Irradiation data on Gilsocarbon graphites for high temperature nuclear reactors

Reasons for the initial selection of Gilsocarbon based graphite for use in High Temperature Reactors are discussed. Data are presented on the dimensional changes, the changes in the technologically most important properties and on the creep, induced by irradiation in the temperature range 600-1200 deg C. A range of fast neutron doses approaching 5 x 10 {sup 21} n.cm{sup -2} is covered.