Chapter 2: Introduction to Nuclear Safety
Consideration of requirements for design safety of NPPs and related applicability of the SAMG-D Toolkit
The high level overview of requirements from SSR-2/1 (Rev. 1) and supporting Safety Guides (including SSG-54 and other safety guides mentioned in the list of Publications) has clarified that “the designs of many existing nuclear power plants, as well as the designs for new nuclear power plants, have been enhanced to include additional measures to mitigate the consequences of complex accident sequences involving multiple failures and of severe accidents. Complementary systems and equipment with new capabilities have been backfitted to many existing nuclear power plants to aid in the prevention of severe accidents and the mitigation of their consequences.
Read more → TECDOC-1894 .
Guidance on the mitigation of the consequences of severe accidents has been provided at most existing nuclear power plants.
The design of new nuclear power plants now explicitly includes the consideration of severe accident scenarios and strategies for their management (para 1.2 SSR-2/1 (Rev. 1)).
However, given that the SAMG-D Tookit is addressed to all categories of currently operating water-cooled reactors mentioned in section 1 (BWR, PWR/VVER, PHWR), regardless of their age and regardless of which requirements were considered for their design (i.e. whether NS-R-1 and previous standards, which did not considered severe accidents within the design envelope, or the most recent requirements in SSR-2/1 (Rev. 1) and supporting safety guides which explicitly considers Design Extension Conditions within the design envelope), the reminder of the Toolkit will encompass both categories of reactors.
Hence, the user of this toolkit is informed that the Toolkit is applicable to currently operating water-cooled reactors designed with standards for design safety established well before SSR-2/1 (Rev.1), despite the fact that the toolkit includes references only to most recent standards (SSR-2/1 (Rev. 1) and supporting safety guides).
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