose equivalent computed for a tissue depth of 1.0 cm
✔✔Lens dose - ✔✔dose equivalent computed for a tissue depth of .3 cm (thickness of
the lens of each eye)
✔✔Geiger-Muller instruments, Ionization Chamber survey instruments, Scintillation
survey instruments - ✔✔Three types of portable survey instruments
✔✔Geiger Muller Instruments - ✔✔utilize a gas detector that is capable of detecting
beta, gamma, and x-radiation. Uses mR/hr for gamma and x, but uses counts per
minute (cpm) for beta.
✔✔Ionization Chamber Survey Instruments - ✔✔Measure radiation exposure in
roentgens. CAn be used at higher exposure rate levels. Considerably more expensive
than Geiger
✔✔Scintillation Survey Instruments - ✔✔utilize a solid sodium iodide crystal coupled to
a sensitive photomultiplier tube as a detector. Excellent at locating multiple sources or
identifying areas of contamination
✔✔Recognizing sources of potential external exposure and controlling internal
contamination - ✔✔Good radiation hygiene
✔✔Time, Distance, and Shielding - ✔✔three cardinal principles for controlling external
radiation
✔✔square of the distance from the source - ✔✔exposure level varies inversely with
✔✔Exposure rate constant - ✔✔exposure rate in air due to a small unit source of
activity at a standard distance. Also called the gamma-factor
✔✔Distance from the source and the number of HVLs of shielding interposed between
the source and the location of interest - ✔✔radiation dose depends on
✔✔Annual Limits of Intake - ✔✔ALI. Represents the quantity of a given radionuclide
that, if ingested or inhaled by an individual will result in the same risk as that attributed
to a radiation worker incurring the maximum permitted annual dose
, ✔✔125-I and 131-I - ✔✔two radioiodines that are significant exceptions to internal
contamination danger. Highly specific for the thyroid gland.
✔✔Authorized User - ✔✔faculty member approved by the Radiation safety Committee
to use radioactive materials
✔✔Radioactivity - ✔✔spontaneous process characteristic of atoms with unstable nuclei
in which the nucleus releases energy either as a particle with kinetic energy or as
electromagnetic energy
✔✔Parent - ✔✔species prior to radioactive decay
✔✔daughter - ✔✔species after transformation
✔✔decay - ✔✔one parent/daughter transition, or disintegration
✔✔Curie - ✔✔traditional unit of radioactivity
✔✔becquerel - ✔✔unit of radioactivity in SI, =1dps
✔✔Alpha decay, Beta decay, electron capture, isomeric transition - ✔✔four most
common types of radioactive decay
✔✔Electron volt - ✔✔represents the energy change experienced by an electron while
undergoing a potential energy change of one volt
✔✔Alpha decay - ✔✔limited to isotopes of the heavy elements, a charged particle
consisting of two protons and two neutrons is ejected from the nucleus with high kinetic
energy. Can be accompanied by emission of a gamma-ray
✔✔Beta Decay - ✔✔emission of an electron from the nucleus. Electron maybe
negatively charged, ordinary (beta particle), or positively charged (positron).
✔✔Simple beta decay - ✔✔Daughter nucleus is at ground state subsequent to the
decay. H3, C14, P32, S35 are examples.
✔✔Excited isomeric state - ✔✔More common state of daughter nucleus after beta
decay, accompanied by gamma ray emission
✔✔Electron Capture - ✔✔converts a proton to a neutron by combining a proton with an
orbital electron capture in the nucleus as it passes through. Orbital electrons rearrange
to fill vacancy. Rearrangement accompanied by x0rays. Chromium-51 and iodine-125
are examples
QUESTIONS WITH ANSWERS GRADED A+
✔✔Shallow dose - ✔✔dose equivalent computed for a tissue depth of 0.007 cm (skin
dose)
✔✔Deep dose - ✔✔dose equivalent computed for a tissue depth of 1.0 cm
✔✔Lens dose - ✔✔dose equivalent computed for a tissue depth of .3 cm (thickness of
the lens of each eye)
✔✔Geiger-Muller instruments, Ionization Chamber survey instruments, Scintillation
survey instruments - ✔✔Three types of portable survey instruments
✔✔Geiger Muller Instruments - ✔✔utilize a gas detector that is capable of detecting
beta, gamma, and x-radiation. Uses mR/hr for gamma and x, but uses counts per
minute (cpm) for beta.
✔✔Ionization Chamber Survey Instruments - ✔✔Measure radiation exposure in
roentgens. CAn be used at higher exposure rate levels. Considerably more expensive
than Geiger
✔✔Scintillation Survey Instruments - ✔✔utilize a solid sodium iodide crystal coupled to
a sensitive photomultiplier tube as a detector. Excellent at locating multiple sources or
identifying areas of contamination
✔✔Recognizing sources of potential external exposure and controlling internal
contamination - ✔✔Good radiation hygiene
✔✔Time, Distance, and Shielding - ✔✔three cardinal principles for controlling external
radiation
✔✔square of the distance from the source - ✔✔exposure level varies inversely with
✔✔Exposure rate constant - ✔✔exposure rate in air due to a small unit source of
activity at a standard distance. Also called the gamma-factor
✔✔Distance from the source and the number of HVLs of shielding interposed between
the source and the location of interest - ✔✔radiation dose depends on
✔✔Annual Limits of Intake - ✔✔ALI. Represents the quantity of a given radionuclide
that, if ingested or inhaled by an individual will result in the same risk as that attributed
to a radiation worker incurring the maximum permitted annual dose
, ✔✔125-I and 131-I - ✔✔two radioiodines that are significant exceptions to internal
contamination danger. Highly specific for the thyroid gland.
✔✔Authorized User - ✔✔faculty member approved by the Radiation safety Committee
to use radioactive materials
✔✔Radioactivity - ✔✔spontaneous process characteristic of atoms with unstable nuclei
in which the nucleus releases energy either as a particle with kinetic energy or as
electromagnetic energy
✔✔Parent - ✔✔species prior to radioactive decay
✔✔daughter - ✔✔species after transformation
✔✔decay - ✔✔one parent/daughter transition, or disintegration
✔✔Curie - ✔✔traditional unit of radioactivity
✔✔becquerel - ✔✔unit of radioactivity in SI, =1dps
✔✔Alpha decay, Beta decay, electron capture, isomeric transition - ✔✔four most
common types of radioactive decay
✔✔Electron volt - ✔✔represents the energy change experienced by an electron while
undergoing a potential energy change of one volt
✔✔Alpha decay - ✔✔limited to isotopes of the heavy elements, a charged particle
consisting of two protons and two neutrons is ejected from the nucleus with high kinetic
energy. Can be accompanied by emission of a gamma-ray
✔✔Beta Decay - ✔✔emission of an electron from the nucleus. Electron maybe
negatively charged, ordinary (beta particle), or positively charged (positron).
✔✔Simple beta decay - ✔✔Daughter nucleus is at ground state subsequent to the
decay. H3, C14, P32, S35 are examples.
✔✔Excited isomeric state - ✔✔More common state of daughter nucleus after beta
decay, accompanied by gamma ray emission
✔✔Electron Capture - ✔✔converts a proton to a neutron by combining a proton with an
orbital electron capture in the nucleus as it passes through. Orbital electrons rearrange
to fill vacancy. Rearrangement accompanied by x0rays. Chromium-51 and iodine-125
are examples
