STRENGTH CRITERIA OF NPP CONTAINMENT UNDER EXTERNAL ACTIONS

Authors:  
Rubric:     Seismic safety and seismic isolation of buildings   
Annotation:
The code of practice in the field of atomic energy establishes the safety targets for NPPs. One of these safety targets regulate the yearly probability of large emergency radioactive release into the air. Accident with reactor pipelines rupture can occur in the case of earthquake. In this case the containment serves as a barrier against radioactive release into the environment. The purpose of this work was to define the strength criteria for containment to ensure the safety targets of yearly probability of large emergency release at seismic and other external events. The results of the work show that in the case of external events the containment strength criteria provide correspondence with safety targets if they are defined with account of yearly probability of the action assumed and with due account of probability of failure (rupture) of reactor pipelines under this action. The strength criteria for containment should be defined with overconsevative reserves, the more is the yearly probability of the action assumed and the more is the probability of reactor pipelines failure under this action. It is shown that at small yearly probability of the action and small probability of the reactor pipelines failure the strength criteria of containment, defined due to the safety target of a yearly probability of large accidental release, became less conservative then civil and erection strength criteria.