The Accident Source Term Evaluation Code (ASTEC) software system, developed by IRSN, simulates all phenomena occurring during a core meltdown accident in a water-cooled reactor, from the initiating event to the discharge of radioactive substances outside the containment. Version V3.1 of the ASTEC software, applicable to other nuclear facilities, is now available.

In addition to modeling severe accidents in pressurized water reactors, the latest version of the ASTEC software benefits from new development methods and coupling with other software, opening it up to broader functionalities and a wider variety of facilities. It has already been used to carry out probabilistic safety studies relating to major accidents in the storage workshops for fission products at the Orano plant in La Hague (Manche department of France). It is also operational for assessing the dispersion of radionuclides in ecosystems and calculating the dosimetric impact on humans in the event of a major accident.

Version V3.1 of ASTEC will facilitate, through its flexibility, the implementation of the new European ASSAS project dedicated to the use of artificial intelligence for the simulation of severe accidents. Studies are underway to make it suitable for the simulation of events that could occur in small modular reactors (SMRs). The culmination of experimental work and modeling, the ASTEC software system is a reference tool for nuclear safety assessments.