We report on our experience with the implementation of project-based teamwork on nuclear energy with 14 ninth-grade students from a lower secondary model school and its assessment using two written questionnaires, which were answered by the students after the completion of the project. The first questionnaire elicited students' opinions about the overall project, while the second questionnaire examined students' acquired knowledge. All the students were satisfied with their experience. The preparation and organization of the team members, their collaboration and discussions, and the presentation at a public seminar were considered the most important stages of the project. In addition, the preparation and organization, the practice in public presentation, the motivation for learning, and critical thinking were important skills and competencies developed. Students benefited from their familiarity with searching and evaluating information and were positive about their contact with scientists. With regard to the knowledge acquired, positive results emerged for the model school students as compared to beginning 1st-year university students from a previous study. The results highlight the importance of project-based work with model school students, as well as the role of the interaction between schools, society, and research institutions.