Abstract: An improved method for embedding one or more sensors in SiC is provided. The method includes depositing a binder onto successive layers of a SiC powder feedstock to produce a dimensionally stable green body have a true-sized cavity. A sensor component is then press-fit into the true-sized cavity. Alternatively, the green body is printed around the sensor component. The assembly (the green body and the sensor component) is heated within a chemical vapor infiltration (CVI) chamber for debinding, and a precursor gas is introduced for densifying the SiC matrix material. During infiltration, the sensor component becomes bonded to the densified SiC matrix, the sensor component being selected to be thermodynamically compatible with CVI byproducts at elevated temperatures, including temperatures in excess of 1000° C.

Abstract: An optical fiber-based gamma-ray calorimeter (OFBGC) sensor array which uses a thermal mass with a low thermal conductivity is provided. Advantages of the OFBGC sensor array include: 1) the number of sensors in the OFBGC sensor array is adjustable and limited only by the spatial resolution of the OFBGC sensors, within the OFBGC sensor array, and 2) the OFBGC sensor design is simpler to build than a conventional optical fiber-based gamma thermometer (OFBGT) sensor array. One purpose of the OFBGC is to determine the power distribution in nuclear reactors.

Abstract: An improved method for embedding one or more sensors in SiC is provided. The method includes depositing a binder onto successive layers of a SiC powder feedstock to produce a dimensionally stable green body have a true-sized cavity. A sensor component is then press-fit into the true-sized cavity. Alternatively, the green body is printed around the sensor component. The assembly (the green body and the sensor component) is heated within a chemical vapor infiltration (CVI) chamber for debinding, and a precursor gas is introduced for densifying the SiC matrix material. During infiltration, the sensor component becomes bonded to the densified SiC matrix, the sensor component being selected to be thermodynamically compatible with CVI byproducts at elevated temperatures, including temperatures in excess of 1000° C.

Abstract: A nuclear fuel cladding with improved thermomechanical properties is provided. The nuclear fuel cladding includes a double-walled construction having inner and outer hexagonal sidewalls. The inner sidewall and the outer sidewall are spaced apart from each other to form a cooling channel therebetween, and the inner sidewall surrounds a nuclear fuel and is spaced apart from the nuclear fuel by a small gap. Helical fins extend into the cooling channel to interconnect the inner sidewall and the outer sidewall. Resilient fingers extend toward the nuclear fuel through the small gap to comply with variations in the size of the nuclear fuel due to fabrication tolerances as well as thermal expansion and swelling of the nuclear fuel, for example UO2, when undergoing fission. The nuclear fuel cladding is formed according to an additive manufacturing process, for example laser powder bed fusion printing.

Abstract: An improved method for embedding one or more sensors in SiC is provided. The method includes depositing a binder onto successive layers of a SiC powder feedstock to produce a dimensionally stable green body have a true-sized cavity. A sensor component is then press-fit into the true-sized cavity. Alternatively, the green body is printed around the sensor component. The assembly (the green body and the sensor component) is heated within a chemical vapor infiltration (CVI) chamber for debinding, and a precursor gas is introduced for densifying the SiC matrix material. During infiltration, the sensor component becomes bonded to the densified SiC matrix, the sensor component being selected to be thermodynamically compatible with CVI byproducts at elevated temperatures, including temperatures in excess of 1000° C.

Abstract: A system and method for determining an object characteristic from a timed sequence of measured characteristics wherein the object characteristic is determined based on a comparison of a current measured characteristic against a variable reference characteristic. The variable reference characteristic is selected by iterating through the timed sequenced and determining a separate quality metric for the current measured characteristic against each earlier measured characteristic and selecting the variable reference as a function of the determined quality metrics. In one embodiment, iteration continues only until an earlier measured characteristics is found with a quality metric that meets or exceeds a threshold value. In another embodiment, iteration continues through a plurality of earlier measured characteristic (perhaps all) and the variable reference is selected as the earlier measured characteristic with the highest quality metric. The measured characteristics may include OFDR measurements.

