Radiation Safety and Protection Principles
Quantities and units
Be fluent in activity, exposure, absorbed dose, equivalent dose, and effective dose, and in the units used for each. Know the dose limits for occupational workers, declared pregnant workers, minors, and members of the public, and know that limits apply to the total effective dose equivalent plus the committed dose from intake. A classic trap is comparing an external dose alone to a limit that also includes internal dose.
ALARA and dose reduction
Understand time, distance, and shielding; the inverse square relationship; and the use of half-value layers. ALARA is a process, not a number, and questions test whether a program investigates, evaluates, and documents rather than whether it merely meets limits.
Contamination, surveys, and monitoring
Know the difference between contamination and radiation levels, the meaning of removable and fixed contamination, and the role of surveys, wipe tests, and air sampling. Understand internal dosimetry concepts: intake routes, bioassay, and the difference between committed dose and dose received in the year.
Worked example
A worker receives 12 mSv external dose and an intake committing 8 mSv. The dose for limit comparison is 20 mSv total, not 12 mSv. If the limit is 50 mSv, the worker is at 40 percent. Questions that offer only the external dose as an answer are testing whether you remembered to add the committed dose.