Which of the following statements about sealed sources is correct?

Sealed sources are designed to contain radioactive material securely within a protective envelope, which can be made of metal, glass, or plastic. This encapsulation prevents the release of radioactive particles into the environment, ensuring that the material remains confined and minimizes the risk of exposure to individuals nearby. The encapsulation also allows for safe handling and use in various applications, including medical, industrial, and research settings.

The other options do not accurately describe sealed sources and their characteristics. Sealed sources are not easily dispersible due to their encapsulated nature, and while they are widely used in medical applications, they also have significant industrial and research applications. Additionally, sealed sources can indeed be detected by scintillation detectors, which are designed to identify radiation emitted from such sources.