Experience of TRACY experiments

Aizawa, Eiju; Yamane, Yuichi  

TRACY (Transient experiment critical facility) is a reactor to perform supercritical experiments using low-enriched uranyl nitrate aqueous solution. In a supercritical experiment, up to 3$ of reactivity is inserted by withdrawing a control rod, called "transient rod," from the center of the core tank or feeding fuel solution into the core tank.Since 1996, TRACY supercritical experiments have been performed and transient data such as power, temperature and pressure have been measured and evaluated. Furthermore, we have developed a system to observe solution behavior under criticality accident condition for the elucidation of transient events. Those experiences we have gained through the TRACY experiments will be presented at the lecture in the 46th reactor physics summer seminar of the Atomic Energy Society of Japan.