NUCLEAR REACTOR FUEL ELEMENT

摘要

FIELD: nuclear power engineering; manufacture of fuel assemblies for nuclear power reactors. SUBSTANCE: displacement of spacer grids over central tube during radiation growth and thermal expansion of fuel elements is confined within their displacement distance due to disposing stop rings on both sides of spacer grid which are secured with aid of bosses in central tube holes at 90 deg. between upper and lower bosses either side of each spacer grid, distance between spacer grid and lower edge of upper stop ring for bottom part of spacer grid being 0.45-05 of central tube diameter; for top part of each spacer grid distance between spacer grid and lower edge of upper stop ring is 0.95-1.0 of central tube diameter; three guide channels spaced 120 deg. apart and equally spaced from central tube carry safety rings on top part above spacer grids which function to limit maximal displacement distance of spacer grids during radiation growth and thermal expansion of fuel elements, distance between spacer grid and lower edge of safety ring in bottom part of spacer grid being 0.65-0.7 of guide channel diameter; for top part of spacer grids distance between spacer grid and lower edge of safety ring is 1.15-1.16 of guide channel diameter. Safety ring is made in the form of snap ring and attached to guide channel by spot welding. EFFECT: reduced cost and facilitated manufacture. 2 cl, 7 dwg