odisha thermal power corporation...

ODISHA THERMAL POWER CORPORATION LTD EIA / EMP studies for 2400 MW (3 X 800MW) Thermal Power Plant near Kamakhyanagar

Dist. Dhenkanal, Odisha

CHAPTER7 ADDITIONALSTUDIES‐ RISKASSESSMENTSTUDIES Page1of28©2017MECONLimited.Allrightsreserved

7.0 ADDITIONAL STUDIES- RISK ASSESSMENT STUDIES

Industrial activities, which produce, treat, store and handle hazardous substances, have a high hazard potential endangering the safety of man and environment at work place and outside. Recognizing the need to control and minimize the risks posed by such activities, the Ministry of Environment & Forests have notified the “Manufacture Storage & Import of Hazardous Chemicals Rules ”in the year 1989 and subsequently modified, inserted and added different clauses in the said rule to make it more stringent. For effective implementation of the rule, Ministry of Environment & Forests has provided a set of guidelines. The guidelines, in addition to other aspects, set out the duties required to be performed by the occupier along with the procedure. The rule also lists out the industrial activities and chemicals, which are required to be considered as hazardous. An Emergency Plan has been prepared to take care of any disaster in the proposed plant and surrounding areas and is detailed as under:

7.1 Hazard Identification Identification of causes and types of hazards is the primary task for planning for risk assessment. Hazard can happen because of the nature of chemicals handled and also the nature of process involved. So for risk analysis first step is to identify the hazardous chemicals which are to be studied for risk analysis. Identification of Hazardous Chemicals is done in accordance with The Manufacture, Storage and import of Hazardous Chemical Rules, 1989. Schedule 1, of the Rule provides a list of the Toxic and Hazardous chemicals and the flammable chemicals. It defines the flammable chemicals based on the flash point and boiling point. "Major accident hazards (MAH) installations" is defined as the isolated storage and industrial activity at a site handling (including transport through carrier or pipeline) of hazardous chemicals equal to or, in excess of the threshold quantities specified in Column 3 of Schedule 2 and 3 respectively. Schedule 3 has classified hazardous substances in an operating plant into 5 groups and has provided the threshold quantities for application of above rules. Group1 & 2 – Toxic substances, Group 3 – Highly reactive substances, Group 4 – Explosive substance, Group – 5 Flammable substances. The Table 7.1 shows the list of major chemicals which are used and stored in different quantities in the proposed plant. Out of these Heavy Furnace Oil (HFO) and Chlorine have been identified as hazardous chemicals in The Manufacture, Storage and import of Hazardous Chemical Rules, 1989 and which are to be considered as Major Accident Hazards (MAH) installations.

Table 7.1 Major chemicals used in the Plant

Chemical Qty. Stored (tonnes) Threshold Quantity




(tonnes) HFO/LDO 2500 25 Caustic Soda Lye 10 - Sulphuric Acid 50 - Chlorine 9 10

The chemicals which are stored more than the threshold quantities are to be considered for major accident hazard. Heavy Furnace oil (HFO)/LDO, used for cold start ups in the boiler, is classified as Flammable liquid as its flash point remains within 30°C–90°C. Its threshold quantity is 25 tonnes. The maximum inventories of HFO/LDO stored at any point of time is 2500 tonnes which is more than the threshold quantity thus, considered for further analysis for risk assessment and hazards due to heat radiation in case of fire in oil tanks have been assessed. Caustic soda lye, sulphuric acid and chlorine are not considered for the study. Both LDO/HFO falls under class C category fuel having flash point 660C. It is a blend of distillate components and a small amount of residual components. The IS specification of LDO/HFO is given below:

Sl. No.

Parameters LDO HFO

1 Specification IS-1460 (Latest Revision)

IS-1593 (Latest Revision) Heavy Grade (HVFO)

2 Acidity (Inorganic) Nil Nil 3 Ash Content 0.02% (max) by

weight0.1% (max) by weight

4 Flash Point (Pensky-Martens,closed)

660C 660C

5 Pour Point (Winter) 120C 500C 6 Kinematic Viscosity 2.5-15.7 Centistokes 170 Centistokes

(maximum) 7 Sediment by weight 0.10% (maximum) 0.25% (maximum) 8 Water content by volume 0.25% (maximum) 1.0% (maximum) 9 Sulphur by weight 1.8% (maximum) 4.5% (maximum) 10 Carbon Residue

(Ramsbottom) by weight 1.5% (maximum) 1.5% (maximum)

11 Gross Calorific Value 10,000 kcal/kg 10,500 kcal/kg 12 Specific gravity 0.85 at 150C 0.95 at 150C

Hazards associated with the above mentioned chemical is presented in Table 7.2 below

Table 7.2 : Hazards associated with HFO

Name of the

Chemical

Type of

Hazard

H a z a r d R a t i n g IDLH Value

Remarks Health Flammability Reactivity

Heavy 1,6,9 1 3 0 - Liquid under normal




Name of the

Chemical

Type of

Hazard

H a z a r d R a t i n g IDLH Value

Remarks Health Flammability Reactivity

Furnace Oil

pressure & stored at ambient temp.

