The demonstrated interest of using iron-chrome-aluminum (FeCrAl) ferritic alloys as accident tolerant fuel (ATF) cladding in light water reactors has recently resurfaced the interest in FeCrAl, which have been used for other purposes for more than eight decades. The main interest for ATF is that FeCrAl alloys are many orders of magnitude more resistant to attack in super-heated steam (>1200°C) than zirconium alloys. Recent research has shown that FeCrAl is also resistant to corrosion in high temperature (~300°C) reactor normal operation conditions hydrogenated water since it develops a protective chromia rich oxide film on its surface. Under accident conditions in superheated steam the surface oxide becomes alumina. If an alumina protected tube is flooded with fresh water after the quenching in accident, the surface oxide returns to chromia. The oxide protection versatility of FeCrAl alloys will be discussed on the several situations that may be encountered in a light water reactor both under normal operation conditions and under the unlikely situation of an accident.