2 SCHEME DESCRIPTION 2.1 OUTLINE OF THE PROPOSED SCHEME 2.1.1 Overview APCL are currently progressing a proposal to develop a power generation plant at a site on the former BP Chemicals Baglan Bay Works at Seaway Parade, Port Talbot, in South Wales. The proposed development will involve the construction of a base load, gas fired Combined Cycle Gas Turbine (CCGT) power plant, with no dual fuel option, which will be connected to the existing zone 13 National Grid System. It will be rated to provide up to 870 MW of generation capacity. The proposed plant will be constructed within the former BP Chemicals Baglan Bay Works Site adjacent to the existing Baglan Power Station, which is operated by GE. The facility will comprise two gas turbine generators with associated Heat Recovery Steam Generators (HRSGs). Exhaust gases from the HRSGs will be discharged from a single multi flue stack. Low level plume abated cooling towers will be utilised to minimise the visual impact. Water for the Circulating Cooling Water System (CCWS) will be provided from the site's existing sources which are the Neath and Tennant Canals. Water will be transferred to site by existing pipelines. At the request of NPTCBC, a small section of pipeline at Warren Hill that currently crosses the Outer Basin of the Neath River, will be re-routed to enable potential future development of this Basin. These works are not integral to the development of the power plant, however, are being undertaken as part of APCL’s commitment to the improvement of the local area. These works are detailed on Figure 2.1 Cooling tower blowdown will be discharged through the site's existing effluent discharge system, via the Long Sea Outfall into Swansea Bay, detailed on Figure 2.1. Electricity will be exported via the National Grid System. The fuel to the gas turbines will be natural gas. There will be no requirement for the use of fuel oil as a standby fuel to cater for periods of gas interruption. ENVIRONMENTAL RESOURCES MANAGEMENT APCL - ABERNEDD POWER PLANT 2-1 Cooling Water Pipeline Existing Effluent Discharge System . 300 Metres KEY: Site New Pipeline Existing Pipeline Redundant Pipeline Existing Pipeline to be Upgraded CLIENT: APCL SIZE: A4 ERM Llandarcy House 11A The Courtyard Llandarcy Swansea Bay, SA10 6EJ Tel: 01792 814907 Fax: 01792 817396 SOURCE: Reproduced from Ordnance Survey digital map data. © Crown copyright, All rights reserved. 2008 License number 0100031673. PROJECTION: British National Grid TITLE: Figure 2.1 Associated Pipelines DATE: 29/05/2008 CHECKED: PW PROJECT: 0064142 DRAWN: CO SCALE: 1:15,000 DRAWING: APPROVED: SD Associated_Pipelines.mxd REV: © ERM This print is confidential and is supplied on the understanding that it will be used only as a record to identify or inspect parts, concepts or designs and that it is not disclosed to other persons or to be used for construction purposes without permission. 1 File: 0064142BaglanBayGIS\mxds\NewB oundary_ES\Associated_Pipelines.mxd 0 2.1.2 Proposed Structures The key physical structures associated with the project are:• • • • • • 2.1.3 a turbine hall containing the gas (GT) and steam (ST) turbine(s); a Heat Recovery Steam Generator (HRSG) associated with each GT power train; a single concrete multi-flue stack; low profile plume abated cooling towers (LPPACT’s); an outdoor switchyard and an administration building, control room, amenities, stores and workshops. Power Plant Site The site for the proposed power plant is located within the NPTCBC administrative area, to the south of the existing GE power plant which is a nominal 500 MW CCGT power plant, presently owned and operated by GE. The proposed power plant will be contained within the larger and former BP Chemicals Works site at Baglan. The site is predominantly flat and comprises circa 600 mm of blast furnace slag and chippings overlaying circa 25 m of sand with boulder clay “rockhead”. The former BP Chemicals plant and buildings have now been demolished leaving a few electrical substations, and the former internal site roads and infrastructure. Most of the former buried services have been isolated and made redundant but there remains some electrical and Towns Water and other service infrastructure which may require some minor relocation as part of this proposed development. Such works do not impact any operations external to the former BP Chemicals site. The site has excellent road access from the M4, at Junction 41 and then via the Baglan Energy Park adopted highway. This is the same route that was used