 Nyorai kupfuurira kweiyi ndima - Caesium-137, nehafu yehupenyu hwemakore 30.17, ndeimwe yezvinhu zviviri zvikuru zvepakati-hupenyu hwekuparadzaniswa, pamwe chete ne90Sr, iyo inokonzera huwandu hwe radioactivity yeiyo yakashandiswa mafuta enyukireya mushure memakore anoverengeka ekutonhora, kusvika kumazana emakore anoverengeka mushure mekushandiswa. Inoumba rutivi rukuru rwemwaranzi yakasara kubva mutsaona yeChernobyluye kunonetsa zvikuru utano nokuda kwokuchenesa ivhu riri pedyo nenzvimbo yemagetsi enyukireya yeFukushima. 137Cs beta inoderera kuva barium-137m isomeri yenyukireya isingagari kwenguva refu uyezve kuva barium-137 isingaparadzi mwaranzi, uyewo inobudisa mwaranzi inonzi gamma. 