IRIS Responsiveness to Generation IV Road-map Goals

The DOE Generation IV road-map process is in its second and final year. Almost one hundred concepts submitted from all over the world have been reviewed against the Generation IV goals of resources sustainability; safety and reliability; and, economics. Advanced LWRs are taken as the reference point. IRIS (International Reactor Innovative and Secure), a 100-335 MWe integral light water reactor being developed by a vast international consortium led by Westinghouse, is one on the concepts being considered in the road-map and is perhaps the most visible representative of the concept set known as Integral Primary System Reactors (IPSR). This paper presents how IRIS satisfies the prescribed goals. The first goal of resource sustainability includes criteria like utilization of fuel resources, amount and toxicity of waste produced, environmental impact, proliferation and sabotage resistance. As a thermal reactor IRIS does not have the same fuel utilization as fast reactors. However, it has a significant flexibility in fuel cycles as it is designed to utilize either UO{sub 2} or MOX with straight burn cycles of 4 to 10 years, depending on the fissile content. High discharge burnup and Pu recycling result in good fuel utilization and lower waste; IRIS has also attractive proliferationmore » resistance characteristics, due to the reduced accessibility of the fuel. The safety and reliability goal include reliability, workers' exposure, robust safety features, models with well characterized uncertainty, source term and mechanisms of energy release, robust mitigation of accidents. IRIS is significantly better than advanced LWRs because of its safety by design which eliminates a variety of accidents such as LOCAs, its containment vessel coupled design which maintains the core safely covered during the accident sequences, its design simplification features such as no (or reduced) soluble boron, internal shielding and four-year refueling/maintenance interval which significantly reduce workers' exposure. IRIS has indeed a superb safety which makes it an excellent candidate to fulfill the Generation IV goal of no off-site emergency response. Finally, the economic goal includes various factors contributing to cost of electricity and capital at risk. Significant uncertainties exist on capital cost of all Generation IV concepts and a consensus is not reached how well advantages of modularity, simplicity and standardized, multiple fabrication compare with economies of scale. Still, IRIS is expected to have attractive economics because of its modular, simplified design which can be constructed in a three-year period and its small-to-medium size which significantly reduces the financial risk. In summary, IRIS is positively responsive to all Generation IV goals and is an excellent candidate for further development by its large international consortium. (authors)« less