A METHOD OF CHARGING A GAS-COOLED HIGH TEMPERATURE NUCLEAR REACTOR

摘要

1,269,804. Fuelling reactors. BROWN BOVERI/KRUPP REAKTORBAU G.m.b.H. 8 May, 1969 [8 May, 1968], No. 23614/69. Heading G6C. A gas-cooled reactor having fuel elements in the form of balls has a core divided into seven compartments 1, 5, 6, 7, 8, 9, 10 by a cylindrical graphite wall 2 and radial graphite walls 4, the core being surrounded by a reflector 3. Each compartment has its own fuel element charging and discharging equipment (not shown), the balls passing through the compartment by gravity. The reactor is fuelled by a method which ensures that each fuel element of one type, i.e. fissile or fertile, spends the same total time in the core. In the case of fissile elements this also ensures uniform burn-up. This method comprises passing the balls consecutively through different compartments in a certain sequence. Thus the balls are introduced into compartments 5, 6, these compartments are emptied and then the balls are introduced into compartments 7, 8. The compartments 7, 8 are emptied and the balls are introduced into compartments 9, 10. Finally, the balls are passed through compartment 1. The method also results in a more uniform power density over the entire section of the core since the fuel elements passing through the central compartment 1 are somewhat exhausted and this reduces the neutron density at the core centre. In a modification (Fig. 2, not shown) for use where the fuel elements comprise a mixture of fissile elements and fertile elements, the reactor core is divided into eight compartments, viz. a central compartment surrounded by seven outer compartments. The fuelling method consists of passing the fuel elements successively through four of the outer compartments during which process the fissile elements become spent. The mixture is then classified on a weight basis to separate the fertile elements and new fissile elements are added to replace the spent fissile ones. The new mixture is passed consecutively through the three remaining outer compartments and finally through the central compartment so that all the fuel elements are now spent.