![Generic criteria and Operational criteria (Triggers)
Generic criteria
Protective action to avoid or minimize
to minimize stochastic effects are applied
generic criteria are values of projected
acquired through certain exposure pathways
The various generic criteria for avoiding
effects and to reduce the risk of stochastic
of IAEA GSR-part 7 [10]
Operational criteria (Triggers)
Operational criteria are values of measurable
(i.e.observables) to be used in the response
in order to initiate appropriate protective
These criteria are also called as triggers
emergency, these triggers include
emergency action levels (EALs) and
later phases, they are based on more
which are termed as operational intervention
be used to facilitate prompt decision
to be optimised on the basis of the exact
Generic criteria and Operational criteria (Triggers)
minimize deterministic effects and protective action
applied on the basis of generic criteria. These
projected effective or equivalent doses that
pathways and for specific integration times.
avoiding or to minimize severe deterministic
stochastic effects are identified in Appendix II
measurable quantities or observable conditions
response to a nuclear or radiological emergency
protective actions and other response actions.
triggers. Usually, in the early phase of an
include the plant specific conditions called as
and the corresponding projected doses. In the
more realistic parameters like measurements,
intervention levels (OILs). These triggers should
making, and should have necessary flexibility
exact circumstances of the emergency.](https://image.slidesharecdn.com/presentationonemergency-250505063440-948f5e5c/85/presentation-on-emergency-made-by-engineer-12-320.jpg)
![EVOLVING EMERGENCY PLANNING ZONES FOR EARLY PHASE
Off-site emergency zones and distances around
identified in advance during the preparedness
can be promptly implemented to protect the
defined:
Precautionary Action Zone (PAZ);
Urgent Protective Action Planning Zone (UPZ)
Extended Planning Distance (EPD); and
Ingestion and Commodities Planning Distance
The sizes of the zones and distances can
analysis, as long as releases that are representative
emergency involving severe damage to reactor
Emergency planning zones and distances
In the site evaluation and design of nuclear
the basis of radiological impact of the operating
Natural Growth Zone (1 – 5 km) and Radiological
However, to cater to emergency situations,
in the preparedness stage to ensure that effective
implemented to protect the public.
Emergency planning zones and distances
arrangements have to be made in the preparedness
effectively. These regions are identified to achieve
on the basis of a graded approach and in accordance
EVOLVING EMERGENCY PLANNING ZONES FOR EARLY PHASE
around the nuclear power plant need to be
preparedness stage to ensure that protective actions
the public. The following areas need to be
(UPZ);
Distance (ICPD).
can be established based on site-specific
representative of those expected for an
reactor fuel are considered .
distances
power plant certain zones are defined on
operating facility – Exclusion Zone (~ 1km),
Radiological Surveillance Zone (5 – 30 km) [11].
zones and distances need to be identified
effective protective actions can be promptly
distances are those identified regions where
preparedness stage to take protective actions
achieve the goals of emergency response
accordance with the protection strategy](https://image.slidesharecdn.com/presentationonemergency-250505063440-948f5e5c/85/presentation-on-emergency-made-by-engineer-24-320.jpg)
![NUMERICAL WEATHER PREDICTION
The system in its present
forecasted meteorological
Weather Prediction
weather forecast model
National Centre for
Forecasting (NCMRWF),
These data are
Emergency Response
via Computer Division’s
using 2 Mbps internet
NUMERICAL WEATHER PREDICTION
present form gets 72 hours
meteorological data [Numerical
(NWP)] from mesoscale
model MM5, operational at
Medium Range Weather
(NCMRWF), Noida, India.
received at IRODOS,
Response Centre, BARC, Trombay
Division’s (BARC) download server
internet data transmission line.](https://image.slidesharecdn.com/presentationonemergency-250505063440-948f5e5c/85/presentation-on-emergency-made-by-engineer-38-320.jpg)
presentation on emergency made by engineer
- 1. Introduction Nuclear Power Plants (NPPs) design safety requirements accidents to very low levels. However, there is a need to actions and other response actions in a Nuclear Power Plant which In such a situation there is a need effective use of protective actions of the emergency. These protective taken before or immediately after environment in the close vicinity environmental monitoring results stage the actions taken should (NPPs) are built taking into consideration all to reduce the probability of severe plan and implement urgent protective actions in the event of a severe accident which results in off-site consequences. need for taking immediate decisions for actions to be carried out in the early phase protective actions need to be justified and after the release of radioactivity into the vicinity (3 – 5 km) of the NPPs., As results may not be available during this do more good than harm.
- 2. Introduction contd.. This early phase is associated limited information of plant parameters data on releases. Selection of protective this early phase of a developing off-site consequences needs optimization It is essential to have proper on the effectiveness of various levels at which the decision on taken. This needs to be developed factors like feasibility of implementation economic criteria, other natural parameters. associated with many uncertainties due to the parameters and unavailability of actual protective actions to be implemented in developing emergency with possible or actual optimization and justification. knowledge at the preparedness stage various protection measures and their trigger specific protection measures are to be developed taking into consideration other implementation of protective actions, socio- natural conditions like meteorological
- 3. Exposure situations Three types of exposure situations are envisaged which cover all situations of exposure. Planned exposure situation This includes exposures that arises from from a planned activity that results in exposure situations, exposure at some exposure is not expected to occur accident or from an event or a sequence certain to occur, it is referred to as “potential Emergency exposure situation This includes exposures that arises act, or any other unexpected event, avoid or to reduce adverse consequences actions have to be considered before arises. However, once an emergency exposures can be reduced only by implementing Three types of exposure situations are envisaged which cover all situations from the planned operation of a source or in an exposure from a source. In planned some level can be expected to occur. If with certainty, but could result from an sequence of events that may occur but is not “potential exposure”. as a result of an accident, a malicious event, and requires prompt action in order to consequences. Preventive actions and mitigatory before an emergency exposure situation emergency exposure situation actually occurs, implementing protective actions.
