7.0 RISK ANALYSIS 7.1 PREAMBLE

Transcription

1 RISK ANALYSIS 7.0 RISK ANALYSIS 7.1 PREAMBLE The continuous aircraft operations need aviation turbine fuel (ATF) or jet fuel. This requirement involves various handling operations from to storage to filling of fuel within airport premises, having a potential of fire/ explosion hazard. Hence, it is necessary to evaluate the risk arising out of storage & handling facilities. Scope of the study The risk assessment has been carried out for evaluating potential hazards of the IOCL and BPCL s ATF tank farm located within the airport boundary which may lead to loss of property, life and interruption in the normal work. The scope of work in risk analysis includes the following: Identification of potential hazard areas; Identification of representative failure cases; Identification of possible initiating events; Assess the overall damage potential of the identified hazardous events and the impact zones from the accidental scenarios (Consequence analysis); Risk Characterization; Suggest suitable measures to reduce accidents; Hazard Identification Identify potentially hazardous materials that can cause loss of human life/ injury, loss of properties and deteriorate the environment due to loss of containment. Identify potential scenarios, which can cause loss of containment and consequent hazards like fire, explosion and toxicity. Consequence Analysis Evaluate the magnitude of consequences of different potential hazardous scenarios and their effect zones. Consequence analysis is a measure of potential hazards and is important for taking precautionary measures for risk reduction as well as for preparation of Disaster Management Plan (DMP). Projects & Development India Limited, Sindri Page 209 of 288

2 RISK ANALYSIS This report has been prepared by applying the standard techniques of Risk Assessment (RA) and the information provided by IOCL as well as field study. 7.2 GLOSSARY The common terms used in RA are elaborated below: Risk is defined as a likelihood of an undesired event (accident, injury or death) occurring within a specified period or under specified circumstances. This may be either a frequency or a probability depending on the circumstances. Hazard is defined as a physical situation, which may cause human injury, damage to property or the environment or some combination of these criteria. Hazardous Substance means any substance, which by reason of its chemical or physico-chemical properties or handling is liable to cause harm to human beings, other living creatures, plants, micro-organisms, property or the environment. Hazardous Process is defined as any process or activity in relation to an industry, which may cause impairment to the health of the persons engaged or connected therewith or which may result in pollution of the general environment. Disaster is defined as a catastrophic situation that causes damage, economic disruptions, loss of human life and deterioration of health and health services on a scale sufficient to warrant an extraordinary response from outside the affected area or community. Disaster occasioned by man is factory fire, explosions and release of toxic gases or chemical substances etc. Accident is an unplanned event, which has a probability of causing personal injury or property damage or both. Emergency is defined as a situation where the demand exceeds the resources. This highlights the typical nature of emergency. It will be after experience that enough is not enough in emergency situations. Situations of this nature are avoidable but it is not possible to avoid them always. Emergency Preparedness is one of the key activities in the overall Management. Preparedness, though largely dependent upon the response capability of the persons Projects & Development India Limited, Sindri Page 210 of 288

3 RISK ANALYSIS engaged in direct action, will require support from others in the organization before, during and after an emergency. 7.3 APPROACHES TO THE STUDY Risk involves the occurrence or potential occurrence of some accident consisting of an event or sequence of events. The description of the tasks of the various phases involved in RA is detailed below: Phase-I: Hazard Identification Hazard identification is a critical step in risk analysis. Many aids are available including experience, checklist, detailed process knowledge, equipment failure experience, hazard index techniques, what-if analysis, hazard and operability studies, failure mode and effect analysis and preliminary hazard analysis for hazard identification. Process information study and relevant data would help in the identification of hazard prone section of the plant. Inventory analysis and Fire and Explosion and Toxicity Indices helps in hazard identification. Phase-II: Hazard Assessment and Evaluation Safety of hazard prone section is studied using Preliminary Hazard Analysis (PHA). PHA is a part of the US Military Standard System Safety Program requirements. The main purpose of this analysis is for an early recognition of hazards, thus saving time and cost, which could result from major facility redesigns, if hazards are discovered at a later stage. Many companies use a similar procedure under a different name. It is generally applied during concept or early development phase of a process facility and can be very useful in site selection. PHA is a precursor to further hazard analysis and is intended for use only in the preliminary phase of facility development for cases where past experience provides little or no insight into any potential safety problems, e.g. a facility with a new process. The PHA focuses on the hazardous materials and major facility elements since few details on the plant design are available and there is likely not to be any information available on procedures. The PHA is sometimes considered to be a review where energy can be released in an uncontrolled manner. The PHA consists of formulating a list of hazards related to: Projects & Development India Limited, Sindri Page 211 of 288

