The Application of Printed Circuit Heat Exchanger Technology in the Pebble Bed Modular Reactor Demonstration Plant

Abstract

The Pebble Bed Modular Reactor (PBMR) Demonstration Plant is a 100 MW(e) gas cooled nuclear reactor being developed by Eskom, the South African state electricity utility. The PBMR uses helium in a closed cycle and operates at pressures up to 7.0 MPa and temperatures up to 900°C. Three heat exchangers are used in the PBMR power generation cycle, a Recuperator, a Pre-cooler and an Intercooler. All three exchangers play an important role in the power generation cycle but the Recuperator represents the most challenging application for heat exchanger technology requiring high performance under demanding operating conditions. Printed Circuit Heat Exchanger (PCHE) technology is being considered for Recuperator for several reasons including its ability to handle high pressures and high temperatures and its compactness. PCHEs are high integrity plate type heat exchangers made by chemically etching fluid flow channels into flat metal plates which are then diffusion bonded. This paper will discuss aspects of the design and construction of PCHEs and look at how this technology is being applied to the PBMR.