VORRICHTUNG ZUM ABTRAGEN DER AUSSENSCHALE VON KUGELN

摘要

Spent nuclear fuel elements of spherical shape are stripped of their outer graphite shell surrounding the graphite matrix in which fuel particles are embedded by being admitted one by one to a work space between a rotary milling disk and an axially shiftable, but non-rotary, reaction disk. The radially ribbed stepped surfaces of low-pitched helical configuration allow the spherical body to shift its position several times per revolution as it rolls around between the disks under pressure from a spring acting on the axially movable disk. A spacing collar prevents the two disks from approaching closer than a minimum spacing sufficient to prevent more than the outer graphite shell to be worn away. By operating the work space with two or more spheres therein at the same time, a damaged or out-of-round fuel element can be ground to a spherical shape if at least one of the spheres in the work space is truly spherical. Pairs of disks may be operated together in coaxial alignment to provide a high throughput rate. The graphite grindings are usable for making new fuel elements.