- 4. • Existing exposure situation • This includes exposures decision on the need for Existing exposure situations exposure to natural background • They also include situations radioactive material that that were not subject remains after an emergency successful hazard • control at the nuclear implementation of protection emergency will transit situation to an existing exposure Existing exposure situation exposures which already exists when a for control needs to be taken. situations include situations of background radiation. situations of exposure due to residual that derives from past practices to regulatory control or that emergency exposure situation. Upon nuclear plant and effective protection strategy, an offsite transit from emergency exposure exposure situation.
- 5. Consequences of a nuclear emergency • Radiological consequences • Psychological consequences • Societal consequences • Economic consequences Consequences of a nuclear Radiological consequences Psychological consequences Societal consequences Economic consequences
- 6. Radiological consequences Adverse health effects of radiation categories: deterministic effects (harmful death/ malfunction of cells following i.e., cancer and heritable effects involving exposed individuals owing to mutation heritable disease in their offspring (germ) cells. For deterministic effects, beyond which the severity of the Stochastic effects occur without a probability is proportional to the dose Psychological consequences Psychological effects reflect apprehensions/concerns exposure. They also manifest due to a lack health effects of low dose radiation and protective measures implemented such concerns and people are affected by the questions. Studies following the Chernobyl that people affected by a nuclear accident helplessness, dissatisfaction, frustration, and lack of control over their individual living conditions, psychological stress. Such situation can induce people, uncorrelated with the actual magnitude radiation exposure are grouped into two (harmful tissue reactions) due to the following high doses; and stochastic effects, involving either cancer development in mutation of somatic cells or offspring owing to mutation of reproductive effects, there is a threshold level of dose, the effect is proportional to the dose. a threshold level of dose and whose dose while severity is independent of it. apprehensions/concerns and considerable fear for radiation of public understanding of the scientific data on also arise as an indirect consequence of the as evacuation. An accident generates many the complexity of the situation and have many and Fukushima nuclear accident have indicated accident can feel anguish, dismay, discouragement, and anger. Many affected people report feeling a conditions, and this is linked to a high level of induce psychological and inner disorders in some magnitude of exposure.
- 7. Societal consequences Management of the accident itself, can the way of life. This introduces societal living conditions; zoning of areas; various of actions; accommodation for displaced implementation of the compensation transport, health care, community support, all affected. Responses by individuals situation in their communities and their have shown that some residents will allowed, and others will leave. Among relocate permanently. Economic consequences These are the consequences caused having direct and indirect impact contamination can affect critical communication systems, food and infrastructures, including public services financial systems, and education facilities condition. The agricultural sector contamination of soil and livestock, affecting and consumption. From an economic response suggest that a large-scale evacuation zones of Chernobyl is significantly that could have been adopted: short remediation followed by a later return can bring about social disturbance and disruption of societal repercussions, such as change in working and various restrictions associated with implementation displaced people; side effects of decontamination; and compensation system. Social infrastructures, such as education, support, public safety, recreation, art and culture, are individuals to such situations depend on the general their personal lives. Experience from past accidents will choose to stay in affected areas, when this is Among those who leave, some will return and others will caused due to the economic fabric of the affected areas impact on the individual. For instance, radiological infrastructures such as public transportation, water supplies. This in turn will affect the social services such as public health and medical facilities, facilities resulting in a stressed socio-economic sector can also be significantly affected due to affecting food production as well as its distribution economic perspective, the inference from the Chernobyl scale permanent relocation of people within the significantly less optimal than an alternative policy short term evacuation coupled with aggressive return of those displaced.
- 8. Emergency phases For the management of a nuclear emergency, into various phases considering aspects such measures required, the availability of resources, Accordingly, the response to a nuclear following phases. Table : Phases of nuclear emergency Early Phase (hour-days) Intermediate phase (Days Month) Pre- Release Release Consequence Management and transition to recovery Emergency Exposure Early Phase protective actions Check/ actions and prepare for long term actions emergency, the timeline of the accident can be divided such as the status of the release, the urgency of resources, and the relevance of exposure pathways. emergency shall be planned in line with the Table : Phases of nuclear emergency Intermediate phase (Days- Month) Late/Recovery Phase (Months- Year) Consequence Management and transition to recovery Recovery/long term measures Emergency Exposure Existing Exposure Check/Reoke early phase actions and prepare for long term actions
- 9. PRINCIPLES FOR PLANNING AND IMPLEMENTING PROTECTIVE MEASURES • Justification • Optimization • Reference levels The principles of planning and implementing based on justification and optimization positive benefit to the exposed population For a better implementation of protective values in the form of reference levels against the residual dose such that information on the quantum of benefit In the early phase, it is also important initiation of protective actions, where protection strategy has to evolve taking PRINCIPLES FOR PLANNING AND IMPLEMENTING PROTECTIVE MEASURES implementing protective measures are broadly optimization of radiation exposure such that there is a net population. protective actions, it is essential to have guidance levels which clearly weighs the protective action that the emergency managers have sufficient benefit from each protective action. important to have trigger values to facilitate the where the basis is the projected dose. The overall taking into consideration all these parameters.
