LPG Storage &Bottling Plant Palakkad (Kerala)

Transcription

1 Quantitative QRA for LPG Storage & Bottling Risk Plant Analysis of HPCL at Palakkad, Report Kerala LPG Storage &Bottling Plant Palakkad (Kerala) Prepared by EQMS India Pvt. Ltd. 304 & 305, 3rd Floor, Rishabh Towers, Plot No. 16, Community Centre, Karkardooma, Delhi (India) June 2016 Page 1 of 37

2 Project: Quantitative Risk Analysis Report for HPCL LPG Storage &Bottling Plant at Palakkad Project No.: EQMS/QRA/HPCL/ /02 Issue and Revision Issue Date Issue Revision ReportIssued to Client A1 It is easy to make difference! EQMS India Pvt. Ltd , 3 rd Floor, Plot No. 16, Rishabh Corporate Tower, Community Centre, Karkardooma, Delhi Phone: Fax: eqms@eqmsindia.org URL: Copyright EQMS All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means without permission of the publisher.

3 TABLE OF CONTENT Chapters 1. Introduction About HPCL About the Project About EQMS.8 2. Facility Description HPCL LPG Storage & Bottling Plant at Palakkad Description of HPCL Palakkad LPG facility Process Description Scope, Objective & Methodology Scope of work Objective of the Study Methodology Consequence Analysis Quantitative Risk Analysis (QRA) Risk tolerability criteria Societal Risk (or Group Risk) Criteria Risk Assessment Quantitative Risk Analysis Input Data for QRA Population Data Ignition Sources Weather parameters Ignition Sources Hazardous Properties of LPG Consequence Analysis Jet/ Pool Fire Radiation Vapour cloud explosion (VCE) Consequence Analysis Results for LPG Bottling Plant QRA Results for LPG Storage & Bottling Facility Individual risk Societal Risk Conclusions & Recommendations Conclusions Recommendations.36 Annexure I: Plant Layout Drawing Page iii

4 List of Tables Table 3.1 : Generic Failure Rate Data for Equipment Items Table 4.1 : Failure scenarios and the relevant input data Table 4.2 : Distribution of People in LPG Bottling Plant, Palakkad Table 4.3 : Pasquill parameters for atmospheric stability Table 4.4 : Relationship between wind speed and atmospheric stability Table 4.5 : Monthly average weather data Table 4.6 : Weather Parameters for Risk Analysis Table 4.7 : Damage Effects due to Jet/ Pool Fire Radiation Table 4.8 : VCE over pressure limit and Observed Effect Table 4.9 : Results of Consequence Analysis for LPG Bottling Plant List of Figures Figure 2.1 : Layout of HPCL LPG Bottling Plant, Palakkad... 9 Figure 3.1 : Flow diagram of quantitative risk assessment (QRA) Figure 3.2 : Iso-Risk Contours on Site Plan (Typical) Figure 3.3 : Individual Risk Criteria Figure 3.4 : Societal Risk Criteria Figure 4.1 : Wind Rose Diagram for Palakkad Figure 4.2 : New Mounded LPG Bullet Liquid Line Leak - Pool Fire Radiation Intensity Figure 4.3 : New Mounded LPG Bullet Liquid Line Leak VCE Overpressure Figure 4.4 : LPG Pump Discharge Line Leak Pool Fire Radiation Intensity Figure 4.5 : LPG Pump Discharge Line Leak VCE Overpressure Figure 4.6 : LPG Compressor Discharge Line Leak Jet Fire Radiation Intensity Figure 4.7 : LPG Road Tanker Failure VCE Overpressure Figure 4.8 : LPG Road Tanker Failure BLEVE/ Fire Ball Figure 4.9 : Iso-Risk Contours on Plot Plan Figure 4.10 : Iso-Risk Contours on Plot Plan (Enlarged View) Figure 4.11 : Maximum Individual Risk at HPCL LPG Bottling Plant, Palakkad Figure 4.12 : Societal Risk due to HPCL Storage & Bottling Plant, Palakkad Page iv

5 Standard Liability Clause Caution Note & Liability: The consulting services conducted by EQMS India Private Ltd (the Company ) were performed in good faith using generally accepted guidelines, standards, and/or practices, which the Company considers reliable. Although the Company performed its consulting services pursuant to reliable and generally accepted practices in the industry, the Company does not guarantee or provide any representations or warranties with respect to HPCL Palakkad LPG Bottling Plant (the Client) s use, interpretation or application of the findings, conclusions, and/or suggestions of the consulting services provided by the Company. Moreover, the findings, conclusions, and the suggestions resulting from the consulting service are based upon information provided by the Client. EQMS does not hold any liability with respect to interpretation or application of the consulting services provided by the Company for this assignment / report. No responsibility, whatsoever it may be is assumed by company for any injury and /or damage to persons or property as a matter of products liability, negligence, or otherwise, or from any use or operation of any methods, products instructions or ideas contained in the material of the report. Client is advised to review the actual text of applicable legislation for analysis & ensuring compliance. Page v

