ASNT Industrial Radiography Radiation Safety Practice Test 2026 – The Comprehensive All-in-One Guide to Exam Success

To determine how many half-value layers are represented by 1.5 inches of steel when 0.50 inches is defined as 1 half-value layer for Ir-192, you start by recognizing that each half-value layer reduces the radiation intensity by half.

Since one half-value layer corresponds to 0.50 inches of steel, you can calculate the number of half-value layers in 1.5 inches by dividing the total thickness by the thickness of one half-value layer:

1.5 inches (total thickness) divided by 0.50 inches (thickness of one half-value layer) equals 3.

This means that 1.5 inches of steel represents three times the thickness defined for one half-value layer. Therefore, it corresponds to 3 half-value layers.

Understanding half-value layers is crucial in radiation safety practices as it helps in estimating the amount of shielding needed to protect individuals from radiation exposure effectively.