Radiation Protection and Environment

TECHNICAL NOTE
Year
: 2021  |  Volume : 44  |  Issue : 1  |  Page : 47--53

Planning, preparedness, and response to nuclear/radiological emergency


Shashank S Saindane1, S Murali1, Sanjay D Dhole2, NR Karmalkar2,  
1 Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
2 Savitribai Phule Pune University, Pune, Maharashtra, India

Correspondence Address:
Shashank S Saindane
Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai - 400 085, Maharashtra
India

Abstract

Planning and preparedness for response to any kind of radiation emergency are an evolving and dynamic assignment with expertise developed over a period of time. The lessons learnt in this specialized field are from the past/reported emergencies, guiding documents available on response to radiation emergencies in national/international arena, worldwide security scenario on the use of nuclear and other radioactive material including attempted malicious usage and requirements of national/international regulatory framework. The above sources help us to evolve the planning, preparedness, build response capability, and periodic revision in overall capabilities. Response planning is to mitigate the consequences of nuclear emergency – a low probability, high impact scenario at the sites/general public living in the vicinity of operating nuclear facilities, and radiological emergency – a moderate probability, low impact scenario at any locations in public domain due to typical initiating scenarios – although could be different, most of our radiation emergency response centers, developed, revised to respond to any such challenges and response procedures are evolved, set. This article on planning, preparedness for response to radiation emergency describes the present level of planning and response capability by Department of Atomic Energy, India.



How to cite this article:
Saindane SS, Murali S, Dhole SD, Karmalkar N R. Planning, preparedness, and response to nuclear/radiological emergency.Radiat Prot Environ 2021;44:47-53


How to cite this URL:
Saindane SS, Murali S, Dhole SD, Karmalkar N R. Planning, preparedness, and response to nuclear/radiological emergency. Radiat Prot Environ [serial online] 2021 [cited 2021 Jul 30 ];44:47-53
Available from: https://www.rpe.org.in/text.asp?2021/44/1/47/317953


Full Text



 Introduction



An abnormal radiation event due to failure of inbuilt safety systems, human error or combination of both at operational radiation facilities, man-made events either inadvertent or deliberate ones that could pose higher amount of radiation hazard such as personnel exposure, wide spread contamination, remnants of radioactivity at undesired locations at the place of event, site, environment affecting flora, fauna, livestock, property, and members of public. Such an event of large scale impact is termed as “Radiation Emergency.”[1],[2]

The term “Radiation Emergency”; encompasses both:

Events due to “criticality” fission chain reaction of fissile material with larger impact, more number of victims, wider area affected is referred to as– the “Nuclear Emergency.” Predominantly, these events could originate from operating nuclear facilities. The probability of a major event at nuclear facilities leading to nuclear emergency is always ensured to be negligibly small. Such nuclear events may lead to acute personnel exposures that could even be fatal, large number of victims of with less amount of exposure, medical and psychological victims, wide area contamination, and release of radioactivity in large quantities into the environment. The cost of remediation in such case could be very high or even impossible to bring back near normalcy situationsEvents due to radioactive materials or fissile materials not associated with criticality with limited impact, less number of victims, smaller area affected is referred to as – the “Radiological Emergency.” Predominantly, these events could have potential to occur anywhere, including locations in the public domain. The potential for radiological emergency could be marginally higher due to wider application of radiation technology. The radiological events could originate due to failure of inbuilt safety systems at radiation facilities, event due to loss of high active radiation source, spillage of radioactivity or deliberate/malicious[3] attempts to disperse radioactivity in undesired locations or accidents during transportation in public domain may lead to radiological emergencies resulting in personnel exposure, wide area contamination, release of large quantity of radioactivity into environment. Such radiological emergencies are low consequences events may not lead to fatal personnel exposures (acute), but there could be large number of victims of with less amount of exposure, medical and psychological victims, wide area contamination, and release of large quantities of radioactivity into the environment. Cost of remediation of these events could be very high, denial of areas, and large volume of radioactive wastes.