6 ABBREVIATIONS ALARP BLEVE COMAH DNV HPCL ISIR kg kw/m 2 LPG LSIR MoEF MoP&NG MT OGP OISD psig QRA ROSOV SH&E UK_HSE VCE As Low As Reasonably Practicable Boiling Liquid Expanding Vapour Explosion Control of Major Accident Hazards Det Norske Veritas Hindustan Petroleum Corporation Limited Individual-specific individual risk Kilogramme Kilowatt per square metre Liquefied Petroleum Gas Location-specific individual risk Ministry of Environment & Forests (Government of India) Ministry of Petroleum & Natural Gas (Government of India) Metric Tonne International Oil & Gas Producers Association Oil Industry Safety Directorate Pounds per square inch gauge Quantitative Risk Assessment Remote operated shut off valve Safety, Health & Environment United Kingdom Health & safety Executive Vapour cloud explosion Page vi

7 1.1. About HPCL 1. INTRODUCTION Hindustan Petroleum Corporation Limited (HPCL) headquartered in Mumbai and employing around people, is a Public Sector Undertaking (PSU) and also a Navaratana Company. HPCL is among the few Indian representatives in the Fortune 500 companies. HPCL operates in the Indian Oil & Gas Industry through different verticals. The company s infrastructure includes petroleum refineries, import facilities, cross-country pipelines, petroleum product terminals, petroleum depots, liquefied petroleum gas (LPG) bottling plants & storage facilities, lube-blending plants, petroleum retail outlets, and Aviation Turbine Fuel (ATF) service facilities. Thus it is engaged in the business of Refining, Storing, Marketing and Distribution of all kinds of petroleum products. Its refineries are located at Mumbai and Visakhapatnam. In both the refineries, it produces a host of petroleum products, such as Motor spirit, Naphtha, High speed diesel, kerosene, liquefied petroleum gas, automotive and industrial lubricants, ATF, FO, LSHS and other heavy distillates and distributes the same through its widespread retail network so as to reach out to its customers. During the year ( ), HPCL s refineries at Mumbai and Visakhapatnam maximized crude processing, which resulted in achieving a combined refining output of million tonnes with a capacity utilization of 109%.The refineries have been benchmarked by an international agency for various performance parameters. The refineries also in the year ( ) achieved a highest ever combined distillate yield of 77.5%, by improving the yields of value-added products. Both the refineries are recipients of numerous awards in recognition of their efforts in the field of energy conservation, environment and safety. Both the Refineries have grown over the years and maintained their capacity utilization above 109% of their installed capacity. HPCL has equity participation in ONGC s Mangalore Refinery & Petrochemical Ltd and HMEL s Guru Govind Singh Refineries Ltd. To-day, Liquefied Petroleum Gas (LPG) has become the single most popular house hold clean fuel. During the year , 380 new retail outlets were commissioned; taking the total number to retail outlets. A record number of 120 retail outlets were modernised with an outlay of Rs. 234 crore. HPCL released 41.9 lakh new connections of HP GAS through a network of 3952 LPG distributors, achieving a total customer base of over 47.1 million domestic LPG consumers. HP Gas reaches the customer after through checking at every stage right from bottling to distribution About the Project In order to meet the increasing demand for LPG fuel, HPCL is making continuous effort to increase the capacity in its existing LPG storage and bottling plants. As part of this programme, HPCL plans to increase the capacity of its unit in Palakkad, Kerala by installing three mounded LPG bullets with total capacity of 1350 MT to replace the Page 7 of 37

8 existing three above-ground bullets out of six having total capacity of 600 MT, thereby also improving safety aspects of LPG storage. Being a Company committed to high standards of safety management, HPCL have engaged the services of EQMS India Private Limited, Delhi to carry out detailed Hazard & Operability (HAZOP) Study to identify the hazards involved in the LPG storage and handling systems and ensure that all necessary protective measures are incorporated About EQMS EQMS is a leading ISO 9001:2008 certified consulting company dedicated to providing strategic services in the areas of environmental impact assessment (EIA)/ environmental management plan (EMP), risk assessment, environmental audits, due diligence assessments, quality/ occupational health & safety/ social accountability management systems, enterprise level behaviour based safety (BBS) management; EHS performance benchmarking & post-project management. EQMS has conducted EIA, hazard identification and risk assessment studies for many clients including refineries, oil & gas installations, power plants etc. EQMS is pleased to submit this report on QRA for the HPCL LPG storage &bottling plant at Palakkad with the trust that it will help HPCLin achieving high standards of SH&E management. Page 8 of 37