4 RISK ANALYSIS Pipeline / equipments; Interface among system components; Operative environment; Operations (tests, maintenance, etc.); Facility; and Safety equipment The results include recommendations to reduce or eliminate hazards in the subsequent plant design phase. The PHA is followed by evaluation of MCA and Consequence Analysis. Phase-III & IV: Disaster Management Plan (DMP) and Emergency Preparedness Plan (EPP) Safety review of especially vulnerable process units is covered in this phase. This helps in reducing the risk qualitatively while the outcome of Phase-I and Phase-II would reduce risk in quantitative terms. EPP based on the earlier studies is covered in this activity. Customarily, major industries to have their EPP s and therefore, there is a need to look into those details and recommend a realistic EPP based on the above studies. 7.4 HAZARD IDENTIFICATION Introduction Identification of hazards in the proposed project is of primary significance in the analysis, quantification and cost effective control of accidents involving storage and handling of flammable liquids. A classical definition of hazard states that hazard is in fact the characteristic of system/plant/process that represents potential for an accident. Hence, all the components of a system/plant/process need to be thoroughly examined to assess their potential for initiating or propagating an unplanned event/ sequence of events, which can be termed as an accident. Typical schemes of predictive hazard evaluation and quantitative risk analysis suggest that hazard identification step plays a key role. Estimation of probability of an unexpected event and its consequences form the basis of quantification of risk in terms of damage to property, environment or personnel. Therefore, the type, quantity, location and conditions of release of a toxic or flammable substance have to be identified in order to estimate its damaging effects, the area involved and the possible precautionary measures required to be taken. Maximum Projects & Development India Limited, Sindri Page 212 of 288

5 RISK ANALYSIS Credible Accident Analysis (MCAA) method for hazard identification has been employed in this study: Classification of Major Hazardous Substance Hazardous substances may be classified into three main classes namely flammable/explosive substances, unstable substances and toxic substances. Flammable substances require interaction with air for their hazard to be realized. Under certain circumstances the vapours arising from flammable substances when mixed with air may be explosive especially in confined spaces. However, if present in sufficient quantity such clouds may explode in open air also resulting in the vapour cloud explosion. 7.5 MAXIMUM CREDIBLE ACCIDENT ANALYSIS (MCAA) APPROACH Introduction A Maximum Credible Accident (MCA) can be characterized, as an accident with a maximum damage potential, which is still believed to be probable. MCA analysis does not include quantification of the probability of occurrence of an accident. Moreover, since it is not possible to indicate exactly a level of probability that is still believed to be credible, the selection of MCA is somewhat arbitrary. In practice, the selection of accident scenarios representative for a MCA-Analysis is done on the basis of engineering judgement and expertise in the field of risk analysis studies, especially accident analysis. Major hazards posed by flammable storage can be identified taking recourse to MCA analysis. MCA analysis encompasses certain techniques to identify the hazards and calculate the consequent effects in terms of damage distances of heat radiation, toxic releases, vapour cloud explosion etc. A host of probable or potential accidents of the major units in the complex arising due to use, storage and handling of the hazardous materials are examined to establish their credibility. Depending upon the effective hazardous attributes and their impact on the event, the maximum effect on the surrounding environment and the respective damage caused can be assessed. As an initial step in this study, a selection has been made of the processing and storage units and activities, which are believed to represent the highest level of risk for the Projects & Development India Limited, Sindri Page 213 of 288

6 RISK ANALYSIS surroundings in terms of damage distances. For this selection, the following factors have been taken into account: Type of compound viz. flammable; Quantity of material present in a unit or involved in an activity; and Process or storage conditions such as temperature, pressure. In addition to be above factors, the location of a unit or activity with respect to adjacent activities is taken into consideration to account for the potential escalation of an accident. This phenomenon is known as the Domino Effect. The units and activities, which have been selected on the basis of the above factors, are summarized; accident scenarios are established in hazard identification studies, while effect and damage calculations are carried out in MCAA Studies Methodology Following steps are employed for visualization of MCA scenarios: Chemical inventory analysis; Identification of chemical release and accident scenarios; Analysis of past accidents of similar nature to establish credibility to identified scenarios; and Short-listing of MCA scenarios. Analyse the poor maintenance of equipments Common Causes of Accidents Based on the analysis of past accident information, common causes of accidents are identified as: Poor housekeeping Poor maintenance Improper use of tools, equipment, facilities Unsafe or defective equipment facilities Lack of proper procedures Improvising unsafe procedures Failure to follow prescribed procedures Jobs not understood Lack of awareness of hazards involved Lack of proper tools, equipment, facilities Lack of guides and safety devices Lack of protective equipment and clothing Projects & Development India Limited, Sindri Page 214 of 288

7 RISK ANALYSIS Failures of Human Systems An assessment of past accidents reveal human factor to be the cause for over 60% of the accidents while the rest are due to other component failures. This percentage will increase if major accidents alone are considered for analysis. Major causes of human failures reported are due to: Stress induced by poor equipment design, unfavourable environmental conditions, fatigue, etc. Lack of training in safety and loss prevention Indecision in critical situations Inexperienced staff being employed in hazardous situations. Poor health and increasing age. Often, human errors are not analyzed while accident reporting and accident reports only provide information about equipment and/or component failures. Hence, a great deal of uncertainty surrounds analysis of failure of human systems and consequent damages Maximum Credible Accident Analysis (MCAA) Hazardous substances may be released as a result of failures or catastrophes, causing possible damage to the surrounding area. This section deals with the question of how the consequences of the release of such substances and the damage to the surrounding area can be determined by means of models. It is intended to given an insight into how the physical effects resulting from the release of hazardous substances can be calculated by means of models and how vulnerability models can be used to translate the physical effects in terms of injuries and damage to exposed population and environment. A disastrous situation is generally due to outcome of fire, explosion or toxic hazards in addition to other natural causes, which eventually lead to loss of life, property and ecological imbalance. Major hazards posed by flammable storage can be identified taking recourse to MCA analysis. MCA analysis encompasses certain techniques to identify the hazards and calculate the consequent effects in terms of damage distances of heat radiation, vapour cloud explosion etc. A host of probable or potential accidents of the major units in the complex arising due to use, storage and handling of the hazardous materials are Projects & Development India Limited, Sindri Page 215 of 288

