DS510 - Revision of 2 SSGs on RRs (SSG-20 and SSG-24)

Status: STEP 11

Revision von SSG-20  (Ex DS396) und SSG-24 (Ex DS397)


Specific Safety Guide

STEP 12    



Kommentare der SSCs und IAEO-Bewertung IAEO-Zusammenfassung nach STEP 11



Kommentare der Mitgliedsstaaten
und IAEO-Bewertung DS510A

Kommentare der Mitgliedsstaaten
und IAEO-Bewertung DS510B
IAEO-Zusammenfassung nach STEP 8



Kommentare der SSCs DS510A (SSG-20)

Kommentare der SSCs DS510B (SSG-24)



STEP 4 Kommentare der SSCs IAEO-Zusammenfassung nach STEP 4
STEP 3 Kommentare der SSCs und IAEO-Bewertung IAEO-Zusammenfassung nach STEP 3

Document Preparation Profile "DPP"

Zurück zur Übersicht "In Entwicklung befindliche Safety Standards"

Background Information

Amendments of the proposed Guides are needed to address the following:

  • There are several new requirements in SSR-3 and others have been substantively modified from their original form in NS-R-4. These requirements are not fully addressed in the Guides, particularly Req. 22, Design Extension Conditions; Req. 55, Emergency Response Facilities on the Site; Req. 76, Material Conditions and Housekeeping; and Req. 90, Interfaces between nuclear safety and nuclear security.
  • Some statements in the Guides that are expressed as “should” statements do, in fact, duplicate some requirements of SSR-3 and GSR Parts 1-7. As such they do not add any value in the Guides and could confuse users about whether something is a requirement or a recommendation. Such statements should be carefully rechecked and either removed from the Guides (as no value added) or modified to make them useful recommendations, supporting the appropriate requirements.
  • IAEA Safety Standards Series No. SSG-22, Use of a Graded Approach in the Application of the Safety Requirements for Research Reactors, was published in 2012. The Guides proposed for revision in this DPP were published at the same time as SSG-22 and contain information about applying a graded approach in their respective areas. This information needs to be removed from the Guides where necessary and consolidated in a harmonized manner in a revision to SSG-22 that will be proposed under a separate DPP.
  • The publication of SSR-3 expanded the scope of the safety requirements for research reactors to include subcritical assemblies. As they were both published prior to SSR-3, the Guides do not provide explicit guidance about how subcritical assemblies should implement the safety requirements. Although most requirements in SSR-3 are universally-applicable to research reactors and subcritical assemblies, SSR-3 makes several explicit references to the safety of subcritical assemblies (for example, SSR-3, Paras. 6.62 and 6.66). The Guides need to be updated to address subcritical assemblies in general and the specific references in SSR-3.
  • An analysis of the guidance and information in NS-G-4.4 and SSG-20 was made to assess whether the two publications should be combined. The analysis showed there are benefits in retaining two separate publications to support member states to enhance safety in these two separate and distinct areas.
  • In some cases, parts of the Guides have to be updated to better reflect the current operational practices at research reactors and the state-of-the-art in relevant technologies.


The added value of the revised Guides will be to provide target users with comprehensive, consistent and up-to-date guidance for implementing the safety requirements in SSR-3 and the General Safety Requirements as they apply to research reactors.