1.
Gas-filled detectors are highly efficient for detection of high-energy gamma photons and x-rays as well as low-energy beta particles.
Correct Answer
B. False
Explanation
Gas-filled detectors have very low efficiency for the detection of high-energy gamma photons and x-rays due to the low density of the gas. Detection of gamma/x-ray photons is much higher using high-density materials such as sodium iodide (NaI).
2.
Which of the following radiation detectors are classified as ionization chambers?
Correct Answer
C. Dose calibrator
Explanation
A dose calibrator is an example of an ionization chamber, a gas-filled detector that operates within the ionization region. A Geiger counter, which is also a gas-filled detector, operates within the Geiger Mueller region. NaI is a solid-state scintillation detector.
3.
Because of the near-maximal ionization of the gas molecules in a Geiger counter in response to each radiation event interacting with a gas molecule in the detector, Geiger counters cannot be used to distinguish between types of radiation.
Correct Answer
A. True
Explanation
Geiger counters cannot be used to distinguish between types of radiation due to the near-maximal ionization of gas molecules in response to each radiation event. This means that regardless of the type of radiation (alpha, beta, gamma, etc.), the gas molecules in the detector will be ionized in a similar manner. Therefore, Geiger counters can only detect the presence of radiation, but not provide information about the specific type of radiation.
4.
Select the three most effective ways to reduce exposure when working with radioactivity.
Correct Answer(s)
A. Reduce the time spent in the vicinity of a radioactive source.
C. Maintain the maximum possible distance from the source.
D. Shield the radioactive source.
Explanation
The most effective way of reducing exposure to radiation is through the radiation protection principles of time, distance and shielding
5.
The maximum allowable exposure to the household contacts of a patient receiving radioactivity is 5 mSv (500 mrem).
Correct Answer
A. True
Explanation
The statement is true because the maximum allowable exposure to the household contacts of a patient receiving radioactivity is indeed 5 mSv (500 mrem). This limit is set to ensure the safety of individuals who may come into contact with a patient who is undergoing radioactivity treatment. It is important to limit exposure to radiation to prevent any potential health risks.
6.
After the discovery of a medical event, the licensee is required to contact the NRC/Agreement State no later than 5 calendar days.
Correct Answer
B. False
Explanation
A medical event must be reported within 1 calendar day following discovery.
7.
Which section of 10 CFR 35 is applicable to I-131 thyroid ablation treatments for which a written directive is required?
Correct Answer
C. 10 CFR 35.300
Explanation
The correct answer is 10 CFR 35.300. This section of 10 CFR 35 specifically pertains to I-131 thyroid ablation treatments that require a written directive. It likely outlines the regulations and requirements for such treatments, including the necessary documentation and procedures that must be followed.
8.
DOT hazardous materials training is required within 90 days of employment and retraining must be received at least once every 3 years.
Correct Answer
A. True
Explanation
DOT hazardous materials training is required within 90 days of employment and retraining must be received at least once every 3 years. This means that employees who handle hazardous materials must undergo training within the first 90 days of their employment. Additionally, they must receive retraining every 3 years to ensure they are up to date with the latest regulations and safety procedures. This helps to ensure the safe handling and transportation of hazardous materials, reducing the risk of accidents and potential harm to individuals and the environment. Therefore, the statement is true.
9.
Which of the following statements are true about radionuclide generators?
Correct Answer
D. None of the above
Explanation
A generator must always have a parent nuclide with a longer half-life than the daughter nuclide. Transient equilibrium occurs when the parent half-life is 10-100 times greater than the daughter half-life, while secular equilibrium occurs when the parent half life is at least 100 times over that of the daughter. Finally, the parent nuclide must remain tightly bound to the column over the generator so that the daughter nuclide may be eluted for use.
10.
Technetium-99m and molybdenum-99 are good examples of which type of equilibrium?
Correct Answer
A. Transient equilibrium in which the parent half-life is 10 to 100 times that of the daughter.
Explanation
Technetium-99m and molybdenum-99 are good examples of transient equilibrium because the parent half-life (molybdenum-99) is 10 to 100 times longer than the daughter half-life (technetium-99m). In transient equilibrium, the parent isotope decays into the daughter isotope, but the parent isotope decays at a slower rate compared to the daughter isotope. This results in a temporary balance between the production and decay of the parent and daughter isotopes.
11.
During an equilibrium state within a 99Mo–99mTc generator, the total activity of 99mTc is always less than the total activity of 99Mo because 14% of 99Mo decays directly to 99Tc, bypassing the metastable state.
Correct Answer
A. True
Explanation
During the equilibrium state of a 99Mo-99mTc generator, the total activity of 99mTc is always less than the total activity of 99Mo because 14% of 99Mo decays directly to 99Tc, bypassing the metastable state. This means that some of the 99Mo does not undergo the decay process that leads to the formation of 99mTc. As a result, the total activity of 99mTc will be less than the total activity of 99Mo.
12.
Of the three types of impurities present in a Tc-99m elution, which QC test for these impurities is optional?
Correct Answer
B. Hydrolyzed Reduced Tc to test for radiochemical impurity.
13.
The radiation dose rate at any point on the surface of an excepted (limited quantity) package of class 7 radioactive material cannot exceed what value?
Correct Answer
A. 0.5 mrem/hr
Explanation
According to 49 CFR 173.421, the radiation level at any point on the external surface of the package does not exceed 0.005 mSv/hour (0.5 mrem/ hour).
14.
Which option is NOT a Type A package labeling requirement?
Correct Answer
D. All Type A packages (White I, Yellow II, Yellow III) require a Transport Index
Explanation
Radioactive White I packages do not require a Transport Index.
15.
Shipper must provide a telephone number that can be contacted in case of emergency during normal business hours only.
Correct Answer
B. False
Explanation
A 24-hour emergency contact number must be provided and monitored at all times while the hazardous material is in transit. The number must be for a individual who is either knowledgeable of the hazardous material being shipped and has comprehensive emergency response information, or has immediate access to such a person
16.
Radiation surveys must be performed within how many hours of receipt during normal working hours?
Correct Answer
B. 3 hours
Explanation
Radiation surveys should be performed as soon as practical after receipt of the package, but not later than 3 hours after the package is received at the licensee's facility if it is received during the licensee's normal working hours, or not later than 3 hours from the beginning of the next working day if it is received after working hours.
17.
In the event of handling a radioactive spill, what equipment will you not need?
Correct Answer
D. Dose calibrator
Explanation
A dose calibrator is not needed in the event of handling a radioactive spill. A dose calibrator is a device used to measure the activity of a radioactive substance, typically used in medical settings to measure doses of radiopharmaceuticals. However, in the case of a spill, the focus is on containment and cleanup, rather than measuring doses. Therefore, a dose calibrator is not necessary in this situation.
18.
When taking into account quality factors values for equivalent dose, gammas, x-rays and betas have a value of 1.
Correct Answer
A. True
Explanation
The statement is true because when considering quality factors for equivalent dose, gammas, x-rays, and betas all have a value of 1. This means that these types of radiation have the same biological effect on human tissue. Therefore, when calculating equivalent dose, these types of radiation are considered to have equal importance and are given a value of 1.