Occupational Health Hazards, Safety &Environmental
management in THERMAL POWER PLANTS
Presented By V.KODANDA PANI
ADE/TMD/STAGE III
ANDHRAPRADESH POWER GENERATION CORPORATION LIMITEDRAYALASEEMA THERMAL POWER PROJECT
H S E POLICY
Health, Safety & EnvironmentWHAT IS HSE H Health (Occupational) Prevention of occupational sickness S Safety Prevention of Accidents / Injuries E Environment Protection of Environment
Every minute there are: 2 Occupational Fatalities 475 Occupational Injuries 300 Occupational Diseases
H S E OBJECTIVESContinuous reduction in the incidence of work related injuries, fatalities, diseases, disasters and loss of national assets.
Continuous enhancement of community awareness regarding safety, health and environment at workplace related areas.
Improving safety, health and environment at workplace by creation of “green jobs” contributing to sustainable enterprise development
OCCUPATIONAL HAZARDS IN
THERMAL POWER PLANTS
HAZARD
HAZARD – Condition with the potential to cause personal injury, death and property damage
Occupational health refers to the potential risks to health and
safety for those who work outside the home
Hazard something that can cause harm if not controlled.
Occupational disease Disease directly caused by a person’s occupation.
Types Of Occupational HazardsDepending upon occupation of an employee may be exposed to five types of
hazards
Physical hazardsHeatNOISEVIBRATIONILLUMINATIONRADIATION
ChemicalBiologicalMechanical-electricalPsychosocial
Disorders Clinical features
Prickly Heat (Miliaria rubra) Pruritic rash
Heat cramps Cramps in the body, usually legs
Heat exhaustion Dizziness, blurring of vision, cold and sweaty skin
Heat stroke Cyanosis, muscle twitchings
Heat Syncope (fainting) Falling unconscious because of too much exposure to high temperatures
Health Effects of Heat Stress
HEAT EXHAUSTION
At high temperatures body circulates great amounts of blood to the skin to eliminate heat through perspiration. Less blood to vital organs including brain.
HEAT STORKEBody stops sweating and making it impossible to dissipate heat.
Body temperature may rise to dangerous level in short time.
Increasing air changesReducing radiated heat by
insulationReflection of heatDrinking plenty of water
and intake of saltUse of personal protective
equipments
Effective temperature and heat effect in an environment can be controlled by:
NOISE Industrial noise can give rise to deafness
Non auditory effects are irritation, nervousness, annoyance, fatigue, inefficiency etc
Hearing loss in most cases is not sudden but increases with the length of the work time in the noisy zone.
Types of Noise-Induced Hearing Loss Temporary Threshold Shift (auditory fatigue)
temporary loss of hearing acuity after exposure to loud noise recovery within 16-48 hrs
Permanent Threshold Shift irreversible loss of hearing
Other Harmful Effects of Noise
• Hypertension• Hyperacidity• Palpitations • Disturbs relaxation
and sleep
Threshold Limit Value for noisy working conditions:(An 8 hour shift in all following cases)
8 hours work – 90 dBA4 hours working – 95 dBA2 hours working – 100 dBA1 hour working – 105 dBAhalf hour work – 110 dBA Threshold of hearing – 125 dBA Sudden deafness/rupture of ear drum can occur at 140 dBA
NOISE
Noise can be controlled by;1. Reducing vibrations2. Enclosing the noise
producing equipment3. Enclosing the operator4. Moving away from the
noisy area5. Use of personal
protective equipments
NOISE CONTROL
Segmental Vibration: Vibration especially 10 to 500 Hz, can affect hand and arm after years of exposure
• Health Effects:— Hand Arm Vibration Syndrome (HAVS)
The fine blood vessel of finger becomes increasingly sensitive to spasm
(white fingers).— Tingling, numbness, blanching of fingers
pain
Whole Body Vibration:Health effects:
FatigueIrritabilityHeadacheDisorders of the spine
Continuous working should be avoidedUsing Anti vibration tools using Anti vibration glovesSafe working practicesEmployee education
VIBRATION CONTROL TECHNIQUES
Inadequate IlluminationHealth Effects
POOR ILLUMINATION EXCESSIVE BRIGHTNESSVisual Fatigue Blurring VisionEye pain Discomfort
annoyanceHeadachesPainful irritation Lacrimation(flow of tears)
CONTROL
Insufficient Light as a hazard in working condition can be controlled by
Providing Sufficient lighting at working areas & increasing Light requirements with age of a
person to see and work on the object.
