Flow measurements by noise analysis of thermocouple signals from the BOCA experiment at the Studsvik R2 reactor

• Published in: Progress in nuclear energy (New series) Vol. 43; no. 1-4; pp. 289 - 296
• Main Authors: Karlsson, J.K.-H., Morén, M., Jonsson, B., Tomani, H., Bergdahl, B.-G.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Tarrytown, NY Elsevier Ltd 2003; Oxford Elsevier
• Subjects: Applied sciences; delay time estimation; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; flow rate measurement; fuel testing; Installations for energy generation and conversion: thermal and electrical energy; noise analysis; Studsvik research reactor; Sweden; Europe; Studsvik research reactor; flow rate measurement; fuel testing; delay time estimation; noise analysis; Background noise; Signal analysis; Research reactor; Flow measurement; Nuclear reactor; Thermocouple
• ISSN: 0149-1970
• DOI: 10.1016/S0149-1970(03)00037-4

At the Studsvik research reactor R2, a Boiling Capsule (BOCA) is used for long-term irradiation of BWR and PWR fuel rods. The BOCA experiment consists of a pressurised container that can hold a number of fuel rods in a bundle type configuration. The water flow inside the tube is driven by natural circulation. The coolant flow rate is not normally measured in the BOCA rig. Only thermocouples, measuring the water temperature at pertinent locations, are located inside the pressure tube. To confirm calculated values of the flow rate, transit time determination through the cross-correlation technique has been implemented. Campaigns of noise measurements have been performed at five different occasions. The measurement campaigns have included ∼10 thermocouples at 3–4 different power levels. The results for the flow rate range between 0.15 and 0.35 m/s depending on reactor power level. The statistical accuracy of the results has also been evaluated. This paper shows that signal processing of thermocouple signals can be used to obtain rather accurate values of the flow rate in BOCA.