Optimization of design and field activities times

It is well known that systematic efforts to decrease the construction time of a nuclear unit may quickly become expensive because the savings on financial costs are often lower than the extra costs needed to minimize the construction time. On the other hand, the construction time alone cannot be analyzed independently from the design implementation. A significant decrease in this construction time, which appears to be done in Japan, necessitates the beginning and the end of the detailed design well in advance and forbids any major change in the design after the start of construction. By contrast, in the French economic and social context, Electricite de France (EdF) estimates that it has found an optimum solution by undertaking almost in parallel the civil works construction and the electromechanical design. This optimization leads to an earlier launching of construction activities but a later beginning of design studies and, compared with the other option, results in the following: (1) similar total time for design and construction; (2) lower cost because no special action is taken to speed up construction; and (3) more flexibility for deciding late improvements in design. However, this option, to be successful, requires special attention to be paid tomore » the interfaces between the designer and the construction personnel. In France, the cost of EdF's investments and construction times are among the lower in the world; therefore, EdF can claim it has succeeded in this matter.« less