RADIATION
RADIATIONA. Non ionizing (Ultraviolet) Radiation hazard- Seen in work with arc welding and mainly affects the eyes. Exposure to such radiation may lead to Conjunctivitis and Keratitis (Welder’ s flash)
B. Ionizing radiation hazards[X room/ CT]Anemia LeukemiaCancerUlceration In extreme cases death can take place
Chemical Hazards
Chemical hazards –1. Dust 2. Smoke3. Fumes 4. Poisonous gases5. Acids6. Alkalis
Chemical Hazards They enter our body through Skin Inhalation Mouth EFFECTS Skin diseases Lung diseases Internal blood and other diseases
DUST
These dusts enter our body through inhalationRespirable dust particles can enter our lung sacks and reduce our
breathing capacity since this dust settles there,Normally dust particle less than 2.5 micron only can enter in our
lung sacks.Bigger dust particles either remain in our nose or get stuck in
throat. Then they go into stomach and get removed from our body system in natural way.
Disease which can occur due to inhalation of coal dust is known as “pneumoconiosis” and is irreversible till person is shifted from job
Prevention of Pneumoconiosis1.Dust control- Reduction of dust emission by suppression by wetting
coal in wagons, at the time of tippling, water spray in coal conveyors
· Proper Ventilation · Exhaust · Enclosed apparatus · Good house keeping2.Personnel protection· Mask, clothing, apron, boots barrier cream etc3.Personal hygiene
4.Health education about respiratory evolvement and personal protection5.Medical control
Periodic medical check up for early detection
Chemical HazardsSmoke: inhalation of smoke which can contain poisonous gaseous fumes also and can have effects on our health;
Fumes: fumes emanating from liquid chemicals can cause ill effects on our health when inhaled;
Vapor: vapors of chemicals liquids are also dangerous to our health when inhaled. Vapours of hydrazine hydrate can cause unconsciousness when inhaled. Poisonous gases leads to suffocation and asphyxia(Reduction oxygen). Asphyxiating gases are – CO, Cyanide, SO2, Chlorine etc
Chemical Hazards Hazardous chemicals used in thermal power stations:
Chlorine Hydrochloric acid Euphoric acid Hydrazine hydrate Liquor ammonia Sodium hydroxide
Chemical Hazards
It is the most hazardous chemical used It is used in water treatment plantIt is procured in toners for use in
chlorinationationWhen more than 10 tons of chlorine is stored/
handled/used in any industry, a Disaster Management Plan (DMP) is required to be prepared and submitted to statutory authorities.
This DMP is required to be practiced through mock drills periodically and review meeting are to be conducted for checking discrepancies.
Chlorine
Chemical Hazards
Chlorine vapor is poisonous when inhaledWill cause burn in eyesChlorine liquid can cause burn on skin and
eyesThreshold Limit Value (TLV) for chlorine is 1
ppmAt 100 ppm it can be fatal.
EFFECTS OF CHLORINE
PREVENTION To avoid chemical accidents some points to be kept
in mind.1. knowledge of chemicals2. knowledge of processing plant3. knowledge of operator
Chemical Hazards
MECHANICAL HAZARDS
• Point of OperationPoint of Operation - where work is performed on material by the machine
• Cutting• Shaping• Drilling• Stretching• ging
Belts
Where Mechanical Hazards are present
• Power Transmission ApparatusPower Transmission Apparatus - Part of the machine that transfers energy to the part of the machine performing the work
• Flywheel• Pulley• Cams• Gears• Connecting rods• Couplings• Chains• Belts
Entanglement caused by contact with single rotating surface
Rotation Hazard
ROTORY MOTION HAZARDHere, the operator is reaching into the machine, which due to the rotary motion of the drums can force his hand and arm into a dangerous position that could result in injury.
• Parts rotating in opposite directions while being parallel to each other
Pinch Point
• Between rotating and tangentially moving parts
Pinch Points
• Between rotating and fixed parts Pinch Point
Rotation Hazard
Hazard Recognition
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Rotary Motion Hazard:Rotary Motion Hazard:
– Hazard is increased when projections are present on rotating components which can strike the operator
the rotary motion of the bobine is grabbing and forcing the operators arm into the machine, potentially causing injury to the arm.