9 2. FACILITY DESCRIPTION 2.1. HPCL LPG Storage & Bottling Plant at Palakkad HPCL Palakkad LPG storage and bottling plant is located at Kanjikode on the south side of National Highway 544 (formerly NH 47) between Salem and Kochi.The site map of the plant and surrounding area is shown in Figure 3.1. HPCL Palakkad LPG Plant Figure 2.1 : Layout of HPCL LPG Bottling Plant, Palakkad 2.2. Description of HPCL Palakkad LPG facility In the HPCL Palghat LPG Bottling plant bulk LPG from Kochi Refinery and from Mangalore LPG Import Facility is received by road tankers of 17/ 18 MT capacity. The LPG tankers are unloaded with the help of 6 unloading bays (4 old Bays and 2 new Bays). At present LPG is stored in 6 above-ground bullets having total capacity of 600 MT. These will be replaced by 3 Nos. new mounded bullets each with 350 MT capacity and existing 3 above-ground bullets out of 6 thus making total storage capacity of 1350 MT. Replacement of above-ground bullets with mounded bullets will also greatly improve the safety aspects of LPG storage. At HPCL Palakkad LPG Plant with current storage capacity, the number of bottling days for which the bulk will last is less than 2 days on basis of double shift bottling operation. The storage capacity augmentation would increase the number of bottling days to about 5 days on the basis of double shift bottling operation. Page 9 of 37

10 In order to meet the requirement of LPG cylinders in all the districts falling under Kochi LPG Regional Office, HPCL proposes to augment the storage and bottling capacity of LPG Palakkad LPG Plant by installing 3 nos. of Mounded Storage Vessels of 350 MT capacity each and addition of 2 Tank Truck unloading gantries to the existing 4 gantries. This will enhance the total storage capacity from 600 MT to 1350 MT. The above ground bullets (6 nos.) will be removed after commissioning of new Mounded Bullets (3 Nos.). Details of the HPCL Palakkad LPG facility are as follows: LPG Storage Description Nos. Capacity Each Total Capacity Remarks Mounded Storage Vessels 3 Nos. 350 MT 1050 MT Out of 6*100 MT bullets, 3 above ground bullets will be retained in expansion phase having total capacity of 300 MT LPG Unloading Pumps Type Nos. Capacity Discharge Pressure Centrifugal M 3 /hr 13.5 kg/cm 2 g LPG Compressor Type Nos. Capacity Discharge Pressure Reciprocating type M 3 /hr 12 kg/cm 2 g LPG Tank Truck Unloading Bays Existing: 4 Nos. Additional: 2 Nos. Total: 6 Nos. Page 10 of 37

11 2.3. Process Description LPG is received from Road Tankers and transferred to a storage vessel (LPG Bullet). The LPG vapour pressure in the storage vessel is about 7 kg/sq.cm. The LPG pressure is boosted to about kg/sq.cm. by pump and sent to integrated carousel machine (LPG filling area) through pipe lines using an LPG Pump. The LPG cylinders are washed with multiple forced jet of water to remove mud, dirt, stains, etc., from the outer surfaces. Subsequently the cylinders coming out of washing unit are dried by blowing the air on the sides and top surfaces of the cylinders as they move. Measured quantity of LPG is filled into cylinders at the filling shed under pneumatic control. The Purging Unit which is on-line equipment creates a vacuum in the first stage and fills LPG vapor in the second stage in new / hot repaired empty cylinders. Aluminium seal crimping unit/hot air sealing unit crimps the aluminium cap and seal around the cylinder valve as a final operation on the filled LPG cylinder.auto cap fixer fixes safety caps on to the valve of LPG cylinders. Filled cylinders are subjected to 100 % weight check, presence and effectiveness of O ring inside cylinder valve and checks for leak and bung leak. Tamper proof seals are fixed on the valves of sound cylinders. These cylinders are loaded to stake trucks and dispatched to various markets. Cylinder movement inside the Plant is achieved using chain conveyors driven by electrical motors through worm gear reducers/planetary gear reducers. LPG is filled in the cylinders from 14.2 kg weight to 19.0 Kg Weight (as per requirement) in the integrated carousel machine and filled cylinders after leak testing, weight testing and fixing safety caps are stacked in the filled cylinder shed near the delivery end as per rules laid down by OISD/Gas Cylinder Rules, Filled cylinders are delivered only to the authorized LPG distributors. Drivers of the trucks carrying LPG are having valid license and are having training in safety & fire fighting procedures. The total storage facility will be covered properly by the following safety systems Entire fire protection/ hazard control and detection system has been made to meet OISD 144 standard. Two fire water tanks of total capacity of 5085KL have been installed. This storage Capacity will also take care of requirement for the three additional mounded bullets. Page 11 of 37

