Elaborate precautions are taken in the site selection, design, construction and operation of Nuclear Power Plants (NPPs) to ensure safety. The concept of defense-in-depth is adopted to meet the safety objectives. Further, to address those events of small probability which have a potential to affect safety of plant personnel, public and environment, a detailed emergency preparedness and response plan is necessary. The nuclear and radiological safety of operating NPPs in India is ensured by Atomic Energy Regulatory Board (AERB). AERB has developed codes and guides for Emergency Preparedness and Response (EPR) for nuclear and radiological facilities. The EPR plan includes the emergency response organization, their responsibilities and action plan, guidelines for evaluation of emergencies, resources and facilities; communication system, coordination and support of various organizations; other technical aspects, and maintenance and updating of plan. Prior to the issuance of a license for the operation of NPPs, AERB ensures that the site specific emergency preparedness and response manuals are in place and tested. Emergency exercises are mandatory as a part of EPR plan and are carried out periodically to check the overall effectiveness of the plan. Feed back of emergency exercises serves as input for upgrading the plan. This paper highlights the current level of emergency planning and preparedness and also improvement in the emergency management programme over the years including the role of the National Disaster Management Authority (NDMA) after the promulgation of Disaster Management (DM) Act 2005. The major challenges in off-site emergency management include public awareness programme, training to the district authorities, development of infrastructure within the emergency planning zone and include simulation of all possible scenarios in exercise.
Nuclear power plants in India are sited, designed, constructed and operated with highest priority to nuclear safety. Atomic Energy Regulatory Board (AERB) is the national regulator to enforce nuclear and radiation safety in the country. A variety of measures like engineered safety features, quality assurance of the plant equipments and components during its entire life, multiple barriers against the release of radioactivity to environment together with highly trained and licensed operators
ensure the protection of the people and the environment from the effects of radiation from Nuclear Power Plants (NPPs).
The concept of defense-in-depth is pursued in every stage to assure safety. These defenses help to reduce both the probability and consequences of nuclear accidents. However, the probability of nuclear accidents, even though small, cannot be ruled out which may result in the release of radioactivity to the environment. To mitigate the consequences of a major nuclear accident in public domain, protection of public is ensured through elaborate emergency preparedness and response plans at NPPs. Safety considerations for establishing emergency planning zones are key aspects during siting evaluation of a NPP.
2.0 EMERGENCY PLANNING AND PREPAREDNESS
2.1 AERB Standards on Emergency Preparedness & Response for Nuclear and Radiological Facilities
AERB is responsible for the regulatory oversight with respect to all aspects related to emergency preparedness in NPPs. AERB derives this mandate from Rule 33 of the Atomic Energy (Radiation Protection) Rule of 2004 and its constitution order. AERB’s role with respect to emergency preparedness is to establish the requirements and guidance; review and approve onsite EPR plans, prepared by NPP operator; ensure implementation of onsite EPR plan; and participate as observers in periodic exercises to verify various EPR elements. The facility operator, in coordination with State & District authorities, develops the offsite EPR plans. AERB reviews offsite EPR plans & recommends approval to District Authorities.
AERB has developed several regulatory documents in the form of codes, guidelines and guides for emergency preparedness and response for nuclear and radiological facilities in India in line with relevant safety standards of International Atomic Energy Agency (IAEA). Some of the applicable safety codes and guides of AERB relevant to the EPR are given below (AERB regulatory documents are available in the website):
- Safety Code “Regulation of Nuclear and Radiation Facilities” (AERB/SC/G)
- Safety Code “Code of Practice on Safety in Nuclear Power Plant
- Operation” (AERB/SC/O)
- Safety Guide “Site Considerations of Nuclear Power Plants for Off-site Emergency Preparedness” (AERB/SG/S-8)
- Safety Guide “Role of the Regulatory Body with Respect to Emergency Response and Preparedness at Nuclear and Radiation Facilities” (AERB/SG/G-5)
- Safety Guide “Preparedness of the Operating Organisation for Handling Emergencies at NPPs” (AERB/SG/O-6)
- Safety Guidelines “Preparation of Site Emergency Plans for Nuclear Installation” (AERB/SG/EP-1)
- Safety Guidelines “Preparation of Off-Site Emergency Plans for Nuclear Installation” (AERB/SG/EP-2)
- Safety Guidelines “Criteria for Planning, Preparedness and Response for Nuclear OR Radiological Emergency” (AERB/SG/EP-5)
2.2 Classification of Emergencies
Emergencies are classified based on the extent and severity of the incident. The emergency situations for an NPP are classified as Plant emergency, Site Emergency and Off-site Emergency
Plant Emergency: Accident situations due to release of hazardous chemicals/radioactive materials, fire/explosion in the plant but with consequences confined within the plant boundary.
