Methods to Evaluate Embedded Sensor Performance and Reliability in TCR Components

The next generation of nuclear reactors are under development to leverage innovative technologies to deliver safe, low-cost, and clean electricity and support new applications for nuclear energy. Among these advanced nuclear power plants are microreactors which are factory-fabricated, transportable reactors that can be designed to operate for extended periods of time without refueling as autonomous self-regulating systems. Microreactors will take advantage of developments in additive manufacturing technologies including embedded instrumentation to enable applications such as structural health monitoring of plant components. However, additive manufacturing and embedding processes can greatly affect sensor performance (i.e., accuracy and response time). Therefore, it is essential that there exist in-situ test methods that can characterize the performance and reliability of embedded sensors to realize the benefits of additive manufacturing technologies for nuclear applications. To facilitate the use of additive manufacturing technologies and embedded sensing for advanced nuclear systems, a research and development effort is proposed involving the testing of embedded sensors in components fabricated using additive manufacturing techniques under the Transformational Challenge Reactor program. More specifically, this work will include the development of in-situ methods to characterize the accuracy and response time of sensors before, during, and after the embedding processes to ensure that data from embedded sensors will yield reliable information for applications such as component structural health monitoring and autonomous reactor operations. This work will result in hardware and software to support the testing of embedded instrumentation. The research and development effort proposed herein will employ a hands-on approach to develop test methods to measure in-situ sensor performance and determine the degree to which embedded sensors are bonded to the host material. The sensors and materials under test will include components produced using additive manufacturing techniques and will be subjected to steady-state and transient thermal testing to evaluate the impact on sensor performance. In addition, a laboratory materials testing evaluation will be performed to yield insight into the embedding processes such that they may be optimized to the benefit of the advanced and micro nuclear reactor industry seeking to adopt these innovative technologies to support reactor design, operations, and maintenance. The testing results will be used to develop procedures and the conceptual design of a prototype system to be built in Phase II. In the near-term, the commercialization of this project will focus on developing a test system to be used on embedded sensors in additively manufactured components of the Transformational Challenge Reactor, microreactors, and other advanced nuclear energy systems. This will enable more accurate information for applications including component qualification, structural health monitoring, and autonomous operations. In the long-term, this system will be adapted for use in non-nuclear industries such as automotive and aerospace.