So water-cooled reactors are built inside of big, thick concrete buildings called containment buildings, which are meant to hold all of the steam that would come out of the reactor if you had an accident where you lost pressure.
Por ello, estos reactores se construyen dentro de edificios de hormigón macizo llamados edificios de contención, capaces de soportar todo el vapor que saldría del reactor en caso de un accidente con pérdida de presión.