12 Hydrant ring main system around the new Bullets will be provided with fire hydrant points and monitors as per requirements of OISD. The proposed Mounded Bullets will also be provided with a fire hydrant system all around and water sprinkler system as required In addition, adequate numbers of portable fire extinguishers of dry chemical type will also be provided. Supplementary protection of bullets by medium facility of water spray system hooked up with fire detection system. Provision of Fire Extinguishers as per requirement of OISD and TAC. Existing water storage capacity and fire pumps will be augmented as per OISD to meet the requirement of the plant post-augmentation. Safety distances between facilities and new proposed LPG Bullets will be provided as per PESO/ OISD norms. Mock fire drills are conducted at regular intervals and the observations are recorded. Personnel intended to operate the plant are well qualified and well trained. Plant operations are supervised by a responsible Officer. The working personnel are well informed and well trained for fire hazards and fire fighting systems. Bottling Plant security system has been so envisaged to ensure strict compliance of safety requirements and to take up prompt and proper action in case of any emergency. Page 12 of 37

13 3. SCOPE, OBJECTIVE & METHODOLOGY 3.1. Scope of work The scope of work of this study covers the Quantitative Risk Assessment (QRA) for the LPG storage and bottling installation of HPCL at Palakkad (Kerala) including the proposed addition of three mounded bullets each 350 MT capacity and related facilities Objective of the Study The objectives of this study are as follows: Identifying the potential failure scenarios for release of flammable/ toxic material in the LPG storage and bottling installation. Carrying out consequence analysis for significant accident scenarios. Carrying out for Quantitative Risk Analysis Estimating the individual risk and societal risk due to the installation. Assessing the risk with respect to the risk tolerance criteria Identifying risk reduction measures wherever warranted to ensure that the risk is as low as reasonably practicable Methodology Risk arises from hazards. Risk is defined as the product of severity of consequence and likelihood of occurrence. Risk may be to people, environment, assets or business reputation. This study is specifically concerned with risk of serious injury or fatality to people. The flow diagram of QRA is shown in Figure 3.1. The following steps are involved in quantitative risk assessment (QRA): Study of the plant facilities and systems. Identification of the hazards. Enumeration of the failure scenarios. Estimation of the consequences for the selected failure incidents. Risk analysis taking into account the failure frequency, extent of consequences and exposure of people to the hazards. Risk assessment to compare the calculated risk with risk tolerability criteria and review the risk management system to ensure that the risk is As Low As Reasonably Practicable (ALARP) Page 13 of 37

14 Figure 3.1 : Flow diagram of quantitative risk assessment (QRA) Consequence Analysis Consequence analysis for the selected failure scenarios is carried out using DNV Phast software. Consequence analysis provides results for the following: Dispersion of toxic clouds to defined concentrations Heat radiation intensity due to jet fire and pool fire Explosion overpressure The renowned DNV Phast software package is used worldwide for consequence modelling and quantitative risk analysis. Phast is based on Unified Dispersion Modelling to calculate the results of the release of material into the atmosphere. It can model both heavy gas dispersion and buoyant dispersion of lighter-than-air gases. Phast has extensive material database and provides for definition of mixtures. Page 14 of 37

15 Quantitative Risk Analysis (QRA) The quantitative risk analysis is carried out using the renowned software packagephast Risk (also known as SAFETI) developed and marketed by Det Norske Veritas (DNV) of Norway. The following input data are required for the risk calculation: Process data for release scenarios (material, inventory, pressure, temperature, type of release, leak size, location, etc.) Estimated frequency of each failure case Distribution of people in the plant/ adjoining area during the day and night time. Distribution of wind speed and direction (wind rose data). Ignition sources The failure frequencies for different types of equipment are estimated using generic failure rate databases published by organizations such as International Oil & Gas Producers Association (OGP). OGP Report No Process Release Frequencies for equipment & piping For objective and comprehensive risk analysis, whole range of leak sizes is considered in each section containing large inventory of hazardous material Small leak (5 mm diameter) Medium leak (25 mm diameter) Large leak (100 mm diameter) Full bore leak. Extract of generic failure rates for equipment items relevant to this study from OGP database publication is shown in Table 3.1. Page 15 of 37

