Radioactive Substances Regulations Environmental Permit Application for Hinkley Point C

Transcription

1 Radioactive Substances Regulations Environmental Permit Application for Hinkley Point C Summary of the application by NNB Generation Company for a permit under the Environmental Permitting (England and Wales) Regulations 2010 Radioactive Substance Regulation

2 Contents 1 About NNB GenCo and Our Proposed Site at Hinkley Point C Introduction Introducing NNB Generation Company Ltd and EDF Energy Our proposed site at Hinkley Point C Our applications for environmental permits Our management systems Our design reference 7 2 Our Radioactive Substances Activities at Hinkley Point C The radioactive substances activities being applied for Technical description of our radioactive substances activities 8 3 Operating Techniques to Protect the Environment and People Our commitment to protecting the environment and people Our optimisation process Best available techniques 13 4 Disposal of Radioactive Waste from Hinkley Point C Quantitative estimates of our radioactive waste discharges and disposals Our proposed limits for radioactive waste discharges and disposals 16 5 Monitoring Measuring and assessing our discharges from Hinkley Point C Measuring and assessing the impacts (effects) of our discharges from Hinkley Point C 18 6 Impacts on the Environment and People from our Discharges at Hinkley Point C Background Radiation Our Impacts on the Environment Our Impacts on People How we calculated the impacts 24 7 Conclusions and Forward Programme Our forward programme Conclusion 25 8 Glossary 26 NNB-OSL-REP Page 2 of 27

3 1 About NNB GenCo and Our Proposed Site at Hinkley Point C 1.1 Introduction NNB GenCo proposes to build and operate a new nuclear power station at Hinkley Point in Somerset. During the operation of the power station small amounts of radioactivity will be disposed in a controlled and strictly regulated way to the atmosphere, to the sea and appropriately permitted locations away from the site. These activities are tightly regulated by the Environment Agency. NNB GenCo is applying for an environment permit under the relevant regulations to enable it to make these disposals. This summary document provides information on our organisation, where our radioactive waste comes from and what we do to minimise the quantities that will be disposed. We have also included a summary of the information on the maximum amount of radioactivity we plan to dispose and the impact that would have on members of the public living near to Hinkley Point C. The full submission document can be found at Our application shows the design and how we will operate Hinkley Point C. It shows that people and the environment are protected and that NNB Generation Company is demonstrating the application of Best Available Techniques. Following the impact of the earthquake and tsunami in Japan and its impact on the Fukushima nuclear power station, EDF Energy has welcomed the interim report from Dr Mike Weightman into the implications for the UK nuclear industry and has pledged to implement all of its recommendations. On his interim report Dr Weightman concluded Flooding risks are unlikely to prevent construction of new nuclear power stations at potential development sites in the UK over the next few years and There is no need to change the present siting strategies for new nuclear power stations in the UK. There are clearly important lessons that need to be applied from the events at Fukushima. However, the subject of this application, made under Schedule 23 of the Environmental Permitting Regulations, is specifically limited to the disposal of radioactive wastes arising from routine operations. It is therefore considered, given the findings of the interim report and the way forward expressed by Dr Weightman, that the application for an RSR environmental permit for Hinkley Point C can responsibly be made without prejudging the outcome of Dr Weightman's final report. On receipt of our application the Environment Agency, having assessed it completeness, that it is duly made and having placed it on the public register, will invite comments as part of the consultation process. The scope of the Environment Agency consultation will be limited specifically to the relevant environmental permit applications made. Environmental Permits do not cover the following matters: nuclear safety and transport issues, including storage of radioactive waste, (responsibility of the Office for Nuclear Regulation, an agency of the Health and Safety Executive) planning matters such as traffic, access to the site, visual impact and land use (responsibility of Infrastructure Planning Commission) the need or justification for nuclear power stations (responsibility of the Department of Energy and Climate Change). The Environment Agency may engage in additional consultation activities including consultation on the draft permit. The Environment Agency s approach is tailored to specific local circumstances. Responses to the Environment Agency s consultation on our application can be made on their website: NNB-OSL-REP Page 3 of 27

