Degradation Mechanism and Mitigation Measures of Key Parts of ПГВ-1000 Horizontal Steam Generator in Operation

The degradation mechanism of key parts of ПГВ-1000 horizontal steam generator in operation for several WWER-1000 units in Russia, Ukraine and Bulgaria are tracked and studied for a long time. The damage problems in the contact zone of punched area of cold collecting pipe and the 111 welded joint between collecting pipe and casing connecting section are collated and analyzed. And several improvements, mitigation and supervision measures are proposed to provide reference for the operation and aging management of the same type of horizontal steam generator in domestic WWER units or other facilities.