Safety Science 70 (2014) 308–315

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Safety Science

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A HIRARC model for safety and risk evaluation at a hydroelectric powergeneration plant

http://dx.doi.org/10.1016/j.ssci.2014.05.0130925-7535/� 2014 Elsevier Ltd. All rights reserved.

⇑ Corresponding author.E-mail address: saedi_82@yahoo.com (A.M. Saedi).

A.M. Saedi a,⇑, J.J. Thambirajah b, Agamuthu Pariatamby a

a Institute of Biological Sciences University of Malaya, 50603 Kuala Lumpur, Malaysiab Faculty of Medicine, AIMST University, 08100 Bedong, Kedah. D.A, Malaysia

a r t i c l e i n f o a b s t r a c t

Article history:Received 30 March 2013Received in revised form 4 April 2014Accepted 2 May 2014

Keywords:Hydroelectric damPower generation plantHazard identificationRisk assessmentRisk control (HIRARC)

There are many formal techniques for the systematic analysis of occupational safety and health ingeneral, and risk analysis in particular, for power generation plants at hydroelectric power stations. Thisstudy was initiated in order to create a HIRARC model for the evaluation of environmental safety andhealth at a hydroelectric power generation plant at Cameron Highlands in Pahang, Malaysia. The HIRARCmodel was used to identify the primary and secondary hazards which may be inherent in the systemwhich were determined as a serious threat for plant operation and maintenance. The primary tools ofthe model consisted of, generic check-lists, work place inspection schemes which included task observa-tion and interview, safety analysis as well as accident and incident investigation. For risk assessment, theLikert scale was complemented by the severity matrix analysis in order to determine the probability andextent of safety and health at the study power generation plant. These were used to identify and recom-mend control measures which included engineering and administrative aspects as well as the use ofpersonal protective equipment (PPE). A total of forty-one important hazard items were identified inthe system at target power generation plant. These hazards were mainly identified by means of checklistswhich were sourced from literature and subsequently customized for the current purpose. Riskassessment was conducted by initially classifying the hazards into three levels such as Low, Mediumand High. Generally 66% of the hazards identified were at low risk, 32% at medium and 2% at high risk.This indicated that there was sufficient awareness and commitment to safety and health at the studypower station. Meanwhile the Power Station was also certified by MS 1722:2005, OHSAS 18001, MSISO 14001:2004, MS ISO 9001:2000 and scheduled waste regulation 2005 which give credibility to thecurrent study in creating a working model which may find widespread application in the future.

� 2014 Elsevier Ltd. All rights reserved.

1. Introduction

1.1. Background

Hydroelectric power generation plants are becoming increas-ingly popular in many parts of the world. This may be attributedmainly to the rapidly decreasing conventional energy resourceswhich have been used extensively through time. There is also aneed to look for green, clean and renewable energy sources withrespect to the requirements of environmental issues. Althoughrisks from dams are seldom encountered perhaps due preventivemeasures but the implications are of a high consequence. Dambreaks destroy buildings, wreak economic havoc and affect theenvironment. The context of dam safety depends on a number of

varied safety decisions and the dedication of dam owners(Bowles, 2001).

In order to maintain the safety and health of employees work-ing in hydroelectric power stations it is absolutely essential to havea safety management system (SMS) in place. With respect to this apolicy involving the identification and evaluation of major hazardsis necessary in order to implement steps for identifying the riskelements during usual and special operations and to predict thelikelihood and severity. The safety management system involveschoosing risk analysis methods and their outcome in terms offrequency of occurrence and extent of consequences (Demichelaet al., 2004). Over the past ten years, heightened interest in apply-ing dam safety risk assessment has been in tandem with a searchfor criteria underlying risk for making decisions (Bowles, 2001).

According to the Department of Occupational Safety and Healthof Malaysia (DOSH) an occupational safety and health policyinvolves a written document expressing an organization’s

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dedication to employee health, wellbeing and safety. It is a basisfor efforts made to ensure a proper workplace environment. Thispolicy must encompass all the organization’s activities related tostaff, equipment and materials selection, work procedures anddesign as well as provision of goods and services (Department ofOccupational Safety and Health Malaysia, 2011).

