The U.S. Department of Energy has recently completed a research program to support the development of the compact heat exchanger (CHX) for use in high temperature advanced reactors. The project was executed by an Integrated Research Project (IRP) and includes team members from the University of Wisconsin–Madison, University of Michigan, Georgia Institute of Technology, University of Idaho, North Carolina State University, Oregon State University, Electric Power Research Institute, MPR Associates, and heat exchangers manufacturers CompRex and Vacuum Process Engineering.
The objective of the research was to enable the use of compact heat exchanger designs in high temperature advanced reactor service in order to improve plant efficiency and economics. A necessary step for achieving this objective is to ensure that the ASME Boiler and Pressure Vessel Code, Section III has rules for the construction of CHXs for nuclear service. However, construction rules alone are not sufficient to deploy a compact heat exchanger in an advanced reactor. ASME Section XI Rules for the Inservice Inspection (ISI) of a heat exchanger in an operating nuclear reactor will be required, and mostly likely ISI will be conducted in according with ASME Section XI, Division 2, Reliability and Integrity Management (RIM) methodology, which is a non-deterministic, technology neutral, approach to inservice inspection.
Since a RIM based ISI program is developed by an owner considering the entire reactor technology safety case, owners will need specific information regarding the performance, failure modes, reliability, and inspection options for compact heat exchangers. Previously, ICONE27-1139 provided strategies for inservice inspection of compact heat exchanger that outlined how an owner can use the planned IRP research to support the development of an ISI program that includes compact heat exchangers.
Now that the IRP research is completed, this paper updates the earlier strategy to reflect the results of the research. Failure mechanisms for compact heat exchanger are unique and not widely understood. The IRP has studied the failure mechanisms, monitoring and inspection technologies and this research may be used to enable an owner/operator of an advanced nuclear reactor to develop a RIM based inservice program.