High temp. nuclear reactor hot gas duct shielding - prevents direct radiation shine to pod heat exchanger

摘要

Gas cooled nuclear reactor has heat exchangers mounted separately from the reactor vault, e.g. in surrounding pods in the vessel wall, hot gas leaving the reactor passes through a (radial) duct to the space below each heat exchanger. On leaving this radial duct the hot gas enters an annular space beneath the heat exchanger and separated from the central chamber beneath the heat exchanger by an inner annular wall possessing passages radially through it communicating between the annular chamber and central chamber. These openings are angularly offset from the point of entry of the hot gas radial duct into the annular chamber, so that there is no direct line of sight for the radiation from the reactor region to the space below the heat exchanger. The shielding arrangement shown ensures that no direct line of sight of radiation occurs along the hot gas duct to the heat exchanger pod, but at the same time it has a minimal effect upon the gas flow, excessive pressure drop is not produced and there is through mixing of the gas.