8 RISK ANALYSIS examined to establish their credibility. Depending upon the effective hazardous attributes and their impact on the event, the maximum effect on the surrounding environment and the respective damage caused can be assessed. The MCA analysis involves ordering and ranking of various sections in terms of potential vulnerability. 7.6 RISK ANALYSIS Properties of Material Handled Petroleum products Aviation Turbine Fuel (ATF) will be handled in the aircraft operations. The product is a combination of hydrocarbons which are highly inflammable. ATF is of Class-B type (Flash point between 33 o C and 55 o C) petroleum hydrocarbon according to convention. The product, when spilled from the containment will cause fire, if they get any source of ignition. Incomplete combustion of the hydrocarbon may generate carbon monoxide, which may cause toxicity as well as explosion. However, fire is the main hazard in such installation. Lower the flash point, higher is the possibility of ignition and hazard. The light hydrocarbons will evaporate from these petroleum oil liquids, which may catch fire, if they get into contact with an ignition source. Properties of the product handled is given in Table Table PROPERTIES OF LIQUID HANDLED S. No Properties Value 1] Boiling point, ( o C) (range) ] Density at 15 o C ] Flash point, ( o C) >46 4] Auto ignition temp. ( o C) 210 5] LFL (% V/V) 0.9 6] UFL (% V/V) Hazards of Equipment/Pipeline Handling Petroleum Products The hazard of equipment/pipeline handling petroleum products is the potential loss of integrity of the containment with subsequent release of liquid causing fire. The pipelines carry large quantities of petroleum liquid. A rare pipeline fracture releases large quantities of hydrocarbons. The product gets collected in the neighbourhood of the pipeline and may lead to a fire hazard if it gets source of ignition and improper precautions. Catastrophic failure of the shell of a storage tank is a very rare phenomenon, which may occur due to earthquake or due to aerial bombardment during war. However, Projects & Development India Limited, Sindri Page 216 of 288

9 RISK ANALYSIS vapour coming out through the vent line of fixed roof tank or through vapour seal around the shell in floating roof tanks may be ignited through lightning. However, such cases are also very rare. In such cases, the whole tank may be on fire. Corrosion in the tanks may cause small holes resulting in release of petroleum liquid from the tanks. However, in such cases the oil will be contained in the dyke. In case of oil spill collected on ground, an oil pool will be formed. An ignited pool of oil is called Pool Fire. It creates long smoky flames. The wind may tilt the flame towards ground causing secondary fires and damages. Radiation from the flame can be very intense near the fire but falls off rapidly beyond 3-4 pool diameters. Such fires are very destructive within the storage area and near the source of generation. In case of formation of small holes on the above ground pipeline, the liquid may escape in the form of jet and may catch fire if it gets an ignition source. Damage due to heat radiation from such jets is mostly limited to objects in the path. However, the ignited jet can impinge on other vessels and the pipelines causing domino effect Brief Review of Safety Related Facilities Because of the inherent hazard potential of the petroleum products used in the installation, due care shall be taken in handling of the same in tanks, pipelines and other associated facilities e.g. Well planned layout. Provision of weather resistant painting for protection of exposed areas of pipelines, valves and equipment. Provision of dykes and/or fire walls around storage tanks. Well planned Fire Fighting Facilities. Well trained manpower for operation and maintenance. Projects & Development India Limited, Sindri Page 217 of 288

10 RISK ANALYSIS Fire Fighting Facilities i] Well planned Fixed Fire Fighting Facilities as per OISD guideline shall be provided in the installation e.g. a) Fire Hydrants and Monitors Fire Hydrants and monitors around the dyke walls of storage tanks. They shall be considered for Pump Manifold, Pump Bay & Road Tanker Loading gantry. Layout of fire hydrants & monitors and isolation valves shall be in such a way that Fire Tenders can approach to put out fire in any possible area. b) Spray Protection System Storage tanks shall be provided with water spray protection. Perforated spray water pipes shall be provided around the shell of the storage tanks and are located at the top of the shell. ii] Portable Fire Fighting Apparatus Fire Extinguishers and other fire fighting apparatus shall be provided in vulnerable areas of the depot, Fire Water Pump House, TLD Gantry etc. as per OISD guidelines. 7.7 RISK ASSESSMENT Introduction The IOCL s ATF storage depot at Patna Airport premises, which includes the facilities for receipt, storage and filling of petroleum products mainly poses fire hazard due to unwanted and accidental release of hydrocarbons. However, due safeguard has been taken in design, installation and operation of the system to prevent any unwanted release of hydrocarbons from their containment. In the event of release of hydrocarbons from their containment, there is a risk of fire. This section deals with various failure cases leading to various hazard scenarios, analysis of failure modes and consequence analysis. Consequence analysis is basically a quantitative study of hazard due to various failure scenarios to determine the possible magnitude of damage effects and to determine the distances up-to which the damage may be affected. The reason and purpose for consequence analysis are manifolds like: Projects & Development India Limited, Sindri Page 218 of 288

