NUCLEAR REACTOR FUEL ELEMENT Russian patent published in 2002 - IPC

FIELD: nuclear power engineering; fuel rods for uranium-graphite fast reactors. SUBSTANCE: fuel element meant for use in type RBMK-1000 power reactors has pile of nuclear fuel pellets placed in tube which is closed on both ends with sealed plugs. Tube has space on one end accommodating compensating spring that functions to hold pellet pile tight against opposite plug. Plug to which pellet pile is pressed is made in the form of can that holds member being deformed at initial deformation pressure. This pressure exceeds operating pressure of compensating spring by minimum 50%. Member to be deformed should be better made in the form of compression spring; supporting disk is installed between this member and pellet pile. One end of pellet pile is free to move within tube in case of wedging of its other end; tube is free from longitudinal tensile stresses in the event of moisture ingress. EFFECT: avoided plug separation and radioactive fuel ingress in coolant. 3 cl, 1 dwg