Additional Funding Sources
This work was supported in part through the Department of Energy Advanced Sensors and Instrumentation program under DOE Idaho Operations Office Contract DE-AC07-05ID14517.
Abstract
Since the 2011 Fukushima Daiichi Nuclear Power Plant disaster, there has been a greater need for real-time monitoring of irradiation conditions to advance the safety and reliability of nuclear reactors. The nuclear industry has previously relied on time consuming and costly methods, such as post-irradiation experimentation, to observe fuel rod deformation. The harsh environmental conditions of the nuclear reactor also pose challenges for accurate sensing abilities of strain gauges. However, the rise of additive manufacturing (AM) techniques has enabled the direct fabrication of in-pile sensing technology to replace traditional methods of measuring strain. In this study, AM capacitive strain gauges made from silver ink printed on aluminum 6061 with an aerosol jet printer could be a viable option to monitor fuel rod cladding as well as other materials systems within a reactor. The proposed work demonstrates the feasibility of capacitive strain gauges for accurate sensor performance at varied levels of relative humidity (RH) and mechanically imposed strain using a cantilever beam in an environmental chamber. Results indicate that strain sensors are not greatly affected by low levels of humidity (i.e. 20% RH). At 90% RH, the strain gauges will continue to increase in capacitance for five hours before remaining constant whether mechanical strain is applied or not. The AM strain sensors show great promise for use in low RH reactor environments.
Characterizing the Sensing Performance of Additively Manufactured In-Pile Strain Gauges in High Humidity Environments
Since the 2011 Fukushima Daiichi Nuclear Power Plant disaster, there has been a greater need for real-time monitoring of irradiation conditions to advance the safety and reliability of nuclear reactors. The nuclear industry has previously relied on time consuming and costly methods, such as post-irradiation experimentation, to observe fuel rod deformation. The harsh environmental conditions of the nuclear reactor also pose challenges for accurate sensing abilities of strain gauges. However, the rise of additive manufacturing (AM) techniques has enabled the direct fabrication of in-pile sensing technology to replace traditional methods of measuring strain. In this study, AM capacitive strain gauges made from silver ink printed on aluminum 6061 with an aerosol jet printer could be a viable option to monitor fuel rod cladding as well as other materials systems within a reactor. The proposed work demonstrates the feasibility of capacitive strain gauges for accurate sensor performance at varied levels of relative humidity (RH) and mechanically imposed strain using a cantilever beam in an environmental chamber. Results indicate that strain sensors are not greatly affected by low levels of humidity (i.e. 20% RH). At 90% RH, the strain gauges will continue to increase in capacitance for five hours before remaining constant whether mechanical strain is applied or not. The AM strain sensors show great promise for use in low RH reactor environments.