Modeling a Helical-coil Steam Generator in RELAP5- 3D for the Next Generation Nuclear Plant

Document Type



U.S. Department of Energy Office of Nuclear Energy

Publication Date



Options for the primary heat transport loop heat exchangers for the Next Generation Nuclear Plant (NGNP) are currently being evaluated. A helical-coil steam generator is one heat-exchanger design under consideration. Helical-coil steam generators are preferred over other steam generators for their increased heat transfer and compactness. Safety and reliability are an integral part of the helical-coil steam generator evaluation for NGNP. Transient analysis plays a key role in evaluating the safety of steam generators. Operational transients, such as start up, shut down, and loss of coolant accidents, are transients of interest. The helical-coil steam generator is modeled using RELAP5-3D, an Idaho National Laboratory in-house code. The transient response of an exponential loss of pressure (simulating double-ended shear) in the primary side of the steam generator is simulated. The exponential loss of pressure models a break of the steam generator inlet pipe. This report details the development of the helical-coil steam generator model and the loss of pressure transient. Background on high temperature gas-cooled reactors and steam generators is provided to aid the reader in understanding the material presented. A detailed description of the RELAP5-3D helical-coil steam generator model is presented. An explanation is given of each of the RELAP5- 3D components used in modeling the steam generator. Also reported is the response of the steam generator primary and secondary systems to the exponential loss of primary pressure.

This document is currently not available here.