Case Study: BAY-LOGI assesses nuclear weld safety with MSC Software Marc

Marc Simulates Welding of Nuclear Pressure Vessel Reactor Nozzles

BAY-LOGI, the Institute for Logistics and Production Engineering, worked with MSC Software to study how welded nuclear pressure vessel nozzles would perform after long service. The team needed to understand residual stress, distortion, and long-term safety margins in welds that had already seen 20 to 30 years of operation, without relying on measurements from the reactor itself or expensive duplicate testing.

Using MSC Software’s Marc nonlinear FEA software, BAY-LOGI simulated the heterogeneous welding process, including multi-pass welding, phase transformation, and large deformations. The model was validated with mock-up welding results and then applied to a 3D nozzle joint built from 98 weld runs and more than 400,000 hex elements, solved in approximately 18,000 nonlinear increments. The simulation helped BAY-LOGI realistically assess weld and heat-affected-zone properties, determine temperature and residual stress distributions, and avoid building a duplicate structure, saving millions of dollars.

BAY-LOGI

Zoltan Bezi

Research Fellow