Recent progress of computer vision and micro-fabrication technologies has greatly reduced the cost and difficulty of three-dimensional modeling of maintenance and dismantling work environments. The model building process is so simple and inexpensive that models can be updated frequently, meaning that we can believe that the model represents the current work environment properly. This assurance enables us to conduct maintenance and dismantling work computer simulations with higher reliability, which might change the methods used for maintenance and dismantling work. The models, which are useful for work procedure planning and evaluation, training, and information sharing among workers, can be a basis for providing safe and efficient maintenance and dismantlement of nuclear power plants. This article presents recent progress of three-dimensional scanning technologies and their possible application to enhance safety and efficiency during plant maintenance and dismantlement.