Construction aspects of containment structures of a typical large atomic power project

The Containment Structure of a Reactor Building in a Nuclear Power Plant is a very important structure as it houses the main reactor. The containment system has to be designed and constructed to withstand high pressures and temperatures released during postulated accidents in case of any accidents and to act as a biological shield against leakage of radiation. Construction of the Containment structure, which is a safety-related structure, is a key activity in the overall project implementation of a Nuclear Power Project. Typically in India, the containment system consists of a double containment structure with a part-spherical dome on top. Usually the inner containment is in prestressed concrete and the outer containment is in reinforced concrete. Special types of concrete such as High Performance Concrete with temperature control and Heavy Concrete are used in the construction. The need for accurately positioning many special embedded parts and through pipes at various locations poses a challenge. The construction methodologies, techniques for prestressing, special formwork systems etc need special attention. Other techniques such as mechanisation, use of automated climbing formwork system, increase in height of concrete pours after mock-ups, use of threaded couplers for rebars, etc also merit attention. The paper also discusses the various safety, quality and construction management systems used at site for better implementation of the projects. (authors)