%0 Journal Article %T Analyses of the OSU-MASLWR Experimental Test Facility %A F. Mascari %A G. Vella %A B. G. Woods %A F. D'Auria %J Science and Technology of Nuclear Installations %D 2012 %I Hindawi Publishing Corporation %R 10.1155/2012/528241 %X Today, considering the sustainability of the nuclear technology in the energy mix policy of developing and developed countries, the international community starts the development of new advanced reactor designs. In this framework, Oregon State University (OSU) has constructed, a system level test facility to examine natural circulation phenomena of importance to multi-application small light water reactor (MASLWR) design, a small modular pressurized water reactor (PWR), relying on natural circulation during both steady-state and transient operation. The target of this paper is to give a review of the main characteristics of the experimental facility, to analyse the main phenomena characterizing the tests already performed, the potential transients that could be investigated in the facility, and to describe the current IAEA International Collaborative Standard Problem that is being hosted at OSU and the experimental data will be collected at the OSU-MASLWR test facility. A summary of the best estimate thermal hydraulic system code analyses, already performed, to analyze the codes capability in predicting the phenomena typical of the MASLWR prototype, thermal hydraulically characterized in the OSU-MASLWR facility, is presented as well. 1. Introduction Today, considering the sustainability of the nuclear technology in the energy mix policy of developing and developed countries, the international community, taking into account the operational experience of the nuclear reactors, starts the development of new advanced reactor designs. Some of the new nuclear reactor designs use passive safety systems based on the use of the natural circulation for the cooling of the core during the designed operational condition and for the removing of the residual heat during transient conditions [1¨C5]. Emergency systems based on natural circulation are considered, for example, in the AP600/1000 design, WWER-1000/V-392 and WWER-640/V-407 designs, AC-600 design, SMART design, IRIS design, SWR 1000 MWe design, and in the ESBWR design [4¨C7]. Examples of reactors that rely on natural circulation for the removing of the core power during normal operation are the MASLWR, the ESBWR, the SMART, and the CAREM design [5¨C7]. The MASLWR integral reactor concept [1, 2, 8¨C13], developed by Idaho National Engineering and Environmental Laboratory, OSU, and NEXANT¡ªBechtel, Figure 1, is a small modular PWR relying on natural circulation during both steady-state and transient operation, which includes an integrated steam generator (SG) consisting of banks of vertical helical tubes contained %U http://www.hindawi.com/journals/stni/2012/528241/