GB928236A — Improvements in or relating to organic liquid moderated and cooled nuclear reactors

USPTO Abstract

928,236. Nuclear reactors. UNITED KING- DOM ATOMIC ENERGY AUTHORITY. Nov. 20, 1961 [Nov. 22, 1960], No. 40084/60. Class 39 (4). A nuclear reactor is cooled and moderated by an organic liquid which makes two passes through the core, the first pass extending in close proximity to the fuel and having a lower polymer content than the second pass which is separated from the first by dividing means, and restrictor means are provided in the second pass to equalize pressure across the dividing means. The first pass, which contains about 30% of a terphenyl polymer of high molecular weight, cools the fuel sealed in the cartridges 1, which are spaced on a triangular pitch lattice, enters the compartment 5 and is circulated by the pump 11 through the heat exchanger 14. The more viscous second pass, containing about 50% of the polymer, acts as a moderator and is restricted in its passage through the compartment 6 by baffles 6a which introduce a pressure drop in the compartment. To purify the moderator which has deteriorated, the tapping 17 leads some of the liquid to the distillation column 18, and purified distillate is returned into pipe 10. Waste products are dumped through pipe 20. The distillation column may be provided with means for connecting it into the moderator or coolant circuit as required. A further tapping 21 leads the liquid from the near stagnant region of the coolant circuit to the second circuit.