Site Emergency: Accident situations in the plant involving radioactivity transgressing the plant boundary but confined to the site, or involving release of hazardous chemicals/ explosions/ fire, whose effects are confined to the Site with off-site consequences expected to be negligible.
Off-Site Emergency: Accident condition involving excessive release of radioactive material from the plant into the public domain and calling for intervention
Emergency preparedness and response plans for plant, site and off-site emergency are prepared, approved and exercised periodically. Each nuclear power plant has plant specific plant emergency manual, site specific site emergency manual and off-site emergency manual giving the details of organizational setup, emergency communication, resource facilities, emergency control centers, emergency equipment centers, emergency survey vehicles, sheltering centers, counting laboratories, first aid centers, roles and responsibilities, demographic information etc. for effective implementation of the protective actions.
The preparedness encompasses the training of all persons who will be involved in implementing the emergency plans, the acquisition of resources and facilities, and the testing of emergency plans and procedures by means of exercises to ensure effective response in the event of an emergency.
2.3 Objectives of Protection in Nuclear & Radiological Emergency
The basic objectives of the implementation of protective actions during the emergency are as follows:
- To regain control of the situation
- To prevent or mitigate consequences of the scene
- To prevent occurrence of health effects in workers and the public
- To render first aid and manage the treatment of radiation injuries
- To protect the environment and property
- To take into account the need for resumption of normal social and economic activity.
In the event of the nuclear and radiological incident, protective actions need to be implemented during the emergency phase and post emergency phase. Emergency phase is a situation in which source is not under control and projected radiological exposures are high. The post emergency phase is a situation in which radioactive source is fully under control, radiological exposure could be due to deposited radioactive contamination and projected doses are low.
2.4 Organizations for Handling Emergency
Plant emergencies are handled by the plant emergency committee, site emergency is handled by the site emergency committee in coordination with all site facilities. The implementation of offsite EPR plans is the responsibility of the National, State and District Disaster Management Authorities. To mitigate the consequences of the off-site emergency, district authority in consultation with site emergency director, implements protective actions in the public domain.
The Crisis Management Group of Department of Atomic Energy (CMG, DAE) provides the technical support to the district authorities by activating DAE emergency response centres. AERB is a member of the Crisis Management Group of DAE, which coordinates with the National Crisis Management Centre (apex body for coordination at the national level), to provide technical advice to the government in preparedness and in response to emergencies.
The public authorities at local (District), regional (State), and national level should have appropriate arrangements as per emergency response plan. This is done in consultation with operating organization. It is mandatory that licensee shall prepare an emergency preparedness and response plan addressing requirements specified by AERB and submit this EPR plan to AERB for review and approval before First Approach to Criticality.
The quality of plans are verified through emergency exercises (plant, site and off-site), during periodic regulatory inspections, review of exercise reports, periodic review of EPR plans etc. AERB has a Nuclear and Radiological Emergency Monitoring Cell (NREMC) to monitor, review and advice during the emergency.
2.5 Emergency Planning Zone (EPZ)
The Emergency Planning Zone defined around the plant up to 16 km radius provide a basic geographic framework for decision making on implementing measures as part of a graded response in the event of an emergency. The population around a NPP has been limited by setting up the exclusion zone and Natural Growth Zone.
The exclusion zone extends upto a distance of 1.6 km around the plant where no public habitation is permitted. This zone is physically isolated from outside areas by plant fencing and is under the control of NPP. The Natural Growth Zone is an area where extension of activities is controlled to limit influx of population. Natural growth is however allowed in this zone. This area extends upto a radius of 5 km from the plant. Emergency Planning Zone is up to 16 km radius around NPP and divided into 16 sectors. Each emergency plan needs to include the details of the Nuclear Installation, site maps, demographic characteristics, site meteorology, nature of land and produce, emergency organization and responsibilities, guidelines for evaluation of emergency, communication facility, resources and facilities, mechanism for declaration and termination of emergency, action plan for responding to emergency, maintenance and updating of emergency plan and public awareness programme.
In EPZ, protective actions are taken as specified in the plan such as warning & advice, traffic diversion, sheltering, prophylactics distribution, evacuation, decontamination etc.
Protective actions in each zone are well defined and depend on the assessment of the emergency situation. Immediate actions will be initiated in the Natural Growth Zone to assure public safety followed by other zones depending on the severity.