1.2. Research purpose

The HIRARC model consists of a comprehensive series of phasesfor the identification of hazards, assessment of risk and the deter-mination of control measures for the implementation of safety andhealth in the operations (Insert Fig. 1 here). An important elementof risk assessment is the identification of existing hazards, evaluat-ing the probability or chance of occurrence and recommending rel-evant controls. The hazards in hydroelectric power generationplants are quite varied and have a significant effect on employees,facilities and the environment. Hence the current study was under-taken to identify the hazards, estimate the risks and determinecontrol measures based on the data collected in order to derive acomprehensive HIRARC model for the study power generationplant in Cameron Highlands in Pahang, Malaysia.

1.3. Related literature

Kim Froats and Tanaka (2004) found that public safety in thevicinity of hydroelectric power generating stations has become amajor concern among the facility managers and operators. Water-ways associated with hydroelectric power plants are often setaside for recreation. The recreational uses should be weighedagainst the risks and hazards of strong currents, rising water levelsand rugged topography. Although hydroelectric generating sta-tions account for only a minority of these accidental deaths, it isimperative for operators to ensure that public safety issues areaddressed.

Numerous generic risk evaluation methods are available fordetermining the extent of risk. However, drowning is the obviousmajor public hazard given the amount of deep water in reservoirs.Falling, presents another major hazard. A risk assessment is the ini-tial step in devising a waterway safety management plan. Accord-ing to Au Yong and Hui Nee (2009) as far as hydroelectric powerstations are concerned each facility can include the followingstructures which may have a direct relation to hazards in the plant:a) head pond b) water conveyance structure to include dam

Fig. 1. Hazard identification, risk assessment and risk control model. Source:Department of Occupational Safety and Health Malaysia (2008).

structure, power intake canal, overflow spill walls, stop log sluicesand sluice gates c) spillway d) powerhouse tail-race and e)downstream.

Among the variety of hazards associated with hydroelectricpower generation plants, some are common to all employees whileothers are limited only to those working with or maintaining elec-trical or mechanical equipment (McManus, 2011). According toLamark et al. (1998) the following types of failure, not ranked inorder, which can cause costly damage and power outages areresponsible for the most frequent losses in hydroelectric powerplants:

� Failure in the stator winding of the generator.� Failure in switch control room and set of electrical tracks and

cable fire.� Failure in control equipment.� Disappearance of auxiliary and power supply.� Failure in transformers.� Cracks and breakage in shovels and other turbine failures.� Failure in bearings with lubrication and cooling systems� Flooding of machine hall and other room for machinery equip-

ment, and� Fire in the machine hall or other engine rooms.

Thus, in order to ensure the safety of hydroelectric power plantoperations, maintenance and supervision programs should beincluded in the safety and health management plans. These shouldinclude a schedule for essential upgrading as well as renewal ofplant equipment. This is critical for cost efficiency, safety and toavoid material damage and breakdown. In unmanned stationswhich are common today, evaluations are generally carried outaccording to schedule, hence placing a higher demand on the reli-ability of control and safety measures. Early automatic detection ofsome incidents such as flooding is very difficult in unmanned facil-ities. Table 1, indicates a risk exposure matrix for a hydroelectricpower plant (Lamark et al., 1998). Smith (2000) explained thatongoing hazard monitoring and effective control measures areessential for ensuring a continuous improvement process in occu-pational safety and health.

Although, data on safety and health in hydroelectric power sta-tions are highly specialised and focused, information from diversedisciplines with actual and potential applications to causal model-ing for the HIRARC model was reviewed. In this study the HIRARCmodel proposed by the National Institute of Occupational Safetyand Health (NIOSH) of Malaysia was used to investigate the safetyand health in the study hydroelectric power generation plant, inCameron Highlands, Malaysia.

2. Work operations

2.1. The power station

According to McManus (2011) a hydroelectric generating stationhas a dam that traps a large quantity of water, a spillway for con-trolled release of surplus water and a powerhouse. The powerhousecontains channels guiding water through turbines that convert thelinear water flow into a rotating flow. Since the turbine and gener-ator are joined together, the rotating turbine causes the generatorrotor to rotate. The electric power potential from water flow isrelated to water mass, the fall height and gravitational acceleration.The mass depends on the amount of water available and its rate offlow. Power station design determines the height of the water. Themajority of designs take in water from the top of the dam to dis-charge it at the base into an existing downstream river bed. Thisoptimizes height while ensuring controlled water flow.

