Radiation Safety & Protection Flashcards

What is the inverse square law relationship between distance and radiation intensity?

Answer: Intensity decreases with the square of distance

The inverse square law states that radiation intensity is inversely proportional to the square of the distance from a point source.

A survey meter reads 40 mR/hr at 5 feet from a source. Using the inverse square law, what is the approximate dose rate at 10 feet?

Answer: 10 mR/hr

Doubling the distance reduces intensity by a factor of 4 (2²), so 40 mR/hr ÷ 4 = 10 mR/hr.

What is the primary biological effect of concern from low-level, chronic radiation exposure to workers?

Answer: Stochastic effects such as cancer induction

Stochastic effects like cancer induction are the primary concern for chronic low-level occupational exposure, with no threshold dose.

Which document must accompany a sealed radioactive source during transport by a radiographer?

Answer: Shipping paper with proper UN number and description

DOT regulations require shipping papers identifying the radioactive material, UN number, quantity, and hazard class during transport.

What condition defines a 'High Radiation Area' under NRC regulations?

Answer: Dose rate exceeds 1 mSv/hr at 30 cm

A High Radiation Area is defined as any area where dose rates can exceed 1 mSv/hr (100 mrem/hr) at 30 cm from the source or surface.

During a radiographic exposure, personnel not involved in the operation should be positioned where the dose rate is no greater than what value?

Answer: 0.02 mSv/hr

Non-radiation workers (members of the public) must be kept at distances where dose rates do not exceed 0.02 mSv/hr (2 mrem/hr).

What is the recommended action if a radiographer's personal dosimetry reading for a quarter approaches the investigational level set by the licensee?

Answer: Notify the RSO and investigate the cause

If a dose approaches the licensee's investigational level, the Radiation Safety Officer must be notified and the cause investigated.