– Struck by or caught between the stationary part and moving part of the up-and-down or back-and-forth motion
Abrasive / Rubber Surfaces
– Contact with an abrasive or sticky surface in fast motion
Prevention of mechanical hazards
PREVENTION OF INDUSTRIAL HAZARDS• Maintenance of temperature- 69 to 80 deg. F is the comfortable
zone • Proper ventilation• Good housekeeping• Proper illumination• Personal protection• Personal hygiene• Health education• Job rotation • Periodic health Check up• Preventive maintenance• Adequate job training• Ensuring safe working environments• Establishment of safety department with qualified safety engineer• Periodic survey for finding out hazards• Application of ergonomics
ACCIDENTS
Unplanned & unexpected event which results into injury or property damage is known as accident.
98% accidents were either un safe actions/un safe conditions or both
Types of AccidentsFALL TO
same levellower level
CAUGHTinBetween
RUBBED OR ABRADED BYfrictionpressurevibration
CONTACT WITHchemicalselectricityheat/coldRadiation
STRUCK Against
stationary or moving object
protruding object sharp edge
Policy & ProceduresEnvironmental Conditions
Equipment/Plant DesignHuman Behavior
Slip/Trip FallEnergy Release
Pinched Between
Indirect Causes
Direct Causes
ACCIDENTACCIDENTPersonal Injury
Property DamagePotential/Actual
Basic Causes
Unsafe Acts
Unsafe Conditions
CAUSES OF ACCIDENTS
Basic CausesManagement
Environment
Equipment
Human Behavior
Systems & Procedures
Natural & Man-made
Design & Equipment
Management
Systems & ProceduresLack of systems &
proceduresAvailabilityLack of
Supervision
Environment
Physical Lighting Temperature
Chemicalvaporssmoke
• Biological–Bacteria–Reptiles
Design and Equipment DesignWorkplace layoutDesign of tools &
equipmentMaintenanceEquipment
SuitabilityStability
GuardingErgonomicAccessibility
Human BehaviorCommon to all accidents
Not limited to person involved in accident
Human FactorsOmissions
Deviations from SOPLacking Authority Short CutsRemove guards
Indirect Causes of accidents Unsafe conditions
Unprotected platforms, openings an un guarded m/c
untidy work areaUsing Defective tools poor lighting in work areaBad house keepingUn safe clothing,loose hair,ornaments etc
Unsafe actusing equipment without having proper knowledgefailing to use the appropriate protective equipment Operating without authorityusing tools or equipment incorrectly.
ACCIDENTEEPain, worry, No recreation, In capacity to perform normal work, loss of wages, Medical expenses, Loss of life
SUPERVISORWorry, Loss of prestige, A good man lost, Selecting and training a substitute, More supervision on trainee,losss of output, Loss of morale
MANAGEMENTProduction delays ,legal complications, compensation & medical costs, Damages to equipment ,Repair/replacement cost
1.DISCOVERING THE CAUSES INVESTIGATION OF ACCIDENTS Inspection of plant, equipment and work conditions Maintaining proper records of all activities like O&M, testing and analysing them2.ELIMINATING by Recruiting and placing properly trained personnel Safety education and training Supervision Discipline Motivating for safety Safe guarding all machines, work space etc Adequate suitable illumination and ventilation Safe dress and PPE Preventive maintenance displaying warning notices in vulnerable places
Electrical Hazards
Biological Hazards
•Exposure to infective and parasitic agents like viruses,fungi,bacteria etc at the place of work
•Insect bite Dog bite Snake bite
PREVENTION
• Personal Protection• Post Control
PSYCHOSOCIAL HAZARDSFACTORS -• Mal adjustment with work environment• Lack of job satisfaction• Insecurity• Poor human relationships• Excessive work• Sexual harassment• Bullying
Health problems Fatigue Headache Hypertension Heart diseasePeptic ulcer
Behaviors changes •Anxiety/Depression•Tension•Inability to concentrate•Irritability•Memory loss
PREVENTION
• Good induction program.• Management by participation.• Establishment of Proper communication channel.• Establishment of Healthy personnel policies• Establishment of healthy HR relationship.• Regular stress management program.
Psychosocial Hazards
How to Control Hazard ?
