DS523 - Development and Application of Level 1 Probabilistic Safety Assessment for Nuclear Power Plants

Status: STEP 13

Revision von SSG-3 (Ex DS394) 

Beteiligte IAEO-Komitees: NUSSC, NSGC

Specific Safety Guide

STEP 13    
STEP 12 Kommentare der SSCs und IAEO-Bewertung IAEO-Zusammenfassung nach STEP 12
STEP 11 NUSSC 53 silence procedure
     clean                track changes
STEP 11 Kommentare der SSCs und IAEO-Bewertung
IAEA Resolution FINAL (after 53.NUSSC)
IAEO-Zusammenfassung nach STEP 11
      clean                track changes
   clean FINAL       track changes FINAL
STEP 8 Kommentare der Mitgliedsstaaten
und IAEO-Bewertung
IAEO-Zusammenfassung nach STEP 8
STEP 7 Kommentare der SSCs IAEO-Zusammenfassung nach STEP 7
STEP 4    
STEP 3 Kommentare der SSCs und IAEO-Bewertung IAEO-Zusammenfassung nach STEP 3


Zurück zur Übersicht "In Entwicklung befindliche Safety Standards"

Background Information

An analysis of the scope and content of the Guide concluded that it largely remains valid in its technical content but has outdated references and requires revision in order to address changes incorporated in the relevant Safety Requirements. In addition, the above-mentioned analysis has shown that the Guide requires incorporation of the recent developments in Member States in specific areas related to PSA, such as multiunit PSA, passive systems reliability and computer based systems reliability.

The revision of the Guide covers the following considerations:

  • Revisions implemented in IAEA Safety Standards;
  • Lessons from the accident at the Fukushima Daiichi nuclear power plant;
  • Expanding the scope of PSA;
  • Recent developments in Member States related to PSA;
  • Experience gained with IAEA PSA review services (i.e. TSR-PSA).


More specifically, amendments of the Guide are needed to address the following aspects:

  • Development of multiunit Level 1 PSA models, to reflect the changes introduced in GSR Part 4 (Rev. 1) and experience cumulated within the IAEA activities in the area of Multiunit PSA;
  • Expanding the scope of the Guide to cover also the spent fuel pools as a source of radioactive material;
  • Considerations of combined or correlated hazards, to supplement corresponding discussion in Sections 6 and 8 of the current Guide);
  • Recent developments in the area of reliability analysis of passive systems and softwarebased systems, to supplement the paragraphs 5.114-5.120 of the current Guide;
  • Recent developments in the area of use and applications of PSA, to supplement Section 10 of the current Guide;
  • Experience gained from IAEA PSA review services in various Member States (i.e. TSRPSA) in terms of applicability of certain paragraphs of the Guide for review purposes.


The added value of the revised Guide will be to provide Member States with comprehensive, consistent and up-to-date recommendations for the development and application of Level 1 PSA for NPPs covering a wider scope.