 Incident Free Safe Operations in India – Past Experience



In India, as per the mandate of the national regulator Atomic Energy Regulatory Board (AERB), Prevention, Preparedness and Response capabilities for Radiation Emergency have to be set by the operator, with set of approved documents available, even prior to the commissioning of any approved radiation technology operations. In India, there had been no life loss attributable due to operational activities of radiation facilities of Department of Atomic Energy (DAE) for little over six decades. There was an isolated event at Mayapuri, Delhi (2010), as a non-DAE event, with reported life loss of a victim and few radiation over-exposure cases, due to an inadvertent mishandling of radiation technology device in the public domain, wherein DAE expertise was rendered on response to mitigate the consequences. Hence, Prevention and Preparedness for Radiation Emergency of both kinds assumes greater significance than response as a postevent mitigated measure. Thereby, prevention and preparedness to radiation emergency is paramount important for planning, establishment, and commissioning.

 Present Status – Planning, Preparedness, Response To Radiation Emergency



Present status on planning

Nuclear facilities, under regulatory framework, are periodically reviewed for the operational aspects – on quarterly, annual reviews and exercises. Procedures, guidelines document, technical specifications document (Tech Spec) with criteria for limiting operating conditions are set for both normal operations and emergency situations. The operating procedures for handling emergency are drafted, approved by AERB before the commissioning of the nuclear facility. Nuclear emergency response plan is set in a graded approach based on the potential of abnormal event – scaled up such as alert, emergency in the local area, and Emergency in the Plant leading to Site Emergency and Off-Site Emergency (OSE) scenarios. Plant operating authorities, technical services personnel, experts on radiation safety, training and logistics authorities, personnel from regulatory body, administration personnel are included in committees – local level safety committee, plant level safety committee, unit level safety committee, and site level safety committees. The committees are constituted with mandate on review, authorize operations, and give clearances for safety-related unusual occurrences/reported events based on the missed category of events/smaller events/exercises and situations that warrant regulatory purview are reviewed by safety committee for review of operations of AERB for giving directives on safety and modifications if any for continued operation of the nuclear facility. Emergency Response Plan for off-site is drawn up (reviewed periodically) by the local administration of the districts wherein Nuclear Power Plant (NPP) is located in consultation with the concerned NPP, on similar line with the National Disaster Management Plan (NDMP) specifying the role of each and every response agency in a clear manner. After obtaining concurrence from the AERB, detailed emergency response plans and procedures are mock exercised periodically for handling offsite nuclear emergencies of the respective districts of the state where the nuclear facility is located.

Present status on preparedness toward nuclear emergency

The probability of occurrence of an event at any nuclear facility leading to nuclear emergency is always found to be low probability event (negligibly small), although it could be with large impact, if any event has occurred. However, effective implementation of the prompt counter-measures can reduce the consequences to the members of public, even in the event of an accidental release of radioactivity into the environment takes place.

The nuclear emergency preparedness has following objectives:

Reduce occurrence of severe deterministic effects in workers and in the publicLimit, to the extent practicable, the occurrence of probabilistic (stochastic) effects in exposed population.

In our country, nuclear facilities have definite action plans and provisions for handling any emergency event:

Operating procedures for the assessment of emergency condition and its mitigationIdentified abnormal situations leading to the classification of plant and site emergencyFacility-specific, approved nuclear emergency response plans specifying the jobs of all the functionaries with assigned rolesSounding the emergency siren and making announcement to alert plant personnelAdequate means for communicating a notification to the local DAE- RERC, the district and state authorities, CMG-DAE and the central government authoritiesIdentified assembly points for plant personnel and casual visitors with head-count, and assessment of persons trapped in the radiological areasFormation of teams for rescue operations and activation of a triage area and decontamination centerRadiological surveillance inside/outside the facility and its boundaryAvailability of meteorological parameters such as wind speed, wind direction helps in prediction of affected sector in the downwind directionMobilize the services of the medical staff at site, if requiredInstruments, personal protective kits, and response material for handling emergency kept at identified and designated place.