4 1.2 Introducing NNB Generation Company Ltd and EDF Energy NNB Generation Company Limited (Company Number ) is the company that will build and operate the proposed new nuclear power station at Hinkley Point. NNB Generation Company Ltd is the applicant for this environmental permit and is the prospective permit holder. NNB Generation Company Ltd is part of EDF Energy which operates eight nuclear power stations in the United Kingdom, including the 2 units at the neighbouring Hinkley Point B power station. Through the EDF Group of companies we have full access to the expertise and experience of the world s largest nuclear utility company. We have made and will continue to make extensive use of this expertise and experience throughout the design, construction, operation and eventual decommissioning of Hinkley Point C. 1.3 Our proposed site at Hinkley Point C Hinkley Point is situated on the Severn Estuary approximately eight miles from Bridgwater and the M5 to the south, 15 miles from Minehead in the west and roughly six miles from Burnham-on-Sea. Hinkley Point has been determined by the UK Government in its Revised National Policy Statements for Nuclear Power Generation as potentially suitable for the deployment of new nuclear power stations. We will construct Hinkley Point C power station adjacent to the nuclear facilities that are already present at the Hinkley Point site. Figure 1 Hinkley Point Power Station Complex NNB-OSL-REP Page 4 of 27

5 Our proposed power station will consist of the following facilities: Two UK European Pressurised Water Reactors (EPR) where water which is pumped through the reactor is heated by the energy generated by the fission of atoms. This water is kept under pressure to prevent it boiling. The heated water then flows to a heat exchanger where it transfers its thermal energy to a secondary system where steam is generated and flows to turbines. Turbine and generators which convert the energy from the reactors into electricity. Pumping station for the sea water which we use for cooling. A Radioactive Waste Management Facility in which we will process and package our solid radioactive wastes. These wastes will either be disposed of or sent to our Interim Storage Facility. An Interim Storage Facility for Intermediate Level Waste in which we will store and monitor our higher activity solid radioactive waste until we can dispose of it to a dedicated waste management facility. An Interim Storage Facility for Spent Fuel in which we will store and monitor the fuel that we have used to generate the electricity. We will store the fuel underwater until we can dispose of it to a dedicated waste management facility. A Laundry where we can wash work wear and other items from areas where we handle radioactive materials and waste. This will allow them to be reused. Electricity distribution systems, offices, workshops and welfare facilities where radioactive materials or wastes will not be processed or stored. The two UK EPR reactors and associated facilities at Hinkley Point C will each have the capacity to generate approximately 1,650 megawatts of electricity. They will provide a combined generating capacity of approximately 3,300 megawatts which is enough electricity for around 5 million homes. Each reactor will have processes for managing gaseous and liquid radioactive wastes and discharging them to the environment in accordance with the conditions and limits set by the Environment Agency. More information on the proposed site and its surroundings is presented in Chapter 1 of the main submission document. 1.4 Our applications for environmental permits We need an environmental permit before we can legally dispose of radioactive waste. The disposal of radioactive waste from our power station at Hinkley Point C will be regulated by the Environment Agency under the Environmental Permitting (England and Wales) Regulations Therefore we are applying for an environmental permit to allow us to engage in the controlled and regulated disposal of radioactive waste from our activities at Hinkley Point C. The process of obtaining our development consent order from the Infrastructure Planning Commission requires that we apply for our environmental permit in parallel with the application for our development consent. This is because the Infrastructure Planning Commission must satisfy itself that, amongst other things, there is no good reason to NNB-OSL-REP Page 5 of 27

