| 摘要 |
1,214,136. Reactor shields. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. 23 Jan., 1968 [24 Feb., 1967], No. 9006/67. Heading G6C. In a liquid sodium cooled, fast reactor, the tank containing the core and coolant is closed by a horizontal, top shield which is rotatable through peripheral gearing. Liquid seals are provided at the inner and outer faces of the shield to prevent the loss of the sodium vapour and the inert gas blanket. The shield has an upper layer of concrete or steel shot and a lower layer through the top section of which flows a cooling gas, the bottom section being formed of stainless steel sheeting. The outer face seal is formed with mercury and the lower, or inner, face with sodium. The latter is maintained at a temperature lower than the reactor temperature by being embedded in the steel layer. To prevent leakage through the liquid seals blanket gas is fed into the clearance annulus between the shield and tank at a pressure to cause it to bubble through the liquid into the tank. A step is provided in the cylindrical shield wall to prevent ejection of the shield. A plate is attached to the inner face of shield to prevent frothing at the coolant-blanket gas interface. |