16 Table 3.1 : Generic Failure Rate Data for Equipment Items Leak size Equipment Item 5 mm 25 mm 100 mm 2" Pipe 1.80E E " Pipe 8.50E E E-07 2" Flange 7.60E E " Flange 1.10E E E-06 2" Valve (Manual) 7.70E E " Valve (Manual) 1.20E E E-06 2" Valve (Actuated) 7.30E E " Valve (Actuated) 6.60E E E-06 Instrument Connection 6.80E E-05 0 Pressure Vessel 2.00E E E-05 Centrifugal Pump 1.00E E E-05 Reciprocating Pump 1.20E E E-04 Reciprocating Compressor 8.00E E E-04 Note: Failure rate notation: 1.0E-05 per year means 1.0 x 10-5 per year The results of quantitative risk analysis are commonly represented by the following parameters: Individual Risk Societal Risk Individual risk is the risk that an individual remaining at a particular spot would face from the plant facility. The calculation of individual risk at a geographical location in and around a plant assumes that the contributions of all incident outcome cases are additive. Thus, the total individual risk at each point is equal to the sum of the individual risks, at that point, of all incident outcome cases associated with the plant. The individual risk value is a frequency of fatality, usually chances per million per year, and it is displayed as a two-dimensional plot over a locality plan as contours of equal risk in the form of iso-risk contours as shown in Figure3.2. Page 16 of 37

17 Figure 3.2 : Iso-Risk Contours on Site Plan (Typical) Risk tolerability criteria For the purpose of effective risk assessment, it is necessary to have established criteria for tolerable risk. The risk tolerability criteria defined by UK Health & Safety Executive (UK-HSE) are normally used for risk assessment in the absence of specific guidelines by Indian authorities. UK-HSE has, in the publications Reducing Risk and Protecting People and Guidance on ALARP decisions in control of major accident hazards (COMAH) enunciated the tolerability criteria for individual risk. The guidance on QRA also can be taken from MoEF, Gov. of India from their publication Technical EIA Guidance Manual for Offshore and Onshore Oil and Gas Exploration Development and Production, September and Bureau of Indian Standards Hazard Identification and Risk Analysis (IS 15656:2006). An individual risk of death of one in a million (1 x 10-6 ) per annum for both workers and the public corresponds to a very low level of risk and should be used as a guideline for the boundary between the risk acceptable and ALARP regions. An individual risk of death of one in a thousand (1 x 10-3 ) per annum should on its own represent the dividing line between what could be just tolerable for any substantial category of workers for any large part of a working life, and what is unacceptable. For members of the public who have a risk imposed on them in the wider interest of society this limit is judged to be an order of magnitude lower, at 1 in 10,000 (1 x 10-4 ) per annum. Page 17 of 37

18 The upper limit of tolerable risk to public, 1 x 10-4 per year is in the range of risk due to transport accidents. The upper limit of acceptable risk, 1 x 10-6 per year, is in the range of risk due to natural hazard such as lightning. The tolerability criteria for individual risk are shown in Figure 3.3. Figure 3.3 : Individual Risk Criteria Page 18 of 37

19 Societal Risk (or Group Risk) Criteria Societal Risk parameter considers the number of people who might be affected by hazardous incidents. Societal risk is represented as an F-N (frequency-number) curve, which is a logarithmic plot of cumulative frequency (F) at which events with N or more fatalities may occur, against N. Societal risk criteria indicate reduced tolerance to events involving multiple fatalities. For example a hazard may have an acceptable level of risk for one fatality, but may be at an unacceptable level for 10 fatalities. The tolerability criteria for societal risk as defined by UK-HSE are shown in the following Figure3.4 below. Figure 3.4 : Societal Risk Criteria Risk Assessment Based on the results of QRA, necessary measures to reduce the risk to ALARP are to be formulated. For this purpose Phast Risk software provides the information regarding risk contribution from each leak scenario modelled. Page 19 of 37

20 4. QUANTITATIVE RISK ANALYSIS 4.1. Input Data for QRA S.No. The failure scenarios and the relevant input data for QRA of HPCL LPG storage and bottling plant at Palakkadare shown in Table 4.1. Description LPG Bullets 1. LPG Mounded Bullet Liquid Inlet Line 2. LPG Mounded Bullet Liquid Outlet Line 3. LPG Mounded Bullet Vapour Line LPG Transfer Pumps 4. LPG Transfer Pump including discharge to stationary filling system Table 4.1 : Failure scenarios and the relevant input data Material & Phase Temp. (C) Pressure (kg/cm 2 g) Leak Size (mm) Leak Frequency (per year) LPG Liquid E E E-05 LPG Liquid Liq. Head 5 3.0E E E-05 LPG Vapour E E E-05 LPG Liquid E E E-05 LPG Compressor 5. LPG Compressor LPG Vapour E E E-04 LPG Road Tanker & Unloading Arm 6. LPG Tanker LPG Liquid E-05 &Unloading Arm E-05 Note: Failure rate 1.0E-05 per year means 1.0 x 10-5 per year Page 20 of 37

