Thu Jul 24, 12:05 PM ET

MOSCOW (AFP) - Authorities evacuated the airport terminal in Vladivostok, in Russia's far east, after a flight arriving from Seoul set off a radiation alarm.

The alarm was called off when security officials pinpointed the source -- a woman who had just received radiation therapy, Interfax news agency reported Thursday.

The woman was released when it was established that South Korean doctors had treated her with iodine-131, a radioactive isotope used in nuclear medicine, giving her a level of radioactivity 15 times greater than the norm.

"Iodine 131 is a short-lived isotope, so the passenger should be back to normal in a month," Interfax quoted a customs spokeswoman at Vladivostok airport as saying.