Abstract: Process and device for emergency cooling of a nuclear reactor comprising a steam generator (2) heated by a primary circuit and cooled by a secondary circuit producing steam, and in which in case of an emergency shutdown of the reactor, the emergency feed (50) of the secondary circuit is provided from an emergency reservoir (5), by an auxiliary pump (51) driven by steam derived at the output from the generator. At least part of the steam continuing to be produced during the cooling process is condensed in an air condenser (6) and the condensed water is recycled to the emergency reservoir (5). The power for the air condenser is supplied from another withdrawn portion (70) of steam.