21 4.2. Population Data Plant operations are carried out only during day time in general shift. The distribution of personnel in the HPCL Palakkad LPG storage bottling plant is shown in Table 4.2. Table 4.2 :Distribution of People in LPG Bottling Plant, Palakkad S. No. Area No. of Persons I Shift II Shift III Shift Gen. Shift Total 1. Pump House TT Gantry Valve changing shed Filling shed Storage shed Unloading shed Loading shed MCC room Resting shed Administrative building Planning room Security cabin Total Ignition Sources Ignition sources are strictly controlled in the LPG bottling plant area. All electrical equipment and fittings are flame-proof type. No vehicle is allowed inside the premises without approved spark arrestor in the engine exhaust. The following sources of ignition are considered in the risk analysis. Substation Diesel generator LT yard/ Transformer Canteen Page 21 of 37

22 4.4. Weather parameters Weather parameters play a significant role in dispersion analysis. The notable parameters for assessing the atmosphere are wind speed, atmospheric stability, ambient temperature, humidity and topographic parameters. Atmospheric stability represents the vertical turbulence in the air due to temperature differentials caused by heating of the earth by solar radiation. Atmospheric stability effects are represented through Pasquill parameters as follows shown in Table 4.3. Table 4.3 : Pasquill parameters for atmospheric stability Stability Class A B C D E F Atmospheric Condition Very Unstable Unstable Slightly Unstable Neutral Stable Very Stable The relationship between wind speed and atmospheric stability is shown in Table 4.4. Table 4.4 : Relationship between wind speed and atmospheric stability Wind speed Day-Time: Solar Radiation Night-Time Cloud Cover (m/s) Strong Medium Slight Thin <3/8 Medium >3/8 Overcast >4/5 <2 A A-B B - - D 2-3 A-B B C E F D 3-5 B B-C C D E D 5-6 C C-D D D D D >6 C D D D D D Category D (neutral) is the most probable at sites in moderate climates and may occur for up to 80 % of the time at relevant sites. Stability F (very stable) represents the most adverse condition in which dispersion extends over longer distances horizontally. Normally, stability F occurs for short periods in the year, mainly during winter nights. Weather data (monthly average maximum & minimum temperature and rain fall) for Palakkadare indicated in Table4.5. Page 22 of 37

23 Table 4.5 : Monthly average weather data Month Max. Temperature ( C) Min. Temperature ( C) Precipitation (mm) January February March April May June July August September October November December Wind rose diagram for distribution of direction from which wind is blowing and wind speed is shown in Figure 4.1. Figure 4.1 : Wind Rose Diagram for Palakkad Page 23 of 37

24 The representative combinations of weather parameters for the site considered in this study are shown in Table 4.6. Table 4.6 : Weather Parameters for Risk Analysis Description #1 #2 #3 Temperature (C) Wind speed (m/s) Atmospheric Stability D D D 4.5. Ignition Sources In case of gas leakage, ignition of the gas will result in damage due to fire or explosion. Therefore, identification of ignition sources is important in risk analysis. The electrical and instrument items in the installation conform to the electrical hazardous area classification. Flame-proof electrical items will be installed in the classified areas, and these will not be ignition sources. Vehicles inside the plant are provided with spark arrestors in the exhaust. There is no overhead HT electrical line in the plant area which may act as ignition source. The following ignition sources are identified for input to Phast Risk software. Vehicles moving in the road Electrical switchgear room and transformer area Diesel generator Hazardous Properties of LPG The flammable consequences of LPG release from equipment are mainly the following: Jet fire/ pool fire/ flash fire Vapour cloud explosion Properties of LPG relevant to this QRA study are as follows. Composition: Normal Boiling Point: Lower Flammable Limit (LFL): Upper Flammable Limit (UFL): Auto ignition temperature: Mixture of Propane and Butane (-)6C 1.8 % (vol) 9.5 % (vol) C (approx.) LPG is stored as liquid under pressure. LPG vapours are heavier than air and disperse close to ground level. LPG odorized with ethyl mercaptan is received in the plant so as to provide warning in case of leakage. Page 24 of 37