- 10. Justification Justification is applied in situations public exposure. Application planned exposure situation requires be introduced unless it produces good than harm) to the exposed the radiation detriment it causes Optimization Optimisation is aimed at achieving through an ongoing, iterative best option under the prevailing protection is not minimization actions and measures is intended that have been deemed to be of protection, with restriction risk, is central to the system exposure situations. situations involving occupational and Application of the principle of justification to the requires that no new activities should produces sufficient net benefit (doing more exposed individuals or to society to offset causes. achieving the best level of protection iterative process that involves selection of the prevailing circumstances. Optimisation of minimization of dose. Optimisation of protective intended for application to those situations be justified. The principle of optimisation restriction on the magnitude of individual dose or system of protection and applies to all three
- 11. • Reference levels • In emergency situations the dose to an individual as a result • It is inappropriate to allow residual dose range between emergency exposure situation • Reference levels are used to the phase of emergency. Any careful consideration of the socio • For planning protective measure higher degree of uncertainty metrological conditions, a reference in considering the disturbances adhere to the principal implementation of the protective the reference level is the total annual residual result of the emergency. exposures above this level. ICRP identifies a between 20mSv and 100 mSv as a reference level in an situation. plan protective measures commensurate with Any modification in the reference level requires socio-economic conditions. measure in the early phase where there is a uncertainty with the possible source term and reference level of 100 mSv should be justifiable disturbances each protective measure brings and to of doing more good than harm in the protective action.
- 12. Generic criteria and Operational criteria (Triggers) Generic criteria Protective action to avoid or minimize to minimize stochastic effects are applied generic criteria are values of projected acquired through certain exposure pathways The various generic criteria for avoiding effects and to reduce the risk of stochastic of IAEA GSR-part 7 [10] Operational criteria (Triggers) Operational criteria are values of measurable (i.e.observables) to be used in the response in order to initiate appropriate protective These criteria are also called as triggers emergency, these triggers include emergency action levels (EALs) and later phases, they are based on more which are termed as operational intervention be used to facilitate prompt decision to be optimised on the basis of the exact Generic criteria and Operational criteria (Triggers) minimize deterministic effects and protective action applied on the basis of generic criteria. These projected effective or equivalent doses that pathways and for specific integration times. avoiding or to minimize severe deterministic stochastic effects are identified in Appendix II measurable quantities or observable conditions response to a nuclear or radiological emergency protective actions and other response actions. triggers. Usually, in the early phase of an include the plant specific conditions called as and the corresponding projected doses. In the more realistic parameters like measurements, intervention levels (OILs). These triggers should making, and should have necessary flexibility exact circumstances of the emergency.
- 13. MEASURES TO PROTECT PUBLIC AND ENVIRONMENT A severe accident at a nuclear power leads to a major release of the core the implementation of combination the public. The protective actions that may be from a severe accident at a nuclear Early phase protective actions (including and other response actions that need hours) in order to be effective. Their they are delayed. Intermediate phase protective actions implemented within days to weeks and Early Phase Actions Iodine Thyroid Blocking Agent Sheltering Control of Access Food Restriction and Control MEASURES TO PROTECT PUBLIC AND ENVIRONMENT power plant where failure of containment barriers core inventory into the environment will require of protective actions to reduce the dose to be taken in response to an emergency arising power plant are mainly: (including precautionary and urgent actions) need to be taken promptly (normally within Their effectiveness will be markedly reduced if actions and other response actions can be and still be effective. Intermediate Phase Actions Iodine Thyroid Blocking Agent Relocation Long term Food Restriction Decontamination Medical Screening
- 14. Iodine Thyroid Blocking (ITB) Radioactive iodine (radioiodine) can exposure (from inhalation and ingestion) radioiodine in the thyroid gland results exposure can be reduced or even Prophylaxis, i.e., Iodine Thyroid Blocking Potassium Iodate (KIO3) tablet. The thyroid gland, thereby reducing the quantity gland by isotopic dilution and by direct ITB is a protective action for which preparedness the overall emergency response plan radiation exposure to radioactive iodine, time of administration of stable iodine reduction factors are given below Time of stable iodine Administration Before intake 1 h after intake 6 h after intake 12 h after intake 1 day after intake Iodine Thyroid Blocking (ITB) give rise to both external exposure and internal ingestion). The selective and rapid concentration of results in internal radiation exposure of the thyroid. This prevented by proper implementation of Iodine Blocking (ITB) agent – Potassium Iodide (KI) or The oral administration of ITB agents saturates the quantity of radioiodine that could reach the thyroid direct action on thyroid metabolism. preparedness arrangements can be made as part of to prevent deterministic effects from high levels of iodine, and reduce the risk of stochastic effects. The iodine is important for thyroid dose reduction. The dose Dose reduction (%) 100 80 50 Very little reduction No reduction
