This phase is extremely important since it constitutes the opportunity for the national organizations such as the regulatory body and the operator to start having ‘hands on’ the installation. A site permit has to be issued by the regulator for starting the construction work.

The design is finalized taking into account the site characteristics. Components are ordered by the constructor. Quality assurance is the main objective to be pursued; it includes visits to the companies delivering the large components. Chapter 21 of this book gives the necessary develop­ments for quality assurance.

The detailed instrumentation and control systems are then defined and will influence the procedures to be implemented in operation for normal functioning, incident and accident management. The reference IAEA (2009a), Safety Standards Series, Safety Requirements for the Design of a Nuclear Power Plant, NS-R-1, covers all aspects of designing instrumenta­tion and control systems.

During the construction phase, the role of the national organizations is essentially to ensure the quality of all the materials and components used. To this aim, the national regulator has to perform a number of inspections. Participation and observation of the various tests during the construction require the presence of both the regulator and the operator. This will result in delivering the first authorization which is to start the commissioning phase.

The commissioning phase includes numerous functional tests. The success in this leads to the delivery of fresh fuel and fuel loading. Then starts the start-up test with different phases to obtain first criticality and later power increases up to normal power. This phase usually lasts one or two years depending on the test results. Before full power can be reached, the regula­tor has to issue the official permit to fuel loading and start-up. At this stage procedures for normal operation and incidents have to be available with operators trained on them with the use of functional simulators if possible. During the time of slow power increases, it is necessary to develop, test on simulator and train operators on accident procedures and accident management. Chapter 22 of this books deals with this aspect of plant commissioning.

The emergency plan should also be ready to complete the operational procedures. As referred to in the present chapter under Section 2.4.1 Preliminary phase, principle 9 of the safety fundamentals emphasizes the importance of preparing emergency planning. The necessary infrastructure may include participation of other governmental institutions, various min­istries and neighbouring countries in addition to the national accident man­agement and preparedness. The IAEA or other countries may provide assistance for implementing the emergency plans.