Embedded Cladding Instrumentation Array development
The embedded cladding instrumentation array development project was started in 2017 via a proposal for Nuclear Engineering University Program funding. The proposal was accepted in to the final round of consideration for the 2017 round of funding, however the various partners for the research project were not able to commit to the desired timeline for development, and the project was placed on an indefinite hold until new research partners could be identified. Due to other research obligations taking precedence in 2018, the project has yet to be resumed, but based on feedback from the initial submission, the project is a good candidate for funding if the right partners can be found.
The overall aim of the project was to integrate heat flux sensor arrays into a novel type of layered cladding comprised of a high-tension carbon fiber substrate bonded with an internal silicon carbide tube. The cladding is being investigated as an alternative to metallic cladding for water-cooled and gas-cooled reactors, specifically to increase the temperature limit of the cladding interface. Because the cladding is fabricated using layers of carbon fiber wrapped around a ceramic tube, an ideal interface for heat flux instrumentation is available on the outside of the ceramic tube, protected by the outer wrap of carbon fiber. Integrating the sensor fabrication process into the manufacturing process of the cladding was the desired outcome of the project, including functional testing to determine the sensitivity of the sensor arrays and their ultimate potential for providing critical process data during reactor operation. The initial partners for this study included a U.S. based manufacturer for this novel cladding, as well as material experts from Oak Ridge National Laboratory and testing facilities at Oregon State University.
Although a number of challenges needed to be addressed before this concept could be applied as an instrumentation standard, the potential for critical process measurements directly at the cladding heat-transfer interface provides significant potential to reduce operating uncertainty, allow for improved safety analysis, and better track and optimize fuel loading. Next generation ceramic cladding is an excellent opportunity to include standardized instrumentation as a fundamental feature of the technology, provided the initial research can be completed to refine the manufacturing process and provide testing data to support the claims of the benefits presented.
I hope to continue the project in the future if possible. If you have any questions or want to suggest potential research collaboration, please contact me via E-mail.
Initial proposed design
The concept was started as an extension of my dissertation project research, which is concerned with developing integrated instrumentation for pebble bed HTGR fuel. I was initially interested in the novel ceramic cladding being developed for next generation reactor fuel assemblies and saw the potential for layered cladding to easily integrate sensor fabrication into the manufacturing process.
Selecting a heat flux sensor, specifically one that utilized RTD based temperature measurements, was simply an extension of my work with RTD elements for thermal anemometers. It is likely that more applicable sensor configurations can be utilized, but initial testing with RTD based heat flux sensors was a direct solution for the design challenges presented for funding opportunities via NEUP.
Ceramic cladding will eventually be the industry standard, given the current challenges with metallic cladding and the thermal and chemical durability of the ceramic substrates being considered. Integrated instrumentation allows for the type of innovations that are needed to justify the high cost of pushing the technology toward commercial adoption.
Files
A technical abstract which describes the project, submitted as a portion of the NEUP funding proposal: Technical Abstract
A project narrative which describes the execution of the project, also submitted as a portion of the NEUP funding proposal: Project Narrative