Table 1The risk exposures for a hydroelectric power plant. Source: Lamark et al. (1998).

Item/peril Fire Frequency, machinery, breakdown Natural perils Consequence

Dams – Low Low LargeWater ways – Low, low, medium Low MediumValves – Low, low, medium Low MediumTurbine Low Medium, Low LargeGenerator Low High Low LargeTransformer Low High Low MediumSwitchgear Low Medium Low SmallLines Low Medium Low Medium

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2.2. The power generation hall and switchyard

Most generating stations now have vertically aligned turbo gen-erators. These structures rise above the main floor of the powerstations. The bulk of the structure, such as the generator pit, theturbine pit, intake and discharge tubes are found beneath the vis-ible main floor. In older stations, turbo generators are horizontallyaligned (McManus, 2011). The turbine shaft protrudes into thepowerhouse from a wall, where it connects to the generator orhuge electric motor. The rotor motion and the magnetic field pres-ent in the rotor windings induce electromagnetic field in the statorwindings. The magnetic field maintained in the generator rotorwindings is powered by lead acid or nickel cadmium batteries.

The electromagnetic field induced provides the electrical energysupply for the power grid. Electric voltage is the electrical pressurearising from the flowing water. The electricity flow can lead toelectrical arcing in the exciter assembly of the rotor. This can pro-duce ozone which may damage rubber in fire hoses and other sen-sitive materials. Very high currents and high voltages are producedby hydroelectric power generators. Conductors from the genera-tors join a unit transformer and subsequently connect to a powertransformer for boosting the voltage and reducing the current forlong distance delivery; low current minimizes heat related energyloss during transmission. Some systems use sulphur hexafluoridegas instead of conventional oils as insulators. Breakdown productsof electrical arcing can be more dangerous than sulphur hexafluo-ride (McManus, 2011).

3. HIRARC model

3.1. Hazards Identification

Currently it is apparent that operational safety receives moreattention in contrast to design safety. In the light of this, a numberof potential hazards have been identified at power generationplants of hydroelectric power stations. The unexpected release ofhazardous energy, flammable and explosive atmosphere, oil-filledtransformers, insufficient oxygen, air contamination (toxic chemi-cal material, toxic gas) and chemical reaction leading to oxygendeficiency, electrical cables and switchgear, cooling system andlarge quantities of combustible hydraulic oil are part of the hazardsidentified. There are also numerous areas related to risk such asheat injury, poor visualization, noise pollution, physical barriersor movement limitations (ergonomics) as well as other unsafe con-ditions like electrical hazards, spills and mechanical hazardsrelated to equipment.

In this study hazard identification is referred to the identifyingof undesired events leading to hazard materialization and themechanism of their occurrence. Several techniques were used toconduct hazard identification in the study area. These were depen-dant on the size of the power plant. The following methods wereused to ascertain the hazards at any particular area:

� Hazard identification checklist.� Workplace inspection (observation and interview).� Task safety analysis or job hazard analysis.� Accident and incident investigations.

This article is based on site visits to the power generation plantin Cameron Highlands, with a view to map the process flow of thedam and particularly the power generation plant, interview datafrom employees, safety officers and senior managers and checkingthe plant previous accident/incident documents. It is important tohave opinion and feedback from different levels in organizationregarding to hazards and risks in work environment. A standardchecklist was modified according to study area with experts andused to identify the hazards, the aim of using hazard identificationchecklist in this study was to list all expected and unexpected haz-ards to navigate and better understand the hazard. The hazardidentification checklist was mainly aimed at assessing everyparameter involved in the hazard identification process in the sys-tematic identification of hazards, to review the effectiveness ofsafety measures selected and, where required, to implement thesafety measures to achieve a tolerable residual risk. This studyfocused on some main aspects such as chemical, physical, electri-cal, ergonomical and biological hazards, while the hazards wereidentified in study plant by (standard checklist, interview, tasksafety analysis and plant accident/incident documents).

Hazard identification checklist has been consisted of sevenmain items to cover every aspect of hazards that mentioned above:Hazard chemical exposure, Electrical, Mechanical, Ergonomic, Bio-logical and Method of control.

Follow hazard identification checklist, general work placeinspection checklist has been applied with fourteen main factorsas follow: Worksite general, Training, Work processes, Recordkeeping, Fire emergency procedures, Means of exit, Lighting,Machine guards, Tools and machinery, Confine spaces, Housekeep-ing, Sound level/ Noise, Employee facilities, Personal protectiveequipment.