2.6 Emergency Response Actions / Protective Actions
- Identification, Classification, Declaration of emergency
- On site Notification and Off-site notification : on site notification to all site personnel by using the siren and public announcement system and off-site notification to district/state authorities, DAE ECR, VSB ECR, NPCIL HQ, AERB by fax and telephonic communication.
- Activation of emergency response organizations and emergency control centres (plant, site and off-site emergency control centre) and its operation.
- Radiological monitoring within site area and off-site area
- Mitigatary Action to control the radioactivity release
- Warning and advice in affected village
- Traffic control / Diversion
- Prophylactics distribution
- Prevention of inadvertent ingestion
- Decontamination of individuals
- Food, milk and drinking water control
- Medical management
- Protection of international trade and commercial interests
2.7 Criteria for Planning, Preparedness and Response for Nuclear or Radiological Emergency
The Generic Criteria and Operational criteria are used for initiating the protective actions in the public domain following a nuclear accident or radiological emergency. This AERB safety guideline in line with IAEA guidelines provides various criteria to ensure public safety, control on Food, Milk and Drinking Water if required and control on contamination of equipment and vehicles etc. Reference levels in terms of radiation dose for public and workers in emergency situation are also set in the emergency preparedness arrangements for optimization of safety of the worker, public and environment. Emergency Action Levels (EAL) are plant parameters derived from symptoms, events, observables, degradation in radioactivity barriers and accident analysis which can be a criteria for emergency planning. EAL along with Operational Interventional Levels (OIL) in the form of observables also forms the basis for emergency planning criteria.
2.8 Categorization of Nuclear and Radiation Facilities
Each nuclear and radiation facilities are classified into five hazard categories based on Nuclear and Radiation Related Hazards for the Purposes of the requirements of emergency preparedness. Hazard categories I to V represent decreasing levels of hazard at facilities and therefore correspond to emergency preparedness class I to V in decreasing stringency of requirements for emergency preparedness and response. Facilities in hazard categories I and II warrant extensive on-site and off-site arrangements for emergency preparedness.
2.9 Managing the Medical Response
AERB Safety documents specify the requirements for medical management during an emergency. This includes requirements for first aid, estimation of doses and medical management during an emergency. The AERB safety guide on management of persons exposed in radiation accident (AERB/SG/MED-1) provides guidance for medical management in case of a radiation accident. The AERB safety Manual on Hand Book for Medical Management of Person Exposed in Radiation accident (AERB/SM/MED-2) addresses the medical management during an emergency.
Based on the regulatory requirements and guidance, Site specific plans of NPPs have arrangements to treat contaminated persons including first aid at site, the estimation of doses, medical transport and the initial medical treatment of contaminated or highly exposed individuals in local medical facilities (medical facility of licensee and district) and special hospitals.
In each constituent unit of DAE, doctors have been dedicated and given the necessary training in the medical management of radiation emergencies. All nuclear power plants and the Bhabha Atomic Research Centre (BARC) are equipped with radiation monitoring instruments, have personnel decontamination centres and the necessary stock of antidote medicines and specific de-corporation agents for typical radioisotopes.
3.0 EMERGENCY EXERCISES AT INDIAN NPPS
The emergency plans are tested periodically by conducting exercises. Emergency plans are updated every five years to incorporate the changes based on the exercises, experience gained and elevant safety guides and to take into account changes in population and infrastructure in the area. Training is also organized round the year to various Public Authorities aimed at agencies/individuals involved in emergency management understand the purpose and scope of the protective action as specified in the emergency plans.
For each exercise, the utility creates a hypothetical emergency scenario for use by concerned officials. Based on the meteorological conditions affected sector (from among 16 sectors) is simulated for the protective actions. In each exercise different geographical sectors (from among 16 sectors) and affected villages within these sectors are considered for protective actions. This practice is being followed at each Nuclear power plant in India. Reports of all such plant and site emergency exercises are reviewed for enhancing the emergency preparedness. In order to maintain the state of continual Emergency Preparedness at NPPs, substantial resources and efforts are being deployed. Some of the protective actions taken during the exercise are given below.
Warning & Advice:
Team of Police personnel proceed to the designated area in the affected sector and give warning and advice message to the villagers by mega-phones or siren mounted police vehicles as advised by the offsite emergency director.
Traffic Control & Diversion
Team of Police personnel proceed to the designated traffic diversion points to control the movement of the vehicles in the affected sector as advised by the offsite emergency director.
Team of medical officer and medical staff proceed to the affected sector by primary health centre vehicles and on the advice of offsite emergency director distribute the prophylactics (mock distribution) to the villagers.
