On the effectiveness of some construction and technological solutions for Nuclear Power Plants

The construction of nuclear power plants (NPPs) involves huge amounts of concrete and reinforced concrete works. In the design of the reactor building of modern large unit is placed more than 200 thous. m³ of concrete. The content of metal in the form of rebar, facing, embedded items in many of the elements exceeds 400 kg/m³ of concrete. The reinforced concrete works in the reactor building to a large extent determine the longer duration of construction and, as a consequence, the resulting costs. Such works are performed with traditional technology – piece reinforcement with the use of relatively small meshes, grating, large and small panel prefabricated formwork, and with industrial methods as well. During industrial approach, which reduces the duration of construction, the reinforcement is performed with the large reinforcing or reinforcing-formwork blocks. However, in this case the duration of the preparatory period will double and there will be additional cost items. Large erection blocks include the extra metal for creation of the necessary transport and erection stiffness; and also provide well-equipped workshops for the manufacturing of blocks. In addition, special vehicles and cranes with high lifting characteristics are required. One of the most important structures of NPPs is the foundation slab of the reactor building. The slab area is 5-6 thousand m², thickness of 2.5 -3 m, duration of erection – up to 1 year. In this work was made an attempt to assess the comparative effectiveness of two common construction and technological solutions for the foundation slab – the traditional one, when performing reinforcing works with piece rods, and the industrial one, when reinforcing with blocks. The cost, labor content and duration of construction are determined depending on structure and construction technology. The boundaries of industrial technology were marked. (paper)