Status: STEP 4

Revision von NS-G-3.6 (siehe auch  Ex DS300) 

Beteiligte IAEO-Komitees: NUSSC, WASSC

Specific Safety Guide

Document Preparation Profile "DPP"

Zurück zur Übersicht "In Entwicklung befindliche Safety Standards"

Background Information

In the last few decades, seismic induced geotechnical events affected several nuclear power plants (NPPs), and countermeasures were taken in response to these incidents:

• In 2007, large ground settlements of the foundation induced by the Chuetsu Oki earthquake caused fire and damaged the function of the non-emergency in-house electrical transformer at the Kashiwazaki Kariwa NPP in Japan.
• In 2011, a landslide of the slope induced by the Tohoku earthquake fell down a transmission tower, resulting in the loss of off-site power to Units 5 and 6 of the Fukushima Daiichi NPP in Japan.
• In addition, some countries embarking on nuclear power selected sites that required soil substitutions. Unfavourable soil displacement due to climate change is being reported in areas with permafrost soils.

This revised Safety Guide will enhance and supersede NS-G-3.6 by incorporating the latest knowledge and experiences from Member States and lessons learned from geotechnical events, and expand the scope from NPPs to all types of nuclear installation using a graded approach.

The main objective of the revised Safety Guide is to provide recommendations on how to meet the applicable requirements from SSR-1, SSR-2/1 (Rev. 1), SSR-3, SSR-4 and GSR Part 2, related to geotechnical aspects for nuclear installations.

The second objective is to align the guidance to the current international state of practice in Member States, such as the following:

• Methodologies on considering phenomena such as heave and slope failure;
• Improved calculation methods for assessment of liquefaction hazard and soil-structure interaction;
• Considerations for specific sites located on soft soil at the waterfront;
• Methods for soil replacement in the case of unfavourable soil condition.

This Guide will be applicable to both existing and new installations, including small modular reactors. It will cover geotechnical engineering aspects that are important for the safety of nuclear installations.

Although seismic aspects play an important role in this field, seismic aspects other than geotechnical aspects will be out of the scope of the revised Safety Guide and are covered by DS507.