A team of police personnel, medical staff, Gram Sevaks etc proceed to the shelter locations in the affected sector to provide necessary assistance and law & order.
Based on the simulated radiological conditions in the affected village, sample evacuation involving villagers was done during the exercise. These evacuees were taken at the rallying post. During the exercise the capabilities of the district authorities, co-ordination among different agencies, decontamination of the personnel, food and sanitation at rallying post, medical advice etc were rehearsed. Based on several exercises in the last 30 years conducted at all the NPPs, it could be concluded that the NPPs have a robust emergency preparedness and response manual.
4.0 EMERGENCY PREPAREDNESS & RESPONSE ARRANGEMENTS FOR TRANSPORT OF RADIOACTIVE ACTIVE MATERIAL
The radioactive material including spent fuel bundles is required to be transported from NPPs to other nuclear facility though public domain since the use and handling of radioactive materials has considerably increased with the expansion of nuclear industry. Hence, utmost care is required in permitting shipment of radioactive consignments though public domain. The regulations and procedures of shipment of radioactive materials in India are in line with IAEA safety standards and are aimed at the safe transportation of radioactive materials. Based on ICRP recommendations and IAEA Safety Guidelines, AERB has prepared safety standards (e.g. AERB safety code No.SC/TR-1) and procedures for such transportation which provides guidance on type of various documents required for transportation of radioactive
material and provisions for accidents management during transportation.
AERB is the competent authority for approving design of packages, amount of the activity to be transported and procedures of transportation etc. The shipment flasks are required to meet the requirements specified in the regulatory standards. The requirements for transportation of radioactive materials include the design, fabrication and maintenance of packing and the preparation, consigning, handling, carrying, storage in transit and receipt at the final destination of packages containing radioactive materials.
The Radiation Safety Officers, authorized by AERB for the facility carries out radiological monitoring and surveillance of shipment for clearance for transportation and radiological safety during transportation. Radiation transport index over the surface of shipment package is used to provide control over radiation exposure.
The shipment flak is required to carry documents such as Certificate for Transport of Radioactive Material, shipment transport form, TREM (Transport Emergency) Card, TREM Data, instructions to carrier, labeling on the flak and carrier etc. for safety transport of the shipment flask and emergency management during transportation. The TREM card includes details on the radioactive material, hazard associated, protective equipment to be carried during the shipment, emergency actions to be taken in case of the accidents, communication details with response organisations (Consignor, CMG-DAE, AERB, District Authority).
5.0 NDMA & NDRF PARTICIPATION IN OFF-SITE EMERGENCY EXERCISES AT NPPS
The Disaster Management Act, 2005 has made the statutory provisions for the constitution of the National Disaster Response Force (NDRF) for the purpose of specialized response to natural and man-made disasters. According to the Act, the Force has to function under the general superintendence, direction and control of the National Disaster Management Authority (NDMA) and under command and supervision of Director General, NDRF. After the establishment of NDMA, training and equipping NDRF was vigorously pursued. AERB organized NDRF training at nuclear power plants in consultation with NPCIL as practical training for their effective response during response actions. This force is gradually emerging as the most visible and vibrant multi-disciplinary, multi-skilled, high-tech force of the NDMA capable of dealing with all types of natural and man-made disasters.
With the DM act and participation by the NDMA and NDRF in the emergency exercises, the capabilities and resources available for handling emergencies have increased significantly. The NDMA members and NDRF participated in the recently conducted off-site emergency exercises at all NPPs sites. Their response during the exercises has been very effective in executing the protective actions in public domain. The NDRF force has actively participated in the off-site emergency exercises and carried out response functions such as radiological monitoring, decontamination, rescue operation, first aid and medical assistance. After the recent accident at Fukushima Daiichi, Japan, offsite emergency exercises at all NPPs were carried out by involving plant organization, District Administration, NDMA, NDRF and AERB.
Emergency preparedness and response plans at all Nuclear Power Plant Sites in India are well established and existing based on the AERB safety codes and guides. These safety codes and guides and emergency plans are in line with the IAEA safety standards and international practice. Well-structured mechanism involving various response organizations with the adequate resources and infrastructure is existing to handle the nuclear or radiological emergency. Technical support is provided by the Crisis Management Group (CMG) by activating the DAE emergency response centers. Periodic exercises are conducted by involving district authorities and all other response organizations to test emergency plans, facilities for effective implementation of plan. With the DM act, establishment of NDMA and NDRF organizations the resources and capabilities have enhanced by many fold. The NDRF force has actively participated in the off-site emergency exercises and has ably carried out protective functions to handle radiation emergencies.