Abstract: A system and method for monitoring Fabry-Perot cavity (“FPC”) displacement implementing a predictor-corrector scheme. The system includes an optical interrogator apparatus and a data processing apparatus. The optical interrogator apparatus interrogates the FPC, obtains a spectral interference pattern and outputs a corresponding signal including data associated with a plurality of peaks. The data processing apparatus processes the output signal to produce a prediction for a peak location based on the data associated with the plurality of peaks, and then uses the prediction to identify as correct one of the plurality of peaks. The data processing apparatus then determines and outputs a plurality of FPC length variations. In one embodiment, the data processing system implements a period tracking algorithm to produce the prediction based on the data associated with the plurality of peaks, and uses a phase tracking algorithm to determine an FPC length variation using the identified peak.

Abstract: A fiber optic sensor and a related method of manufacture are provided. The fiber optic sensor includes an embedded optical fiber contained within a metal diaphragm assembly, where the terminal end of the optical fiber is positioned opposite a diaphragm. The method includes forming a metal-embedded optical fiber by ultrasonic additive manufacturing and securing the metal-embedded optical fiber to a housing having a diaphragm that is opposite of the terminal end of the optical fiber. The sensor can provide extremely accurate pressure measurement at high temperatures and in highly corrosive media. An optical fiber-based pressure sensing system is also provided.

Abstract: A nuclear fuel cladding with improved thermomechanical properties is provided. The nuclear fuel cladding includes a double-walled construction having inner and outer hexagonal sidewalls. The inner sidewall and the outer sidewall are spaced apart from each other to form a cooling channel therebetween, and the inner sidewall surrounds a nuclear fuel and is spaced apart from the nuclear fuel by a small gap. Helical fins extend into the cooling channel to interconnect the inner sidewall and the outer sidewall. Resilient fingers extend toward the nuclear fuel through the small gap to comply with variations in the size of the nuclear fuel due to fabrication tolerances as well as thermal expansion and swelling of the nuclear fuel, for example UO2, when undergoing fission. The nuclear fuel cladding is formed according to an additive manufacturing process, for example laser powder bed fusion printing.

Abstract: An optical fiber-based gamma-ray calorimeter (OFBGC) sensor array which uses a thermal mass with a low thermal conductivity is provided. Advantages of the OFBGC sensor array include: 1) the number of sensors in the OFBGC sensor array is adjustable and limited only by the spatial resolution of the OFBGC sensors, within the OFBGC sensor array, and 2) the OFBGC sensor design is simpler to build than a conventional optical fiber-based gamma thermometer (OFBGT) sensor array. One purpose of the OFBGC is to determine the power distribution in nuclear reactors.

Abstract: A system and method for determining an object characteristic from a timed sequence of measured characteristics wherein the object characteristic is determined based on a comparison of a current measured characteristic against a variable reference characteristic. The variable reference characteristic is selected by iterating through the timed sequenced and determining a separate quality metric for the current measured characteristic against each earlier measured characteristic and selecting the variable reference as a function of the determined quality metrics. In one embodiment, iteration continues only until an earlier measured characteristics is found with a quality metric that meets or exceeds a threshold value. In another embodiment, iteration continues through a plurality of earlier measured characteristic (perhaps all) and the variable reference is selected as the earlier measured characteristic with the highest quality metric. The measured characteristics may include OFDR measurements.

Abstract: An improved method for embedding one or more sensors in SiC is provided. The method includes depositing a binder onto successive layers of a SiC powder feedstock to produce a dimensionally stable green body have a true-sized cavity. A sensor component is then press-fit into the true-sized cavity. Alternatively, the green body is printed around the sensor component. The assembly (the green body and the sensor component) is heated within a chemical vapor infiltration (CVI) chamber for debinding, and a precursor gas is introduced for densifying the SiC matrix material. During infiltration, the sensor component becomes bonded to the densified SiC matrix, the sensor component being selected to be thermodynamically compatible with CVI byproducts at elevated temperatures, including temperatures in excess of 1000° C.

Abstract: A fiber optic sensor and a related method of manufacture are provided. The fiber optic sensor includes an embedded optical fiber contained within a metal diaphragm assembly, where the terminal end of the optical fiber is positioned opposite a diaphragm. The method includes forming a metal-embedded optical fiber by ultrasonic additive manufacturing and securing the metal-embedded optical fiber to a housing having a diaphragm that is opposite of the terminal end of the optical fiber. The sensor can provide extremely accurate pressure measurement at high temperatures and in highly corrosive media. An optical fiber-based pressure sensing system is also provided.