3 step process
Step 1: Hazard Identification Techniques
Step 2. List, rank and set priorities for hazardous jobs Step 3. Controlling Hazards
Step 1: Hazard Identification Techniques
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• Safety audit A systematic & independent examination of all or part of a total operating system to determine whether safety activities comply with planned arrangements
Safety surveySafety survey is a detailed & in-depth examination of a narrow field of activity eg...•Individual plants OR A specific problem.• Safety inspectionA routine scheduled inspection of a department or unit which may be carried out by personnel within the unit. During inspection deviations from safety standards, employee’s unsafe work practices and unsafe conditions are checked.
• Safety tourSafety tour is an unscheduled examination of a work area, carried out by any personnel from manager to safety committee members to ensure that company’s safety standards and procedures are being observed.
• Safety samplingA specific application of safety inspection / tour designed for random sampling of any activity posing serious accident potential. During safety sampling number of defects Are observing for immediate corrective actions.
Hazard Identification Techniques
Steps to Control Hazard
Step 2. List, rank and set priorities for hazardous jobs -
List jobs with hazards that present unacceptable risks, based on those most likely to occur and with the most severe consequences. These jobs should be your first priority for analysis.
Steps to Control Hazard Step 3. Controlling Hazards
finding Solutions to Control Hazards and execution of measures
Hazard can be eliminated (i) At the Source(ii) Along the path from hazard to the Worker(iii) At the level of the worker
Hazard Removal at the SourceElimination – Getting rid of a hazardous job, tool,machine or substance is
perhaps the best way of protecting workers.
Substitution – Sometimes doing the same work in a less hazardous way is
possible.
Redesign – Jobs and processes can be reworked to make them safer.
Automation – Dangerous processes can be automated or mechanized.
Hazard Removal along the path from Hazard to Worker1. Barriers - A hazard can be blocked before it
reaches workers. Proper equipment guarding will protect workers from contacting moving parts.
2. Absorption - Enclosures can block or absorb noise.
3. Dilution - Some hazards can be diluted or dissipated. For example, ventilation
systems can dilute toxic gasses before they reach operators.
Hazard Removal at the Level of Worker Work procedures, supervision and training
Job rotations and other procedures can reduce the time that workers are exposed to a hazard
Housekeeping, repair and maintenance programs
Personal protective equipment (PPE)
ENVIRONMENTAL IMPACT OF EMISSIONS OF
THERMAL POWER PLANTS
Material Flow Diagram for Thermal Power plant
Summary Table of Electric Power Generation
Source India Japan U.S.Coal 59.2% 21.2% 51.8%
Oil 13.9% 16.6% 03.1%
Gas 06.3% 22.1% 15.7%
Nuclear 02.5% 30.0% 19.9%
Hydro 17.8% 08.2% 07.4%
Others 00.3% 01.9% 02.2%
ENVIRONMENTAL ISSUES IN COAL BASED POWER GENERATION
Air Pollution :- High particulate matter emission levels due to burning of inferior grade coal which leads to generation of large quantity of fly ash.
Emissions of SO2, NOx & Green house gas (CO2) are also matter of concern.
Water Pollution :- Mainly caused by the effluent discharge from ash ponds, condenser cooling /cooling tower, DM plant and Boiler blow down.
Noise Pollution :- High noise levels due to release of high pressure steam and running of fans and motors
Land Degradation :- The disposal of large quantity of ash has occupied thousands hectares of land which includes agricultural and forest land too.
The major pollutants are Particulate matter(fly ash)CO2 EmissionSulfur oxides (SOX)Oxides of nitrogen(NOX)Probability of emission of CO and unburnt carbon.
SPM Emission Estimates
Thermal Power Plants82%
Sugar10%
Cement7%
Others 1%
Share of Suspended Particulate Matter Load (tonnes/day) by Different Categories of
Industries (With Control Device), Total Load = 5365 tonnes/day
Others1%
Oil Refineries3%
Sulphuric Acid Plants
2%
Thermal Power Plants89%
Steel5%
Share of Sulphur Dioxide Load (Tonnes / Share of Sulphur Dioxide Load (Tonnes / day)day)
By different categories of IndustriesBy different categories of Industries(Total Load = 3715 Tonnes / day)(Total Load = 3715 Tonnes / day)
Fly ash contains a toxic brew of dangerous chemicals and is the largest contributor to mercury pollution
Composition of Fly ashIt contains as main chemical components SiO2 (51.4 wt%), Al2O3 (22.1 wt%) and Fe2O3 (17.2 wt%)
Considerable amounts of toxic elements and heavy metals
Be (16.4 ppm), Cu (106 ppm), Zn (578 ppm), As (40.4 ppm),
Cd (2.6 ppm), Hg (18 ppm), Pb (71 ppm), and U (21.8 ppm)
is found in Fly ash.
