COMPOSITE FUEL ASSEMBLY FOR POWER CONTROL SYSTEM OF NUCLEAR REACTOR CORE Russian patent published in 2001 - IPC

FIELD: nuclear power engineering; water- moderated power reactors. SUBSTANCE: device used for type VVER-440 nuclear power reactors and miscellaneous reactors where local neutron bump should be reduced has fuel assembly in the form of bundled fuel elements with spacer grids in-between placed in tubular can with pressurized tubes filled with fuel pellets and provided with top compensating gas spaces; it also has neutron-absorbing extension piece whose connecting head is joined to tubular can and metal inserts mounted on top fuel pellets; additional neutron- absorbing element is arranged around fuel bundle; this element is made of hafnium or hafnium-zirconium alloy; it is placed around gas spaces and its ends are spaced 30 mm from top end of uppermost fuel pellet. EFFECT: improved uniformity of fuel burn-up among fuel elements; reduced cost of power generated , improved safety of plant. 7 cl, 3 dwg