Speaker
Description
On the night of the 25th November 2025,ESS experimented a voltage sag from the incoming 12.5 kV power. As a consequence, an oil compressorof the accelerator Cryopant and the main water pump of the Target Moderator cooling system failed.
The consequences of those two failures were:
· Oil compressor: Stop of the compressor, stopping the Accelerator Cryoplant. When restarting the system, 3 burst disk were damaged in the Superconducting Linac, requiring their replacement, and 2 weeks of stop of operations.
· Water pump: Stop of the water circulation, leading to freezing of the water in the systems, damaging the system and requiring extensive intervention.
This poster reviews the incident, examining the four main aspects: electrical disturbances, MCR reaction, ACCP failure, and Target Moderator failure.