The ELSMOR facility was built in 2022 at SIET (Piacenza, Italy) in the frame of the ELSMOR European Project (Grant Agreement number: 847553 — ELSMOR NFRP-2018) to validate a decay heat removal system for the E-SMR. Based on the passive mechanisms of natural circulation, the system aims to dissipate the reactor decay heat to a water pool, using two heat exchangers: a plate-type one coupling the primary side to the secondary side, and a vertical tube one coupling the secondary side to the water pool.