Materials for nuclear power plant

  Over 30% of Japan's total electric power comes from nuclear power generation. In the more than 40 years since Hitachi began development of nuclear power technology, we have been involved in many nuclear power projects, and we continue to contribute to reliable and safe nuclear power generation to provide a stable supply of electricity that allows us peace of mind based on the technology we have developed.
To provide reliable and safe nuclear power generation plant that gives us a sense of security, Hitachi research laboratory is developing evaluation technology for materials and integrity to support nuclear reactor and plant integrity.
  For example, while material, stress, and environmental factors contribute to stress corrosion cracking (SCC), in this research, we develop technology for evaluating and improving materials and stress to contribute to the maintenance of nuclear power plant integrity.

  Evaluation of the material factors involved in SCC by TEM, EBSD and other such analytical techniques has a role in development of SCC suppression technology and SCC-resistant materials.

  Weld residual stress in welds is another factor in the occurrence of SCC. We are developing techniques for analyzing the residual stress from welding by the finite element method. Those techniques have a role in the development of ways to reduce residual stress. We are also moving forward with the development of crack growth analysis techniques.

  As a technique for relieving residual stress, we developed a water jet peening (WJP) technique that uses the cavitation effect. This technique is used on the in-core structural elements of many nuclear reactors.