11 RISK ANALYSIS Computation of risk Aid to better plant layout Evaluate damage & protective measures necessary for saving properties & human lives Ascertain damage potential to public and evolve protective measures Formulate safe design criteria and protection system Formulate effective DMP The results of consequences analysis are useful for getting information about all known and unknown effects that are of importance, when failure scenarios occur and to get information about how to deal with possible catastrophic events. It also gives the plant authorities, workers, district authorities and the public living in the area, an understanding of the hazard potential and remedial measures to be taken Modes of Failure There are various potential sources of large/small leakages in any installation. The leakages may be in the form of gasket failure in a flanged joint, snapping of small dia pipeline, leakages due to corrosion, weld failure, failure of loading arms, leakages due to wrong opening of valves & blinds, pipe bursting due to overpressure, pump mechanical seal failure and any other sources of leakage Damage Criteria The damage effect of all such failures mentioned above are mainly due to thermal radiation from pool fire or jet fire due to ignition of hydrocarbons released since the ATF is highly inflammable. The petroleum product fuel released accidentally due to any reason will normally spread on the ground as a pool or released in the form of jet in case of release from a pressurised pipeline through small openings. Light hydrocarbons present in the petroleum products will evaporate and may get ignited both in case of jet as well as liquid pool causing jet fire or pool fire. Accidental fire on the storage tanks due to ignition of vapour from the tanks or due to any other reason may also be regarded as pool fire. Thermal radiation due to pool fire or jet flame may cause various degrees of burns on human bodies. Also its effect on inanimate objects like equipment, piping, building and other objects need to be evaluated. The damage effects due to thermal radiation intensity are elaborated in Table & 7.3. Projects & Development India Limited, Sindri Page 219 of 288

12 RISK ANALYSIS Table DAMAGE DUE TO INCIDENT THERMAL RADIATION INTENSITY Incident Thermal Radiation Intensity Type of Damage kw/m Can cause heavy damage to process equipment, piping, building etc Maximum Flux level for thermally protected tanks Minimum energy required for piloted ignition of wood. 8.0 Maximum heat flux for un-insulated tanks. 4.5 Sufficient to cause pain to personnel if unable to reach cover within 20 sec. (First Degree Burn). 1.6 Will cause no discomfort to long exposure. 0.7 Equivalent to solar radiation. Table PHYSIOLOGICAL EFFECTS OF THRESHOLD THERMAL DOSES Dose Threshold kj/m 2 Effect 375 3rd Degree Burn nd Degree Burn st Degree Burn. 65 Threshold of pain, no reddening or blistering of skin caused 1 st Degree Burn Involve only epidermis, blister may occur; example: sun burn. 2 nd Degree Burn Involve whole of epidermis over the area of burn plus some portion of dermis 3 rd Degree Burn Involve whole of epidermis and dermis; subcutaneous tissues may also be damaged Dispersion and Stability Class In calculation of effects due to release of hydrocarbons, dispersion of vapour plays an important role as indicated earlier. The factors which govern dispersion are mainly Wind Speed, Stability Class, Temperature as well as surface roughness. One of the characteristics of atmosphere is stability, which plays an important role in dispersion of pollutants. Stability is essentially the extent to which it allows vertical motion by suppressing or assisting turbulence. It is generally a function of vertical temperature profile of the atmosphere. The stability factor directly influences the ability of the atmosphere to disperse pollutants emitted into it from sources in the plant. In most dispersion problems relevant atmospheric layer is that nearest to the ground. Projects & Development India Limited, Sindri Page 220 of 288

13 RISK ANALYSIS Turbulence induced by buoyancy forces in the atmosphere is closely related to the vertical temperature profile. Temperature of the atmospheric air normally decreases with increase in height. The rate of decrease of temperature with height is known as the Lapse Rate. It varies from time to time and place to place. This rate of change of temperature with height under adiabatic or neutral condition is approximately 1 0 C per 100 metres. The atmosphere is said to be stable, neutral or unstable according to the lapse rate is less than, equal or greater than dry adiabatic lapse rate i.e. 1 0 C per 100 metres. Pasquill has defined six stability classes ranging from A to F A = Extremely unstable B = Moderately unstable C = Slightly unstable D = Neutral E = Stable F = Highly stable Selected Failure Cases The mode of approach adopted for consequence analysis is first to select the probable failure scenarios. The failure scenarios selected are given in Table-7.4: Sl. No Table LIST OF FAILURE CASES Failure Scenarios 1. Hole on Tank (IOC) a. 10mm leak b. 25mm leak 2. Storage tank on Fire c. ATF Tank BPCL Storage tank on Fire ATF Tank Hole on TLF Pump discharge lines a. 10mm leak b. 25mm leak Likely Consequences Pool fire Thermal Radiation Pool fire Thermal Radiation Pool fire Thermal Radiation 4. TLF Hose failure a. 10 mm leak b. 25 mm leak c. Full bore rupture Jet fire, Pool fire Thermal Radiation Projects & Development India Limited, Sindri Page 221 of 288

