A Regulated-Current Network Analog for Reactor Fuel End-Cap Temperatures
An analog of resistors and regulated-current sources has facilitated the thermal design of end caps for nuclear reactor fuel elements. The analog permits cylindrical-symmetric representation of the end caps, adjacent fuel, and sheath. With the analog, temperature distributions in various complex geometry end-cap designs can be readily determined. Non-uniform radial and axial heat source distributions, external uniform or non-uniform heat transfer coefficient distributions, and arbitrary internal contact conductance distributions between components can be treated. A feature of the analog design is the regulation of currents to the nodal points within the simulated fuel region, insuring independence of the current loadings at other nodal points. This facilitates rapid setting of the required heat source distribution. The analog has been used in the design of end caps of fuel elements for different fuel designs. Screening of proposed designs has been accomplished, and design configurations optimized. The principles of the design can be applied to analogs used for many other purposes.