Interview questionnaire has been applied to get somecomplimentary date about safety and better understanding ofhazard in plant. Interview conducted to plant internal manage-ment, safety officer and shift supervisors. This interviewquestions adapted from (Cox, S. & Cox. T. 1996) with some mod-ification according to the plant and study objectives, it has beenincluded 6 items: Attitudes toward safety, Safety program, Atti-tudes toward the program, Incentives, Safety awareness/Trainingand Miscellaneous.

Analyses of above factors were helped to identify hazards byseparating the negative answers from the positive point of thechecklists. Those negative points that observed considered asactive hazards items in the selected plant, 27 different factors thatmentioned above, including 258 questions were applied viachecklists and interview, 41 negative answers were detected asactive hazards items in plant. These items were applied for riskassessment.

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3.2. Risk assessment

Risk assessment consists of a series of processes related to riskanalyses, assessment of the magnitude of risk, judgment onwhether the risk is acceptable or unacceptable, and creating andassessing risk control options, to attain this goal. Thus, after thehazards in the system are identified, the probability of occurrenceand magnitude of harm is determined, the risk is estimated, andrisk control options are evaluated based on the results. Risk assess-ment plays an important role in the decisions made by an organi-zation in order implement safety and health policies in a rationalmanner (Nippon Kaiji Kyokai, 2009). Fig. 2, illustrates the riskassessment procedure for a facility.

Risk measures the likelihood and severity of the accident/eventsequences in order to gauge the magnitude and to prioritize iden-tified hazards. Risk assessment can be done by quantitative, qual-itative, or semi quantitative approaches. This study consisted of amixture of the three methods in order to ensure completeness. Lik-ert (1932) proposed a summated scale for the assessment of surveyrespondent’s attitudes. Individual items in Likert’s sample scalehad five response alternatives: Strongly approve, Approve, Unde-cided, Disapprove, and Strongly disapprove. Likert noted thatdescriptors could be anything. It is not necessary to have negativeand positive responses. He implies that the number of alternativesis also open to manipulation. Indeed, in contemporary work manyclassifications are used besides the traditional five point classifica-tions (Clason and Dormody, 1994).

In this study the assessment of likelihood in the plant was basedon supervisor and worker experience, analysis or measurement.Likelihood levels ranged from ‘‘most likely’’ to ‘‘inconceivable’’.Table 2, elaborates different ranges of likelihood with their rating.

Severity is generally divided into five categories. It is based onan increasing level of injury to an individual’s health, the environ-ment, or to property. Table 3, shows the rating of severities.

The likelihood and severity of forty-one hazard items evaluatedby Tables 2 and 3 respectively. In this step qualitative data were

Fig. 2. General flow of risk assessment.

converted to quantitative data. The rates were given to hazards fol-lowed the guideline of DOSH Malaysia 2008.

One of the most common risk assessment tools to evaluate riskis risk matrix ranking which includes consequence, likelihood andseverity axis, so the combination of these parameters give us anestimate of risk or risk ranking (see Table 4).

Risk is calculated as follows:L � S = Relative riskL = LikelihoodS = Severity

3.3. Controls

In this study control measures were determined with respect tothe source of the hazard and the application of engineering con-trols, administrative controls, and personal protective equipment.The controls which were used to verify and regulate hazards werecarried out by conducting a parallel experiment or by comparingwith standards in order to reduce or prevent hazards.

4. Results

The data collected from the study power generation plant wasbased on walk through surveys, interview, hazard checklist, acci-dent and job hazard analysis. A Total of forty-one important haz-ards were identified in the operations which were assessed by achecklist analysis technique. Table 5 shows, framework of HIRARCin the study hydroelectric power station.

The results of forty-one important hazards with the level ofrisks were shown in Table 6 as below.

Based on identified parameters, the results were classified intothree levels with three degrees of risks followed by the methodol-ogy of risk assessment. Risk assessment is presented in percentageof number of items as shown in Fig. 3.

Source: Nippon Kaiji Kyokai (2009).

Table 2Likelihood values in hazard identification. Source: Department of Occupational Safety and Health Malaysia (2008).