14 RISK ANALYSIS It may be seen that most of the probable cases of failures have been considered for Consequence Analysis. 7.8 CONSEQUENCE ANALYSIS Consequence Analysis of the selected failure cases have been done with the help of Phast Risk Micro Software of DNV Technica to evaluate and identify possible consequences as well as to incorporate suitable measures to prevent and mitigate such events Storage Tanks (IOC Tank Farm) (Compliance of TOR Point No.12) Failure Case: Hole on Storage tank i.e: a. 10mm, b.25mm leak & c. Catastrophic Failure of Storage tank Details of proposed Tank farm of IOCL: 4 x 200kL A tank is susceptible to fire hazard, if a static charge or a spark ignites the vapour being released from the vent or rim seal (in case of FRVT tank) causing fire. If the fire is not controlled at the initial stage, it can lead to collapse of roof and total liquid is exposed to fire. The hazard posed by such failure and subsequent fire is intense thermal radiation. The thermal radiation emanating from such tank fire can cause damage to nearby tanks and persons' in the vicinity. As per IP Code, thermally protected facilities and storage tanks can withstand a thermal radiation of 32 kw/m 2 while unprotected tanks and process facilities can withstand only up to 8 kw/m 2. Normal persons can withstand an intensity of 1.5 kw/m 2 for a long duration. A radiation intensity of 4.5 kw/m 2 can cause 1 st degree burn if a man is exposed for more than 20 seconds. Hazard distances due to thermal radiation as a result of fires in storage tanks are shown in Table Input Material: ATF Temperature: 30deg C Pressure: Atmospheric pressure Projects & Development India Limited, Sindri Page 222 of 288

15 RISK ANALYSIS Table Hazard Distances due to Hole on Tank and Storage Tanks on Fire Pool Fire Sl. No. Thermal Radiation Intensity kw/m 2 Distances from radius of the pool (m) at wind speed & stability classes of 2B 3 B-C 3D 5D 2F 10 mm dia. hole on tank (Release rate: 0.623kg/sec) mm dia. hole on tank (Release rate: 3.89kg/sec) Catastrophic failure of storage tank NR NR NR NR NR NR = Not Reached It is evident from the above table that in case of tank on fire or pool fire due to leak of ATF as well as catastrophic failure, the hazard distance for thermal radiation level for 4.5 kw/m 2 will extend up to a maximum distance of 28m, 45m and 244m for 10mm, 25mm leak and Catastrophic failure of storage tank. Hence, it is important that in case of fire due to any storage tank, cooling of tanks nearby should be started quickly through cooling water pipes/water jet to avoid failure of nearby tanks. Frequency for tank on fire of floating roof tanks is 1.6x10-5 /tank year Storage Tanks (BPCL Tank Farm): Failure Case: Catastrophic failure of Storage tank Details of existingtank farm of BPCL: 1 x 30kL A tank is susceptible to fire hazard, if a static charge or a spark ignites the vapour being released from the vent or rim seal (in case of FRVT tank) causing fire. If the fire is not controlled at the initial stage, it can lead to collapse of roof and total liquid is exposed to fire. The hazard posed by such failure and subsequent fire is intense thermal radiation. The thermal radiation emanating from such tank fire can cause damage to nearby tanks and persons' in the vicinity. As per IP Code, thermally protected facilities and storage tanks can withstand a thermal radiation of 32 kw/m 2 while unprotected tanks and process facilities can withstand only up to 8 kw/m 2. Normal persons can withstand an intensity of 1.5 kw/m 2 for a long duration. A radiation intensity of 4.5 kw/m 2 can cause 1 st degree burn if a man is exposed for more than 20 seconds. Projects & Development India Limited, Sindri Page 223 of 288

16 RISK ANALYSIS Hazard distances due to thermal radiation as a result of fires due to catastrophic failure of storage tanks are shown in Table Input Material: ATF Temperature: 30deg C Pressure: Atmospheric pressure Sl. No. Table Hazard Distances due to Storage Tank on Fire Pool Fire Thermal Radiation Intensity kw/m 2 Distances from radius of the pool (m) at wind speed & stability classes of 2B 3 B-C 3D 5D 2F Catastrophic failure of storage tank NR NR NR NR NR NR = Not Reached It is evident from the above table that in case of catastrophic failure of tank on fire or pool fire due to ATF, the hazard distance for thermal radiation level for 4.5 kw/m 2 will extend up to a maximum distance of 116m for Catastrophic failure of storage tank. Hence, it is important that in case of fire due to any storage tank, cooling of the tank on fire as well as nearby tanks should be started quickly through cooling water pipes/water jet to avoid failure of nearby tanks. Frequency for tank on fire of floating roof tanks is 1.6x10-5 /tank year TLF Pumps discharge lines failure for ATF Failure case: 10mm and 25mm leak Considering the TLF pump discharge line sizes are of 6". Full Bore Failure of these diameter lines is non-credible in nature. Consequence analysis has been conducted to evaluate the hazard distances and presented in Table No Projects & Development India Limited, Sindri Page 224 of 288

