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Reactor control

The reactor is controlled by three control rods which contain boron carbide as absorber material. When these rods are fully inserted into the reactor core, the neutrons continuously emitted from a start-up source (Sb-Be photo-neutron source) are absorbed by the rods and the reactor remains sub-critical.

If the absorber rods are withdrawn from the core (two of them by an electric motor and one pneumatically), the number of fissions in the core and the power level increases. The start-up process takes roughly five minutes for the reactor to reach a power level of 250 kW from the sub-critical state. The reactor can be shut-down either manually or automatically by the safety system. It takes about 1/10 of a second for the control rods to fall into the core.