Record of Programme and Discussion at Symposium of Papers from Dragon Contractors Held at A.E.R.E., Harwell 14th - 16th March 1966. Dragon Project Report

The first type, for the A.V.R.-reactor, contains 6 g of heavy metal as (U, Th)C₂, with fully enriched U and a U:Th ratio of 1: 5. It has an unfuelled shell about 5 mm thick and a kernel in which the particles are dispersed, It is fabricated by the following steps: (i) Preparation of the graphite powder by mixing pure natural and artificial graphite powder with small amounts of carbon black and resin binder, (ii) overcoating of coated fuel particles with this powder, (iii) prepressing the centre of the sphere at low pressure and room temperature ina rubber die by the so-called semi-hydrostatic pressing method, (iv) forming the shell in a second rubber die and moulding the kernel in this shell to full pressure, and (v) heating the spheres to 1800°C in vacuum.