- 15. NOTE : The groups most likely to benefit from breastfeeding women, whereas individuals over ITB . If the supply of stable iodine is limited, adolescents. Neonates and people older than effects if they receive repeated doses of stable doses of radioiodine (e.g. emergency workers likely to benefit from ITB irrespective of their age After careful review of the data from Chernobyl and cancer risk in exposed children, it is recommended on age, predicted thyroid exposure, and pregnancy Table: Threshold thyroid radioactive exposure and group specific recommendation in case of limited supply of ITB agents. Different risk groups Adults over 40 yrs Adults over 18 through 40 yrs Adolescents over 12 through 18 yrs Pregnant or lactating women Children over 3 through 12 yrs Over 1 month through 3 years Birth through 1 month from ITB are children, adolescents, pregnant and over 40 years of age are less likely to benefit from limited, priority should be given to the children and 60 years are at higher risk of adverse health stable iodine. Individuals at risk of exposure to high involved in rescue or clean-up operations) are and should be given priority. Chernobyl relating estimated thyroid radiation dose recommended that administration of KI be based pregnancy and lactation status. Table: Threshold thyroid radioactive exposure and group specific recommendation in case of limited supply of ITB agents. Predicted Thyroid exposure (mSv) >5000 >100 >50
- 16. Recommended Age specific ITB dosage Age Group Mass tablet ( Adults and Adolescents: > 12 years Pregnant Women and Children: 3 years – 12 years Infants: 1 month – 3 years Neonates: birth – 1 month Sheltering Sheltering may be a very effective depending upon the type of building the site of accident. There is, however, means of communicating with the Sheltering-in-Place (SIP), as the name action in the early phase, especially when exposure to the plume can be reduced cases where proper protection is not individuals shall be moved to community stage. Normally, community centers, marriage halls, etc., are chosen for this Recommended Age specific ITB dosage Mass of KI tablet (mg) Mass of KIO3 tablet (mg) 130 170 65 85 32 42 16 21 protective action early in an emergency, available and its location with respect to however, a need to have a rapid and effective the people who are advised to shelter. name implies, is the most effective protective when the release is continuing. Inadvertent reduced by this protective action. In certain not available for SIP, then the affected community shelters identified in the preparedness centers, schools, colleges, religious places, this purpose.
- 17. • Sheltering is generally implemented for a short period detrimental impact of non of food, potable water, psychological • However, in the longer term, plume, sheltering can continue radiation dose from radionuclides. • In this circumstance, recommended for longer interferes with normal distress, particularly when might be in different locations, recommended to be period of time due to the non-radiological effects (lack psychological effects etc.). term, after passage of the continue to avert external ground deposits of sheltering may be longer periods of time. This living and may cause when members of a family locations,
- 18. The advantages and disadvantages be assessed when justifying and may be alleviated by advising people for necessary activities will not, exposures. Sheltering not only also makes it easier for the authorities TV or the internet. The justification should include consideration industry, trade and dose to the (e.g. police). It is also appropriate identified groups (pregnant individuals) within the population, a whole. The protection factors (P.F) depends affected villages and this needs dose by Sheltering-in- Place. The below Table. Type of shelter Pathway of Exposure and protection House Shelter Inhalation with air exchange of 2 hrs in plume Large multi-storey building shelter Inhalation disadvantages of a part-time sheltering strategy should and optimizing the protection strategy. Anxiety people that short periods of time spent outdoors not, in many situations, result in very high serves to protect against radiation exposure, it authorities to keep the public informed via radio, justification and optimisation analysis for sheltering of monetary losses to individuals, society, first responders implementing the intervention appropriate to give separate consideration to special women, small children and hospitalized population, in addition to the exposed population as depends on the type of shelters available in the needs to be considered in calculating the averted The typical P.F provided by sheltering is given in Pathway of Exposure and protection factor Ground Shine – 0.4 Cloud Shine – 0.6 Inhalation with air exchange of 2 hrs in plume – 0.5 Ground shine – 0.02 Cloud Shine – 0.3 Inhalation with air exchange of 2 hrs in plume – 0.2
- 19. Evacuation An evacuation represents a major comparison with other early measures and sheltering. Evacuation is the urgent, the affected or potentially affected accommodation, food and water can release and release phase) of a nuclear severe deterministic effects and reduce out in time, this measure provides avoid external and internal radiation disruptive protective action and should consideration to all other protective justified when the projected doses lead Evacuation before release (preventive The difficulty in making a decision radioactivity lies in the limited amount Judgment is required on the nature escalation and the projected doses evacuation is to be made on the involved and of possible changes in major intervention in the lives of the public in measures such as iodine thyroid blocking (ITB) urgent, temporary removal of persons from affected area to locations unaffected where can be provided during the early phase (pre- nuclear emergency. It is intended to avoid reduce the risk of stochastic effects. If carried the most effective protection as it helps to radiation exposure. Evacuation is the most should be implemented after giving due protective actions. However, evacuation is always lead to severe deterministic health effects. (preventive evacuation) decision to evacuate prior to a release of amount of information that may be available. nature of the accident, the probability of doses. The decision to implement preventive the assessment of the condition of the plant in meteorological conditions.