6 believe that the Environment Agency will not subsequently grant an environmental permit for our proposed activities. We understand that the Environment Agency will consult on our application and will consider any responses during its determination process. Full details of the Environment Agency s permitting process for radioactive waste disposals can be found on its website at We are also applying for a number of further permits that will facilitate the construction and operation of our power station. These permits cover activities such as the discharge of non-radioactive liquid effluents to the sea, the use of standby generators and the management of construction wastes. The practice of generating electricity using the EPR developed by AREVA NP has been justified by the UK Government. This has established that the benefits to society from the EPR developed by AREVA NP outweigh any potential detriments including health impacts that may result from exposure to radiation associated with activities at the power station. The UK Government is also submitting information on radioactive discharges from Hinkley Point C to the European Commission. This information will be used to allow the Commission to form an opinion on the impact of our discharges on neighbouring member states. A favourable opinion is required before the Environment Agency can issue a permit for the disposal of radioactive waste. The Office for Nuclear Regulation regulates the design, construction, operation and decommissioning of any nuclear installation for which a nuclear site licence is required under the Nuclear Installations Act NNB Generation Company will submit an application for a Nuclear Site Licence at Hinkley Point C. EDF and AREVA NP, who have jointly developed the UK EPR, are seeking a statement of design acceptability through the Generic Design Assessment process. This process has been developed by the Environment Agency and the Office for Nuclear Regulation and involves a rigorous and structured examination of design information over a period of several years. At the end of the assessment period the regulators will issue reports on their findings stating whether they judge the generic design to be satisfactory from safety, security and environmental aspects. 1.5 Our management systems NNB Generation Company is committed to setting its own high standards in ensuring compliance with all of its legal and regulatory obligations. We are developing appropriate management arrangements for Hinkley Point C that will utilise best practice and to take advantage of guidance prepared by the Environment Agency and international organisations such as the World Association of Nuclear Operators (WANO) and the International Atomic Energy Agency (IAEA). We are also taking full advantage of the best practices from our parent company and affiliates, who are experienced designers, constructors and operators of nuclear plant. A key aspect of our management arrangements is that they will be part of a fully integrated management system. Throughout the design, construction and operation of our power station, we will have management arrangements that are aligned with the practical needs of the facility and will meet our regulatory obligations. We plan that our management arrangements will be industry leading. NNB-OSL-REP Page 6 of 27

7 NNB Generation Company s strategy for developing management arrangements that are appropriate for compliance with the environmental permit is to develop arrangements that are fit for purpose and implemented in a timely manner throughout the lifecycle of the power station. Therefore, the management arrangements in place at the point of permit application will reflect the requirements to ensure there are appropriate arrangements to control all pre-construction activities. We will continue to develop forward work plans to implement future management arrangements to provide the appropriate controls and robust processes to deliver environmental protection and compliance with the environmental permit conditions. More information on our management arrangements are presented in Chapter 11 of the main submission document. 1.6 Our design reference The information contained in our application is based on the reference design presented to regulators during the Generic Design Assessment. The current reference design is comprised of: Generic Design Assessment Pre-Construction Environment Report Generic Design Assessment Pre-Construction Safety Report Relevant Regulatory Observations and Technical Queries raised during the Generic Design Assessment process and responded to before submission of the application A site specific Pre-Construction Safety Report has been developed as part of the process for obtaining a Nuclear Site Licence. This complements the Generic Design Assessment Pre-Construction Safety Report which includes the structures that are specific to Hinkley Point C. The design presented in our application is consistent with the site specific Pre-Construction Safety Report. Our application includes a number of site specific features that were not included within the Generic Design Assessment: These features are: The height of stacks through which the majority of the gaseous wastes will be discharged to the environment The location of the marine outfall structure The identification of additional site specific structures not defined in the Generic Design Assessment, including: o o o Interim Storage Facility for Spent Fuel Interim Storage Facility for ILW Extension to Radioactive Waste Treatment Building for the second of the two reactor units NNB-OSL-REP Page 7 of 27

8 2 Our Radioactive Substances Activities at Hinkley Point C 2.1 The radioactive substances activities being applied for The radioactive substances activity that we are applying for a permit for is the disposal of radioactive waste on or from the premises. We have defined the premises as those parts of the Hinkley Point C site that will be licensed under the Nuclear Installations Act 1965 (as amended). The premises also include the pipeline that will be used to discharge our cooling water into the Severn Estuary. 2.2 Technical description of our radioactive substances activities Where the radioactive waste comes from Our power station at Hinkley Point C uses nuclear fission to generate heat which is then used to make steam. Each of our two units has a pressurised water reactor which uses water to transfer the heat to the steam generator. The water in the reactor is kept under pressure to stop it from boiling. The steam passes through turbines which turn the generating sets that produce the electricity which we export to the National Grid. The steam is then condensed with cooling water taken from the sea before being returned to the boilers to be heated again. Figure 2 Generic layout of the electricity generating process in a PWR The fuel we use in our reactors is radioactive. Nuclear fission involves splitting atoms which creates heat, other radioactive substances which are called fission products, neutrons and radiation. Our fuel is designed to contain the radioactive substances both during operations and subsequent storage. However, some of the NNB-OSL-REP Page 8 of 27

