10 research outputs found

    Considerations in relation to off-site emergency procedures and response for nuclear accidents

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    The operation of nuclear facilities has, fortunately, not led to many accidents with off-site consequences. However, it is well-recognised that should a large release of radioactivity occur, the effects in the surrounding area and population will be significant. These effects can be mitigated by developing emergency preparedness and response plans prior to the operation of the nuclear facility that can be exercised regularly and implemented if an accident occurs. This review paper details the various stages of a nuclear accident and the corresponding aspects of an emergency preparedness plan that are relevant to these stages, both from a UK and international perspective. The paper also details how certain aspects of emergency preparedness have been affected by the accident at Fukushima Dai-ichi and as a point of comparison how emergency management plans were implemented following the accidents at Three Mile Island 2 and Chernobyl. In addition, the UK’s economic costing model for nuclear accidents COCO-2, and the UK’s Level-3 Probabilistic Safety Assessment code “PACE” are introduced. Finally, the factors that affect the economic impact of a nuclear accident, especially from a UK standpoint, are described

    The post-yield behaviour of an internally pressurised cylinder having a pad attachment

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    A study of pressurised cylinders having attached pads was made. The possibility of a fatigue crack developing along one side of the pad was noted. For both defect-free components and components having axial crack-like defects, finite element and limited experimental studies of the local and global deformations were made and results were found to be in close agreement. Both welded and integrally machined pads were studied. It was observed that for defect-free components, the method of pad attachment has little effect on the burst pressure. The presence of a pad was found to increase the burst pressure of cracked components by a small but significant margin. A finite element-based parametric study of pipes with part-penetrating defects and a range of pad geometries has demonstrated that pad size has little influence on the limit load for any of the cracked cases considered. However, pipes with penetrating defects were strengthened by the presence of pads, particularly for thin-walled sections

    Simplified J-estimations based on the engineering treatment model for homogeneous and mismatched structures

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    This paper presents simplified J-estimation equations for defective homogeneous and strength mismatched structures, based on the engineering treatment model (ETM). For homogeneous structures, two modifications are made to the existing ETM J-estimation equations; firstly a modification of the contained yielding solutions, and secondly modification of J-estimation equations for materials exhibiting Lueders strain. Based on the proposed J-estimation equations for homogeneous structures, J-estimation equations for welded structures with strength mismatch are proposed. The proposed J-estimation equations for both homogeneous and mismatched structures are then compared with selected elastic-plastic finite element results. The comparisons show excellent agreement and so provide confidence in the use of the proposed J-estimation equations for defect assessment. Finally, comparison with another simplified method, the R6 method, is discussed. (orig.)Also published in: Engineering Fracture Mechanics 68 (2001), 9-27Available from TIB Hannover: RA 3251(2001/2) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
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