Advanced Designs and Concepts
The purpose of this task area is to increase the understanding of advanced fuel design concepts, including use of new cladding materials, increases to fuel lifetime, and expansions to the allowable fuel performance envelope. These improvements will allow the fuel performance related plant operating limits to be optimized in areas such as operating temperatures, power densities, power ramp rates, and coolant chemistry. Accomplishing these goals leads to improved operating safety margins and improved economic benefits.
The Advanced Designs and Concepts task includes development of specific technologies for advanced nuclear fuels and benchmarking and test activities for developed computer models. This task consists of testing advanced fuel designs and features in prototype forms. The goal is to demonstrate design features that can be used in advanced nuclear fuels. The benchmarking is intended to provide confidence in the derived computer models and make accurate applications possible.
The use of successively complex experiments will demonstrate steady-state, transient, accident, and failure behavior of nuclear fuel. This information will be used to capture information required to define the licensing basis of advanced fuel.
The irradiation design studies of advanced fuel designs will center on design of rodlets and lead test assemblies for an irradiation campaign for advanced technology fuel. Testing and measurement equipment required to derive experimental results will be designed and qualified. The rodlets and fuel will be designed and manufactured. The goal of the experimental program is to provide data required to define the safety and licensing information for production fuel. Testing performed in the reactor will require additional testing out of the reactor to define mechanical properties related to repeated stress, thermal cycling, and failure modes.
This series of tests will increase in complexity from steady state, transient, accident, and failure mode testing. The increasing complexity of the experimental design will build on previous results and evolve for improving performance.
Mechanistic Understanding of Fuel Behavior
This task area will involve testing and modeling of specific aspects of LWR fuel, cladding, and coolant behavior. Examples include pellet cladding interaction, fission gas release (FGR), coolant chemistry effects on corrosion, and crud (oxide) formation. Improved understanding of fuel behavior can be used in fuel design, licensing, and performance prediction.
An improved fundamental understanding of phenomena that impose limitations on fuel performance will allow fuel designers, fabricators, plant chemists, and code developers to optimize the performance of current fuels and the designs of advanced fuel concepts. A life-cycle concept will be applied so that optimization will be applied to fabrication, in-reactor use, and performance as spent fuel in storage. Fundamental mechanistic models will provide a foundation for supporting the LWRS Program strategic objectives in developing advanced fuels.
This task area will use increased understanding of specific fuel performance phenomena that will be integrated into encompassing fuel performance advanced tools. These advanced tools, including modeling and simulation codes, advanced experimental capabilities, and real-time performance monitoring, will be developed to enhance plant and repository efficiency. In addition, the advanced tools developed will be used to minimize the time required to realize the gains made through this R&D effort by decreasing the amount of time needed for materials development and fuel qualification