Characterization of Embedded Sensors in Stainless Steel Test Articles and Design/Planning for MAGNET Testing

Strain gauge for testing microreactor hexagonal core blocks in the Single Primary Heat Extraction and Removal Emulator

“…Commercially available RSGs (Kyowa, KHC-20-120-G9-13) were attached to an additively manufactured stainless steel alloy 304 (SS304) hexagonal core block that was printed at Los Alamos National Laboratory [2]. The RSG are composed of two elements that consist of a primary active strain sensing element and a secondary dummy element that reduces temperature effects and allows for temperature compensation [3].…”

“…Core block-A was used for initial attachment trials of the strain gauge and preliminary systems testing in SPHERE. Core block-B (Figure 1b) had the UAM embedded sensors from ORNL and was used to support the testing outlined and discussed in Holden et al [2].…”

“…To provide critical data on mechanical properties during testing, a prototypic seven-hole hexagonal test article that is based on the core block design of a heat pipe-based microreactor was instrumented with embedded sensors (Figure 1) at Oak Ridge National Laboratory (ORNL). ORNL used an ultrasonic additive manufacturing (UAM) technique to embed a distributed strain sensing fiber optics, distributed temperature sensing fiber optics, and type-K thermocouples onto the surface of the test article [2]. The U.S. DOE's Advanced Sensors and Instrumentation (ASI) program provided added support for the testing of the UAM embedded strain sensing optical fibers by providing and attaching weldable resistive strain gauge (RSG) to the core block.…”

Performance of Microreactor Test Article with Embedded Sensors During Testing in The Single Primary Heat Extraction and Removal Emulator

“…Nonembedded polyimide coated fibers (Fibercore) were also chosen for distributed temperature measurements. More information on the fibers can be found in previous reports [6,24]. Additionally, Type K TCs (Omega Engineering) and a hightemperature strain gauge (Kyowa Electronic Instruments) were chosen to compare the temperature and strain measurements recorded by the fibers.…”

“…However, conventional SS processing via casting and subsequent working is not ideal for embedding fragile fiber optics. Therefore, recent studies have used additive manufacturing (AM) to rapidly prototype new component designs with geometric complexities [20,21] and embed fiber-optic sensors during the fabrication process [12,15,16,[22][23][24][25].…”