Dimensional and Physical Property Changes of High Temperature Reactor Graphites Irradiated at Temperatures in the Range 600 — 1200°C

During the past ten years the feasibility of helium cooled high temperature reactors (H.T.R) has been studied in some depth both in Europe and the United States. At the present time it can be stated that the feasibility stage has been completed and that the developments which have accrued from the work, in particular the concept of coated particle fuel and the use of helium in the three operating reactors (Dragon, A.V.R, and Peach Bottom), have been so successful that phase two of the work, that of commercial exploitation has been entered. This has generated an increasing requirement for materials property data, particularly in the graphite field.