When the fact that information changes and increases very quickly today is taken into account, individuals' ability to adapt to this change shows parallelism with the education they will receive. This study aims to determine the effect of a planned technical trip made to the Nuclear Research Reactor located in Istanbul Technical University Energy Institute campus on science teacher candidates' attitudes and opinions. The research, quantitative data of which were collected by the "Nuclear Power Plants Attitude Scale" developed by Özdemir and Çobanoglu (2008) and qualitative data of which were collected by a semi-structured interview form developed by the researchers, was designed as a mix-method research in which both methods are used together. In the study, a planned technical trip to a nuclear reactor was organized along with 17 teacher candidates studying in the 4th year (or senior year) of Science Teaching at Abant Izzet Baysal University. As a result of the research, a significant change was determined in teacher candidates' attitudes concerning nuclear power plants. In addition, 9 semi-structured interview questions were applied to the teacher candidates before and after the trip. As a result of the content analysis performed, 22 codes in total were identified under 4 theme titles, and a positive increase in terms of quality was determined in teacher candidates' opinions after the trip. Based on these findings, it can be said that candidate teachers' opinions on nuclear power plants to be established in our country changed for the establishment of nuclear power plants in our country by the effect of the technical trip made.