Preliminary Hazard Analysis and Risk Assessment …

1 THE WOOD CENTRE development , southwood RESOURCES HUONDEVELOPMENT PROPOSAL AND ENVIRONMENTAL MANAGEMENT PLANFORESTRY TASMANIAP reliminary Hazard AnalysisandRisk Assessmentfor theWood Centre development , southwood Resources - HuonTHE WOOD CENTRE development , southwood RESOURCES HUONDEVELOPMENT PROPOSAL AND ENVIRONMENTAL MANAGEMENT PLANFORESTRY TASMANIAJane D Mac:DesktopFolder:DPEMP_APPENDICES:APP_T _RISK_ 2 of 15 TABLE OF CONTENTSPRELIMINARY Hazard Analysis AND RISK 4 Hazard 4 FUEL ID: Fire :.. ID: No Water :..5 Hazard ID: Feed Flow Rate :..5 Hazard ID: Presence of Contaminants in :..6 STEAM ID: High Pressure Steam :.. ID: Inadequate Turbine :..6 COOLING ID: Cooling Tower :..7 PARTICULATE FILTER ID: Blocked :..7 Hazard ID: Non-functional Electrostatic Precipitator (ESP)..7 Actions/Recommendation.

2 7 AIR CIRCULATION ID: Non-functional Air Circulation :..8 CHEMICAL STORAGE ID: Fork Lift :..8 Hazard ID: Chemical :..9 RISK 9 PRINCIPAL SITE WOOD CENTRE development , southwood RESOURCES HUONDEVELOPMENT PROPOSAL AND ENVIRONMENTAL MANAGEMENT PLANFORESTRY TASMANIAJane D Mac:DesktopFolder:DPEMP_APPENDICES:APP_T _RISK_ 3 of A HAZOPS TEMPLATE GUIDE B POWER STATION PROCESS FLOW C RERAC RANKING WOOD CENTRE development , southwood RESOURCES HUONDEVELOPMENT PROPOSAL AND ENVIRONMENTAL MANAGEMENT PLANFORESTRY TASMANIAJane D Mac:DesktopFolder:DPEMP_APPENDICES:APP_T _RISK_ 4 of 15 Preliminary Hazard Analysis AND RISK ASSESSMENTI ntroductionA Preliminary Hazard identification and risk Assessment was conducted on the powerstation by SEMF to satisfy the requirements of Section of the DPEMP guidelines.

3 This condition requires a Preliminary Hazard Analysis to be undertaken onthe power station. This study was done in accordance with AS/NZS 4360, 1999 RiskManagement potential hazards were systematically identified using a Preliminary HAZOP study (Appendix A HAZOPS Template), (Perry , 1998) in conjunction with theschematic process flow diagram for the power station (Appendix B Power StationSchematic). These identified hazards are detailed under each specific operational area,together with relevant actions and recommendations on solutions for determine whether a quantitative risk Assessment is required, the RapidEnvironmental Checklist (RERAC), (Jones 1995) has been selected and adaptedin conjunction with Hazard Frequency Tables (Klietz 1992) as a suitableprocedure for providing a Preliminary quantitative Assessment of the likelihood andseverity of a hazardous incident occurring.

4 With this Preliminary Assessment , accuratejudgements can be made on the necessity of a quantitative risk HAZOP study allows systematic identification of potential hazards associatedwith risks to people, process plants, and the environment. In this study, it has beenused to identify hazardous effects caused by deviations in normal process RERAC Process is primarily used to quantitatively assess Hazard scenarios andits associated risks to the environment. In this study, its principal function was toassess the major hazards identified in the previous HAZOP study. A more detailedexplanation of the RERAC method can be found in the following Risk IdentificationThe following section makes use of Appendix A to identify hazards associated withthe relevant area/process unit. Recommendations on mitigation measures are alsodetailed.

5 Fuel StockpileHazard ID: Fire HazardLarge amounts of fuel wood are stored for fuel supply to the boiler. The fuel stockpilepresents an ideal situation for the propagation of a WOOD CENTRE development , southwood RESOURCES HUONDEVELOPMENT PROPOSAL AND ENVIRONMENTAL MANAGEMENT PLANFORESTRY TASMANIAJane D Mac:DesktopFolder:DPEMP_APPENDICES:APP_T _RISK_ 5 of 15 Action/Recommendation:The appropriate fire hydrants are to be available, to enable containment and reduce therisks of further boiler s primary function is to generate heat by complete combustion of fuelwood with air. This heat is utilised to generate steam from water. The followinghazards were identified as having the most significant impact. Other possibledeviations, which do not constitute any foreseeable hazards are not mentioned ID: No Water FlowFailure of the feed water pump to the boiler will result in no water flow into the boiler,therefore no heat sink for the combustion process.

