Selenium-75 in industrial radiography

Selenium-75 is a radioactive isotope used as a gamma-radiography source in suitable industrial applications. Its use is a regulated radiation-safety activity, distinct from the interpretation of the resulting radiographic image.

What it means in an examination

Source selection depends on the component, material, thickness, geometry, required image quality and the authorised technique. A brief isotope description cannot establish a usable thickness range or an exposure time for a particular examination. Those decisions require the appropriate procedure, equipment information and qualified personnel.

Important distinctions

A sealed source continues to emit radiation without an electrical power supply. Source security, transport, storage, operation and emergency arrangements therefore require the controls applicable to the jurisdiction and the authorised organisation. A training article does not provide authority to possess or operate a source.

Using the term correctly

For procurement or inspection planning, ask the authorised provider to confirm source and equipment suitability, image-quality requirements, access constraints and the records supplied with the examination. Keep radiation-protection responsibilities separate from the customer’s acceptance criteria for the component.

ASNT radiographic-testing overview · Radiographic testing guidance · Discuss an examination scope