The SLOÉ reactor is an open core pool type reactor. It was built in 1963 at the Centre d'Etudes Nucléaires de Grenoble, one of the research centers of the CEA (Commissariat à 1'Energie Atomique). It was modified in 1988 to meet new safety requirements. For instance, a new design of the pool assembly including a stainless steel tank and lining now makes it capable of supporting the most severe reactivity accidents and earthquakes up to level 8 on the MSK scale. The reactor control and display assembly have been upgraded to integrate progress in electronics and ensure high reliability.