Each phase in the life of a nuclear power plant requires a license or approval from the RB. Table 20.1, derived from Annex 1 in INSAG-22, describes the main phases and the safety infrastructure needed by countries to establish and maintain a licensing process (INSAG, 2008a). The major phases and the corresponding licensing stages for an NPP are the site, construction, commissioning, operation and decommissioning licenses. Some of these licenses may be divided in sub-stages like ground breaking, first pour of concrete, and the erection of major equipment to facilitate working out the detailed design in parallel with the civil construction work. In that case, the requirements of safety review and submission of technical documents for each sub-stage, together with their submission schedule, should be clearly specified. Conversely, it may be decided to issue the construction and oper­ating licenses in one step, in which case the entire design, including its details, should be submitted before the start of the review process.

Table 20.1 Major activities required by applicants and regulatory bodies at each of the main phases in the life of a nuclear power plant Phase Duration (years) Applicant activities Regulatory activities 1. Design certification 3-4 • Submit documents in accordance with existing regulations and guidance. • Develop requirements and guidance. • Conduct public participation. 2. Siting 2-3 • Select and characterize the site: seismicity, extreme meteorology, flooding, man-made external events, combinations of the above, population density, use of affected land. • Demonstrate compatibility between site and plant. • Submit documents in accordance with requirements. • Develop requirements for siting. • Evaluate compatibility of site parameters with plant design. • Evaluate compatibility of the plant with the site. • Evaluate compatibility of site and plant with emergency planning. 3. Design and construction 5-7 • Develop a preliminary safety analysis report and other required documents. • Construct the plant in accordance with the project and the terms in the license. • Assure quality during design, procurement, assembling and testing. • Develop requirements for design, construction, testing and quality assurance. • Establish a programme of inspections covering equipment fabrication, plant construction, testing and quality assurance. 4. Commissioning 1-2 • Establish an organization to transfer the plant from construction to operation. • Develop a plan for testing and plant acceptance. • Develop the final safety report and apply for operating license. • Prepare operators for accreditation. • Develop requirements for commissioning and operation. • Create a body of experts to witness tests and accept their results. • Establish a process for license reactor operators.

Table 20.1 Continued

Duration Applicant activities (years)

Regulatory activities

• Operate and maintain the plant in accordance with established requirements.

• Perform periodic testing and inspection on components, systems and structures relevant to safety.

• Conduct self-assessments and external peer reviews.

• Retrofit operating experience.

• Conduct emergency drills.

• Define the need and cause for modifications.

• Analyze the impact of the modifications on the overall safety of the plant.

• Submit the application for approval.

• Conduct the modification in agreement with the applicable standards and conditions.

• Develop documentation for submittal of a request.

• Introduce an ageing management system.

• Review the safety analysis report and the probabilistic safety assessment to prove the validity of the renewal. [109]

• Develop requirements for operation, maintenance, testing, reporting events, conduct self-evaluations, peer reviews and feedback from operating experience.

• Create a continuous oversight system and a body of resident inspectors, enlarged inspection teams and safety evaluators.

• Determine and request the need for plant improvements.

• Be prepared to evaluate plant modifications by establishing guidance for submittals and procedures for evaluation.

• Verify that improvements and modifications comply with the applicable standards and conditions.

• Develop requirements for operation renewal.

• Develop capacity to evaluate the ageing phenomena and their impact on the safety of the plant.

• Develop an inspection and oversight programme to verify the progress of ageing.

• Develop requirements for decommissioning.

• Evaluate the decommissioning plan and the plan to manage radioactive wastes.

• Create a system to inspect and monitor dismantling operations.

Source: derived from Annex 1 in INSAG-22 (INSAG, 2008a).

An operating license is normally issued for the design life of the NPP. However, during the long operation period, which may extend to several decades, the safety status of the NPP is reviewed from time to time, for example by conducting detailed periodic safety reviews. This is to confirm that the NPP, in spite of the ageing of its structures, systems and components (SSCs), meets the current safety requirements and is likely to continue to do so until the next safety review. Towards the end of the license period, if requested by the operating organization, the operating license may be extended for a further period provided a detailed safety review clearly establishes that the NPP can be operated safely for that length of time.

After the NPP is finally shut down at the expiry of the operating license, or due to economic or other reasons, there is likely to be a waiting period to allow for the natural decay of short-lived radionuclides, to reduce the radiation fields on the SSCs to make their dismantling, handling, packaging and transportation to a radioactive waste disposal site easier. Dismantling should never start while fuel is still in the reactor core or in the used fuel decay pool, since as long as nuclear fuel is present an NPP is considered operational and the relevant licensing conditions continue to apply. Even after the fuel is removed from the core and the decay pool, an NPP will have to be kept under surveillance to ensure that there is no undue expo­sure of plant personnel to radiation, and that no unauthorized release of radioactivity is made to the environment. The NPP’s license should be modified appropriately during such periods.