Experience from reactor vessel internals segmentation - mechanical cutting

There is an ongoing upgrade process in the Nordic BWR power plants (NPP) with the aim to extend the operation life time, to increase the power output and also to adapt to the new nuclear safety regulation. The upgrade process includes replacement of reactor internals. Westinghouse has developed a system that allows the highly radiated internals to be removed and disposed in storage buildings. Westinghouse concepts to dismantle and segment the reactor internals are based on clean, safe and reliable techniques. All segmentation work are performed with mechanical cutting, this to comply with the NPP requirements. Westinghouse has since 1999 received almost all segmentation projects of internals in the Nordic area. The two latest segmentation projects where performed in Forsmark-Sweden and in Olkiluoto-Finland. (author)