Tsarin wutar lantarki wani nau'i ne na makamashin nukiliya wanda ake kiyaye sarkar da ke dawwama da kai ta hanyar amfani da kayan fissile, kamar uranium ko plutonium. Halin da ake yi yana haifar da zafi, wanda ake amfani da shi don samar da tururi wanda ke tafiyar da injin turbin kuma yana samar da wutar lantarki. Ana sarrafa yanayin sarkar ta hanyoyi daban-daban, ciki har da sanduna masu sarrafa neutrons, da kuma sanyaya da ke ɗauke da zafi daga ma'aunin reactor.