Type of Hazard

1. Flammable substance 2. Oxidising substance, reacts with reducing agents 3. Emits a toxic gas or vapour 4. Emits an irritating gas or vapour 5. Emits a narcotic gas or vapour 6. Gas or vapour not dangerous other than displacing air 7. Causes skin irritation or burns 8. Toxic substance 9. Explosive material under certain conditions Hazard Rating

a. Health

1 None 2 Minor 3 Moderate, could cause temporary incapacitation or injury 4 Severe, short exposure may cause serious injury 5 Extreme, short exposure may cause death

b. Flammability 1 None, Material does not burn 2 Minor, material must be preheated to ignite

3 Moderate, moderate heating is required for ignition and volatile vapours are released

4 Severe, material ignites at normal temperature 5 Extreme, very flammable substance that readily forms explosive mixtures

c. Reactivity 1 None, stable when exposed to fire 2 Minor, unstable at high temp. or press and may react with water

3 Moderate, unstable but does not explode, may form explosive mixture with water

4 Severe, Explodes if heated or water added 5 Extreme, readily explosives under normal condition

7.2 Hazards Scenarios

7.2.1 Nature of Hazard from Oil Storage:




Diesel is a petroleum product. It is a highly flammable liquid having flash point between 32–96°C. However its auto ignition temperature is 256°C. Its boiling point ranges between 150-400°C. Furnace Oil is of similar characteristics having flash point above 66°C. Major Hazards from oil storage can be fire. Maximum credible accidents from oil storage tank can be

a) Tank Fire b) Pool / Dyke fire.

(a) Tank Fire:

Oil is stored in floating roof tank. Leak in rim seal leading to accumulation of vapour is a source of fire. Lighting can be a source of ignition and can cause tank fire. Overflow from tank leading to spillage may cause vapour cloud formation. This can catch fire and it can flash back to the tank to cause tank fire.

(b) Pool / Dyke Fire: If there is outflow from the tank due to any leakage from tank or any failure of connecting pipes or valves, oil will flow outside and form a pool. Where the tank is surrounded by a dyke, the pool of oil will be restricted within that dyke. After sometime, the vapour from the pool can catch fire and can cause pool or dyke fire.




7.2.2 Heat Radiation and Thermal Damage Criteria: The level of damage caused by heat radiation due to fire is a function of duration of exposure as well as heat flux (i.e. radiation energy onto the object of concern). This is true both for the effect on building and plant equipment and for the effect on personnel. However, the variation of likely exposures times is more marked with personnel, due to possibility of finding shelter coupled with protection of the skin tissue (clothed or naked body). Further, it is assumed that everyone inside the area by the pool fire will be burned to death (100% lethality) or will asphyxiate. Radiation at various heat flux levels which are critical in risk analysis, are given in the Table 7.3.

Table 7.3: Effect of Heat Radiation

Heat Radiation Effect 37.5 kw/m2 Damage to equipment 30.0 kw/m2 Limit for Class 1 building materials 12.5 kw/m2 Melting plastic 4.0 kw/m2 Blistering 1.6 kw/m2 Severe hot feeling

The damage and fatality (percentage of the exposed people to be killed) due to the exposure time is very important in determining the degree of fatality and corresponding effect distance. It is observed that the exposed persons normally find shelter or protection from the heat radiation (e.g. against a wall) within 10 seconds. However, exposure time of 30 seconds is normally assumed for pessimistic calculation which applies if people do not run away immediately or when no protection is available. The variation of the effects on humans due to heat flux and duration of exposure have been developed in the form of a equation which gives following values for human fatality levels in Table 7.4.

Table 7.4: Heat Radiation and Fatality

Radiation Level (kw/m2)

Exposure Time in seconds for % Fatality1 % 50% 99%

1.6 500 1300 3200 4.0 150 370 930 12.5 30 80 200 37.5 8 20 50

7.3 Consequence Analysis:

Consequence models estimate the potential hazards of the release of a chemical. It is done based on the release characteristics of the chemical concerned. A number of formulae and softwares are used for these purposes. For the present study, for Pool fire and Tank fire, steady state burning is assumed. Also for large fire wind speed is considered insignificant. Heat radiations at different distances have been calculated using PHAST software.