Likelihood (L) Example Rating

Most likely The most likely result of the hazard/event being realized 5Possible Has a good chance of occurring and is not unusual 4Conceivable Might be occur at sometime in future 3Remote Has not been known to occur after many years 2Inconceivable Is practically impossible and has never occurred 1

Table 3Indicates severity in hazard identification. Source: Department of Occupational Safety and Health Malaysia (2008).

Severity (S) Example Rating

Catastrophic Numerous fatalities, irrecoverable property damage and productivity 5Fatal Approximately one single fatality major property damage if hazard is realized 4Serious Non-fatal injury, permanent disability 3Minor Disabling but not permanent injury 2Negligible Minor abrasions, bruises, cuts, first aid type injury 1

Table 4Example of risk matrix to identify the risk value. Source: Department of Occupational Safety and Health Malaysia (2008).

Table 5Framework of (HIRARC) in the study hydroelectric power station.

Activities Hazard identification Riskassessment

Hazard Consequences Risk control L S R

Measuring and changingchemical component intransformer and coolingsystem

Chemical oil exposure Inhalation and skinirritation

PPE with providing respiratory system, clothes andgloves

2 3 6(M)

Running of cooling systemand oil supply tank

Leaking of lubrication and oil supply incooling system

Environmental pollution,water contamination

Engineering control with high maintenance 4 4 16(H)

Crane operating withcarrying loads overemployees and system

Failing the heavy items Body injury anddamaging the equipment

PPE with wearing the safety boots and hat, AD controlwith giving the proper instruction to crane operator andworkers, and checking the crane frequently. Engineeringcontrol with designing safety guard for equipment

1 4 4(L)

Using hand tools or handparts or objects withemployees, (gripping,pulling. . .)

Ergonomic hazard by extra forces withtheir hand and body

Hand sprained and bodycramp, hand injury andtwisting

AD control with giving announcement to workers andapplying machine to settle work, PPE with offering gloves

3 3 9(M)

Influence of sediment inoperating systemspecially cooling systemand turbine

Blocking and damaging the coolingsystem and its filter, damage turbinepropeller, stuck sediment in pipe anddraft tube

Increasing maintenancecost, flashback of waterand sinking theequipment

Administrative control by controlling the amount ofsediment, Engineering control with keeping the system inhigh maintenance

3 3 6(M)

L = Likelihood, S = Severity, R = Risk.

312 A.M. Saedi et al. / Safety Science 70 (2014) 308–315

A.M. Saedi et al. / Safety Science 70 (2014) 308–315 313

The main hazards at marked hydroelectric power station wereidentified as chemical, physical, electrical, biological and ergo-nomic. The results are classified based on five items and presentedin percentage of number of items (Fig. 4) the bar chart shows thatphysical hazards at 36.58% are the main cause of hazards followedby biological hazards at 21.96% as well as chemical and ergonomichazards constituting 17.07% and 14.63% respectively. Electricalhazards at 9.76% constituted the minimum.

Fig. 3 shows 66% of total risk relevant to low level of risk inaddition 32% of that total risk is considered as medium risk as well

Table 6Results of forty-one important hazards with the level of risks.

Hazards

1. Chemical oil exposure due to measuring and changing chemical component in2. Failing of the ventilation system at underground power station3. Mishandling of auxiliary equipment by employees4. Exposure to asbestos and chemical component5. Leaking of lubrication and oil supply in cooling system6. Contact directly or indirectly with parts which have become live under faulty c7. Thermal radiation (heat) or the projection of molten particles8. Failing of bushing due to partial discharge degradation in insulation under high9. Create hazard due to not cutting off the power supply in the event of overload

10. High voltage electricity and it radiation at switchyard and surrounding area11. Crane operating and failing the heavy items12. Drowning, falling due to fixing and maintenance of draft tube13. Collapsing and blocking cause by swelling clay, ageing, land slide or water pres14. Breaking or cavitation on turbine shaft, shovels or propellers15. Failing of rotor caused by short circuit, increasing the temperature by failing of16. Ergonomic hazard by extra forces with hand and body (gripping, pulling. . .)17. Lifting and carrying of semi or heavy items, goods weight and Ergonomic hazar18. Oxygen deficiency by working in confined space19. Discharging heat air into the power house and make biological heat hazard20. Noise pollution and vibration by running the whole system21. Physiological and psychological stresses due to Employee activities such as wo22. Biological hazard by entering birds and animals, accumulation of conductive du23. Influence of sediment in operating system, blocking and damaging the cooling sy