during the construction of the existing GE Power Station. Figure 2.2 shows the area proposed for the CCGT site, Figure 2.3 shows a basic plant layout. ENVIRONMENTAL RESOURCES MANAGEMENT APCL - ABERNEDD POWER PLANT 2-3 CLIENT: Site Footprint APCL SIZE: TITLE: A4 ERM Llandarcy House 11A The Courtyard Llandarcy Swansea Bay, SA10 6EJ Tel: 01792 814907 Fax: 01792 817396 SOURCE: Unspecified PROJECTION: British National Grid © ERM This print is confidential and is supplied on the understanding that it will be used only as a record to identify or inspect parts, concepts or designs and that it is not disclosed to other persons or to be used for construction purposes without permission. Figure 2.2 Site Footprint DATE: 29/05/2008 CHECKED: SL PROJECT: 0064142 DRAWN: CO SCALE: NTS APPROVED: SD DRAWING: SiteFootprint2.2.mxd REV: 0 File: 0064142BaglanBayGIS\mxds\NewBoundary_ES\SiteFootprint2.2.mxd KEY: FIGURE 2.3 Plant Layout 2.2 PROCESS DESCRIPTION 2.2.1 Introduction A CCGT plant is a highly efficient mode of generating electricity. This higher efficiency is attained primarily through the combination of a gas turbine with a steam turbine to recover and use the exhaust heat generated by the former. The main process stages of the proposed CCGT are explained below. 2.2.2 Gas Turbines Natural gas, supplied from the existing Transco network, will be used as the fuel source to supply the gas turbines contained within the enclosed machinery hall. Each of the gas turbines will draw combustion air from the atmosphere via intake filters to remove particulate matter that might otherwise damage the internal components of the machine. Fuel gas, mixed with combustion air, is injected into the combustion chamber of the gas turbine, where it burns to produce hot, high pressure, gases. These are expanded through a power turbine which drives the compressor and electrical generator. The gas turbine power plant generally comprises a turbine compartment, accessory compartment and inlet and exhaust systems. The turbines are equipped with electric starting motors, or static frequency converters, and are located indoors to reduce the noise emanating from the site. The exhaust arrangement includes silencing and ducting. Combustion gases exit from the exhaust system to the HRSG(s). 2.2.3 Heat Recovery Steam Generators An HRSG is provided for each gas turbine. Each of the units comprises separate steam circuits, complete with all necessary integral pipework, equipment and instrumentation required for the safe and efficient operation of the plant. The exhaust gases from the gas turbines pass through the HRSGs where heat is extracted to raise and superheat steam. Exhaust gases are subsequently discharged to atmosphere via a single multi flue stack. The height of the stack required to ensure adequate dispersal is assumed to be of the order of 90m, but the precise height will be agreed with the Environment Agency during the PPC process. For the purposes of this EIA, the stack height has been assessed at 90m. 2.2.4 Steam Turbines Steam from the HRSG is conveyed to the steam turbine which is provided with multiple admission points, one for each pressure level. The turbine itself will probably comprise a high pressure cylinder and double flow, low pressure cylinders. This steam turbine subsequently drives an electrical generator similar to those driven by the gas turbines. ENVIRONMENTAL RESOURCES MANAGEMENT APCL - ABERNEDD POWER PLANT 2-7 The steam discharged from the steam turbine is condensed and then recirculated back to the HRSG and reconverted back to steam. 2.2.5 Condenser Cooling Cooling for the steam turbine condensers will be provided by a circulating water system incorporating two banks of hybrid cooling towers. 2.2.6 Water Source and Discharges The cooling water for the power plant will be provided from the site's existing supply: the Neath and Tennant Canals. All appropriate abstraction licenses will be obtained by APCL prior to operation. Some works will be required to the existing pipeline from the Neath Canal. These will include upgrading and re-routing of a short section of the pipeline (refer to Figure 2.1). Expelled cooling water will be discharged into Swansea Bay via the existing Long Sea Outfall. Minimal connection works only will be required to the existing outfall and all licenses will be agreed with the Environment Agency Wales (EAW) prior to discharge. 