Failure Scenarios for HFO and Consequences This study is intended to find about the worst-case scenarios, as that will cover the other scenarios. A number of scenarios have been considered and finally the following failure scenarios have been analyzed following the MCA approach which will cover all the worst scenarios in this installation. Table 7.5 shows the heat radiation zones for different scenarios.

Table 7.5: Tank Fire Heat Radiation

Consequence Heat dose (KW/m2)

Tank Fire Distance from Centre,

m Heavy Damage to Plant Equipment, 99% Fatality 36.5 30 Limit for Class 1 building materials 30 40 Melting Plastic, 1% Fatality 12.5 80 First degree burns in 20 seconds, non-fatal 4.0 140

In case of pool fire or tank fire, risk contours are developed for radiation levels of 12.5 kw/ m2 and 4.5 kw/ m2 and are shown in Fig. 7.1 below:




Fig. 7.1: Risk Contours for radiation levels Radiation levels of 12.5 kw/ m2 will be observed at a distance of 80 m and radiation levels of 4.5 kw/ m2 will be observed up a distance of 140 m from the centre of tank.




7.5 DISASTER MANAGEMENT

In order to prevent occurrence of any disaster, the plant will be provided with various safety and disaster control facilities. Normally, in the power plant no major disaster affecting nearby population areas are foreseen. However, accidents inside the plant affecting workplace in vicinity cannot be ruled out. Work-force inside the plant shall be exposed to various high pressure system pipelines and vessels, acids and chemicals, fuel such as coal and furnace oil and other process equipment which, if not properly operated and maintained, can cause serious accidents affecting life and property in the vicinity of accident site. In addition to these, numerous material handling systems, heavy road transport, high-tension electric lines, level crossings, overhead cranes and various other handling and transport systems always have chances of accidents.

(a) Definition of Disaster A situation will be called a `Disaster' if it entails any one or more of the following factors: i) Risks of loss of human lives - ten or more in one single situation. ii) Loss of property as a consequence of the incident is over Rs.1 crore and/or

bears a potential to the above. iii) A situation which goes beyond the control of the available resource of the plant. iv) A situation apparently may not have much loss but its long-term severity can

affect loss of life, production and property. The types of possible disaster are given below:

(b) Type of disasters i) Disaster due to emergencies on account of:

- Fire - Explosion - Oil spillage - Electrocution

ii) Disaster due to natural calamity on account of:

- Flood - Earth quake / cyclone / Storm / Cloud burst / lightning

iii) Disaster due to external factors on account of:

- Food poisoning / water poisoning - Sabotage - War

(c) Objectives

Objectives of disaster control/management plan for proposed Power Plant are:




i) To identify type of major disasters that may occur in the proposed plant. ii) To collect data on type of disasters that has happened already in other thermal

power plants. iii) To prepare an action plan to handle disaster. Identification of hazardous process / area 1. Boiler area - Explosion 2. Oil tanks - fire & spillage 3. Turbine Hall - Explosion Electrical premises 1. Electrical Rooms - Fire & Electrocution 2. Transformer area - Fire & Electrocution 3. Cable Tunnel - Fire & Electrocution Other premises Storage facilities for coal and fuel oil -Fire/spillage

(d) Level of accident If there is any disaster in any part of the plant /work place due to any reason the area which may be affected can be classified in the following four classes. 1. Level I - Operator level 2. Level II - Local/community level 3. Level III - Regional/ national level 4. Level IV - International level Only level I and II class of accidents can be considered for the thermal power plant. Level I Under this level, disasters may happen due to fire, explosion, oil spillage and spontaneous ignition of inflammable materials. This level has probability of occurrence affecting persons inside the plant. The various shops, which have been mentioned as potential hazard areas, will be affected during this level of accident. Level II In case of sabotage/complete failure of all automatic control/warning systems the fuel oil stored in tanks and covered by tank bends may leak out. However, the




probability of this is very low due to adequate security and training of persons of the plant operating such system.

7.5.1 Disaster preventive measures If any disaster takes place it is not easy to control if contingency plans are not available. For effective control of disaster adequate manpower, technical know-how, alertness and internal help are necessary. It always better to take preventive measures to avoid any disaster. In proposed plant following prevention measures will be taken to prevent disaster.

(a) Plant layout: i) Design, manufacture and construction of all plant and machinery’s and buildings

will be as per national and international codes as applicable in specific cases and lay down by statutory authorities.

ii) Provision of adequate access ways for the movement of equipment and personnel are kept.

iii) Minimum two numbers of gates for escape during disaster shall be provided. iv) Siting of fuel oil storage shall be in protected fenced area inside tank bend. v) Water spraying in coal storage area.