- 20. • Evacuation following release • The efficiency of evacuation radioactive materials to the ability to notify and transport evacuation and the capability radionuclides in the environment • Evacuation could increase exposure the passage of a plume, because exchanges with the outside and vents are closed. • Evacuation is only appropriate effects are less severe than the dose. release evacuation following the release of the environment depends on the transport people quickly, the timing of the capability to predict the dispersion of environment. exposure if it is implemented during because the air inside a vehicle air even when all the windows appropriate when its risks and secondary the risk of the projected radiation
- 21. Control of access Control of access to an area automatically follow the declaration it is not possible to give trigger action, control of access avoids otherwise enter the area and has the spread of contamination. The difficulties associated with physical, social, topographical enforcement, following prolonged action. The plan and implementation also take into account the responders. Justification and control are therefore necessary other long-term protective actions area affected by an accident shall declaration of a nuclear emergency. While trigger levels of dose for this protective avoids exposure of people who would has the additional benefit of reducing with controlling access mainly arise from topographical and geographical limitations of prolonged implementation of this protective implementation of control of access should the collective dose of emergency optimisation of long-term access necessary and will also influence decisions on actions.
- 22. • Food restriction and control • The imposition of restriction on consumption particularly from local produce and a very important protective action warranting urgent protective actions grown in the open space (local produce, mushrooms), milk from animals consumption are contributors to produce can be a concern within within two days . • For a radioactivity release in an very complex and will be constantly the relatively small ongoing releases weeks may result in hotspots that rainwater and animal feed. Controls for considerable periods of time some radionuclides move slowly from and animals in the food-chain. Subsequently, concentration in food should be control to be better defined. control consumption of food and water (open sources), and supply to areas beyond the affected zone, is action in the early phase. Following a release actions off the site, consumption of vegetables produce, to include wild-grown products (e.g. grazing on contaminated grass, and rainwater the dose. Consumption of rainwater and local hours of the release and consumption of milk emergency, the patterns of the deposition are constantly changing if there is an ongoing release. Even releases expected to occur over a period of days or that could cause contamination of food, milk, Controls on food may be required to remain in force if long-lived radionuclides are involved, since from contaminated ground or water into plants Subsequently, results of measurements of activity be available and will permit the extent of food
- 23. Triggers for early phase protective actions Of the various protective actions to emergency, the important ones are – and Food restriction and Control. protective actions, that are to be included summarised in Table below. a trigger appropriate, as values below the generic effect may not be justified. Protection Measures Trigger Values in Early Phase Organ Dose Effective Dose Sheltering Iodine Thyroid Blocking 50 mSv Evacuation Restriction on water and food from open source (milk and green vegetables) Partial-Sheltering indoors (advise to restrain unnecessary outside movement) * Considering the ease and effectiveness of implementation taken. Triggers for early phase protective actions be implemented in the early phase of the –ITB administration, Sheltering, Evacuation The triggers for initiating these specific included in the overall protection strategy, are trigger of 100 mSv effective dose is considered generic criteria for reducing the stochastic Trigger Values in Early Phase Integration Time and Exposure Pathways Effective Dose 100 mSv* External exposure and committed dose from inhaled radioiodine as a result of not taking any measure and staying outdoor for a period of 7 days. External exposure and committed dose from inhaled radionuclide as a result of staying outdoor for a period of 7 days 100 mSv External exposure and committed dose from inhaled radionuclide as a result of not taking any measure and staying outdoor for a period of 7 days. 10 mSv Exposure due to Ingestion of Radionuclide for a period of 1 year 10 mSv External exposure and committed dose from inhaled radionuclide as a result of not taking any measure and leading normal life for 7 days. implementation a value between 20 and 100 mSv may be
- 24. EVOLVING EMERGENCY PLANNING ZONES FOR EARLY PHASE Off-site emergency zones and distances around identified in advance during the preparedness can be promptly implemented to protect the defined: Precautionary Action Zone (PAZ); Urgent Protective Action Planning Zone (UPZ) Extended Planning Distance (EPD); and Ingestion and Commodities Planning Distance The sizes of the zones and distances can analysis, as long as releases that are representative emergency involving severe damage to reactor Emergency planning zones and distances In the site evaluation and design of nuclear the basis of radiological impact of the operating Natural Growth Zone (1 – 5 km) and Radiological However, to cater to emergency situations, in the preparedness stage to ensure that effective implemented to protect the public. Emergency planning zones and distances arrangements have to be made in the preparedness effectively. These regions are identified to achieve on the basis of a graded approach and in accordance EVOLVING EMERGENCY PLANNING ZONES FOR EARLY PHASE around the nuclear power plant need to be preparedness stage to ensure that protective actions the public. The following areas need to be (UPZ); Distance (ICPD). can be established based on site-specific representative of those expected for an reactor fuel are considered . distances power plant certain zones are defined on operating facility – Exclusion Zone (~ 1km), Radiological Surveillance Zone (5 – 30 km) [11]. zones and distances need to be identified effective protective actions can be promptly distances are those identified regions where preparedness stage to take protective actions achieve the goals of emergency response accordance with the protection strategy
- 25. Precautionary Action Zone (PAZ) This is the area where comprehensive arrangements notify the public and have the public start to take hour of the declaration of an Off-Site Emergency other response actions before the start of a release order to prevent severe deterministic effects. The to minimize evacuation times and evacuation of over evacuation of the UPZ. In addition, provisions of personnel staffing special facilities such as hospitals, be immediately evacuated. Urgent Protective Action Planning Zone (UPZ) This is the area where comprehensive arrangements notify the public and have the public start to take of the declaration of an Off-Site Emergency. The response actions before or shortly after the start the site, but in such a way as not to delay the actions within the PAZ. In this zone, the protective manner, but instead is dependent on the release Extended Planning Distance (EPD) This is the area around a facility within which monitoring following the declaration of a general emergency response actions to be taken off radioactive release that would allow the risk of to be effectively reduced. The area within the purposes and may not be the actual area in areas where early protective actions such as relocation arrangements are made at the preparedness stage to take precautionary protective actions within one Emergency. The goal is to initiate protective actions and release warranting protective actions off the site, in The boundary of the PAZ needs to be established of the PAZ to beyond the UPZ is given priority provisions are made within this zone for the protection hospitals, nursing homes and prisons that cannot Urgent Protective Action Planning Zone (UPZ) arrangements are made at the preparedness stage to take the urgent protective actions within one hour The goal is to initiate protective actions and other start of a release warranting protective actions off the implementation of the precautionary protective protective actions are not implemented in a blanket release pattern. Extended Planning Distance (EPD) which emergency arrangements are made to conduct general emergency and to identify areas warranting off the site within a period following a significant of stochastic effects among members of the public extended planning distance serves for planning which monitoring is to be conducted to identify relocation are necessary.
