A Pressurized Water Reactor (PWR) is a major reactor type for power generation in the world. A large-scale power uprate is one of the best way to enhance the economy of the PWR. It is indispensable to introduce an innovative fuel concept for this aim. A most promising concept is a dual-cooled annular fuel which has the cooling flow inside as well as outside the surface unlike the conventional cylindrical fuel. This drastic change can greatly decrease the fuel temperature and so provide a potential of high power density fuel. Recently KAERI launched a R&D program for dual-cooled annular fuel technology. Now an excellent manufacturing technique for annular sintered pellet has been successfully developed. Several annular test rods with those pellets are being irradiated in HANARO reactor. In parallel, thermal-hydraulic and mechanical tests are also planned to investigate the characteristics of a tight lattice which is inevitable in annular fuel array. A final goal of this R&D program is to develop the dual-cooled annular fuel which is capable of accommodating 20% power uprate for the existing OPR-1000 reactor.

The manufacturing technology of U powder was firstly developed in the world using an atomizing method. This atomized U powder is superior in the in-reactor performance and in manufacturing cost to the conventional crushed powder. Commercial grade powder samples have been provided 12 times for all the fuel vendors in the world, as of the end of 2008. Foreign fuel vendors have been developing fuel manufacturing technology and carrying out the in-reactor tests. Up to now, our atomized U powder has been recognized internationally as the most promising powder for the next generation fuel.

The manufacturing technology of HANARO fuels has been developed without a reliance on foreign technology. During this period, a mass production facility was designed and constructed, additionally quality control technology has been established. From 2006, high quality fuels have been supplied to HANARO reactor.

To increase the utilization of limited uranium resources and diversify technologies related to back-end fuel cycle, basic fabrication and design technology for LWR MOX fuel have been developed since 1997.

Two test MOX fuel rods were fabricated with equipment and technology developed by KAERI through international cooperation, which had been successfully irradiated in the Halden reactor up to 50 GWd/tHM. In addition, fuel behavior during the test was predicted accurately by the COSMOS code developed by KAERI for analyzing MOX performance. Post irradiation examination (PIE) showed that microstructure of the KAERI’s test rods is comparable to that of the one fabricated by one of the advanced MOX manufacturing companies.

All the information obtained thus far proves that the developed fabrication and design technology for LWR MOX fuel is satisfactory.