(b) Fire Fighting It is proposed to have a well equipped fire fighting group for the proposed power plant with 4 officers, 50 workers trained in this field. Following (Table 7.6) fire-fighting equipment shall also be provided: - Fire Tender 1 No. - Jeep 4 Nos - Portable Extinguishers Lot - Foam generator Lot - Static tanks Lot

Table 7.6: List of Fire Extinguishers Required at Different Locations

Name of site Type Turbo generator Area Cable galleries High voltage panel Various control rooms

CO2 Foam type Dry Chemical type CO2 Foam type Dry Chemical type CO2 Foam type Dry Chemical type CO2 Foam type




Name of site Type Various MCC rooms Various pump houses Fuel Tank Area Guest Houses & offices Go downs Crusher House

Dry Chemical type CO2 Foam type Dry Chemical type CO2 Foam type Dry Chemical type CO2 Foam type Dry Chemical type Sand Baskets Dry Chemical powder type Foam type CO2 Foam type Dry Chemical type

However before installing fire station & safety equipment, an experienced fire officer would be appointed who carry out an in-depth study and shall decide about the selection of equipment.

(c) Safety For proposed plant safety department will conduct regular safety awareness courses by organizing seminars and training of the personnel among the various working levels. Safety awareness will also be created by the various posters highlighting the safe working practices in different shops, hazards in working area, public places and roads etc. Safety engineers of the plant will conduct regular checks and mock exercises on the safe working of their department and report will be given to departmental head for corrective measures to improve the safety conditions.

(d) Training A department of training will also be set up to train officers. They will arrange training on safety accident prevention, first aid, hazard control, housekeeping and environmental management. Special emphasis with mock drills in disaster control will also be planned.

(e) Communication




The proposed plant will be provided with up-to-date communication facilities with telecommunication and wireless facilities, walkie-talkies, telecommunication and loud speakers in each shop, office and gate to warn workers in case of an accident.




7.6 Organization to Combat Contingency The proposed contingency plan is prepared from the experiences of accidents that have occurred in various other Power Plants. The contingency plan being a dynamic plan will need periodical reviews and modifications with new experiences. Even with all precautionary measures taken to avoid disaster, disaster may occur. To tackle situations during and after disaster, a well-defined contingency plan is a must. The Emergency Plan, in brief, involves noticing an emergency by an employee, summoning of Declarer of Emergency by Shift In-charge, declaring of emergency with or without shutting the plant by sounding the coded siren, controlling of emergency, performing rescue, leakage control and repair functions by respective teams under Works Incident Controller, informing the local authorities in the event of a likely off-site emergency and making available all the resources for safety and security of the people inside and outside the plant, sounding of 'All Clear Signal' after having complete control over emergency to indicate that everything is normal again. Emergency Organization chart is given below :




7.7 Action Plan for Handling Emergency Situation.

A long-term strategy and action plan have been drawn for the following identified disasters. 1. Chlorine Leakage 2. Fire accident in Oil storage tank.

(a) Controlling Emergency Related to Chlorine Leakage Emergency scenario may arise in the event of a chlorine leakage. Toxic chlorine gas, being heavier than air, will form a heavy cloud and disperse in the prevalent wind direction. The emergency team will perform the same exercise as has been described above in the case of pool fire / vapor cloud explosion. Some ‘DOs’ and ‘DONTs’ during emergency situations on the event of a chlorine leakage are given below : ‘DOs’ 1. If the cylinder is leaking liquid chlorine, turn it, if possible, so that the gas

instead of the liquid escapes. The quantity of gaseous chlorine is about one fifteenth the amount of a chlorine leak through the same size hole.

2. Reduce pressure in the chlorine cylinder by removing the chlorine as gas (not as liquid) to the water pipe

3. Apply emergency kit device to contain leaks (gas masks and personal protective clothing are not included). The kits are used to cap off leaking valves or seal off a leak in the side wall. Capping devices are also provided for fusible plugs.

4. If the leak is in a connecting pipe, at least two persons should wear BA , find the leak by means of ammonia fumes or otherwise and secure the valves at the containers. When the system is brought down to atmospheric pressure, only then steps should be taken to make necessary repairs.

5. Chlorine should preferably be passed into the alkali absorption system through a suitable connection properly submerged and weighted to hold it under the surface.

‘DONTs’

1. Never spray water on chlorine leakage 2. Never immerse the chlorine in the alkali absorption 3. Never attempt to neutralize chlorine with chemicals by direct application on

the leak 4. While providing First-Aid, never give anything by mouth to an unconscious

person.




Apart from the above, the following design aspects will also be considered during detail engineering stage:

� Chlorine detector will be placed in strategic locations to detect leakage of Chlorine.

