Sodium removal from sodium wetted under sodium ultra sonic scanner

• Published in: Nuclear engineering and design 2013-01, Vol.254, p.120-128
• Main Authors: Ignatius Sundar Raj, S., Sreedhar, B.K., Murugesan, N., Gunasekaran, T.G., Ramesh, C., Rajan, K.K., Ganesan, V.
• Format: Article
• Language: English
• Subjects: Applied sciences; Controled nuclear fusion plants; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; Fuels; Installations for energy generation and conversion: thermal and electrical energy; Moisture; Nuclear engineering; Nuclear fuels; Nuclear power generation; Nuclear reactor components; Nuclear reactors; Sodium; Sonics
• ISSN: 0029-5493; 1872-759X
• DOI: 10.1016/j.nucengdes.2012.09.010

[Display omitted] ► Sodium wetted USUSS was subjected to sodium cleaning by water vapour–CO2 process. ► Hydrogen released during the process was monitored and regulated in safe limit. ► The temperature of USUSS was maintained below 80°C to prevent caustic corrosion. ► The experiment revealed intricacies involved in the cleaning operation. ► The operational parameters for safe cleaning were optimised. Sodium is used as a coolant in primary and secondary heat transport systems of Liquid Metal cooled Fast Breeder Reactors (LMFBR). The Prototype Fast Breeder Reactor (PFBR) is in advanced stage of construction at Kalpakkam, India. Under Sodium Ultra Sonic Scanner (USUSS) is used to image the components dipped in sodium and more specifically the gap between Sub Assembly (SA) heads and the control plug. This is essential to confirm that no SA is protruding from its position. USUSS has to be qualified in sodium before its use in the reactor. After sodium testing, sodium adhering to the USUSS needs to be removed to prevent reaction with oxygen and moisture present in air when it is taken out. The sodium removal process is based on the use of moist carbon-di-oxide (CO2) at a temperature of about 353K. The reaction rate is controlled by varying the ratio of CO2 to moisture. Hydrogen released during the reaction of sodium with moisture is continuously monitored to ensure safe limits of hydrogen concentration. This paper describes the details of the experimental setup used in a cleaning pit for the removal of sodium adhering on USUSS and the technical details of the cleaning process.