The level of preparedness for response will depend on the severity of the hazard. Few of the systems have been developed and demonstrated for early detection and warning capability such as: Geographical Information System (GIS)-based Decision Support Systems (DSS), Radiological Impact Assessment system/tool and Mobile monitoring with systems for use on-field (mobile radiological assessment laboratory); the systems deployed provides the inputs for planning response and implementing countermeasures. The response action within the boundary of the nuclear facility is the responsibility of the management of the nuclear facility while the implementation of the emergency response plan beyond site boundary (general public termed as public domain) is the responsibility of the concerned district authority. Recently, National Disaster Management Authority (NDMA) with its document NDMP– 2009 has mandated the districts wherein the NPP facilities are located to draft the District Disaster Management Plan in line with NDMP. Thus, in the event an OSE the authorities in the civil domain would be coordinating the response with technical inputs from experts of DAE. There are response plans by DAE for situations having the potential leading to trans-boundary effects, in accordance with the country's international obligations. There is an emergency response plan with operating nuclear facilities in India which is to be invoked in the event of an emergency and is regularly tested during periodic exercises as per international practice.

Present status response actions

Following response actions are carried out in case of low probability, high impact event of nuclear emergency arise. Depending on the emergency's magnitude, some or all of these actions get initiated at the appropriate time as listed:

Recognize the abnormal situation's existenceIdentify, characterize the source and its originInitiating quick and reliable monitoring to detect the onset of an accident/emergency condition and assess its level of magnitudeCommunicate the situation to nodal emergency response center and to the responders including firefighting and medical services, police, civil defence, transport, and other agenciesRapid, continuous assessment, and future projection of the emergency situation as it developsEstimation of the dose through the relevant pathwaysIdentification of area where countermeasures are requiredDecision making on protective measures for the population and environmentPredict the contamination situation, consequences of protective action in time and spaceEarliest distribution of iodine tablets (iodine prophylaxis), if required,Mobilization of resources in the shortest period and responding quickly to the situationEarliest initiation of countermeasures (for relief and rescue operations on the basis of actual radiation dose levels prevailing in different zones)Ensuring that ministries concerned/departments of the state/central governments and district administrations are aware of the precise measures to be taken by them as the situation develops and also that the actions taken by the various agencies are well coordinatedPrior information (do's and don'ts) for public likely to be affected by the emergency.

These include points on: (a) Evacuation/temporary relocation of the affected population, if required, (b) Withdrawal and substitution of supplies of food and drinking water (based on actual measurement of contamination found in food and drinking water), (c) Animal husbandry and agriculture department personnel to ensure radiological protection following a nuclear emergency (d) Initiation of recovery phase at a suitable time.

 Response Plan for Various Types of Emergencies



OSE response plan is prepared by the local administration in consultation with the concerned NPP, specifying the role of each response agency clearly. After obtaining concurrence from the AERB, detailed emergency response plans and procedures for handling offsite emergencies are approved by District Collector of the place where nuclear facility is located. Procedures are periodically reviewed by carrying out drills/exercises to rehearse and are corrected/updated based on the lessons learned from the exercises. For handling an OSE condition in an NPP, there is an OSE committee headed by the district magistrate of the concerned district, supported by the chiefs of all public service departments relevant to emergency management in the district and Chairman, Site Emergency Committee (SEC) of the nuclear facility for technical advice. SEC takes decisions pertaining to the handling of a nuclear emergency outside the site boundary and ensures the implementation of countermeasures such as sheltering, prophylaxis, evacuation and resettlement, including maintaining law and order and civil amenities. All the activities on the handling of an OSE are guided/coordinated from Regional Emergency Response Committee located outside the boundary of the nuclear facility. The public relation officer of the district ensures responsible information to the media to avoid panic and spreading of rumors. As per regulatory requirement each NPP has to periodically carryout the radiation emergency exercises of various kinds to verify the efficacy of emergency response.