2.2.7 Water Demineralisation Plant The condensed steam is returned via a deaerator and feed system, back to the waste heat recovery boiler in a closed loop steam cycle. System losses will be replenished by high purity make-up water produced by an on-site demineralisation plant using towns water as the raw feed. Treated effluents from this demineralisation unit will be neutralized and then disposed to process drain. 2.2.8 Fuel Supplies The proposed plant will utilise the existing buried underground natural gas pipeline from national Grid Transco’s pipeline on the mountain above Tonna to the north west of the site, to transport gas to the Baglan site. Natural gas is a clean fuel and does not produce the particulate emissions associated with burning coal or oil; consequently flue gas cleaning equipment is not required. Natural gas will be supplied directly to an on-site gaseous fuel conditioning area, where the pressure is regulated to match that required by the gas turbines. 2.2.9 Electrical Power Transmission The plant will be connected into the existing 275 kV National Grid, substation on the Baglan Site. There may be a requirement for new overhead power lines but this is outside the scope of this EIA and should this be required, any potential impacts will be assessed separately as part of a Section 37 of the ENVIRONMENTAL RESOURCES MANAGEMENT APCL - ABERNEDD POWER PLANT 2-8 Electricity Act, 1989, Application. However, to support this EIA, an initial desk based assessment has been undertaken in order to provide an indication of the likely significant environmental impacts of these associated works, which is reported in Chapter 14 of this ES. 2.2.10 Materials Handling Utilities and Infrastructure During normal operation a range of products will be delivered to the power plant. Natural gas and canal water will be imported by pipelines and others (such as machinery lubricating oil, spare parts) will be delivered by road in drums and packages. Most of these shipments will be stored in an amenities and storage area. The following utility systems will be provided: • Water to supply the demineralisation plant will be supplied by a raw water pipeline from the towns water system. • Cooling water make-up will be drawn from the Neath and Tennant Canals, via the existing pumping stations. • The fire extinguishing system for the proposed CCGT power plant will consist of: • • • • a hydrant main; a wet pipe sprinkler system over the large transformers, the steam turbine house, stores areas, and other possible oil leakage areas; a carbon dioxide (CO2) system in electrical equipment rooms; and a CO2 system in the gas turbine compartments. Areas with no extinguishing systems will be fitted with an automatic fire annunciating system, and buildings will be appropriately located to facilitate connections to on-site firewater mains with fire water piping for the use of the local fire brigade. 2.3 EMISSIONS TO THE ENVIRONMENT 2.3.1 Air Emissions The principal emission to the atmosphere will arise from the process of natural gas combustion in the gas turbines: the main stacks will be sources of oxides of nitrogen (NO and NO2) and carbon dioxide (CO2). Carbon dioxide is the most important of the greenhouse gases and is believed to contribute more than half to global warming effects. Gas combustion from a CCGT power plant produces approximately 57% of the CO2 per unit of energy generated when compared with coal combustion. This is due to the higher thermal efficiency achieved by CCGT power plant and the greater specific energy content of the gas. ENVIRONMENTAL RESOURCES MANAGEMENT APCL - ABERNEDD POWER PLANT 2-9 Plant emissions will comply with the requirements of the Environment Agency Wales, as determined by the PPC process. Chapter 12, Air Quality presents an assessment of the likely environmental impacts associated with the current proposals. 2.3.2 Liquid Emissions Cooling waters will be discharged through the Dwyr Cymru Welsh Water (DCWW) existing pipeline which extends approximately 2 km offshore into Swansea Bay. Such a discharge would be subject to approval through the PPC licensing system, under the Pollution Prevention and Control Regulations, 2000. Four other discharges will also arise as a result of the operational facility: • • • • 2.3.3 surface drainage water discharge from site; foul drainage from sources such as sanitary waters; neutralised effluent from the demineralisation plant; and process water discharge from the water/steam circuits. Solid Wastes Solid wastes will arise during the construction and operation of the CCGT power plant. Where appropriate these wastes will be collected and disposed of by licensed waste disposal contractors. 