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

www.discountppe.com

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

78

• 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.