6 This will lead to a release ofabnormally hot flue gases. This may cause thermal damage to equipment down stream,and ultimately result in release of very hot gases at the :Proper control alarms in place will warn of any deviation in temperature, or waterflow, and alert operators on cause of malfunction and allow them to shut down theprocess before the deviation causes ID: Feed Flow Rate DeviationA deviation in the levels of fuel wood and combustion air will have an effect on thecombustion products generated. A defined fuel:air ratio must be complied with, tooptimise the combustion process. The effects of deviations such as more fuel woodand/or less air are: incomplete combustion, and a release of larger amounts ofparticulate matter, undesirable gaseous compounds, including VOC s, noxious gases,and other combustion by-products.

7 These gases are potentially harmful in significantconcentrations, and contribute to the greenhouse gas :Control systems are to be put in place to monitor and regulate the flow rates of thefuel wood and air, as well as the temperature within the boiler furnace. Any deviationwill warn the operators, and immediate corrective action is required. All effluent gasstreams are to comply with set DPIWE guidelines for air ID: Presence of Contaminants in FeedContaminants present with the fuel wood, such as off specification fuel woodmaterial, or the boiler water. The latter may occur due to abnormal water treatment ordomestic water supply composition. The former will result in abnormal compositionsin flue gases, and perhaps will have some effect on the generated heats of latter will produce a blowdown stream with an abnormal chemical compositionbound for the sewage treatment plant.

8 Provided that the sewage treatment plant isTHE WOOD CENTRE development , southwood RESOURCES HUONDEVELOPMENT PROPOSAL AND ENVIRONMENTAL MANAGEMENT PLANFORESTRY TASMANIAJane D Mac:DesktopFolder:DPEMP_APPENDICES:APP_T _RISK_ 6 of 15robust enough to handle such deviations, then this incident will pose no :The level of Hazard and course of action relating to the abnormal flue gas compositionwill depend on the types and concentrations of chemicals present. Control systemsand continuous monitoring of the quality of the fuel wood going into the boilers willprevent LinesCarries live high-pressure steam from the boiler to the ID: High Pressure Steam Build-upThe event of high-pressure steam build-up, due to blocked lines or throttled valves,may lead to line rupture and pressure loss at the weaker joints. Consequently, thispressure loss will result in decreased turbine efficiency, and venting material maycause electrical and structural damage and pose a Hazard to nearby :Regularly scheduled maintenance on all piping infrastructures, repair any leaks as soonas possible, and regular structural the heat energy harnessed from the high pressure steam, to work, andgenerates ID: Inadequate Turbine MaintenanceInadequate maintenance such as failure to properly service the machine, or incorrectinstallation, will result in physical contact between moving metallic parts within theturbine.

9 This will lead to increased wear, and eventually cause severe internalmechanical damage. There is no foreseeable effect of turbine malfunction on theenvironment or human :A proper and rigorous maintenance procedure should be implemented and compliedwith, to prevent this event from towerCools and recycles the cooling water used to condense the low-pressure steam fromthe WOOD CENTRE development , southwood RESOURCES HUONDEVELOPMENT PROPOSAL AND ENVIRONMENTAL MANAGEMENT PLANFORESTRY TASMANIAJane D Mac:DesktopFolder:DPEMP_APPENDICES:APP_T _RISK_ 7 of 15 Hazard ID: Cooling Tower Non-functionalReduced cooling water flow due to cooling water pump malfunction will result in aless effective condenser, therefore a less efficient turbine, due to the back pressureexerted by uncondensed steam. The reduced amount of steam being condensed willeventually result in a build-up of steam upstream of the condenser, leading to lineruptures.

10 Line ruptures are potentially hazardous to nearby workers, mechanical, andelectrical equipment. This Hazard has no foreseeable effects on the :Instrumentation measures such as: flow meters installed in the cooling water lines willdetect reduced flow; a pressure transmitter in the line upstream of the condenser willindicate any deviation from the set point pressure, and alert operators of the the event that the line pressure does increase significantly, pressure relief valveswill be present to vent out the extra pressure, and reduce the likelihood of filter systemFilter out particles produced during combustion in two stages: a coarse filtration,followed by a fine filtration ID: Blocked FiltersBacklog of hot flue gases, due to the blocked lines, will cause an increased resistance atthe induced draft fan, resulting in limited out flow of gas.