ASNT Industrial Radiography Radiation Safety Practice Test

How much total dose will be received by a radiographer after making 24 exposures at 30 mR/h for 5 minutes each?

1. 60 mR (600 μSv)

2. 30 mR (300 μSv)

3. 120 mR (1200 μSv)

4. 15 mR (150 μSv)

The correct answer is: 60 mR (600 μSv)

To determine the total dose received by the radiographer after making 24 exposures at a dose rate of 30 mR/h for 5 minutes each, we need to perform a few calculations. First, we calculate the dose received during each individual exposure. Since the exposure time is 5 minutes, we convert this time to hours for our dose rate calculation: 5 minutes = 5 / 60 hours = 1/12 hours. Given that the dose rate is 30 mR/h, we can calculate the dose for one exposure using the dose formula: Dose = Dose Rate × Time. Substituting in the values: Dose for one exposure = 30 mR/h × (1/12) h = 2.5 mR. Now, since there are 24 exposures in total, we multiply the dose received from one exposure by the number of exposures: Total Dose = Dose per exposure × Number of exposures Total Dose = 2.5 mR × 24 = 60 mR. This results in a total dose of 60 mR, which is equivalent to 600 μSv. This is how the correct answer is derived.