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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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Work advances on X-energy’s TRISO fuel fabrication facility
Small modular reactor developer X-energy, together with its fuel-developing subsidiary TRISO-X, has selected Clark Construction Group to finish the building construction phase of its advanced nuclear fuel fabrication facility, known as TX-1, in Oak Ridge, Tenn. It will be the first of two Oak Ridge facilities built to manufacture the company’s TRISO fuel for use in its Xe-100 SMR. The initial deployment of the Xe-100 will be at Dow Chemical Company’s UCC Seadrift Operations manufacturing site on Texas’s Gulf Coast.
J. H. Brindley
Nuclear Science and Engineering | Volume 23 | Number 4 | December 1965 | Pages 313-328
Technical Paper | doi.org/10.13182/NSE65-A21067
Articles are hosted by Taylor and Francis Online.
Flat-plate fuel-element surface temperatures in the Organic Moderated Reactor Experiment were monitored by 0.005-in. (0.013-cm)-diam chromel-alumel thermocouple wires, spot-welded to the stainless-steel fuel-plate surface. The thermocouple assembly, being exposed to the coolant stream, is subject to thermal-loading errors; as a result, thermocouple-calibration tests were performed in a forced-convection heat-transfer loop with Santowax O-M flowing over an electrically heated test plate containing typical thermocouple specimens. The tests were conducted under the following simulated reactor conditions: coolant temperatures from 300 to 600°F (149 to 316°C), coolant velocities from 10 to 20 ft/sec (3.1 to 6.1 m/sec), and heat fluxes ranging from 0.50 × 105 to 1.6 × 105 Btu/(h ft2) (15.77 to 50.46 W/cm2). Test results demonstrate that at reactor operating conditions, 600 °F organic coolant flowing at 17.5 ft/sec (5.34 m/sec), the observed fuel-plate surface temperature is 700 °F (371 °C), while, in reality, the actual surface temperature is 750 °F (399 °C). The thermocouple thermal-loading errors were found to be a function of the coolant Reynolds and Prandtl numbers. Heat flux had no effect on the calibration. Excellent agreement was obtained between the experimental and predicted (Dittus-Boelter) heat-transfer coefficients for the organic coolant. Thermocouple-calibration factors for correction of observed surface temperatures over a wide range of operating conditions, are presented as a function of the organic-coolant heat-transfer coefficient on the fuel-plate surface. An electrical-analogue model of a thermocouple assembly on the surface of an OMRE fuel element was constructed to: a) verify experimental results; b) study the effect of a fouling film on surface-temperature measurements; and c) provide an inexpensive means of calibrating surface-attached thermocouples on fuel plates for future use. Prediction of thermal-loading errors associated with this type of surface-temperature measurement by the use of existing mathematical results is discussed. Good agreement was obtained between the electrical-analogue results, the analytical predictions, and the experimental data. Film formation on the fuel plate and the thermocouple wire was observed to reduce the thermocouple-calibration factor by as much as 45%.