- 26. Ingestion and Commodities Planning Distance (ICPD) This is the area around a facility for which emergency emergency response actions following the declaration risk of stochastic effects among members of the public as a result of the distribution, sale and consumption commodities other than food that may have contamination area within the ingestion and commodities planning for emergency response actions to monitor and domestic use or international trade. The actual area conditions in an emergency. As a precaution, some the ingestion and commodities planning distance water and to prevent the use of commodities that radioactive release. Evaluation of PAZ and UPZ During the early phase of the nuclear emergency, into place in the Precautionary Actions Zone and evaluation of these zones in the preparedness stage The assumptions on the release characteristics insights from in-house source term studies and the releases to the atmosphere following severe the volatile fission products. The reported release due to Fukushima accident identifying the emergency planning zones (PAZ appropriate, considering the design and advanced Ingestion and Commodities Planning Distance (ICPD) emergency arrangements are made to take effective declaration of a general emergency in order to reduce the public and to mitigate non-radiological consequences consumption of food, milk and drinking water and the use of contamination from a significant radioactive release. The planning distance serves for planning purposes to prepare and control commodities, including food, either for area will be determined on the basis of the prevailing some urgent protective actions may be warranted within distance to prevent the ingestion of food, milk or drinking that may have contamination following a significant emergency, the precautionary and urgent protective actions fall and Urgent Protective Actions Planning Zone. Hence, the stage is of utmost importance. characteristics following a severe accident takes consideration of the and experience from Fukushima accident. The majority of severe fuel damage are projected to contain about 0.5–3% of accident was 2.7 % and for Chernobyl it was 10 %. For (PAZ and UPZ) for an Indian PHWR, a release of 3 % is advanced engineered safety features.
- 27. PAZ recommended sizes and description Case Dosimetric Basis 700 MWe 1 Gy in 1 (via Cloud Shine, Inhalation Ground Shine) 220 MWe UPZ recommended sizes and description Case Dosimetric Basis 700 MWe 100 mSv in 7 Days (via Inhalation) 220 MWe (a) Only significant volatile radionuclides considered.(b) No protective actions Masse release over a period of 10 considered. (a) Only significant volatile radionuclides – I masse release over a period of 10 hours.(c) 5 years PAZ recommended sizes and description Dosimetric Release from Containment (a) PAZ Radius(b) Suggested Protective Action day Cloud and Shine) 3 %(c) 2.1 km(d) Evacuation, ITB, SIP, reduce inadvertent ingestion < 1.5 km(d) UPZ recommended sizes and description Release from Containment(a) PAZ Radius(b) Suggested Protective Action 3 %(b) 18 km(c ) ITB, SIP, reduce inadvertent ingestion, food restriction and control 9.5 km(c) radionuclides – I-131, Cs-137 and Te-132 – are have been assumed to be in place.(c) This is an En- 10 hours.(d) 5 years of meteorological data was I-131, Cs-137 and Te-132 – are considered.(b) This is an En- years of meteorological data was considered.
- 28. DEVELOPMENT OF A PROTECTION Different strategies may have to be evolved consideration to the degree of uncertainty – degree (intermediate and late phase). A complete is expected to improve with the availability assessment. The choice of protective actions conditions, and socio-economic factors. For of the protection strategy, factors other than execute an orderly evacuation, possibility congestion and incidents/accidents involving Hence, in the planning stage, protection strategies possible scenarios/conditions. Protections strategy identified by evaluating the effect of various to arrive at a justified and optimized protection Protection strategy evolved during the planning Reference Level in accordance with the phase areas that are likely to be affected. As explained earlier, a reference level of 100 accident depending on the level of uncertainty This level can be subsequently lowered based consequence through measurements and analysis The Triggers for each protective action can be for its inclusion into the strategy. The residual against the Reference Level in order to establish PROTECTION STRATEGY evolved in accordance to the emergency phase with – this varies from a higher (early phase) to lower complete understanding of the actual consequence availability of data from field measurement and further actions should also consider the site specific For example, if evacuation is considered as a part than the avertable dose, like resources, capability to of public moving on their own, possible traffic involving vehicle movements should also be considered. strategies have to be identified for the various strategy for each of these scenarios should be protective actions individually or in combination protection strategy. planning stage must take into account setting up of the phase of emergency and the projected doses in the 100 mSv can be set during the early phase of an uncertainty in the source term and the weather conditions. based on the improved knowledge on the actual analysis. be used for choosing a particular protective action residual dose of each strategy must be assessed establish its effectiveness.