9 radioactivity may pass through the fuel casing. Very occasionally some of the radioactivity in the fuel may enter the water in the reactor. We have systems to detect and remove as much of this radioactivity as possible but some will be disposed of to the environment. The neutrons that are generated during nuclear fission interact with other materials that are present in the reactor to create additional radioactive substances. These are called activation products and typically account for a significant proportion of the radioactivity in our radioactive discharges. Activation products are present in solid, liquid and gaseous form. We have invested significant efforts to reduce the amount of activation products that will be generated during the operation of the reactors at Hinkley Point C. We also have a range of techniques that allows us to capture activation products so minimising their discharge to the environment. Our reactors are designed to contain as much of the radioactivity as possible during electricity generating operations. Periodically we must shut down our reactors for routine maintenance and surveillance activities. This means that some of the fission products and activation products that have accumulated in the reactor during electricity generation will become wastes. We have a range of techniques for managing and minimising these radioactive wastes but some of the radioactivity will be discharged to the environment. We have a number of waste management processes that are designed to capture radioactivity and prevent or minimise its discharge to the environment. These processes generate a range of wastes where the radioactivity is in a concentrated form. The concentrated form allows us to manage the waste more easily. These wastes must be disposed of or carefully stored to prevent the radioactivity escaping and entering the environment. NNB-OSL-REP Page 9 of 27

10 Figure 3 Typical layout of a single EPR We will store the fuel that we have used in each of our reactors on-site until a dedicated waste management facility has been developed in the UK. A small amount of radioactive waste will be generated, such as water evaporating from the pools that are used to store the fuel. Hinkley Point C will be equipped with a wide range of systems, processes and facilities that provide a safe and pleasant environment for those who work there. These include ventilation systems, changing rooms and offices. Some of the wastes from these areas are slightly radioactive and are disposed of to the environment following appropriate treatment. How we manage radioactive waste We have plant, processes and systems to manage all of our radioactive waste from the time that it is created through to its eventual discharge to the environment or disposal to a waste management contractor. The main features of our waste management system are: Gaseous wastes. We dry radioactive gases from the reactor and hold them in charcoal filled tanks. This allows some of the radioactivity to decay and significantly reduces the amount of radioactivity that we discharge. All gaseous radioactive waste is passed through filters which captures any radioactive particles that might be present. We sample all of the gaseous waste that we discharge. Liquid waste. We have drainage systems in which we segregate liquid waste, depending on its source and how radioactive it is. We use a number of techniques including ion-exchange and filtration to remove some of the radioactivity from the liquid waste. All the processed liquid waste is collected in tanks to allow it to be sampled and analysed before its disposal. Solid waste. We segregate solid waste based on its physical, chemical and radioactive properties. Solid wastes with higher levels of radioactivity are processed to ensure they meet long-term safety requirements and then stored in our Interim Storage Facility for Intermediate Level Waste. Solid NNB-OSL-REP Page 10 of 27

11 wastes with lower levels of radioactivity are processed using a number of techniques such as shredding and low force compaction before being packed into disposal containers. They are then held in our transit store until they can be disposed of to an appropriately permitted waste contractor. How we discharge and dispose of radioactive waste We have dedicated facilities for the low level, limited discharge of radioactive waste to the environment and for its disposal to waste management contractors. These facilities, which are designed to minimise the impacts of discharges and disposals, are: Gaseous waste. We will discharge low level filtered gaseous radioactive wastes into the environment from a number of stacks located across the site. A stack will be provided for each of the two UK EPR units and the Interim Storage Facility Spent Fuel. Liquid waste. We will discharge low level aqueous liquid radioactive waste with the cooling water into the Severn Estuary. The waste will enter the environment through an outfall structure which is at the end of a 2km tunnel that we will construct under the sea bed. Solid waste. We have confirmed that the wastes produced at Hinkley Point C are disposable. Arrangements to dispose of lower level radioactive waste through a number of waste management contractors will be agreed prior to the generation of any radioactive waste. We expect to dispose of this waste to the national low level waste repository, to metal recycling facilities, to appropriately permitted landfill sites and to high temperature incinerators. Further information on the generation, treatment, management and disposal of radioactive waste is presented in Chapter 2 of the main submission document. NNB-OSL-REP Page 11 of 27