� Audio visual alarm should be provided in local panel as well as in the main control panel for any Chlorine leakage detected by Chlorine detector.

� The first isolation valve of the Chlorine tank shall be closed immediately on detection of Chlorine leakage by Chlorine detector.

� Safety shower and eye wash arrangement should be installed near chlorine tonner area or chlorine leakage prone area.

� Instruments in hazardous location shall be intrinsically safe and explosion proof type as applicable.

� An automatic chlorine absorption system will be installed for the proposed units.

� The electrical and instrument devices in side hazardous areas must comply with IS codes (IS 5571, 5572, 5780, 2148, 7389, 8240 & 8241) and FM guidance.

Action Plan for Chlorine Leakage ACTIVITY ACTION BY

Identify Leakage D.M. Plant operator/Any employee Information to Main Control Room regarding Cl

2

gas leakage

First informer

Information to Site Main Controller( Director Operation), Incident Controller (T.L, WTP) Personnel Manager, Safety Officer, etc.

Shift In Charge , Main Control Room

Information to Site Main Controller( Director Operation), Incident Controller (T.L, WTP) Personnel Manager, Safety Officer, etc.

Shift In Charge , Main Control Room

Rush to site with Self Contained Breathing Apparatus to stop the Cl

2 leakage

D.M. Plant operator

Evacuate & Cordon the affected area Security Officer Declare emergency through coded siren Site Main Controller (Director Operation/

Factory Manager) Search & Rescue of affected person Search & Rescue Team First aid to affected person Trained First aider at the scene Medical Aid Medical Aid group Proper function of Site Emergency Control Room

Site Main Controller (Director Operation/Factory Manager)

Co-ordination without side agencies Personnel Manager (Head,P&A) Ensure that the leakage is arrested fully Incident Controller (T.L,WTP) Blow All Clear Siren Site Main Controller (Director -Operation /




Factory Manager) (b) Controlling Emergency Related to LDO/HFO Spillage

LDO/HFO presents a major FIRE HAZARD. There are several possible events that might occur when there is a release of liquid LDO/HFO and a pool is formed. A spark of energy from an ignition source near the pool may ignite the vapor from the pool and lead to a pool fire. The other possibility is that there is no initial ignition. In that case, the vapor from the pool will be dispersed by the wind. This vapor may be ignited by any ignition source within the wind dispersion zone (i.e. the propagation passage of the explosive gas mixture) resulting in the burning of the cloud which may trigger a flash fire or pool fire ( if pool still exists). The other possibility is that the cloud may explode to create an explosion and / or burn back to form a pool fire ( if the pool still exists ). Even if the cloud does not ignite at all, the unignited cloud may create an asphyxiant effect. Fighting the pool fire will be the primary emergency action by On-site fire crew under the direction of Incident Controller for which number of fire hydrants connected to pressurized water main will be installed round the tank farm. Radiant heat @ 31.5 kW/m2 would have impact on the surrounding area and in order to prevent the thermal radiation, water curtains or heavy duty sprinklers should be used in combination with DCP / foam monitor to douse the fire. The fire has to be fought by On-site fire crew from outside the 4.5 kW/m2 line to prevent thermal injury to themselves. If people were at work within the 5 kW/m2 damage circle they must be trained to retreat to safety within 13 seconds. If scale and location of fire are such that hydrants are enveloped by 4.5 kW/m2 damage circle then the fire crew must either be equipped with reflective aluminized protective clothing or fight the fire from outside the 4.5 kW/m2 damage circle with extension hoses. Portable monitors are more effective as their retreat circle is large. The crew members must carry adequate B.A. Sets to the scene of the incident.




ACTIVITY ACTION BY.

Identify Fire Any employee Information to Main Control Room regarding fire.

First informer

Information to Site Main Controller, Incident Controller, Personnel Manager, Safety Officer, Fire Officer.

Shift In Charge, Main Control Room

Rush to the site with fire extinguisher for fire fighting

Shift Operator

Evacuate & Cordon the affected area Security Officer Fight the fire with Medium Velocity Water Spray System (MVWS), Foam system, Fire hydrant connected to foam making branch pipe

Combat Group, Safety Officer, Fire Officer.

Cool the adjacent LDO tank through continuous water spraying by hydrant

Combat group

Search & Rescue of victims Search & Rescue Team Emergency planned shutdown (if required) Emergency plant shut down group First aid to affected persons, victims First aider at scene Medical Aid to victim Medical aid group Co-ordination without side agencies Personnel Manager (HEAD P&A) Repair the affected equipment & building Mech. Maint. Team Blow all Clear Siren Site Main Controller (Director

Operation / Factory Manager 7.7.1 General Measures for Controlling Emergency

Preventive & tactical features of On-site Emergency Plan which come into focus under an emergency scenario are: - Speedy detection of an accidental spill/leakage of chemical and removal of ignition sources in the area.

