Rupture of the internal structures supporting the packing: origin, expertise, remediation and monitoring

摘要

January the 3rd 2002. In the early evening, alarm is raised: a water flood of several m~3/sec is spilling over the cold water basin of Tihange NPP unit 3 cooling tower, threatening some underground installations of being ineluctably flooded. Decision is then taken to manually stop the 1000 MW/h production of the plant in order to allow a complete stop of the circulation pumps sending 35 m~3/s to the cooling tower. In the cold water basin it is a horrible sight: 2 of the packing supporting beams have fallen from their supports, causing the drop of tens of m~3 of packing whose debris clogged the water outlets of the basin, causing its overflowing. This paper present this incident, explain its origins, the short term engineering used in order to keep as short as possible the stops of the plant. Long term corrective measures were also taken to avoid any further similar rupture which can happen to any natural draught cooling tower ...