The purpose of the TOPAS project has been to maintain and develop stationary reactor physics code system, covering a wide range of calculation needs. Main results have been the development of a new Monte Carlo code Serpent, advanced methods for burnup calculations, and the development of sensitivity and uncertainty analysis methods. There has also been a strong interest in educating new competent people to work in field of reactor physics and nuclear safety. Several university degrees have been taken during the project, and the educational objectives have been well fulfilled. International co-operation has also been active. The results of the project will serve the needs of both the safety authorities and the power utilities.