12 3 Operating Techniques to Protect the Environment and People 3.1 Our commitment to protecting the environment and people We are part of EDF Energy which is one of the United Kingdom s major energy utility companies. Safety is our number one priority. We care for the environment and are committed to the principles of sustainability. Improvement of our environmental performance is as important to us as any of our other business objectives. We have developed a number of key principles which guide all of our work activities: We will always meet all applicable environmental legal requirements, regulations and other codes of practice. Each of us must always be committed to improving the environmental performance. We learn from our experience and those of others to prevent environmental damage and reduce the chance of harm next time. Each of us will spot, report and deal with hazards to help prevent harm to the environment. All employees and any contractors working on our behalf, will apply due care for the environment no matter how urgent or important the task. These principles are a fundamental part of our environment policy which can be viewed on our website at Our optimisation process Protecting the environment and people from the potentially harmful effects of radioactive substances is central to what we do. This objective is undertaken in parallel with other objectives such as safety, use of resources and operational performance. We achieve an optimum balance through a process of environmental optimisation in which we carefully examine those factors that will influence our approach. This is a continuous process that we will apply throughout the life of our power station at Hinkley Point C. It ensures that our discharges and impacts have been minimised and will always be well below legal limits. The key principles of our process are: Evolution. Our approach draws on our experience of designing, constructing and operating our fleet of nuclear power stations in the UK and those of our parent company in France. We will learn from our fleet-wide continuous improvement programme, from the experiences of other nuclear operators and from guidance produced by recognised bodies. Integration. All members of our project team have responsibilities for identifying and implementing improvements that will reduce the possible harmful effects of radioactive substances on the environment and people. NNB-OSL-REP Page 12 of 27

13 Opportunity. We will determine the most appropriate time to develop and implement optimisation measures. This will ensure that we achieve the best return on investment for the measures we employ. The deliberations and outcomes of our optimisation process is compiled in our environment case which we will maintain throughout the life of Hinkley Point C. The case demonstrates that we are employing best available techniques, referred to as BAT, to optimise our performance. What are we doing and what will it achieve? We will apply a range of techniques including engineered systems and management arrangements that will minimise the amount of radioactivity in the waste we create and dispose of. How will we decide what to do and when is the best time to do it? We will apply processes and procedures that will describe the basis for selecting most appropriate systems and controls and to demonstrate that they are the best available. 3.3 Best available techniques We have undertaken a rigorous and systematic process to demonstrate that we are applying the best available techniques to optimise our environmental performance. We have examined and assessed a comprehensive range of techniques. We have carefully appraised the contribution we expect each technique to make towards fulfilling our optimisation requirements and reducing the impacts from our activities. This evidence is gathered into a series of arguments related to our environmental performance. Taken together the arguments allow us to claim that we are applying the best available techniques. This claim-argumentevidence approach is similar to that adopted for the development of nuclear safety cases. Our environment case mirrors the waste hierarchy which is used for domestic and industrial waste management. It focuses on reducing the quantity and harmfulness of the waste that we will produce and ultimately dispose of to the environment around Hinkley Point C. In the sections that follow we have summarised some of the key arguments that support our claim that we are applying the best available techniques. Further information on environmental optimisation, including the demonstration of the application of best available techniques, is presented in Chapter 7 of the main submission document. Reducing the amount of radioactive waste requiring discharge or disposal We have invested considerable efforts to prevent the creation of radioactive waste at source. This is fundamental to environmental optimisation because wastes that are prevented do not need to be managed or disposed of. Any potential impacts associated with the waste are therefore avoided. Key techniques are: Fuel pins. The fuel pins are designed to prevent the fuel and any fission products contained within them from entering the reactor and contaminating the reactor cooling water. NNB-OSL-REP Page 13 of 27

