DS491

Status: STEP 11

Beteiligte IAEO-Komitees: NUSSC, RASSC, WASSC, EPReSC

STEP 8 Kommentare der Mitgliedsstaaten  
STEP 7 Kommentare der Mitgliedsstaaten  Bewertung der Kommentare durch die IAEO
STEP 4c    
STEP 4b    
STEP 4a

Kommentare der Mitgliedsstaaten

Grafik Bewertung Deutsche Kommentare

Bewertung der Kommentare durch die IAEO
STEP 3 Kommentare der Mitgliedsstaaten Bewertung der Kommentare durch die IAEO

Zurück zur Übersicht

Background Information

Existing document (SSG-2) was published in 2009, the scope remains essentially unchanged.

The current revision (DS491) was initiated to

  • comply with the long term structure of Safety Standards approved in 2008
  • provide guidance and recommendations to help meeting Safety Requirements from SSR-2/1 (Rev.1) and GSR Part 4 (Rev.1), both published in 2016
  • ensure coherency and consistency with the other relevant IAEA Safety Standards
  • incorporate feedback on application of SSG-2, on operating experience through the IAEA Incident Reporting Systems and from the accident at the Fukushima-Daiichi NPP
     

The new information in DS491 includes

  • Separation between basic concepts and specific guidance
  • Less statements of explanatory nature and general considerations
  • Further guidance to address the main aspects of Deterministic Safety Analysis
  • Specific recommendations to meet Safety Requirements
    • in all plant states, including Design Extension Conditions
    • to support ‘practical elimination’
       

Other Changes

  • Applications of Deterministic Safety Analysis moved to the Annex
  • References updated
     

Fukushima Daiichi Implications

  • National regulations adopted after the accident and lessons have been taken into account
  • Specific aspects included in all sections, such as
    • Section 3. Identification and categorization of postulated initiating events and accident scenarios
      • Identification of Design Extension Conditions
      • Event sequences and accident scenarios to be ‘practically eliminated’
    • Section 7. Deterministic Safety Analysis for plant states and accident scenarios
      • DSA for DEC without significant fuel degradation
      • DSA for DEC with core melting
      • DSA in support of ‘practical elimination’