NDT - Non-Destructive Testing Radiographic Testing Safety Questions and Answers — Questions and Answers
Question 1: The fundamental principle of radiation protection, which states that all radiation exposure should be kept as low as reasonably achievable, is known by what acronym?
- ALARP
- ALARA (Correct answer)
- OSHA
- SCUBA
Correct answer: ALARA
ALARA stands for "As Low As Reasonably Achievable." It is the cornerstone principle in radiation safety, guiding all practices to minimize radiation doses to workers and the public without compromising the benefits of the activity.
Question 2: A radiographer is setting up for a field radiographic exposure. Which of the following is the immediate priority upon discovering that their radiation survey meter is not functioning correctly?
- Proceed with the exposure but use a teammate's survey meter for the post-shot survey.
- Complete the setup but do not expose until a new battery is installed.
- Stop all radiographic operations until a calibrated, functioning survey meter is available. (Correct answer)
- Estimate the boundary based on previous similar setups and proceed with caution.
Correct answer: Stop all radiographic operations until a calibrated, functioning survey meter is available.
Regulatory requirements mandate that a calibrated, operable survey instrument be available and used for all radiographic operations. Proceeding without a functioning meter is a serious safety violation, as it's impossible to verify the source is shielded, determine boundary locations, or ensure public and worker safety.
Question 3: During a gamma radiography operation, the source fails to retract into the shielded position. What is the radiographer's MOST critical first action?
- Immediately attempt to manually retract the source using emergency tools.
- Secure the controlled area to prevent unauthorized entry and then notify the Radiation Safety Officer (RSO). (Correct answer)
- Quickly dismantle the guide tube to identify the location of the stuck source.
- Leave the site immediately to find the RSO and report the incident in person.
Correct answer: Secure the controlled area to prevent unauthorized entry and then notify the Radiation Safety Officer (RSO).
In an emergency where a source fails to retract, the first priority is to protect people from exposure. This is achieved by securing the controlled area to prevent anyone from entering the high radiation field. Once the area is secure, the radiographer must notify the RSO for further instructions. Attempting a retrieval without proper assessment and authorization is extremely dangerous and against procedure.
Question 4: Which of the following is a key safety advantage of using an X-ray generator compared to a gamma-ray source for industrial radiography?
- X-ray equipment is always more portable and requires no power source.
- The radiation from an X-ray tube can be turned off completely. (Correct answer)
- X-ray sources provide better penetration for very thick steel sections.
- Gamma-ray sources decay over time, making them less predictable.
Correct answer: The radiation from an X-ray tube can be turned off completely.
A primary safety advantage of X-ray systems is that they only produce radiation when electrically powered on. In contrast, a gamma-ray source, like Iridium-192 or Cobalt-60, emits radiation continuously and cannot be turned off, posing a constant potential hazard that requires secure shielding at all times.
Question 5: A "High Radiation Area" must be posted where an individual could receive a dose equivalent in excess of:
- 2 mrem in 1 hour at 30 cm from the source.
- 5 mrem in 1 hour at 30 cm from the source.
- 100 mrem in 1 hour at 30 cm from the source. (Correct answer)
- 500 mrem in 1 hour at 30 cm from the source.
Correct answer: 100 mrem in 1 hour at 30 cm from the source.
According to regulations (like those from the NRC and incorporated by states), a "High Radiation Area" is an area where radiation levels from external sources could result in an individual receiving a dose equivalent in excess of 0.1 rem (100 mrem) in 1 hour at 30 centimeters from the radiation source or from any surface that the radiation penetrates.
Question 6: Which of the following personnel monitoring devices is designed to provide an immediate, real-time reading of accumulated radiation dose and often includes an alarm feature?
- Film Badge
- Thermoluminescent Dosimeter (TLD)
- Optically Stimulated Luminescence (OSL) Dosimeter
- Electronic Personal Dosimeter (EPD) (Correct answer)
Correct answer: Electronic Personal Dosimeter (EPD)
An Electronic Personal Dosimeter (EPD), also known as an alarming dosimeter, provides a direct, digital readout of the accumulated dose in real-time. It can be set to alarm at a preset dose or dose rate, providing immediate warning to the radiographer. Film badges, TLDs, and OSLs are passive dosimeters that record the cumulative dose over a period (e.g., a month or quarter) and must be processed by a lab to be read.
NDT - Non-Destructive Testing Radiographic Testing Safety Questions and Answers
The fundamental principle of radiation protection, which states that all radiation exposure should be kept as low as reasonably achievable, is known by what acronym?