CONFIRMATION OF CANDU SHUT-DOWN SYSTEM DESIGN AND PERFORMANCE DURING COMMISSIONING.

To CANDU reactors the shutdown system design and safety analysis are appreciably influenced by neutronic decoupling of reactor segments, delayed neutron holdback, and asymmetric insertion of reactivity devices. Tests carried out during the commissioning phase of the first two units of the Bruce power plant have confirmed the shutdown system reliability and the predicted magnitude of the above effects. This extended abstract discusses the dynamic and static tests and their mathematical confirmation.