STOP DEVICE FOR HIGH-TEMPERATURE NUCLEAR REACTOR

A shutdown system for a high temperature nuclear reactor where absorber material elements in the form of balls pass from an elevated reservoir into a vertical channel formed by aligned vertical cavities in horizontal, nose-shaped projections from the side reflector. The balls are transported back to the reservoir by way of a conveyor device. It must be insured that even in the case of accidents the absorber balls arrive in the cavities and that a rapid return of the absorber balls into the reservoir takes place. For the purpose, the reservoir is provided with an automatically-actuated and controllable device for releasing an opening between the reservoir and the vertical channel feed line. Below the channel is a removal tube terminating in a housing and arranged to form a pile of the absorber balls which seals the removal tube. To return the absorber balls, a metering gas acts on the pile and brings the absorber balls to a carrier gas. The carrier gas returns the absorber balls into the reservoir while the gaseous proporation of the carrier gas flow is returned for the reservoir into the pressure vessel.