25 4.7. Consequence Analysis Jet/ Pool Fire Radiation The effect from jet fire and pool fire is thermal radiation intensity on the receptor surface as shown in Table 4.7. Table 4.7 : Damage Effects due to Jet/ Pool Fire Radiation Heat Observed Effect Radiation Intensity (kw/m 2 ) 4 Sufficient to cause pain to personnel if unable to reach cover within 20 seconds; 0% lethality Minimum energy required for piloted ignition of wood, melting of plastic tubing Sufficient to cause damage to process equipment. Thermal radiation intensity exceeding 37.5 kw/m² may cause escalation due to damage of other equipment. Thermal radiation intensity exceeding 12.5 kw/m² may cause ignition of combustibles on buildings and impairment of escape route. Thermal radiation intensity exceeding 4 kw/m² may cause burn injury on personnel injury Vapour cloud explosion (VCE) When a large quantity of flammable vapour or gas is released, mixes with air to produce sufficient mass in the flammable range and is then ignited, the result is a vapour cloud explosion (VCE). In the LPG installation large release of LPG from equipment or piping has potential for vapour cloud explosion. The damage effect of vapour cloud explosion is due to overpressure as shown in Table 4.8. Table 4.8 :VCE over pressure limit and Observed Effect Over-pressure Effect bar(g) psig Observed Damage Safe distance (probability 0.95 of no serious damage below this value); projectile limit; some damage to house ceilings; 10% of window glass broken Repairable damage; partial demolition of houses; steel frame of clad building slightly distorted Partial collapse of walls of houses Heavy machines in industrial buildings suffered little damage; steel frame building distorted and pulled away from foundations. Page 25 of 37

26 Consequence Analysis Results for LPG Bottling Plant Results of consequence analysis by Phast software for significant leak scenarios relevant to the LPG bottling plant are shown in the Table 4.9. Graphical results plotted on the site map drawings are shown in Figure4.2 to 4.8. Table 4.9 : Results of Consequence Analysis for LPG Bottling Plant S.No. Description Parameter 1. LPG Bullet Liquid Line Leak Downwind Distance (metres) Weather (Wind speed & Stability) 2 m/s; E 3 m/s; D 5 m/s; D Pool Fire Radiation Intensity 4 kw/m kw/m kw/m VCE Overpressure 0.02 bar LPG Pump Discharge Line Leak 0.07 bar bar Pool Fire Radiation Intensity 4 kw/m kw/m kw/m VCE Overpressure 0.02 bar LPG Vapour Compressor Discharge Line Leak 0.07 bar bar Jet Fire Radiation Intensity 4 kw/m LPG Road Tanker Failure 12.5 kw/m kw/m VCE Overpressure 0.02 bar bar bar BLEVE/ Fire Ball Radiation 4 kw/m kw/m kw/m 2 Not reached Not reached Not reached Page 26 of 37

27 (1) New Mounded LPG Bullet Liquid Line Leak Figure 4.2 : New Mounded LPG Bullet Liquid Line Leak - Pool Fire Radiation Intensity Figure 4.3 : New Mounded LPG Bullet Liquid Line Leak VCE Overpressure Page 27 of 37

28 (2) LPG Pump Discharge Line Leak Figure 4.4 : LPG Pump Discharge Line Leak Pool Fire Radiation Intensity Figure 4.5 : LPG Pump Discharge Line Leak VCE Overpressure Page 28 of 37

29 (3) LPG Vapour Compressor Discharge Line Leak Figure 4.6 : LPG Compressor Discharge Line Leak Jet Fire Radiation Intensity Page 29 of 37

30 (4) LPG Road Tanker Failure Figure 4.7 : LPG Road Tanker Failure VCE Overpressure Figure 4.8 : LPG Road Tanker Failure BLEVE/ Fire Ball Page 30 of 37

31 4.8. QRA Resultsfor LPG Storage &Bottling Facility The detailed results of QRA for HPCL LPG bottling plant in Palakkadprovided as outputs from Phast Risk software are presented in this section Individual risk The iso-risk contours for LPG bottling plantare shown in Figure E-05 per year 1E-06 per year Figure 4.9 : Iso-Risk Contours on Plot Plan Enlarged diagram of iso-risk contours for LPG bottling plantare shown in Figure Page 31 of 37

32 1E-05 per year 1E-06 per year Individual Risk to Public Figure 4.10 : Iso-Risk Contours on Plot Plan (Enlarged View) Risk contour of 1.0E-06 per year is mostly within the plant boundary. Only on the eastern boundary, it extends slightly outside. The maximum individual risk at this boundary is 3.0E-06per year. Individual Risk to Plant Personnel The highest iso-risk contour inside the plant area is 1.0E-05 per year. Therefore the individual risk at any location in the plant does not exceed 1.0E-04 per year. By taking risk transect at different locations, it is found that the maximum locationspecific individual risk (LSIR) in the plant area is4.5e-05 per year. However, any individual person is present in the plant location only for a limited period in a year. The individual-specific individual risk (ISIR) is calculated taking into account the fraction of time the individual stays at the location. Normally the plant personnel work in daily shift of 8hours. Therefore the maximum individualspecific individual risk, ISIR = LSIR x (8/24) per year. = (4.5E-05) x (1/3) per year = 1.5E-05 per year The maximum value of individual risk to plant personnel in the HPCL Palakkad LPG bottling plant is1.5e-05per year. Page 32 of 37

