| 摘要 |
978, 016. Controlling reactors. BABCOCK & WILCOX Ltd. April 6, 1961 [April 7, 1960 No.12453/61. Heading G6C. A reactor is controlled by the variation with temperature of a neutron absorbing vapour in a closed tube 2 in the reactor core. The aluminalined stainless steel tube has a thicker ribbed lower end at the edge of the core, which contains liquid or solid absorber and is heated by coolant leaving the core; the tube also contains a gas, e.g. He, and is enclosed in a graphite sleeve. The gas pressure and absorber are chosen so that the boiling point of the absorber is near the operating temperature of the reactor. Suitable absorbers are Cd, Hg, rare earth metals, halides of these, and boron compounds. Materials with higher boiling points or which sublime may be used in tubes as safety devices for emergency shut-down. |
