ASNT Industrial Radiography Radiation Safety Practice Test

The exposure rate from 30 Ci of Iridium is best described as:

1. 30 R/h

2. 156 R/h

3. 5.2 R/h

4. 1 R/h

The correct answer is: 156 R/h

The exposure rate from a radioactive source, such as Iridium-192, is directly related to its activity measured in curies (Ci) and is influenced by various factors including the type of radiation emitted and the distance from the source. In the case of Iridium-192, a commonly used isotope in industrial radiography, it produces significant levels of radiation due to its relatively high activity. The exposure rate can be calculated using specific constants. At a standard distance, the exposure rate is often found to be approximately 156 R/h for an activity of 30 Ci. This figure is derived from established radiation safety standards and practices that have determined that this exposure rate correlates with the characteristics of Iridium-192. This value is important for radiographers and radiation safety professionals as it helps in assessing the potential radiation exposure to personnel and the public, ensuring appropriate safety measures are in place when working with or around radioactive materials. Understanding this exposure rate also aids in calculating shielding requirements and implementing safety protocols effectively.