14 Materials. Materials have been specified that are less susceptible to activation by neutrons generated by nuclear fission. Materials have also been selected to minimise the potential for corrosion and to prevent the unnecessary movement of radioactivity throughout the power station. Coolant chemistry. The water that is used for transferring heat in various parts of the power station is chemically treated to prevent corrosion. This maintains the integrity of fuel and engineered containment systems which in turn prevents the spread of contamination. In the reactor, it also prevents the generation of corrosion products which can become activated if eroded particles pass through the reactor core. Reducing our discharges to the atmosphere and to the sea A limited amount of radioactive waste will be unavoidably created during the operation and maintenance of our power station at Hinkley Point C. We will employ the following techniques to reduce the amount of controlled, low level radioactivity that will be discharged to the atmosphere or to the sea. Containment systems. Radioactive substances are contained to prevent their unnecessary introduction into waste discharge systems. Decay storage. Some of the radioactive wastes we create quickly become less radioactive through a natural process known as decay. We use techniques to store these wastes for a period of time to benefit from this effect before they are discharged. Abatement. We use a number of techniques such as ion-exchange and filtration to capture the radioactivity in gaseous and liquid wastes before it is discharged to the environment. This allows the radioactivity to be managed and contained in a more concentrated form. Reducing the impacts from our discharges to air and water We are not able to remove all of the radioactivity from our gaseous and liquid wastes. We therefore need to discharge some limited radioactivity to the atmosphere and the sea. We employ techniques that ensure that the potential impacts on the environment and people from our discharges are very low. Partitioning. The potential effects of some radioactive substances on the environment and people can be different depending on whether they are discharged to the atmosphere or to the sea. Our waste management systems help us to dispose of our radioactive waste to that part of the environment where they have the lowest impact. Optimised dispersion. Having minimised the generation of radioactive waste and abated the radioactivity as far as reasonably possible, we discharge our wastes in ways that ensure its rapid dilution and dispersion into the environment. We have undertaken modelling to demonstrate that the effects of our discharges on the environment and people are very small indeed. NNB-OSL-REP Page 14 of 27

15 Efficient management of our solid wastes Our preference is to efficiently manage the radioactivity in our waste in solid form. This approach accords with the Government s policy of concentrate and contain over dilute and disperse. We recognise that disposal capacity for solid radioactive waste at engineered disposal facilities is both limited and expensive. We will employ the following techniques to minimise our demands on disposal capacity and to reduce our costs. Waste volume reduction. We will employ techniques to contain and segregate solid waste at source to minimise the amount of additional waste that is created from operational and maintenance activities. We will also use equipment such as shredders and low-force compactors to ensure that we can make the most efficient use of waste containers. Efficient abatement techniques. We have selected a range of techniques such as pre-filters and ion-specific ion-exchange resins that will reduce the quantity of solid radioactive waste requiring management and disposal. NNB-OSL-REP Page 15 of 27

16 4 Disposal of Radioactive Waste from Hinkley Point C 4.1 Quantitative estimates of our radioactive waste discharges and disposals The unit of radioactivity is the becquerel (Bq) which relates to one radioactive disintegration per second. Discharges of radioactive wastes are measured and reported in becquerels. In this document we present the information in gigabecquerels (GBq). Each gigabecquerel is equal to 1,000,000,000 Bq. We have calculated the very best performance that we can expect in terms of radioactive discharges from our power station at Hinkley Point C. This performance is presented in the tables that follow. The calculations take account of operational experience at our other power stations in the UK and France and assume that Hinkley Point C will continuously perform in the top 25% of our fleet. Actual performance will be affected by a range of factors such as reactor shut downs, maintenance activities, fuel defects and the performance of our waste management systems. These factors have been taken into account in the limits that are presented in Section 4.2. Table 1 Estimated Best Performance for Discharges of Gaseous Radioactive Waste to the Atmosphere Radionuclide Best Performance Discharge (gigabecquerels per year) Tritium 1,000 Carbon Noble gases 1,600 Iodine Fission and Activation products Table 2 Estimated Best Performance for Discharges of Aqueous Radioactive Waste to the Sea Radionuclide Best Performance Discharge (gigabecquerels per year) Tritium 104,000 Carbon Caesium Fission and Activation products Our proposed limits for radioactive waste discharges and disposals We are proposing limits for radioactive waste discharges and disposals that reflect the performance that we expect to achieve during the operation of our power station at Hinkley Point C. We have selected specific NNB-OSL-REP Page 16 of 27

17 radionuclides or groups of radionuclides for limitation based on a range of factors that are included in guidance published by the Environment Agency. These factors include the potential impact on people and the environment; the quantity discharged/disposed of; the potential to persist or accumulate in the environment; and the degree to which they indicate plant performance. Our proposed limits include a number of contingencies that have been developed to take account of factors that we are anticipating during routine operations. These include reactor shut downs, maintenance activities, fuel defects and the performance of our waste management systems. These contingencies explain why, in some instances, the proposed limits are considerably higher than the best performance that we have calculated and presented in section 4.1. Table 3 Proposed Limits for Gaseous Radioactive Discharges to the Atmosphere Radionuclide Proposed Limit (gigabecquerels per year) Tritium 6,000 Carbon-14 1,400 Noble gases 45,000 Iodine Other Fission and Activation products 0.24 Table 4 Proposed Limits for Liquid Radioactive Discharges to the Sea Radionuclide Proposed Limit (gigabecquerels per year) Tritium 200,000 Carbon Caesium Other Fission and Activation products 18.1 Further information on the proposed limits is presented in Chapters 3 and 4 of the main submission document. NNB-OSL-REP Page 17 of 27