- Movement of equipment for fire fighting, first aid etc. - Raising of the alarm to activate the plan. - Hazard reduction (removal of tanker, cylinder, tonner etc.). - Heavy-duty sprinkler protection of the tank/bullet. - Fast emergency response. First step would be to stop the flow of gas/liquid to the atmosphere.

- Use of portable water and foam monitors. - Use of floodlights / flashlights if adequate light is not available - Evacuation of the storage area and adjacent vulnerable areas by other workmen in 40 seconds.




- Use of equipment required for personal protection and rescue will include, inter alia, the following:

Stretchers and stretcher carriers. Industrial safety belts and harnesses. Flameproof industrial clothing. Clothing for protection against intense heat for short periods. General purpose industrial safety helmets. Industrial eye-protectors. Self contained Breathing Apparatus (B.A.) sets. Safety shoes.

Site main controller and his team mates will take several key actions: - Identify the source of leak/ignition - Send the trained personnel of fire crew with B.A sets, Hydrocarbon escape masks and leak arresting gear to the identified source.

- Alert first aid center and nearby hospitals and ambulance service to be on standby to pick up and treat persons who are affected.

- Post the Emergency Security Controller at the main gate with suitable briefing to liaise with external agencies

After the leak has been arrested or source exhausted and the explosive vapor cloud has dispersed to harmless concentration throughout the affected zone, SMC terminates the emergency and informs all control rooms and all other concerned to restore things to normal.




7.8 Responsibilities of various functionaries during "on-site" and"off-site" emergency Any one noticing an emergency

A. Actuate the nearest Manual Call Point in case of Fire. B. Inform immediately Plant manager about location and nature of emergency.

Plant manager (WIC)

A. Asses the situation and classify the situation as emergency or minor. B. Initiate action to control emergency. C. Mobilise fire fighting personnel and equipments D. Shift in charge can declare the emergency if the situation is grave.

Declarer of emergency (works incident controller) A. Assess the situation and shut down the plant if not done so. B. Declare Emergency C. Inform Works Manager D. Inform Factory Nearest Hospital Dharwad E. Assemble the Leak Control & Repair Team, Rescue Team and arrange

necessary safety equipments for them. F. Ensure that the paths for evacuation are lit through emergency lighting. G. Keep in touch with the different teams and advise them regarding the

method of control to be used. H. Give an All Clear Signal when the emergency has been controlled. I. Prepare a detailed report. Security A. To co-ordinate attendance of people working, Transporters and visitors

assembly point. B. Help police for sending affected persons to hospitals etc. C. Looking after the law and order within factory premises.

Nearest hospitals

A. Send ambulance to the place of emergency. B. Ensure that those requiring medical attention are separated.

C. Treat all those who can be treated in the Hospital. D. Send the other injured/affected to the local hospitals.

E. Inform outside hospitals about antidotes and supply the same if required. Police

A. Control crowd of onlookers to keep the area clear.




B. Maintain law and order C. Help to take injured to hospitals.

Transport incharge

A. Arrange transportation as required. B. Be in close contact with Works Incident Controller. C. Arrange for ambulance and other vehicles.

Declaration of emergency

When emergency situation arises due to leakage propane fire, any employee who notices the same will inform the Shift in-charge. The Shift in-charge will raise the siren or use radio/mobile communication depending upon the nature of leakage. The Shift in-charge will also assess the situation. Simultaneously – the Chlorine/ Fire detectors installed in various location in the plant shall also trigger alarm when content of release is above the set norm. The works in charge will take necessary action to control the Leakage/fire with the available resources. In case the Emergency situation is of serious nature, the works in-charge will declare the emergency himself. Emergency Alarm – Style and duration: For Major Fires: Continuous Siren for Five Minutes. With this, the emergency is considered to have been declared. The works in-charge will simultaneously take steps to control the emergency and act as WORK INCIDENT CONTROLLER (WIC). In the event, the emergency is of off-site nature, the Works Incident Controller (WIC) will get in touch with the Superintendent of Police (SP) Dhenkanal or alternatively the Dy.Supdt. of Police (Dy.S.P.). The SP/Dy.S.P will act as CONTROLLER OF OFFSITE EMERGENCY and will inform the public with the help of siren and Public Address System mounted on vehicle.

7.9 Evacuation of persons, medical treatment and plant shutdown Evacuation of persons It is natural that the persons inside the factory premises shall get panicky and do things which may expose them to harm. It is therefore very important that in case of emergency, the persons should know exactly which way to go so that they are guided to a safe place. At identified locations escape masks are provided where people can use them and reach the safe assembly point on hearing the emergency siren. People should rush to this point keeping in view the wind direction.