Notification, activation, and request for assistance

It is required that the arrangements/notification process, activation/deployment of response teams in case of any notification by IAEA or of any trans-boundary nuclear emergency are developed and implemented.

Protective actions

In the event of a nuclear emergency, protective actions and countermeasures are to be implemented promptly. The procedure includes the identification and isolation of the affected area, sheltering, evacuation, prophylaxis, protection of food supplies and control on the international trade of goods and products. For countermeasures to be effective, Operational Intervention Levels and Emergency Action Levels are developed in advance, as per the IAEA guidelines, for nuclear/radiological emergencies. The actions are balanced and commensurate with the level of severity, not create unnecessary anxiety and panic among the people.

Response to loss or theft of radioisotopes/radioactive material

In case of loss or theft of a radioactive source, the same needs to be reported immediately to the local police, CMG-DAE and AERB. It is the user's responsibility to maintain an inventory of all source at all times and may seek assistance from a competent authority to trace the lost/misplaced source. Immediate notification may facilitate tracing of the source. Theft of radioactive sources is to be dealt jointly by law and order enforcement agencies along with radiation protection experts. Search for sources need to be done with the use of sensitive radiation monitoring instruments by experienced persons. The recovery of the source, contamination, and external dose rate assessment will be made prior to taking over control of the source and transporting it for safe disposal. Fire service personnel need to wear personal protective gears (PPG) such as dosimeters, masks, aprons, gloves, and gum boots – as guided by technical experts on radiation protection in case of unsealed/destroyed sources.

Radiation detection systems for detecting any abnormal increase in radiation level or unauthorized movement of radioactive material

GM based radiation monitoring systems are used as fixed units and commissioned at places where nuclear and other radioactive materials under authorized conditions are fabricated/handled in nuclear facilities or at industrial/hospital units where it is used. These radiation sensors are installed at the entry/exit points of the facility which helps to detect the movement of radioactive materials that can be illicitly brought inside the facility or a person trying to smuggle the radioactive/nuclear material from the facility (inside) for malicious use. These detectors also act as radiation early warning systems can also be used to detect any abnormal increase in the radiation background level at the facility. The methodology adopted by the detection system works in the two modes of operation namely routine and emergency mode. Analysis of dose rate data acquired during the routine operation helps in environment monitoring around the facilities and changes into the emergency mode of operation when detects abnormal level of radiation. The systems work effectively for the scenarios such as detection of any un-authorized movement of radioactive material from in/out of the site; incidents/accidents near or within the site leading to increase in radiation background; remote possibility of external events affecting the reactor operation/integrity of the reactor containment; unexpected high discharge through the stack/ground level of the NPP facilities or any abnormal event like presence of orphan source leading to rise in environmental radiation field. The system uses different mode of communication methods for data transfer to the control center.

As preparedness against the malicious acts, a self-solar powered gross radiation monitoring sensors (environmental monitoring) are installed across the vital locations in the country, which could lead to an alert in case of elevated radiation field sensed by these installed monitors. Entry points of the country, namely sea ports, air ports, and border/land crossing points have been installed with plastic scintillator-based monitors with data feed to the control room.

The newly designed Mobile Radiation Detection System installed in Police patrol vehicle with preset radiation alarm level, is useful for confirming usage of radioactive material at the blast site, location of the suspected site during any illicit material storage, fabrication of the device or during a postevent demarcation of zone at the affected site for access control. This helps to take appropriate step in the response measures.

Geographical information system-based decision support systems

GIS based DSS helps in emergency preparedness programme for the implementation of counter measures to reduce the consequences are mandatory as per regulatory requirements for all major nuclear facilities. Iodine prophylaxis, sheltering, and evacuation are some of the protective measures to be implemented for members of public in the unlikely event of any significant releases from nuclear facilities. GIS data sets provide the planners with appropriate details to take decision and mobilize the resources in time and follow the Standard Operating Procedures. The standardized datasets consisting of various layers can be effectively used during the response to an emergency.