17 RISK ANALYSIS Table HAZARD DISTANCES TO POOL FIRE - DUE TO TLF PUMP DISCHARGE LINE FAILURE Sl. No. Thermal Radiation Distances from radius of the pool (m) at wind speed & stability classes of Intensity kw/m 2 2B 3 B-C 3D 5D 2F 10 mm dia. hole (Release rate: 1.39kg/sec) mm dia. hole (Release rate: 8.71kg/sec) NR NR NR NR NR NR = Not Reached, As evident from the above table that thermal radiation distances for a thermal radiation of 4.5 kw/m 2 for the failure of 10mm and 25mm leak of discharge line go up to distance of 42m and 64 m respectively TLF Unloading Hose failure Failure Case: 10mm, 25mm leak and Full bore failure ATF if loaded into Tank lorry for refuelling of Aircrafts through unloading hoses. Consequence analysis has been conducted to evaluate the hazard distances due to rupture of this unloading hose and presented in Table No Table HAZARD DISTANCES TO JET FIRE, POOL FIRE DUE TO TLF LOADING HOSE FAILURE Sl. No. Thermal Radiation Intensity kw/m 2 Distances from radius of the pool (m) at wind speed & stability classes of 2B 3 B-C 3D 5D 2F 10 mm dia. hole (Release rate: 1.079kg/sec) mm dia. hole (Release rate: 6.74kg/sec) Full bore failure RR: 35.5kg/sec (Pool Fire) NR NR NR NR NR NR = Not Reached, RR = Release Rate Projects & Development India Limited, Sindri Page 225 of 288

18 RISK ANALYSIS As evident from the above table that thermal radiation distances of 4.5 KW/m 2 for the failure of ATF unloading hose are go up to a distance of 10m, 20m and 64m for 10mm, 25mm leak and full bore failure respectively. 7.9 RISKS AND FAILURE PROBABILITY The term Risk involves the quantitative evaluation of likelihood of any undesirable event as well as likelihood of harm or damage being caused to life, property and environment. This harm or damage may only occur due to sudden/ accidental release of any hazardous material from the containment due to failure of component systems. It is difficult to ascertain the failure probability of any system because it will depend on the components of the system. Even if failure occurs, the probability of fire/ explosion and the extent of damage will depend on many factors like: (a) (b) (c) (d) Quantity and physical properties of material released Source of ignition Wind velocity and direction Presence of population, properties etc. nearby 7.10 RISK ASSESSMENT For the assessment of 'Individual Risk' due to proposed ATF Depot within Patna Airport premises, following has been taken into consideration: a) The individual risk has been calculated as cumulative effect of all the scenarios mentioned for selected failure case as listed in Table for 2B, 3B/C, 3D, 5D during day and 2F during night where 2F, 2B, 3B/C, 3D & 5D are wind speed of 2 m/sec & stable stability class, wind speed of 2 m/sec & unstable stability class & wind speed of 3 and 5 m/sec & neutral stability class atmospheric conditions respectively. b) Probability of wind directions has been taken from IMD table c) No mitigation factors such as shelters, escape etc. are considered which will result in conservative risk estimation. d) During risk assessment population data and source of ignition has been considered. Projects & Development India Limited, Sindri Page 226 of 288

19 RISK ANALYSIS 7.11 Conclusions & Recommendations Conclusion a) It is observed from the Iso-Risk Contour (Drg. No. 7.1) that the acceptable limit of individual risk of 1.0x10-6 per year remains confined within the premises of Patna Airport boundary. b) The Hazard distances arrived from the consequence analysis reveals that in most of the cases hazard is confined within the premises of Patna Airport. c) It is also observed from FN curve (Drg. No. 7.2) that Societal Risk is in an acceptable range to as low as reasonable practicable zone (ALARP). Recommendations The recommendations as revealed from RA Study are as follows: The first body valve on the tank nozzle inside the dyke should be Remote Operated Shut-Off Valve (ROSOV) with remote operation only from outside the dyke as well as from control room. ROSOV should be fail safe and fire safe. It should have only close feature and not open and stop from control room. However, it should have close, open & stop operation from the panel located outside the dyke. The second and third valve should be Plug valve / Ball valve and hand operated Gate valve respectively. Push buttons for ROSOV should be placed just outside the dyke. Proper approach should be provided for operation of body gate valve. All the dykes should be made leak proof. Design, inspection and repair of as per latest API codes. Level indicator with high and low level alarm should be provided. Piping design inside tank dyke area should ensure easy accessibility for any operation inside dyke in the tank farm. Tank Dyke Valves should be provided with position indicator (open/ close) in control room and necessary hardware and instrumentation should be provided for this. CCTV should be installed covering tank farm areas and other critical areas. The CCTV can now-a-days provided with an alarm to give warning in case of deviation from any normal situation. The CCTV monitoring station should be provided both in the control room as well as in the security cabin/ office. Projects & Development India Limited, Sindri Page 227 of 288

20 RISK ANALYSIS Main emergency shutdown switch located in control room should also activate ROSOV to close. Surrounding population like staff colony and other passenger movement areas should be made aware of the safety precautions to be taken in the event of any mishap. This should be done effectively by developing an advisory programme. VHF handsets to be provided to each operating staff The existing practice of Mock Drill is to be continued in consultation with the airport authorities with full activation of shut-down system. The critical operating steps should be displayed on the board near the location wherever applicable. All PPEs as well as safety equipments required during emergency, such as breathing apparatus, fire suit, fire extinguishers, monitors and sprinklers should be regularly tested in presence of safety officers and records to be maintained. All PPEs required during emergency should be located in designated safe areas. Hydro-Carbon (HC) detectors should be installed near all potential leak sources of Class B petroleum products e.g. tank dykes, tank manifolds, pump house manifolds, etc. Further, HC detectors of proper type should be selected and should be proof tested and maintained in good condition. Medium expansion foam generators may be provided in addition to the existing foam generator in the terminal to arrest vapour cloud formation from spilled volatile hydrocarbons. All terminal operating personnel including regular contractors and security personnel should be given safety and firefighting training with the help of reputed training institutes. The security staff should be trained as first responders for firefighting and rescue operations along with facility operating personnel. Vehicles with spark ignition engine should not be allowed inside the Depot. As per OISD-GDN-145, Safety Audit should be done in all the facilities of a Depot minimum once in every year. The firefighting system for storage tanks shall be conforming to OISD-STD-117 norms. Projects & Development India Limited, Sindri Page 228 of 288

