Movements in prestressed concrete reactor vessels

Prestressed concrete reactor vessels (PCRVs) are constructed by placing concrete using lift and bay arrangement. The vessels are built up in a number of individual bays. The size and shape of these bays and the order in which they are cast has a significant effect on the size and sense of construction movements. Lack of information about factors such as age of any bay before prestress, the time of year of casting and the time interval between adjacent vertical and horizontal bays would lead to costly design improvements and could lead to unforeseen technical problems both under operational and ultimate conditions. An attempt has been made to establish a philosophy and a rational method of assessing fairly accurately these movements. Various movements and their causes and effects are discussed in detail. A three-dimensional finite element analysis is developed to predict these movements and to assess the behaviour of the vessel parameters under operational conditions. A computer program, ISOPAR, is developed and is tested against experimental and measured results.