2.4 PROJECT PHASING The power plant will be constructed in two stages. Stage 1 will comprise: • • • • • • GT/Generator 1, HRSG 1, the steam turbine/generator, electrical and mechanical balance-of-plant equipment and systems (part); the fuel gas compressor, the fuel gas above ground installation (AGI); the water treatment plant (part), raw and treated water storage tanks, the cooling water systems; GT Generator Transformer 1, electrical switchgear and electrical and control systems (part), electrical substation works; all buildings and site facilities including control room facilities; and all sub-surface works including excavations, piling works, foundations, civil and drainage systems works. Stage 2 will comprise: • GT/Generator 2, HRSG 2, electrical and mechanical balance-of-plant equipment and systems (balance); ENVIRONMENTAL RESOURCES MANAGEMENT APCL - ABERNEDD POWER PLANT 2-10 • • the water treatment plant (balance); and GT Generator Transformer 2, electrical switchgear and electrical and control systems (balance). This ES reports the likely significant environmental impacts from both stages of development. The construction schedule for the new plant is dependant on the date when National Grid can achieve the connection to the grid system and effect export from the Baglan site. This connection date currently set as follows: • • Stage 1 = 435MW October 2013 ; and Stage 2 = 870MW October 2016. Assuming an Autumn 2013 grid connection date, the indicative high level project programme milestones for stage 1 will be: • • • • • • • • main contract award – spring 2011; site mobilisation – summer/autumn 2011; ground preparation works – summer / autumn 2011 piling & foundation works – autumn 2011 to spring 2012; installation & construction of Stage 1 plant and equipment – spring 2012 to summer 2013; commissioning & testing - autumn 2013; partial site demobilisation – autumn / winter 2013; and Stage 1 plant in commercial operation – autumn 2013. The total construction period for Stage 1 will be approximately 30 months. Assuming an Autumn 2016 grid connection date, the indicative high level project programme milestones for Stage 2 will be: • • • • • • • • main contract award – spring 2011; ground preparation works – summer / autumn 2011 piling & foundation works – autumn 2011 to spring 2012; site remobilisation – summer/autumn 2015; installation & construction of Stage 2 plant and equipment - autumn 2015 to summer 2016; commissioning & testing - autumn 2016; site demobilisation – autumn / winter 2016; and Stage 2 plant in commercial operation – autumn 2016. The total construction period for Stage 2 will be approximately 18 months. Figure 2.4 depicts the project programme. As illustrated, the entire contractual period for the project, from site mobilisation of Stage 1 to site demobilisation of Stage 2, is 54 months. ENVIRONMENTAL RESOURCES MANAGEMENT APCL - ABERNEDD POWER PLANT 2-11 The major project activities are broken into the following phases. • Site preparation and preliminary work. This comprises land clearance, levelling of the site earthworks, construction of the site roads, installation of drainage system, temporary facilities for the main contractors workforce, and construction of laydown areas and access roads. A period of approximately six months is required for this phase of work. • The main construction. This encompasses the laying of plant foundations, erection of all above ground structures and installation of plant. A period of approximately eighteen months is allowed for this phase. • Commissioning and reliability tests. Independent commissioning tests will be undertaken by the contractor to ensure the plant meets all specifications. A period of approximately six months for each of the two stages is allowed for this phase. ENVIRONMENTAL RESOURCES MANAGEMENT APCL - ABERNEDD POWER PLANT 2-12 Figure 2.4 Project Programme STAGE PROJECT TIMELINE 2011 2012 2013 2014 2015 2016 QTR 1 QTR 2 QTR 3 QTR 4 QTR 1 QTR 2 QTR 3 QTR 4 QTR 1 QTR 2 QTR 3 QTR 4 QTR 1 QTR 2 QTR 3 QTR 4 QTR 1 QTR 2 QTR 3 QTR 4 QTR 1 QTR 2 QTR 3 QTR 4 Main Contract Award (for both stages of build), Site Mobilisation (for the first stage of build) and Ground Preparation Works (for both stages of build), Excavations, Piling, Foundation, Drainage, Civil and Building Works (for both stages of build), Installation and Construction of first stage plant and equipment, Commissioning and Testing of first stage plant and equipment Partial Site Demobilisation (leaving skeleton contractor's team on site) Stage 1 plant and equipment in commercial operation Site Remobilisation (for the second stage of build), Installation and Construction of second stage plant and equipment, Commissioning and Testing of second stage plant and equipment, Site Demobilisation, Stage 2 plant and equipment joins stage 1 plant and equipment in commercial operation. 