Development of steam-water cycle chemistry for steam generator of research reactor MBIR

The compatibility of water chemistry with structural materials of steam-water cycle is most important condition for long-term operational reliability of steam generators (SGs). The reverse type steam generators (RSGs) were selected for the multipurpose fast research reactor MBIR under development in Russia by NIIAR and NIKIET. The main design feature of RSG is sodium coolant circulation within the tube bundle while the steam-water medium is going through the shell side. The design of RSG should ensure their reliable and safe operation during 200 thousand hours of service life. The above RSGs will provide both heat removal from the secondary sodium coolant loop to steam-water environment of the third coolant circuit and the generation of superheated steam for steam turbine. Neutral water chemistry was proposed for RSGs of MBIR reactor due to a number of advantages over alternative options, in particularly it will reduce the capital and operating costs, improve environmental performance and ensure high reliability and design life of RSGs. (author)