An approach for radiological consequence assessment under unified temporal and spatial coordinates considering multi-reactor accidents

Abstract

The current approaches and computer code systems for radiological consequence assessment of nuclear accidents have still gaps in assessing consequences of nuclear accidents involving multiple reactors, since multi-reactor accidents should be treated in one unique temporal and spatial system. This paper presents an approach to unify and generalize temporal and spatial coordinates for the consequence assessment of multi-reactor accidents. A code system named Advanced Radiological Consequence Assessment Toolkit (ARCAT) was developed accordingly. ARCAT is intended to support in particular emergency preparedness studies at the nuclear power plant level.To verify ARCAT, an analysis was carried out comparing ARCAT with MELCOR Accident Consequence Code System (MACCS), and the Java-based Real-time Online Decision Support System (JRodos). The results indicate that ARCAT is comparable to MACCS. This means that ARCAT is suitable for offsite radiological consequence assessment and able to support emergency preparedness including cliff-edge effects. Further to this, the effects of a unified temporal and spatial coordinate system are discussed to better recognize the impact of such special characteristics of multi-reactor accidents. A preliminary application based on ARCAT is presented, in which the plume emergency planning zone (PEPZ) for a hypothetical site with two reactors is developed. Finally, potential challenges and further research plans are discussed.