- 29. Influencing Factors for the Protection Strategy Index Type S1 Source Term S2 Sn R1 Release Type R2 R3 D1 Release Duration D2 W1 Wind Direction W2 W3 Stability Category T1 Time of Action T2 A1 Protective Action A2 A3 A4 Influencing Factors for the Protection Strategy Type Variable Source Term Based on EAL-1 for offsite site emergency Based on EAL-2 for offsite site emergency Based on EAL(n) for offsite site emergency Release Type Un-Controlled Release, En-Masse Un-Controlled Release, Continuous Controlled release Release Duration Short term (eg. 6hrs) Long term (eg. 24 hrs Wind Direction Fixed Wind Direction Changing Wind Direction Stability Category A/B/C/D/E/F Time of Action Pre-Release Post Release, 0 hr/1 hr/4 hr/10 hr Protective Action Sheltering ITB Food Control Evacuation
- 30. Steps involved in an optimized protection strategy Evaluate the projected doses for the the scale of health consequences to identify the broad geographical and likely response phases; to plan for effective Identify all protective actions that are than harm). Each should be examined for its projected dose Justification for combined actions Evolve outline for a justified protection Evaluate residual dose after implementing Compare the residual dose with reference If residual dose is above strategy/measures/implementation and If residual dose is likely to be below . For combinations of actions that readily optimized and the relevant averted Steps involved in an optimized protection strategy situations being considered to identify and temporal distribution of the various effective use of resources. are likely to be justified (does more good potential to avert significant portion of protection strategy implementing protection strategy reference level (RL) above the RL then, change the and repeat the comparison with RL. the RL, optimization can be done are largely independent, they can be averted dose can be used as a guide.
- 31. IMPLEMENTATION OF PROTECTION The decision makers need to have implement the protection strategy input factors involves multiple release becomes iterative to identify the best In the early phase of a nuclear exceeded), the plant authorities should available for release, type of release, emergency, the current/predicted strategies formulated in the preparedness strategy for recommendation. For Short Term Releases - In case of a short-term release (en require prompt actions and the protective implemented quickly to reduce the aspects of decision making viz., declaration, authority and initiation of response For Prolonged Releases - In case of a prolonged release, the staying indoors (sheltering-in place) of ITB. In addition, an extended plume be affected may not be constrained to change directions. In such conditions, conditions will assist effective decision PROTECTION STRATEGY DURING AN EMERGENCY have multiple input parameters to identify, assess and strategy during response to an emergency. Since the release scenarios and conditions, the process best suited protection strategy. emergency (declared after relevant EALs are should consider the actual plant conditions (time release, actual source term, etc.) at the time of the meteorological conditions and the database of preparedness stage to identify a suitable protection (en-mass release), the protection strategy may protective actions like ITB and sheltering have to be consequence. In this case, time lines for various declaration, notification, recommendation to public by public authorities are important. the protection strategy may necessitate people place) for extended period and repeated distribution plume phase means that the areas that are likely to constrained to a particular sector (s) if the wind is expected conditions, the capability to predict the future weather decision making.
- 32. In the absence of functional decision or during the release phase, decision thumb approach to implement the identifying the current wind direction recommend implementation of the affected along with the two adjacent (Figure a). Subsequently, the recommendations dispersion calculations or measurements unsteady wind directions during the implemented in the sectors as shown based on dispersion estimation or measurement Figure-a Stable wind Figure-b Stable wind decision support system immediately after an accident decision makers should have a simplistic, rule-of- protection strategy. Decision makers after direction or from historic data for the site, can protection strategy in the sector likely to be adjacent sectors as long as the direction is steady recommendations can be revised once the results from measurements are available (Figure b). In the case of the release, the protection strategy can be shown in Figure 9c and subsequently revised measurement results (Figure 9d). b Stable wind Figure-d Un-Stable wind Figure-c Un-Stable wind
- 33. Guidance regarding the radiological consequences Broadly, the release conditions and its radiological Releases that result in severe deterministic effects Releases that result in elevated risk of stochastic Releases that result in severe deterministic studies and calculations that accident in a deterministic health effect in the public domain, event of such releases, the protection strategy the dominant protective action. Such a strategy PAZ and the evacuees would be moved out of the The non-radiological consequences of this strategy radiological consequence (deterministic effects) strategy would be justified. In order to reduce exposure mode of transport, speed of evacuation and Though unlikely, severe deterministic effects strategy should consider selective evacuation based Releases that result in elevated risk of stochastic effects Releases that result in projected doses that elevate holistic protection strategy. The decision makers should now give weightage evacuation when formulating the strategy. The strategy should include the individual protective action and socioeconomic considerations consequences radiological consequence can be grouped as effects stochastic effects deterministic effects: It is evident from the various 220MWe PHWR does not result in any domain, However, as a generic guidance, in the strategy should primarily consist of evacuation as strategy would fall in place immediately within the the PAZ to beyond the UPZ. strategy would be far outweighed by the effects) during these releases and hence the exposure during evacuation, factors such as and time of evacuation must be considered. effects if expected in the UPZ, the protection based on the affected area. Releases that result in elevated risk of stochastic effects elevate the risk of stochastic effects require a weightage to other protective actions over individual non-radiological health effects of each considerations.
