1The authorization is expected to be granted by the issue of a licence or permit by the regulatory body. Consequently, the term ‘licensing’ is also used in this Safety Guide.

2INTERNATIONAL ATOMIC ENERGY AGENCY, Format and Content of the Safety Analysis Report for Nuclear Power Plants, IAEA Safety Standards Series No. GS‑G‑4.1, IAEA, Vienna (2004).

3The bounding case approach includes the identification of important physical and chemical parameters that might affect the environment for the nuclear power plant considered and the use of those parameters with the highest impact value.

4In some cases (e.g. in States deploying a given reactor design in several units), the amount of information to be provided in the preliminary safety analysis report might depend on the extent to which the proposed reactor design conforms to a generic or standard design for which the licensing process has been followed previously, including the associated safety analysis report.

5See also paras 2.29 and 3.13.29.

6Footnote 16 of SSR‑2/1 (Rev. 1) [3] states: “The possibility of certain conditions arising may be considered to have been ‘practically eliminated’ if it would be physically impossible for the conditions to arise or if these conditions could be considered with a high level of confidence to be extremely unlikely to arise.”

7This information will be used in accordance with national regulations and is typically set out in a separate document that contains sensitive information.

8For this chapter and for other chapters of the safety analysis report, Appendix II provides guidance on describing the design of the nuclear power plant SSCs.

9In this Safety Guide, the term ‘fuel’ means arrays (assemblies or bundles) of fuel rods, including fuel pellets, insulator pellets, springs, tubular cladding, end closures, hydrogen getters and fill gas; burnable poison rods, including components similar to those in fuel rods; spacer grids and springs; end plates; channel boxes; and reactivity control rods.

10This is applicable only to the cables and electrical penetrations requiring environmental qualification for severe accidents.

11These areas include the main control room, the supplementary control room, other emergency response facilities, and other areas or rooms hosting sensitive equipment (e.g. instrumentation and control equipment, electrical equipment, computers).

12The reactor building is the building that shelters the primary containment and, if appropriate, the secondary containment.

13This is sometimes called the ‘steam generator blowdown system’ or the ‘steam generator blowdown purification system’.

14At the construction stage, prior to non‑nuclear commissioning, and for each SSC, tests include vendor inspections, welding inspections, leaktightness tests and pressurized tests for the pressure boundary, and fuel assembly inspections at the fuel fabrication facility and at the nuclear power plant.

15The expression ‘screening of defence in depth’ means the systematic identification of the mechanisms that could affect the performance of safety functions and thus prevent the achievement of safety objectives at different levels of defence in depth (see Ref. [49]).

16Conditions that are considered ‘practically eliminated’ are not part of design extension conditions (see SSG‑2 (Rev. 1) [46]).

17In accordance with IAEA Safety Standards Series No. GSR Part 7, Preparedness and Response for a Nuclear or Radiological Emergency [55], the operating organization should also make on‑site emergency arrangements for preparedness and response for events that are beyond the design basis accidents and, as appropriate, for conditions that are beyond design extension conditions, but these arrangements are beyond the scope of the safety analysis report and this Safety Guide.

18The scope of the environmental protection aspects included in the safety analysis report is typically commensurate with national regulations.

19The transition period refers to the period between the permanent shutdown of operations at the plant and the approval of the final decommissioning plan.