Interactive radiation portal - radiaverse.com
Half-life: 10.7 years
Main emission lines: 514keV
Krypton-85 is used in powerful gas discharge lamps, used in movie projectors. It is also found in neon lamps and neon lamp starters for fluorescent lamps, but the activity for one such starter is not dangerous—usually no more than 1 kBq. Krypton-85 is inexpensive and, if the gas discharge devices remain sealed, it is absolutely safe from radiation, which is why it was widely used in this area in the past.
Krypton-85 is used for technical diagnostics of aviation parts: it helps to detect microscopic defects. This gas penetrates well into small cracks, remains there, and can then be detected by autoradiography methods.
Natural production Krypton-85 is produced in small quantities by the interaction of cosmic rays with stable krypton-84 in the atmosphere.
Much more krypton-85 is produced in nuclear reactions, primarily from uranium-235. When 1000 nuclei of uranium-235 decay, about three atoms of krypton-85 are released.
Significant amounts of krypton-85 are produced in the production and isotope separation of plutonium. Therefore, a sudden local increase in the concentration of this radioisotope in the air is an indicator of possible illicit plutonium production.