Elemental (metallic) mercury ,exposure to excessive levels can permanently damage or fatally injure the brain and kidneys.
It can be absorbed through the skin and cause allergic reactions..
Exposures to Organic compounds of mercury can result in neurological damage and death.
Pollutants Effects (On Man)
SOX Suffocation, irritation of throat and eyes, respiratory, asthma, lung cancer
NOX Irritation, bronchitis, oedema of lungs
H2S Irritation, disease of bone, mottling of teeth, respiratory disease
CO Poisoning, cardiovascular diseases
Particulates (Dust fume mist and soot)
Respiratory diseases like sillcosis, asbetosis
Pollutant Effects on environment
SO2/NO2 On Vegetation: Acidic rains destruction of sensitive crops and reduced yieldsOn Materials: Corrosion
CO2(Green house gas) GLOBAL WARMING
Particulate (Dust fume mist and soot)
On Material: Soiling and corrosion
Power plant pollution control
An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing gas (such as air) using the force of an induced electrostatic charge.
SOX CONTROL FGD – Flue Gas Desulfurization
Flue-gas desulfurization (FGD) is a set of technologies used to remove sulfur dioxide (SO2) from exhaust flue gases of fossil-fuel power plants if sulfuer content exceed 1% in the coal
Limestone slurry is sprayed on the incoming flue gas. The sulfur dioxide gets absorbed The limestone and the sulfur dioxide react as follows : CaCO3 + H2O + 2SO2 ----> Ca+2 + 2HSO3
-+ CO2
CaCO3 + 2HSO3-+ Ca+2 ----> 2CaSO4 + CO2 + H2O
Control Of Nox Emissions
NOx control can be achieved by: Reduce Oxygen concentration in the
flame one. This can be accomplished by:
decreasing the excess air controlled mixing of fuel and air Using high quality coal
NATURAL GREEN HOUSE EFFECTprecipitation of water, formation of clouds, rainfall etc. life in the biosphere depend on these resources.
The warm atmosphere helps in the growth of vegetation and forest etc. These are sources of food, shelter etc.
This effect helps in rapid bio-degradation of dead plants and animals.
HUMAN ENHANCED GREEN HOUSE EFFECT Rising sea levels Change in climate Heat stress in Humans Alteration of habitats and ecosystems
For the proper dispersion of SO2 emission from thermal power plant, stack height criteria have been adopted in country. However, for larger capacities boilers (500MW and above) space provision for installing FGD system has been recommended.
Power generation capacity
Stack Height (mts.)
Less than 200/210 MW H = 14 (Q) 0.3 , where Q is emission rate of SO2 in kg/hr,
H= Stack Height 200/210 or less than 500
MW 220
500 MW and above 275
STACK HEIGHT REQUIREMENTS
Pre-combustion Technologies: Ash, sulphur and other impurities (coal beneficiation)
can be reduced from the coal before it is burned
Combustion technologies : (FBC , AFBC,PFBC, IGCC) Generation of emissions of SO2, NOx and CO2 can be
minimised by adopting improved combustion technologies
Post combustion technologies : End of pipe treatment (installation pollution control
equipments such as ESP, De NOx & De SOx systems)
Emission Standards for PM
Pollutants
Older Units Older New Future
before December 31, 2003 After 2003 to 2006 from January, 2017
<500 MW ≥ 500 MW <500 MW ≥ 500 MW PM 100 mg/ Nm3 50 mg/ Nm3 30 mg/ Nm3
Emission Standards for SOX
Pollutants
Older Units Older New Future
before December 31, 2003 After 2003 to 2006 from January, 2017
<500 MW ≥ 500 MW <500 MW ≥ 500 MW SO2 600 mg/ Nm3 200 mg/ Nm3 - 200 mg/ Nm3 100 mg/ Nm3
Emission Standards for NOX
Pollutants
Older Units Older New Future
before December 31, 2003 After 2003 to 2006 from January, 2017
<500 MW ≥ 500 MW <500 MW ≥ 500 MW NOx 600 mg/ Nm3 300 mg/ Nm3 100 mg/ Nm3
EMISSION STANDARDS AS PER MOEFCC
• Communication: Must be a loop system
• Dedication: From everyone
•Partnership: Between Management and Employees
•Participation:An important part of team working.