| 摘要 |
1,160,219. Energy absorbing devices. COMMISSARIAT A L'ENERGIE ATOMIQUE. 22 Sept., 1967 [28 Oct., 1966], No. 43293/67. Heading F2E. [Also in Division G6] An energy absorbing device for damping the fall of articles such as fuel elements in a vertical duct in a nuclear reactor comprises a first cylinder 26 arranged to receive the impact of the article and to be plastically deformed in order to absorb its energy and a second member 16 supporting the first member 26 and extending below it. The second member 16 has a weaker portion 22 arranged to yield in the event of a severe impact so that the lower end of member 16 is arranged to contact a fixed structure and still provide support for the first member 26. As described, pressure tubes 6 are attached to the calandria bottom 4 of a heavy water-moderated nuclear reactor which is cooled by downward flow of carbon dioxide. A guide 8, comprising two thin metal sleeves separated by thermal insulation, restricts the heating of the heavy water. The deformable tube 26 is crimped to the outer tube 16 and supports a thrust member 30, a dummy bottom fuel element 34 and a series of fuel elements (not shown). The thrust member 30 is arranged to collect debris (e.g. graphite fragments). In the event of a comparatively small impact on member 30, the breaking portion 22 remains intact, the energy being absorbed by deformation of member 26. In the case of a larger impact, portion 22 yields so that the lower end of member 16 is supported by reflective shielding 20 whilst member 26 absorbs the energy by deformation. The thinner portion 22 may be replaced by fastenings, soldered or screwed to the upper and lower portions of member 16. and arranged to break at a calibrated load. |