DSS also intends to provide comprehensive and timely information to the response team handling a nuclear emergency arising from a nuclear facility.[4],[5],[6] Online environmental radiation monitoring network distributed throughout the country, independent and satellite-based communication network, computerized on-line plant information system connecting all NPPs, etc., are part of this system. In view of India's rapidly expanding nuclear power, it is considered imperative to put in place a DSS for nuclear emergencies at all NPP sites to assist OSE management titled “Indian Real time Online DSS (IRODOS).” Some of the salient features of IRODOS system developed and operational are:

Advanced detection and communication network for sensing and assessment of accidental releases.[7] This uses stand-alone solar powered detection system, GSM, and satellite-based communication systemSource term estimation based on above detector information and the real time weather information available from stand-alone automatic weather stations. This uses state of the art inverse calculation approach48 h meteorological and radiological forecast with hourly resolution and update every 24 h. This uses state of the art meso-scale meteorological weather forecast models, dispersion models, and radiological dose calculationsThe above calculations gives site specific results in terms of optimum counter measures (iodine prophylaxis, sheltering, and evacuation) for a region of 75 km radius around NPP s with a spatial resolution of 1sq. km, for minimizing the impact of the accidentThese results are displayed on user friendly GIS for decision-makers to plan the emergency handling.

Consequences of a nuclear emergency can be minimized through an effective and efficient planning and optimal utilization of available resources required for the implementation of countermeasures. The GIS-based DSS provides critical information to the emergency managers/emergency response teams before and/or during the emergency. It links geographic location (spatial) information with data such as population (number of males, females, and children), live stocks, background dose rate of the area, new information based on radiation field measurements, weather measurement, availability of logistics such as vehicle, workforce, etc., allowing analysis for planning and execution of countermeasures.

The prevailing and forecasted meteorological status, i.e., wind vectors at various altitudes is added to the GIS as a separate layer which is super imposed over other layers to obtain the actual movement of the radioactive plume. Based on the level of predicted airborne radioactivity/deposited ground contamination, plume dose rates, etc., along with the display of the area affected, implementation of distribution of iodine prophylaxis, sheltering (advice on stay-in), evacuation, relocation, etc., can be implemented. The GIS-based analysis helps to optimize the countermeasures based on the details of buildings, roads available for transportation of public and the time required for evacuation through the shortest/safest possible routes.

GIS is also used to evaluate and display the impact of standoff distances and selected zones in community planning. A database consisting of population data, established radiation baseline dose rate, sampling locations of the site, road network, vehicle boarding points, sheltering locations, meteorological parameters, major landmarks, various hospitals, major suppliers of emergency supplies and commodities, etc., helps in arranging proper logistics at a proper point by the fastest route and thus minimizing the dose to the public.

 Action Points



Radiation emergency response: RERC and radiation emergency response teams

The radiation emergency response center (RERC) acts as a nodal point from where the command and control actions, management on response would be carried out. As on date, at 25 different locations, RERCs of DAE are established across India, with Nodal RERC operative from BARC, Mumbai. DAE-RERC is equipped with all types of radiation monitoring instruments, protective gears, first aid kits, communication facility, vehicles for transport and availability of trained persons to function as experts at short notice in radiation emergency response teams (RERT). Members of RERT carry out monitoring and assess the radiological data, assist in decontamination of affected area, relocation/evacuation of persons as needed. RERT consist of sub team members as radiation monitoring team, aerial survey team, Source Recovery team, Decontamination team, Waste Management team, Medical team who carry out operations sequentially and help in assessment/assistance of radiological data. At BARC, Trombay, Integrated Centre for Crisis Management is the agency responsible for emergency preparedness, planning and response, work under the guidance of Crisis Management Committee (CMC-BARC). All DAE facilities have their own emergency preparedness plans; centralized agency– Crisis Management Group (CMG-DAE) coordinates the response actions among DAE-RERCs and also with other government agencies.