draft tube24. Workers falling down due to climbing up from crane stairs in power station25. Body injury due to slippery and wet floor cause by lubrication, grease and wate26. Fall in grease tank by greasing over crane27. Slippery and fall down due to greasing the crane sling wire28. Grease and oil splashing due to fixing the cranes, turbines and cooling systems29. Trapped during the drum rotating while greasing the crane sling wire30. Mixing the sludge, water with chemical component due to flushing cooling sys31. Physical hazard with liberated water compressed caused by flushing cooling sy32. Physical hazard by using ladder and falling due to opening and closing valve33. Ergonomic hazard with working in high place without good condition and fall34. Biological hazard due to using chemical cleaner to mopping the floor at underg35. Ergonomic hazard associated with standing in the work area for a long time fo

system36. Physical hazard with mixture splashing and spilling chemical material that cau37. Mixture spilling and contact online life due to shifting chemical material into t38. Ergonomic hazard by downloading and lifting the stack39. Physical hazard by falling goods on leg and hand injury40. Ergonomic hazard with getting involved of Installing and cleaning air hoses at41. Chemical hazard due to storage of hazardous waste (lubricating, wire and etc.)

Fig. 3. Percentage of risk levels in th

as 2% of high level of risk which is a minimum percentage of totalrisk in the study area.

Regarding to the data that has been collected from the studyhydroelectric power station and risk matrix ranking, the result ofclassified risk levels for each specific hazard of risk assessmentare as below.

According to Fig. 5, the result of classified risk levels for eachspecific hazard in the purpose hydroelectric power generationplant indicates 73.34% low risk, 26.66% medium risk and no highrisk from the total 36.58% of physical hazard, chemical hazard with

Risk

transformer and cooling system 6(M)4(L)2(L)4(L)16(H)

ondition 10(M)4(L)

voltage stress 6(M)ing and short circuit 6(M)

4(L)4(L)4(L)

sure 5(M)2(L)

cooling system and overloading 6(M)9(M)

d by musculoskeletal 12(M)4(L)2(L)2(L)

rking position and working schedule 6(M)st at underground power house access tunnel and power house hall 8(M)stem and its filter, damage turbine propeller, stuck sediment in pipe and 6(M)

6(M)r 6(M)

3(L)2(L)2(L)3(L)

tem 4(L)stem 4(L)

4(L)4(L)

round hall 4(L)r measuring and mixing chemical material in transformer and cooling 2(L)

se slippery floor 2(L)he injection container 2(L)

4(L)3(L)

underground power station 4(L)2(L)

e study power generation plant.

Fig. 4. Percentage of main classified hazards in the study power plant.

Fig. 5. Three risk levels for five main hazards in the study hydroelectric powergeneration plant.

314 A.M. Saedi et al. / Safety Science 70 (2014) 308–315

17.07% of total hazard and 71.42% of this amount of hazard is inlow risk condition, 14.29% belong to medium risk and 14.29% ofhigh risk, is one of the main important hazard in purpose studyarea. The electrical hazard allocate 9.76% of total hazards presentedas a lowest hazard in study hydroelectric power plant including25% of low risk, 75% of medium risk and 0% of high risk in the sys-tem; 21.96% of biological hazard with 66.67% of low risk, 33.33% ofmedium risk and 0% of high risk was identified and finally ergo-nomic hazard with 66.67% of low risk, 33.33% of medium riskand no high risk from the total 14.63% of hazard. Generally abovedata present all hazards and their classified levels of risks at thepresent study of hydroelectric Power generation Plant.

5. Discussion

Based on study, the marked hydroelectric power generationPlant currently has an acceptable safety policy. Staying safe atwork means understanding hazards such as mechanical equip-ment, extreme noise, or hazardous chemicals that are inherent inhydroelectric power generation plants. However, others may bedue to human error, structural failures, equipment or machineryfailure and misuse, power system failure or chemical spills.

The main function of the department of safety and health atstudy hydroelectric Power generation Plant is to ensure the safetyand health of employees, work in process and equipment. This is inline with the regulatory requirements set out by OSHA and TenagaNasional Berhad (TNB).

The purpose of the risk control in aimed hydroelectric powergeneration plant is to ensure that risk control methods and

activities are conducted according to the safety plan, in a system-atic manner in order to reduce the risk of residual impact on theenvironment, equipment and employees.

