Severe Accident Management At Nuclear Power Plants – Emergency preparedness and response actions

Abstract

Worldwide, large number of nuclear reactors are in operation and also are under construction and commissioning stage for power production which also saves significant amount of carbon. In India, the number of reactor units in operation are 22 with the capacity of 7680MWe, there are 9 units under construction and commissioning with capacity of 6700MWe. Safety measures in these reactors are strengthened over the period in all the stages of nuclear power plants to ensure safety of people and environment. The concept of defense in depth is used to achieve the safety objectives during the operation of the reactor with emergency management as the 5^th level of defense that can be used in case of severe accidents.  Two major nuclear accidents (i) Fukushima (Japan-March 11, 2011) and (ii) Chernobyl (Former USSR – April 26, 1986) has emphasized the need for strengthening 4^th and 5^th level of defense to meet the safety objectives in case of severe nuclear accident. To address low probability events at nuclear power plant, emergency management plans are established for the protection of people and environment. Prior to the issuance of a license for the operation of NPPs, it is ensured by regulatory body that the site specific emergency management plans are in place and tested.

This paper presents the current developments in the nuclear emergency management to achieve safety objective. The elements of nuclear emergency management system includes legal and regulatory frame work, emergency preparedness and response plans, hazard assessment of the nuclear facilities considering the hypothetical severe accidents for deciding the preparedness category and sizes of emergency planning zones and distances, defining the goals for preparedness and response actions, criteria for classification & notification of emergency, consideration of health consequences and socioeconomic impact for deciding the implementation of protective

^aDirectorate of Radiation Protection and Environment, AERB, Mumbai and Research Scholar, India

^b Health Safety and Environment Group, IGCAR, Kalpakkam, India

^cFaculty of Business Administration, Vellore Institute of Technology, Chennai, India

*Corresponding author E-mail: skpawar@aerb.gov.in

actions in the affected area, generic criteria and operational criteria for taking the protective actions, radioactivity release phases and consideration for protective action, use of reference levels for setting the targets for protection strategy and termination of protective actions, criteria for changeover from emergency to existing exposure situation, dose criteria for the protection of emergency workers, response organization and their coordination, development of operation criteria (emergency action levels (EALs), operational intervention levels(OILs) and observables) from the generic criteria and use of operational criteria for emergency management, implementation of emergency operating procedures (EOPs), implementation of severe accident management guidelines (SAMGs) and emergency response plans and procedures(EPR), careful harmonization and integration  of EOPs, SAMGs and EPR to meet emergency management objectives. This article identifies the important elements of emergency management that influence the decision making and implementation of protective action and protection strategy.  The study identifies requirement to carry out research work to study the various factors affecting effectiveness of each important elements of emergency management to meet the goals of emergency response.