| Title |
Modal Analysis and Testing for a Middle Spacer Grid of a Nuclear Fuel Rod |
| Authors |
류봉조(Ryu, Bong-Jo) ; 구경완(Koo, Kyung-Wan) |
| DOI |
https://doi.org/10.5370/KIEE.2012.61.12.1948 |
| Keywords |
Nuclear fuel rod ; Middle spacer grid ; Modal analysis and testing ; Natural frequencies and modes ; Frequency response function |
| Abstract |
The paper presents modal testing and analysis in order to obtain the dynamic characteristics of a middle spacer grids of a nuclear fuel rod. A spacer grid is one of the important structural elements supporting nuclear fuel rods. Such a fuel rod can be oscillated by its thermal expansion, neutron irradiation and etc. due to cooling water flow under the operation of a nuclear power plant. When the fuel rod vibrates, fretting wear due to repeated friction motion between the fuel rods and spacer grids can be occurred, and so the fuel rod is damaged. In this paper, through modal analysis and testing, natural frequencies and modes of a middle spacer grid were calculated, and the following conclusions were obtained. Firstly the numerical first-seven natural frequencies for spacer grids of a fuel rod having complicated structures have a small difference within 3.8% with experimental natural frequencies, and so the suitability of simulation results was verified. Secondly, experimental mode shapes for a middle spacer grid of a nuclear fuel rod were verified by obtaining lower non-diagonal terms through MAC(Modal Assurance Criteria), and were confirmed by the simulation modes. |