Nuclear fuel assembly - for gas cooled reactor using stacked annular sheathed elements

摘要

The fissile or breeder material used is in the form of particles esp. coated in any suitable way e.g. with pyrolytic carbon, and these are retained between coaxial or parallel vertical perforated walls so that they form an annular bed through which the coolant gas flows freely in a radial direction either from the inside out or vice versa. To minimize clogging of the free gas channels through the particles due to accumulated pressures caused by gravity and/or thermal expansion, the annular bed is made up of a number of vertically stacked sections of equal height. These are so shaped that the stack is stable.