21 RISK ANALYSIS Health check-up and maintenance of the equipments and pipelines should be done at regular intervals as per OISD-RP-124, OISD-STD-125, OISD-STD-126, OISD- STD-129, OISD-STD-130 etc to avoid any major failure. Instruments and trip interlocks should be checked and calibrated at regular intervals to prevent any wrong signalling and consequent failures. Firefighting system as well as portable fire-fighting appliances should always be kept in good working condition. Safety appliances should also be checked regularly and kept in good working condition. To reduce the failure frequency, due care should be taken in design/ construction/ inspection/ operation. Well-established codes of practices of OISD should to be followed for inspection and operation of the facility. The Depot should be operated by experienced personnel trained for operation of such facility and firefighting. Smoking should be strictly prohibited inside the Depot. Non-sparking tools should be used for maintenance to avoid any ignition source. The storage tanks, pipelines and facilities in TLF Shed should be properly earthed to avoid accumulation of static electricity. Entry of unauthorised personnel should be restricted inside the licensed area. Good liaison should be maintained with Airport authorities, outside organisations and District Administration, hospitals and nursing homes. Area inside the dyke should be well concreted and free from dry grass/ trees to avoid any fire. All Water Monitors to be converted to Aqua Foam Monitors Foam Barrels should be stored under shed. DCP Fire Extinguishers to be kept above ground level, under proper shed. Fire Walls are not provided/ not effective. Proper Fire Break Walls to be provided. Tank Farm Pump House manifold should be protected with fixed firefighting system. Painting of Tanks & Pipe Lines to be done as per IP/ IS Codes at regular interval to prevent corrosion. Truck loading/ unloading facilities should be located close to product movement gate and should be oriented to provide one-way traffic pattern for entrance and exit. Projects & Development India Limited, Sindri Page 229 of 288

22 RISK ANALYSIS Drawing No. 7.1: ISO RISK CONTOUR Projects & Development India Limited, Sindri Page 223 of 288

23 RISK ANALYSIS Drawing No. 7.2: F-N Curve Projects & Development India Limited, Sindri Page 224 of 288

24 INTRODUCTION The objective of any plant should be safe and trouble free operation and smooth production. This is ensured by taking precautions right from design stage i.e. design of plant, equipment/pipeline as per standard codes, ensuring selection of proper material of construction, well designed codes/rules and instruments for safe operation of the plant. Safety should be ensured afterwards by operating the plant with the help of trained manpower. In spite of all precautionary measures taken, accidents may happen due to human error or system malfunction. Any accidents involving release of hazardous material may cause loss of human lives & property and damage to environment. Industrial installations are vulnerable to various natural as well as manmade disasters. Examples of natural disasters are flood, cyclone, earthquake, lightening etc. and manmade disasters are like major fire, explosion, sudden heavy leakage of toxic and poisonous gases and liquids, civil war, nuclear attacks, terrorist activities etc. The damage caused by any disaster is determined by the potential for loss surrounding the event. It is impossible to predict the time and nature of disaster, which might strike on undertaking. However, an effective disaster management plan i.e. pre-planned procedure involving proper utilization of in-house as well as outside resources helps to minimize the loss to a minimum and resume the working condition as soon as possible. 8.2 STATUTORY REQUIREMENT Disaster Management Plan is a statutory requirement for Patna Airport. The applicable regulations are: a) Factories Act, 1948 and as amended b) Manufacture, Storage and Import of hazardous Chemicals Rules, 1989, notified under Environment Protection Act 1986andamended in c) Rules on Emergency Planning Preparedness and Response for Chemical Accidents, d) Stipulations of OISD-168 e) Public Liability Insurance Act, Projects and Development India Ltd., Sindri Page 225 of 288

25 The Disaster Management Plan has been prepared based primarily on Schedule-11 of Manufacture, storage and Import of hazardous Chemicals Rules, 1989 and amended in OBJECTIVE OF Disaster Management Plan is basically a containment, Control & mitigation Plan. The plan includes activities before disaster, during disaster and post disaster: The objective of disaster management plan is to formulate and provide organizational set up and arrange proper facilities capable of taking part and effective action in any emergency situation in order to: a. Brief the incident under control making full use of inside and outside resources b. Protect the personnel inside the depot as well as public outside. c. Safeguard the depot as well as outside property and environment. d. Carry out rescue operation and treatment of casualties. e. Preserve relevant records and evidences for subsequent enquiry f. Ensure rapid return to normal operating conditions. The above objectives can be achieved by i. Proper identification of possible hazards and evaluation of their hazard ii. iii. potential and identification of maximum credible hazard scenario. Arrange/ augment facilities for firefighting, safety, medical (both equipment and manpower) Evolving proper action plan with proper organizational set-up and communication facilities as well as warning procedure. 8.4 DEFINITIONS Disaster Disaster is a general term, which implies a hazardous situation created by an accidental release or spill of hazardous materials, which poses threat to the safety of workers, residents in the neighborhood, the environment or property. Emergency Emergency condition and Disaster Condition are synonymous. ON-SITE Emergency/Disaster In an On-Site Emergency the effect of any hazard (fire/explosion/release of toxic gases) are confined within the factory premises. An accident taking place inside the depot and its effects are confined within the boundary wall. Projects and Development India Ltd., Sindri Page 226 of 288

