Cut-off device

The cut-off device is a set of equipment designed for hermetic cut-off of "hot" and "cold" headers of the first circuit of the steam generator from the main circulation pipeline for simultaneous fuel reloading works in the reactor plant and repair works on the steam generator (e.g. chemical washing of the steam generator on the second circuit, inspections). It is used at operating and newly commissioned power units of NPPs with VVER. The cut-off device refers to NPP safety elements used during construction (building) of new NPP units, as well as during operation of operating NPPs with VVER.