Se-75

Half-life: 120 days

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Main emission lines: 136keV, 265keV,  401keV

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Where detected

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Selenium-75 has radiopharmaceutical uses. For example, it is used in high-dose-rate endorectal brachytherapy, as an alternative to iridium-192.

Selenium-75 has been particularly successful in replacing X-ray devices in some pipeline crawler applications. Se-75 is excellent for congested work sites since much smaller restricted areas are required.

Selenium-75 is used in technology for non-destructive testing of welds and structural integrity. It is obtained by neutron irradiation of natural selenium in nuclear reactors.