Radiation Shielding and ALARA Principles Flashcards
6 cards from real NRRPT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Radiation Shielding and ALARA Principles flashcards as text
What phenomenon occurs when gamma rays interact with high-Z shielding materials and produce secondary X-rays?
Answer: Bremsstrahlung
Bremsstrahlung ('braking radiation') is produced when charged particles decelerate near the nucleus of a high-Z material, emitting X-rays.
What is the recommended shielding strategy for beta emitters to minimize bremsstrahlung?
Answer: Use plastic or aluminum first, then lead if needed
Low-Z materials like plastic stop beta particles with minimal bremsstrahlung production before any high-Z material is added.
Which of the following correctly describes the build-up factor in shielding calculations?
Answer: A factor that accounts for scattered radiation reaching the detector
The build-up factor corrects for scattered (secondary) radiation that adds to dose behind a shield beyond the primary beam.
How many HVLs are required to reduce radiation intensity to approximately 1% of the original value?
Answer: 7
Seven HVLs reduce intensity by (1/2)^7 = 1/128, which is approximately 0.78%, the closest standard answer to 1%.
What is the NRC annual dose limit for members of the public from licensed operations?
Answer: 100 mrem
10 CFR 20.1301 limits the annual dose to individual members of the public to 100 mrem (1 mSv) from licensed operations.
Which dose quantity is used to compare the biological effectiveness of different radiation types?
Answer: Equivalent dose (Sievert/rem)
Equivalent dose (in rem or Sievert) accounts for radiation weighting factors to compare the biological impact of different radiation types.