METHOD AND AUTOMATED UNIT FOR MONITORING FUEL ELEMENT TIGHTNESS Russian patent published in 2004 - IPC

FIELD: nuclear power engineering. SUBSTANCE: method includes blowing of fuel element surface with ejected annular gas jet upstream of rough-vacuum zone for stepped release of residual pressure. Gas jet builds up preliminary rarefaction at inlet of rough-vacuum chamber. In the course of its flow fuel element is checked for heavy and small leaks. Heavy leaks are recognized by pressure rise in high-vacuum zone for stepped release of residual pressure. Small leaks are detected by signal coming from leak detector. Automated monitoring unit implementing proposed method has tightness monitoring module with gas jet injector installed at its inlet. Circular nozzle of mentioned ejector is concentric to fuel element surface and opposes its movement. Monitoring chamber communicates through valve with high-vacuum pumping facility. EFFECT: preventing mechanical damage to fuel elements in their contact with monitoring unit. 2 cl, 4 dwg