The reactor pressure vessels make up the heart of a nuclear power plant, containing the core, core shroud and coolant. In water-cooled water-moderated energy reactors type power plants, nozzles on the ferritic steel pressure vessel are welded to primary coolant pipes made of austenitic steel. These nuclear power plants were built and started operating 20 to 30 years ago. The company operating one of these power plants needed to know how these welds can be expected to perform after a long period of service. It’s not practical to perform measurements on the reactor itself because of the complex geometry and the presence of radiation. Building and testing a duplicate structure would be expensive and it would also be very hard to replicate the effects of 20-plus years of operation. So the operator of the power plant agreed with the Department of Structural Integrity at Bay Zoltan Institute for Logistics and Production Engineering (BAY-LOGI) to simulate the manufacturing process to better understand the characteristics of the welded joint.