Counting for missing persons Attendance will be taken in this collection point by tuning computerised attendance systems to know the names of the persons who might have been caught in during emergencies Collection Point Attendance I/C(Checkers)

Attendance In-charge (Checkers) should check with other persons to first know the names of missing persons of their sections. He should give these names by telephone to Control Room. Shift In-charge / Works incidence Controller will then send rescue teams to evacuate the trapped persons. Rescue Team : It will comprise of the following persons i) Safety –Assistant ii) Fireman -1 iii) First Aid attendant -1 iv) Security Personnel -1 The above Rescue Team members shall assemble in the Control Room (Site Emergency Control Room) and report to WIC. Ambulances / cars (vehicles) will be used for rescue operation. Drivers shall park these vehicles in front of Administrative Building Entrance. At a time only 4 rescue team members will go in search of trapped persons in the vehicle and send the affected persons to First Aid Centre. During General Shift, HR&A personnel will send a vehicle to the Site Control Room area. In case of Off-Site emergency, the evacuation will be done by police. In case of emergency colony residents should not remain outdoor. They should remain inside a room of the house and should close all windows, doors and ventilators etc. They should try to keep the room air tight by putting old news papers and cloth in the gaps of doors, windows etc. if required. They can use wet cloth on their nose if they smell chlorine or feel difficulty in breathing, they should remain indoor till there is an all clear signal. Important persons in the nearby villages will be informed of the emergency for availing assistance in evacuation. The police will arrange for guarding the property and maintain law and order. Police will arrange for temporary shelter, food and also make arrangements to take the public back to their residences after the all clear signal is given. Medical team and medical treatment




Medical Team will comprise of following persons: i) Medical Officer (Public health Hospital) ii) Security Personnel iii) Shift First Aid attendant

Security Personnel/HR personnel will send the shift vehicle to pickup Doctors from their residence immediately after the declaration of the emergency and then park the vehicle in front of Control Room for use by Rescue Team. Control of emergency The Site in-charge (WIC) performs the function of leakage control, repairs and also rescue of gas affected personnel with help of trained staff. Leak control & repair team consists of following members: 1. Safety Personnel 2. Mechanical Engineer 3. Fitter All clear signal It is the duty of the Declarer of Emergency to inform everyone concerned after the situation is brought under control. Once the signal is given, all the persons inside and outside the plant can perform their normal duties as the emergency has been completely controlled.

7.10 Occupational Health and Safety measures

Occupational health and safety (OHS) aims to prevent accidents and diseases related to work place. The OHS recognizes the connection between the workplace, worker health & safety, and the environment outside the workplace. Effective workplace health and safety programmes can help to save the lives of workers by reducing hazards and their consequences. Health and safety programmes also have positive effects on both worker morale and productivity, which are important benefits. OPTCL management proposes to address all work-related hazards including statutory requirements in order to create and maintain a safe and healthy workplace for their employees. The Integrated Management System Policy of OTPC Ltd is given in Annexure-7.1.

Plant operation will involve storage handling and use of fuels and several chemicals. Some of these chemicals may be hazardous in nature. Information about these chemicals is therefore important for the safety of the employees and the plant. Besides, the health status of the employees is also important which may be affected due to exposure to these chemicals. The exposures may be sudden and accidental or




for a long period. In both the cases there will be different health effects. Therefore safety measures dealing with these chemicals are of vital importance. Occupational diseases are often not curable but they are always preventable. Improving ventilation, wearing protective equipment, changing work procedures and educating workers are the key factors for prevention. Two factors make Hazards easily preventable: first, the causal agents of these diseases can be identified, measured and controlled; secondly, the population at risk are usually easily accessible and can be regularly supervised and treated Major activities People at work during construction/operation phase can encounter four basic classes of environmental stresses:

1. Chemical : Exposure to fumes, dusts, vapours, liquid etc. 2. Physical : Noise, vibration, heat, light, ionising radiations etc. 3. Biological : Insects, mites, yeasts, hormones, bacteria, viruses etc. 4. Ergonomic : Man-machine interaction e.g. body position in relation to task on

machine. Out of the above four, biological stress is less common in power industry. Occupational risks At a coal-fired electricity generating plant, coal is the main raw material of production and it is well expected that employees will be exposed to coal dust (with the probability of developing silicosis because of the prevalence of crystalline silica in coal) at various stages of production. The pulverised coal is highly combustible and is blown from each ball mills into boilers at some 63 tons an hour to be combusted for the generation of steam and ultimately electricity. This coal is burnt in the boilers at temperatures of above 1 000ºC. The oxides of sulphur and nitrogen (SO2

and NOX) are also given off during

the combustion of coal. After all the pulverised coal has been burnt in the boiler, two types of ash are given off. Large particles are removed from the bottom of boiler known as grate or bottom ash. The finer ash is removed from the boiler via the flue gases, known as fly ash. The fly ash is extracted from the flue gases by a series of extractors, usually electrostatic precipitators consists mainly of fine particles Employees at the coal-fired power generating plants are generally not exposed to high concentrations of fly ash dust because the ash is enclosed within the production system. However, there are tasks or activities such as maintenance on electrostatic precipitators, hoppers, bag houses and conveyers whereby employees are likely to be exposed to high concentrations of this dust.




