Although I have no experience in working in nuclear power plants, I want to try to answer your question: there should be many types of work in nuclear power plants, including peripheral work and core work. If you are engaged in nuclear energy-related work, there used to be a saying called "golden man", which means that the training cost of such workers reaches the golden value equivalent to their weight. If so, will the power plant let you go? If you only engage in jobs with low peripheral value and common to all enterprises, I think it may be easier to leave, depending on how you sign a contract with the company.