INES-event
INES 2

Partial loss of post-trip cooling

The planned reactor trip triggered switching of the reactor’s eight Gas Circulators' (GC) power supply from “nominal - 11kV” to “variable speed – 3.3kV”. The 3.3kV power supply is provided by four Variable Frequency Convertors (VFC) and four Variable Speed Drives (VSD). In this case two VFC failed to start, and one VFC and one VSD tripped shortly after starting. Reactor cool down was safely provided by the remaining four GCs for 6 hours when the two failed VFCs were brought into service, which improved cooling margins.

Location: TORNESS-2
Event date: Wed, 15-11-2023
Nuclear event report
Legenda & explanation