Noise Noise has been noted as a problem in coal-fuelled power plants and because engineering controls are often not feasible, control methods in existing power plants continue to be a problem. Depending upon the level and frequency of the noise, exposure duration, and susceptibility of the individual, noise-induced hearing loss may be temporary or permanent. Temporary loss of hearing may be restored if other exposures do not occur before recovery is complete. Heat Stress and Strain Heat strain can cause a rise in body temperature, fainting or fatigue, or increased thirst. Heat Stroke : A heat stroke is a medically urgent situation that results when the heat-balance mechanism malfunctions. Heat Exhaustion : Heat exhaustion is the result of the overtaxing of the heat-loss mechanism. Heat Cramps : Heat cramps are common when job activities require laborious work, but the symptoms are less severe and life threatening than those associated with heat stroke and heat exhaustion. Chemicals Different chemicals like Chlorine, hydrochloric acid, sulphuric acid etc. will be required for water treatment, DM plant, effluent treatment, etc. These chemicals will be handled according to the directions provided by the manufacturers. Emergency bath and first aid facilities will be provided in the handling areas. Breathing apparatus shall be provided for workers handling chlorine. Handling of hazardous chemicals involves risks to workers as they are constantly exposed to these chemicals during various operations and storages. In the event of an accident, not only the workers but also the general public can be exposed to dangers.




Personnel Safety

For safety of working personnel the following steps will be undertaken.

All easily accessible moving parts in the plant will be securely fenced. There will be arrangement for prompt power cut from transmission

equipment, if necessary. Every hoist, crane etc. will be properly maintained and examined at intervals. All working places will have safe means of access and exit.

Emergency fresh water bath will be provided in the hazardous chemical handling areas e.g. storage areas and operating unit areas.

All personal safety equipment like gloves, helmet, goggles etc. will be worn in the required place.

Boilers will be examined in proper manner by proper authority as per statutory requirement

A list of personnel protective equipment is given below:

Medical surveillance guidelines as prescribed in the Factories Act, 1948 (Amended).Under section 41C, shall be followed by OTPCL to ensure a healthy work environment.




Plant will have well equipped Health centre within the plant premises. OTPCL shall engage full time qualified doctors who are trained in occupational health. The duties of the Occupational Health Centre are: • Detection of Occupational Health Hazards • Detection of pneumoconiosis • Prevention of occupational health hazards • Conduction of health awareness and education programmes • First Aid Training and Retraining for different Certificate Courses • Follow-up Care and Rehabilitation • Hygiene survey in canteens (every month) • Record maintenance. Preventive Steps for Occupational Safety The preventive steps (management measures) will be planned to create a healthy and hazard free working environment. Effectiveness of the preventive steps will be examined through regular safety audits, medical records, accident statistics etc. The preventive steps (management measures) are discussed below. Effectiveness of the preventive steps will be examined through accident statistics and medical records.

1. Depending on the hazards at worker’s assigned work area, personal protective

equipments (PPE) viz. helmets, safety boots, ear plugs / ear muffs dust masks etc. have been provided to work persons. Some PPEs like welding goggles, gloves etc. are kept at work places.

2. All new recruits are given basic training on safety before being actually deployed for plant operations. Air quality, water quality and noise levels are monitored regularly. The effects of these environmental attributes on the workers health are communicated to the workers through awareness programmes. Training on occupational safety and health is imparted by the Medical Officer.

3. Risk assessment is carried out in the plant on a regular basis. The goal for each

risk assessment session is to identify hazards, determine risk ratings and controls and to review the implementation of risk controls from previous risk assessment sessions. Also, Safety Audit is carried out on a regular basis. The goal of Safety Audit is to identify hazards, determine risk factors and device control measures which are implemented to mitigate the hazards. Internal Safety Audit is also conducted annually to augment the findings.

Health impact assessment will be carried out through:

Surveillance of the factors in work zones and work practices, which may affect workers’ health.

Periodical medical examination in order to detect the onset of any work related disability / disorder / illness.

odisha thermal power corporation...

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