An Integral Lead Reactor Concept for Developing Countries

An Integral Lead Reactor (ILR) concept is proposed to be used in developing countries. The ILR is an association of the best characteristics of the American Integral Fast Reactor and of the Russian Lead-Cooled Reactor. The reactor is started with U-Zr and shifts cycle-by-cycle to the U-TRU-Zr fuel. Besides electricity generation an association of the ILR and a chemical heat pump for high-temperature industrial processes is idealized.

Homogeneous reactor cores based on the American and Russian experiences on fast reactor technology have been designed for conception evaluation. The main core parameters are evaluated in the first and in the equilibrium cycles as a function of the pin diameter in the 6.35- to 10.4-mm range, pin pitch-to-diameter (p/d) ratio in the 1.308 to 1.495 range, and reactor power in the 300- to 1500-MW(electric) range. To mitigate the transient-overpower accident, a requisite is to have a burnup reactivity (k_Bu) < _eff in the equilibrium cycle. The use of enriched uranium results in a poor core conversion ratio, and this fuel must be replaced as quickly as possible by the generated plutonium. In the equilibrium cycle the burnup reactivity goal is achieved for core power of 300 MW(electric) using a pin diameter of 10.4 mm and p/d of 1.308. The lead void reactivity is negative for reactor power lower than 750 MW(electric). The Doppler effect is small, as expected in a fast reactor loaded with metallic fuel. The fast fluence limit of 4.0 × 10²³ n/cm² is a restrictive parameter of the ILR, and to obtain the burnup of 100 GWd/t HM, a core optimization is needed. All the base accident evaluation and the optimization of the ILR are still to be performed.