4. Sealed and unsealed radioactive sources

Source: Ionactive Resources

Sealed radioactive source

A source of Ionising Radiation in the form of radioactive material which is encapsulated. Sealed radioactive material cannot escape (in all reasonably foreseeable circumstances) and will not cause a contamination hazard. Sealed sources are used in irradiators (food, products, blood), thickness & level gauges quality assurance and similar. The activity of the sealed source can vary from a few Bq to many 10's of TBq.

Sealed radioactive source

Radioactive Sealed Source example (Ir-192)

Unsealed radioactive material

A source Ionising Radiation in the form of radioactive material which is not encapsulated or otherwise contained. Radioactive material can potentially move around, and if uncontrolled would lead to contamination spread. It should be noted that unsealed sources are used extensively in biological research and medicine.

Please also see this Ionactive technical guidance: What is the difference between sealed and unsealed radioactive source?

Unsealed radioactive source spill

Unsealed radioactive source- radioactive material can move around!

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