What is defined as radioactive material in an unwanted place?

The term that best describes radioactive material in an unwanted place is contamination. This refers specifically to the presence of radioactive substances on surfaces, within materials, or within the human body where they should not be. Contamination can occur in various environments, including workplaces, the environment, and even on individuals, posing risks to health and safety.

Contamination is a critical concern in radiological safety, as it can lead to increased exposure risks and can complicate decontamination efforts. Understanding the nature of contamination is essential for radiological workers to implement appropriate safety protocols and clean-up procedures.

Other terms like radiation relate to the energy emitted from radioactive materials, exposure refers to the amount of radiation a person has been subjected to, and decay describes the process by which unstable isotopes transform into more stable forms, reducing their radioactivity over time. These concepts are important in the broader context of radiological safety but do not specifically define the situation of having radioactive material where it is not supposed to be.