According to McManus (2011), most of the controls in hydro-electric power plants focus on Personal Protective Equipment,Engineering and administrative controls. For example oil and lubri-cants are chemical components that can cause chemical hazardswith direct and indirect impact on workers. Noise pollution is acommon cause of concern in the generator hall. This may be dueto steady-state noise from generators and other relevant auxiliaryequipment. Therefore applying noise control technology by con-trolling the noise level is imperative in the plant.

Other aspects of plant safety include battery explosion causedby electrical short circuit. At the study plant this is mitigated byengineering controls by way of fixing shields to battery terminalsand insulated conductors to make suitable barriers. Administrativecontrols are instituted in relevant places in the plant. These areimplemented mainly to create awareness in workers on safetyand to prepare employees for medical surveillance (McManus,2011).

In line with the HIRARC model stipulated by the Department ofOccupational Safety and Health (DOSH) of the Ministry of HumanResource of Malaysia and Act 514 Occupational Safety and HealthAct 1994, the marked hydroelectric power generation plant is incompliance with the existing regulatory requirements having anoverall risk level of only 2% in the power generation plant whichconstitutes a minimum level with regards to safety. This may goup to a maximum of 66% which is regarded as manageable in sucha situation.

According to Lamark et al. (1998) most hydroelectric powergeneration plants have similar hazards which can lead to moreor less costly damage. Failure can happen in the generator’s statorwinding which depends on the machine age, type of installation,rated voltage, design, running conditions and maintenance. How-ever, according to the data collected at study power station thisproblem was not evident probably due to regular maintenanceand control of the stator wings which may have reduced the pos-sibility of occurrence and damage. The other common importanthazards in most hydroelectric power plants are failure in theswitch control room and control equipment of the power genera-tion plant, where the primary electrical system from the generat-ing unit to the transformer and external grid is highly vulnerableto short-circuit in large plants.

Electrical arc short circuits may also cause substance damageand the survey conducted at study plant was not exempted fromthis. This may be attributed to not cutting off the power supplyin the event of overloading leading to short circuit which maydamage the transformer, bushing and wires leading to electricalshock hazards. This was addressed by the safety department whichapplied Engineering controls by providing regular maintenance,checking the system, increasing awareness and providing informa-tion to employees in order to prevent such hazards.

The American Society of Civil Engineers Hydropower TaskCommittee (2007) explained that oil contamination and emer-gency access as other main important hazards that can create riskin every hydroelectric power generation plant. Most hydroelectricplants face oil and lubrication contamination in the system. How-ever, at the study plant the problem was associated with leaking oflubricants and oil in the cooling system which sometimes pene-trated into the transformer section and the shifting of chemicalsinto the injection container caused environmental pollution, watercontamination and chemical hazards. However, at the study plantthe management, as well as, the safety committee followed theOSHA standards by providing regular maintenance of machineryand monthly inspection in order to reduce the hazard and keep itat an acceptable level.

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The study showed that it is important to have a well-established maintenance and supervision program in order toensure the safety and health in hydroelectric power stations. Mod-ern power plant control and automation systems give optimizedmechanical and electrical support in terms of planning, operationsand maintenance for new projects as well as for renovated substa-tions (Brauner, 1995). Very old stations may experience frequentbreak downs in the system. Thus it may be necessary to renovatesuch plants and to provide replacement parts in order to ensureeffectiveness and productivity.

6. Conclusion

In conclusion, marked hydroelectric power generation plant istotally committed toward safety and health, which is reflected intheir certifications, namely MS 1722:2005, OHSAS 18001, MS ISO14001:2004 and MS ISO 9001:2000. With these accreditations,the management at power station hopes to maintain a high qualityof standard in its operations in order to provide a safe workingenvironment.

At study plant waste management is implemented followingthe Scheduled Waste Regulation 2005 under the EnvironmentalQuality Act 1974 for hazardous and non-hazardous wastes. HIRARCis reviewed and updated annually during the document review inorder to ensure the effectiveness of the OH&S Management system.

Acknowledgements

I am grateful to University Malaya to let me to carry out thisresearch, Tenaga Nasional Berhad (TNB) for allowing me to conductthis study at a hydroelectric dam in Cameron Highlands, Pahang,Malaysia.

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