A boiling water reactor (BWR) wani nau'i ne na makamashin nukiliya da ke amfani da tafasasshen ruwa don samar da tururi, wanda sai ya motsa injin turbi don samar da wutar lantarki. A cikin BWR, an sanya man nukiliya a cikin reactor core kuma an kewaye shi da ruwa, wanda aka yi zafi ta hanyar fission. Ana amfani da tururin da ya haifar don kunna injin turbin da samar da wutar lantarki. Ruwan da ke cikin BWR ana kiyaye shi a matsi mai ƙarfi don hana shi tafasa, kuma tururin da injin ɗin ya kera ana ware shi da ruwan ana amfani da shi wajen tuka injin ɗin.