2.5 HEALTH, SAFETY AND HAZARDS ISSUES 2.5.1 Overview The health and safety of the workforce and local population is considered by both APCL and the various authorities to be of paramount importance in the design, construction and operation of the plant. Hence, potential hazards presented by the installation have been considered by APCL and appropriate design measures will be taken and operating procedures will be written to mitigate and manage any risk involved. The developer's statutory responsibilities include ensuring the safe design of plant and apparatus, and the provision and maintenance of safe and healthy working conditions, equipment and systems of work for all of its employees, and for the health and safety of other people who may be affected by its activities. This responsibility arises from the requirements of various Acts of Parliament and government regulations including the Health and Safety at Work etc Act 1974, The Factories Act 1961, the Electricity Regulations 1908 and 1944, The Electricity Supply Regulations 1988, the Electricity Supply Regulations 1988, Noise at Work Regulations 1989, the Offices, Shops and Railways Premises Act 1963 and the Construction (Design and Management) Regulations 2007. 2.5.2 Construction During the design and construction of the CCGT power plant, the Construction (Design and Management) Regulations 2007 will apply. Under the requirements of the Regulations developers must: • appoint competent individuals to the roles of Planning Supervisor, Designer and Principal Contractor, at the earliest point practicable; • prepare a Health and Safety Plan prior to commencement of construction, which details potential risks and demonstrates competence of the contractor; • provide the Planning Supervisor with information about the conditions of the site. The Planning Supervisor will be required to notify the Health and Safety Executive (HSE) about the project, in writing, prior to commencement of construction works. 2.5.3 Design The design of the CCGT power plant will incorporate all required features such as relief valves, alarms and trip systems. The Health and Safety Executive (HSE) will be consulted as appropriate about the safety issues associated with the proposed development. ENVIRONMENTAL RESOURCES MANAGEMENT APCL - ABERNEDD POWER PLANT 2-14 2.5.4 Material Storage The quantities and type of substances and stores used on CCGT power plant site will not require the site to be notified to the HSE under the Notification of Installations Hazardous to Health Regulation 1982 or the Control of Industrial Major Accident Hazards (CIMAH) Regulations, 1984. There will be no significant storage of gas on site (1) . Suitable fire protection systems will be provided as described and Fire Certification will be obtained from the Fire Authority if required. 2.5.5 Fuel Supply Natural gas will be supplied to the CCGT power plant site is via an existing underground pipeline system. The pipeline complies with the Pipelines Act 1962, the Pipeline Safety Regulations (PSR) 1996 and where applicable the Gas Safety (Management) Regulations 1996. Compliance with PSR will result in the development of a Major Accident Prevention Policy (MAPP) whereas compliance with PSR will involve the submission of a detailed Safety Case to HSE. A limited quantity of water treatment chemicals will be used at the plant. These will be handled and stored in accordance with appropriate industry standards. The water treatment chemical tanks will also be located in a bunded area so that any spills will be contained. 2.5.6 Lighting Suitable indoor and outdoor illumination will be provided throughout the power plant to facilitate normal operation and maintenance activities as well as for safety. Stand-by emergency DC lighting will be provided where necessary. 2.5.7 Major Hazard In itself the proposed power plant will not constitute a major hazard and will not therefore be the subject of the CIMAH Regulations 1984. (1) There may be limited quantities of bottled gases for welding,top up hydrogen for the generator cooling system, and CO 2 for the fire fighting systems ENVIRONMENTAL RESOURCES MANAGEMENT APCL - ABERNEDD POWER PLANT 2-15