Trend of large size, integral type component materials for light water reactor piping

As the substitute energy for oil, nuclear power generation is given second look, because it has been technically established, and the fuel price has been stable. The reliability of nuclear power generation and the structural soundness of its equipment have been demanded more strictly. The rationalization of in-service inspection and other measures to improve the operational efficiency are strongly sought. For these purposes, the manufacture of large, one-body components has been promoted for pressure vessels and others in light water reactors. In the piping members occupying large weight quantitatively and qualitatively in nuclear power stations, this tendency has been similarly seen, and forged steel components are materialized. The basic concept of making large, one-body components for piping system is to make seamless pipes and fittings, to elongate pipes, and to make pipes and fittings or two or more fittings into one-body. The typical examples of making large, one-body piping components are shown, and the planning, manufacture and various properties of large, one-body piping components are reported. The manufacturing techniques for piping components can satisfy these demands. (Kako, I.)