26 8.5 CATEGORIZATION OF EMERGENCIES The emergencies at the Patna airport can be classified under several headings. These headings are listed below together with a description of the type of emergency. A. Technical Emergencies 1. Safety Related Emergencies Aircraft Accident on the Airport Aircraft Accident off the Airport (Within Vicinity) Malfunction of Aircraft in Flight (Full Emergency & Local Stand By) Fires on the Ground (Aircraft Related) Medical Emergencies & In-Flight Mass Casualty Incidents on the Airport (Collisions, Fuel Spill) Dangerous Goods Incidents Fires on the Ground Fire on the ground can be aircraft related and non-aircraft related. Fire involving aircraft can be at any location on the taxiway or apron area where the aircraft is parked. Non-aircraft related fire involves mainly the terminal buildings and HSD storage, etc. 2. Securityrelated Emergencies Sabotage including bomb threat Unlawful acts against civil aviation/ unlawful seizure of aircraft Terrorism B. Non-Technical Emergencies 1. Natural Disasters 2. Structural Disasters 3. Public Health Emergencies The airport is located in Seismic Zone IV as per seismic classification. Seismicity is a natural hazard for Patna Airport project. Therefore, necessary design measures have been taken for making structure earthquake proof. Disasters may be governed by three prepositions of impact of disasters given below and therefore the details of the responsibilities shall be as follow. a. When only airport is affected. b. When outside the airport is affected. c. When airport and outside both are affected. Projects and Development India Ltd., Sindri Page 227 of 288

27 8.5.1 When only Airport is affected In case only airport is affected, the disaster scenario in all above cases may render land aids including the runway, NAV Aids, electrical services and other assisting services at airport unserviceable / damaged as such the airport shall be closed for aircraft operation depending on extent of damage. The following actions will be taken up by Airport: 1. Declare the airport closure with tentative timings for resumption of operation; 2. Inform Army/ IAF/ Explosive Department for necessary assistance, as the case may be; 3. A message shall be passed on to aerodrome telephones exchange or over local VHF frequency to HoDs to resort for rescue work within their premises and leave the area to a safer place. Necessary help should be extended to external services who have responded for assistance; 4. Mobilize rescue tools and emergency lights in CFT s before moving to a safe place; 5. Render assistance to city /district/state command team; 6. Maintain contact with ATC/ATCO; and 7. Use of portable pumps, hydraulic cutters, lifting bags, hydraulic jacks, ladders, ropes, life buoys, rafts, first-aid boxes are considered to be very important to meet post disaster scenario When areas outside the Airport is affected In case when disaster has affected the city but airport remaining safe the action taken up by Airport will be: 1. Airport shall remain open round the clock for receiving aids and for dispatching injured causalities, etc. 2. All possible help from each unit shall be extended to city / district / state disaster team. 3. Arrangement for additional crew and rescue equipment may be made for rendering assistance. 4. Since the services at airport are required for aircraft operations, unrestricted assistance cannot be extended to city. Aircraft operation is likely to increase and therefore the availability of AFS is more essential. 5. Establish a command post for dissemination of information. 6. Arrange for change of crew at regular intervals and provide necessary relief for disaster team. Projects and Development India Ltd., Sindri Page 228 of 288

28 7. Standby rescue tools and crew can be utilized for extending help to outside agencies When Airport and outside both are affected In case when disaster has affected the airport as well as the city the action taken up by Airport will be: 1. Establish contact with FIC, city / district / state command center and inform the impact of disaster. 2. Declare airport closed. 3. Establish alternate communication channel through for subsequent instructions. 4. Inform Army/ IAF /Explosive Dept. for necessary assistance. 5. Arrange for salvage operation and remain standby for giving / receiving any assistance. 6. Arrange standby crew and equipment for additional task. 7. Arrange a mobile command post at the airport Other Important Actions and Departments 1. CNS: Additional communication channel should be established among all responding agencies. 2. APSU: Security staff shall be mobilized to provide protection against breach of security. Manpower for rescue and salvage work and any other duty assigned during emergency. 3. Engineering: The role of engineering would be highly desirable during rescue and salvage operation from buildings. Arrangement for additional emergency lighting, skilled labor and heavy- duty equipment like cranes / bulldozer etc. should be made from its own resources or by engaging these services on contract. 4. E&M Workshop: Effects shall be made maximum possible transportation facility as such repair teams along with MT Vehicles at the command post Emergency Resources and Equipments 1. High mast lighting on generator trailers is essential for protracted night operations. A source for fuel for the generators should be identified. 2. A trailer equipped with sufficient backboards and stretchers to accommodate 250+ causalities. 3. Sufficient body bags and causality identification tags. Projects and Development India Ltd., Sindri Page 229 of 288