33 The values of maximum individual risk to public and plant personnel in HPCL Palakkad LPG storage &bottling plant in comparison with the risk tolerance criteria are shown in Figure Risk to Personnel Risk to Public 10-3 per year Max. Individual Risk to Plant Personnel: 1.5 x 10-5 per year Intolerable Risk Risk Tolerable if ALARP 10-4 per year Max. Individual Risk to Public: 3.0 x 10-6 per year 10-6 per year Acceptable Risk 10-6 per year Figure 4.11 : Maximum Individual Risk athpcl LPG Bottling Plant, Palakkad Page 33 of 37

34 Societal Risk The FN Curves for societal risk due tohpcl LPG bottling plant at Palakkadis shown in Figure Figure 4.12 :Societal Risk due tohpcl Storage &Bottling Plant, Palakkad It is seen that the societal risks due to HPCL Palakkad LPG storage &bottling plant at Palakkad is in the Acceptable (Negligible) Risk region. Page 34 of 37

35 5.1. Conclusions 5. CONCLUSIONS &RECOMMENDATIONS The scope of this QRA study covers the proposed three mounded bullets each with 350 MT capacity (to retain existing 3 above-ground bullets of 300 MT capacity out of 6 above-ground bullets with total 600 MT capacity), tanker gantry with two additional bays, pumps, compressor and bottling unit. The conclusions of QRA study are as follows. Maximum individual risk to the public is 3.0E-06 per year which isin the lower part of ALARP region close to the Acceptable Risk level. Maximum individual risk to personnel working in the LPG bottling plant is 1.5E-05per year, which is in the lower part of ALARP region. Societal risk due to LPG bottling plant is in Acceptable region. Based on the above results it is concluded that the LPG storage &bottling plant of HPCL at Palakkad conform to the specified risk tolerance criteria. Results of consequence analysis indicate that significant fire radiation and explosion overpressure effects for maximum credible leak scenarios are mostly within the plant boundary. For worst case scenarios involving catastrophic failure of road tanker the fire ball radiation and vapour cloud explosion effects can extend beyond the plant boundary. However, adequate safety provisions including gas detection system and sprinkler system are provided to prevent such occurrences. The proposed three new LPG bullets are mounded type and hence they are not susceptible to BLEVE hazard. It is therefore commendable that the existing above-ground LPG bullets will be replaced by mounded bullets. HPCL has responsibility to maintain the risk within the ALARP region by ensuring effective safety management system and adopting the best industry practices applicable to operation and maintenance of LPG storage and bottling plant. The LPG storage and bottling plant of HPCL at Palakkad conforms to the requirements of OISD Standards 144, 150 and 158. The proposed addition of LPG storage capacity in the form of mounded bullets represents the industry best practice with regard to safety. Fire protection system has been provided conforming to the requirement of OISD standards. This includes the following: Fire/ gas detectors with alarms Fire water storage and distribution system with hydrants, monitors and sprinklers Remote operated fire-safe type emergency isolation valves, non-return valves and excess flow check valves have been provided as per the requirement of OISD standards. Multiple level instruments of reliable type and overfill protection system have been provided for the LPG bullets. Page 35 of 37

36 Emergency response/ disaster management plan is properly implemented in the installation. This has been updated for the proposed additional LPG storage Recommendations The following recommendations are made to ensure that the risks at HPCL Palakkad LPG storage and bottling plant are maintained at low level. 1. Emergency push buttonsfor closing the remote-operated shut-off valves (ROSOVs) and stop LPG pumps/ compressors are to be provided in control room and other safe locations. 2. Flange joints are potential source of leakage. Raised face flanges with metallic spiral wound gaskets or tongue & groove type flanges should be used in LPG service as specified by OISD. 3. Prevention of ignition The flame-proof electrical equipment should be properly maintained by competent and trained personnel to ensure their integrity. The spark arrestors used for vehicles should be maintained by regular checking. Use of cell phones should not be allowed in the LPG installation. 4. Control room: It is necessary to provide proper control room for housing the instrument panels, alarms from fire & gas detection system, emergency push button and communication equipment. *************** Page 36 of 37

37 ANNEXURE I PLANT LAYOUT DRAWING Page 37 of 37

38