Question

With approval, isotopes may be stored for decay if their half-life is less than _____

A. 45 days.
B. 100 days.
C. 120 days.
D. 180 days.

-Disposition of Radioactive Material

Answer 1

Isotopes with a half-life of less than 120 days, option C, may be stored for decay.

Step-by-step explanation:

Isotopes may be stored for decay if their half-life is less than 120 days, which is choice C. Radioactive materials are constantly decaying and their activity is measured by their half-life—the time it takes for half of the material to decay. Short half-life isotopes, like I-131 with a half-life of 8.02 days, are often used in medical procedures because they decay quickly and do not persist in the body. Material with a half-life under 120 days can be stored and allowed to decay to a level where it can be disposed of more conventionally, without requiring long-term storage or special processing.