FUEL ELEMENT OF NUCLEAR POWER REACTOR Russian patent published in 1995 - IPC

FIELD: nuclear power engineering. SUBSTANCE: fuel element has pelletized fuel rod in sealed zirconium-alloy cladding. End caps are also made of zirconium alloy; one of end caps comes in contact with fuel through getter neck. Neck length is chosen between two and six thicknesses of cladding wall and neck sectional area S_n to head sectional area S_h ratio is within 1/7≅ S_n/S_h≅ 1/2.. Getter head length l_h is found from relationship l_h/l_fp≥ 0,001·(A/3,5-1),, where A is maximum moisture content admitted by manufacturing conditions in fuel pellets amounting to 3,5 ppm≅ A≅ 7,0 ppm;; l_fp is length of fuel pile of fuel element. Neck may be made from stainless steel pipe section to prevent diffusion of hydrogen from head to neck and end cap. EFFECT: improved design. 4 cl, 5 dwg