Agencies for the management of nuclear/radiological emergencies

NDMA has drawn expertise from the DAE to take the responsibility in mitigating operations during the adverse situations. It is assisted for the response operations during nuclear/radiological emergencies by the agencies such as National CMC, CMG (CMG–DAE), regional emergency response committee (RERC), DAE-RERCs at different units of DAE, Ministry of Home Affairs, NDRF, NDRF-ERCs, Civil Administration and Civil Defence.

Network of radiation emergency response centre

In addition to the existing DAE-RERCs established by BARC,[8] it is essential that additional RERCs are set up in all the major cities and other vulnerable locations with necessary trained personnel and equipped with appropriate radiation detection instruments and PPG. The law enforcement agency (local police) is the first responder in any emergency, so additional RERCs can be setup at the District Police Control Rooms/District Police Lines. On the occurrence of any major/near major event, immediately personnel from the nearest RERC will move along-with radiation gadgets and protective gears in a police vehicle for inspecting the site in the normal course and as part of Standard Operating Procedure. On detection of enhanced level of radiation if any, will immediately report the same to the DDMA from where the necessary instructions for handling of such emergency are executed. The response actions include calling experts from DAE-CMG which in-turn activates the nearest RERCs of BARC. If any NDRF battalion is located nearby, their assistance can also be requested as they have been trained by experts from DAE. In the current scenario, DAE-RERCs are established with necessary monitoring instruments, personnel protective equipment, training to the first responders from the police force is imparted and updated periodically. DAE-RERCs are maintained in a ready state to quickly respond to any nuclear/radiological emergency. Radiological assessment at the site of the emergency is necessary to protect rescue workers and medical personnel getting over exposed. Since emergency situations require communication systems for command and control, the communication systems are established between DAE-RERCs and the district authorities. DAE-RERCs have mobile monitoring laboratory equipped with radiation detection systems and protective gear (for RERTs) helps to quickly assess the radiological impact. Some of the action points are given below:

The district collector takes charge as the incident commander for the affected area during off-site nuclear emergencies in NPPs/facilities. The collector is responsible for the arrangement of logistics and initiating counter measures. The task cannot be delegated to a lower levelThe state authorities nominate in advance an incident commander specifically for handling radiological emergencies at metros/big cities. The task cannot be delegated to a lower levelBased on the guidelines of NDMA, the response capacity is built up for various emergencies at the community, district, state, and national levels. Under the guidance of NDMA, the national disaster response plans are developed in consultation with all stakeholders. The plan identifies the responsibilities at each level for different agencies during nuclear emergency, thus are integrated with the state plans (State Disaster Management Plan) for efficient transition from a particular level of emergency to the next, if the need arisesThe structure for response is developed as complementary to one another, thereby, increasing the national capacity for relief operationsAll nuclear facilities have their own response plans and procedures which are periodically reviewed and updated for handling plant and site-level emergenciesvi. All nuclear facilities have committees for emergency response comprising experts from within the facility and are headed by the head of the facility who is also identified to handle the emergency. This committee ensures mitigation of the consequences of the emergency situation, notification, and communication to district authorities and CMG-DAEThe National Nuclear/Radiological Emergency Plan would be activated on receiving information about an incident elsewhere, which might have the potential of radiological impact within country. In accordance with international commitments, information will be provided to the concerned agencies in the event of trans-boundary effects of a major incident.

 Conclusions



Based on the high requirement of the nuclear energy in current years, security scenario situation prevailing at present times, adequate preparedness for response to any kind of radiation emergency needs to be developed and maintained. Training programs to the members of all responsible agencies involved in the mitigation of adverse situations help in the awareness on radiation protection, it can reduce the radiation exposure, consequences, and as well remove the myth on radiation-related concepts. At present, the systems developed by BARC, Trombay can be useful in quick assessment of radiological impact following any nuclear/radiological emergencies.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

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