- 34. Guidance regarding non-radiological consequences The decision makers should consider non-radiological consequence - 1. Loss of Life Estimates (LLEs), particular protective actions; 2. Expected number of injures due protective actions; 3. Economic consequences and feasibility – mass restriction of certain essential of large scale transportation for evacuation Generally, these non-radiological consequences quantify than radiological consequences sufficient site-specific data. However, used to obtain a qualitative understanding consequences of a certain protection radiological consequences consider the following while assessing the if any due to implementation of a due to implementation of different feasibility of protective actions, such as essential food products, cost of mobilisation evacuation etc. consequences are more difficult to consequences due to non-availability of However, an expert-based approach may be understanding of the nonradiological protection strategy.
- 35. Real time Online Decision Support System (RODSS) 1. INTRODUCTION Multi-level safety features are nuclear technology, and these are To reduce the probability of an first place. Limit its magnitude in the unlikely Limit the consequences of the place. Real time Online Decision Support System (RODSS) an inherent characteristic of are incorporated so as to an accident from occurring in the unlikely event of an accident. the accident itself, in case it takes
- 36. In keeping with its safety, nuclear technology the Chernobyl accident the consequences of Design Basis Accident despite the fact that the accident was considered The consequences, necessitate additional the public and the environment adverse radiological contingencies, there Emergency Preparedness traditional emphasis on technology was prompted by accident (1986) to consider of accidents Beyond the Accident (BDBA) scenarios, the probability of such an considered extremely low. consequences, of such accidents additional measures to protect environment from possible radiological impact. It is for such there is need for drawing up Preparedness Plan.
- 37. SALIENT FEATURES OF IRODOS It provides a comprehensive pertaining to nuclear and radiological sufficiently long distances around Nuclear It incorporates state of the art radiological impact on public and surroundings initiate appropriate counter measures, emergency. It provides 72 hours meteorological hourly interval and update every 24 hours It incorporates state of the art communication monitoring stations and reactor status accident. It estimates the likely quantity optimum counter measures to minimise public. It uses a Geographical Information text outputs to guide the emergency emergency management authorities for SALIENT FEATURES OF IRODOS comprehensive integrated decision support system radiological emergency in public domain (covering Nuclear Power Plants). art weather prediction, dispersion of plume and surroundings to support the decision makers to measures, well in advance, during a nuclear meteorological and radiological forecasts with hours. communication between various environmental status data for the prompt identification of an quantity of radionuclides released and predicts the minimise the radiological consequences to the Information System (GIS) for various visual and emergency response team and helps district and plant for decision making.
- 38. NUMERICAL WEATHER PREDICTION The system in its present forecasted meteorological Weather Prediction weather forecast model National Centre for Forecasting (NCMRWF), These data are Emergency Response via Computer Division’s using 2 Mbps internet NUMERICAL WEATHER PREDICTION present form gets 72 hours meteorological data [Numerical (NWP)] from mesoscale model MM5, operational at Medium Range Weather (NCMRWF), Noida, India. received at IRODOS, Response Centre, BARC, Trombay Division’s (BARC) download server internet data transmission line.
- 39. . Environmental radiation monitoring network . Environmental radiation monitoring network
- 40. The indigenously developed radiation monitor to be used in above figure. Data from these and updated at the RODSS data communication devices, Once an event/accident is sensed, to an emergency mode. In this term based on the dose rate monitors (inverse calculations) The atmospheric concentration based on this source term dispersion and dose calculation activated along with the estimation for later phase decisions developed solar powered environmental in the above network is also shown in these monitors are continuously received RODSS centre using GSM based wireless devices, inbuilt in this system. sensed, RODSS system switches over this mode it calculates the likely source rate data received from these ring calculations) or from the NPP status data. concentration and iso-dose contours are updated for early phase action. The entire calculation with the new source term is estimation of optimum counter measures,
- 41. . SOURCE TERM CALCULATION Estimation of the source term after important, difficult and debatable of emergency action plan. In RODSS, there are two approaches First is by using pre-release corporations Centralised Operating are based on actual NPP process scenarios. Second is by using post release rate measurements of the installed The main assumptions used approach is that the integrity however, the release may occur ground level or both. CALCULATION after an accident has taken place is the most component deciding the impact and course approaches for estimating source term release estimates (anticipated from nuclear power Operating Plant Information System; COPIS), which process status and based on postulated accident release estimates based on the gamma dose installed online environmental radiation monitors. in estimating source term using second of the containment would remain intact, occur through stack or through leakages at the
- 42. GEOGRAPHICAL INFORMATION The atmospheric concentration, radiological doses are displayed The various data base include city and village schools, police and fire rallying points, vegetation transportation, logistics available, Figures below show a typical and counter measures predicted release at NAPS, Narora action to be taken by decision INFORMATION SYSTEM (GIS) concentration, deposition and displayed on a GIS platform. base (layers) available in GIS village boundaries, hospitals, fire stations, sheltering and vegetation cover and live stocks, available, road network etc. typical concentration output predicted for a hypothetical Narora for visualisation and for decision makers.
- 43. Display of instantaneous 137Cs Cs concentration on a GIS platform.
- 44. F Display of countermeasures required on a GIS platform Display of countermeasures required on a GIS platform
- 45. Thanks Thanks