Safety objectives and design principles

The safety objectives and principles used in the design should be presented in this section. These should be based on the objectives presented in paras 2.2, 2.4 and 2.5 of Ref. [5], which refers to the general nuclear safety objective, the radiation protection objective and the technical safety objective, as defined by the IAEA. This subject is discussed further in paras 3.43-3.52. 

The Safety Requirements publication Safety of Nuclear Power Plants Design [5] specifies the fundamental safety functions required to be performed to ensure safety as the control of reactivity the removal of heat from the core and the confinement of radioactive material and the control of operational discharges, as well as the limitation of accidental releases. This part of the SAR should identify and justify the fundamental safety functions to be fulfilled by the specific plant design. It should specify the corresponding structures, systems and components necessary to fulfil these safety functions at various times following a postulated initiating event (PIE). 

In addition to the fundamental safety functions, any specific safety functions should be identified. For example, heat removal should be considered a safety function necessary not only for the safety of the reactor core but also for the safety of any other part of the plant containing radioactive material that needs to be cooled, such as spent fuel pools and storage areas. Guidance on the identification of specific safety functions for plants with light water reactors is given in the annex of Ref. [5]. 

If probabihstic safety criteria have been used in the design process, these criteria should be specified in this subsection. The compliance of the design with these criteria should also be briefly discussed here however, the results of the probabilistic safety assessment (PSA) of the final plant design should be provided in the ehapter on safety analyses. 

This subsection should describe in general terms the design approach adopted to meet the radiation protection objective and to ensure that, in all operational states, radiation doses within the installation or due to any planned release of radioactive material from the installation are kept below authorized limits and as low as reasonably achievable (ALARA), as is required, economic and social factors being taken into account (see para. 4.9 of Ref [21]). It should be demonstrated that  

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