18 5 Monitoring 5.1 Measuring and assessing our discharges from Hinkley Point C We will take measurements at locations throughout our power station at Hinkley Point C which will allow us to: Assess the performance of systems and equipment that minimise the generation and disposal of radioactive waste. Demonstrate compliance with the conditions contained within our Environmental Permit. Report the amount of radioactivity that we have discharged to the environment or disposed of to waste management contractors. Demonstrate that our discharges and disposals of radioactive waste remain within our permitted limits, and are as low as reasonably practicable. We will perform these measurements using a range of techniques that will include sampling, tests, analyses and calculations. We will draw on our considerable experience of existing techniques and examine the performance of new and developing techniques. This will ensure that we will use the best available techniques for measuring and assessing our discharges. Where appropriate we will use techniques that are accredited by the Environment Agency s Environmental Monitoring Certification Scheme. 5.2 Measuring and assessing the impacts (effects) of our discharges from Hinkley Point C Environmental monitoring programmes are undertaken in the vicinity of all nuclear sites in the UK. These programmes involve taking samples of food, flora, fauna and environmental media to measure the amount of radioactivity that is present. These measurements are then used to determine the impacts of discharges and disposals of radioactive waste on the environment and people. The results of these environmental monitoring programmes are collated into a UK-wide Radioactivity in Food and the Environment report which is published annually. We provide estimates of our expected impacts in section 6. A comprehensive environmental monitoring programme is already in place at Hinkley Point to measure and assess the impacts from Hinkley Point A and Hinkley Point B. We will use this as the basis of the environmental programme for Hinkley Point C. Our programme will be slightly different because some of the fission products and activation products in the wastes from our pressurised water reactors will be different from those found in wastes from the gas cooled reactors at the neighbouring sites. We will collaborate with our neighbours at Hinkley Point A and B to develop an optimal environmental monitoring programme that will fulfil our combined requirements. Our monitoring programme will take account of the lifestyles and diets of people that live within the vicinity. We have assessed those groups of people that are most affected by our activities and have identified that we expect to sample and analyse the following: Marine environment. Fish and shellfish; beach dose rates; fishing gear; sediment; and seawater. Terrestrial environment. Milk and milk products; and grass. NNB-OSL-REP Page 18 of 27

19 Further information on the proposed monitoring that will take place is presented in Chapters 9 and 10 of the main submission document. 6 Impacts on the Environment and People from our Discharges at Hinkley Point C 6.1 Background Radiation Radiation describes any process in which energy travels through a medium or through space (other than via conduction). There are two broad classes of radiation: ionising radiation which comes from radioactive materials which emit radiation with sufficient energy to cause ionisation and non-ionising radiation (usually electromagnetic radiation, such as radio waves) which come from other sources. In this document the term radiation is used to mean ionising radiation. Everyone is exposed to radiation from natural and man-made sources. The impacts from exposure to radiation are presented as doses. The unit for radiation dose is the sievert (Sv); a millisievert (msv) is one thousandth of a sievert. The Health Protection Agency assess the radiation exposure to the UK population. They have calculated that the average exposure to a member of the public in the UK is 2.7 msv. Approximately 85% of this is due to exposure from natural radiation. The remainder from man-made (artificial) sources is dominated by exposure from medical sources of radiation, such as X-rays. The graph below presents the average breakdown of radiation exposure to a member of the public in the UK. Annual Exposure of the UK population from all sources of ionising radiation (in microsv) Radon 50% Medical 15.5% Internal 9% Gamma 13% Cosmic 12% Artifical Sources 17% Occupational 0.2% Fallout 0.2% Disposals 0.03% Consumer products 0.004% Taken from Health Protection Agency (2005) Ionising Radiation Exposure of UK Population: 2005 review (HPA-RPD-001). Figure 4 Annual average exposure to ionising radiation in the UK NNB-OSL-REP Page 19 of 27

20 6.2 Our Impacts on the Environment We recognise that discharges and disposals of radioactivity from Hinkley Point C could potentially have an impact on the environment around the site. We have undertaken a comprehensive and detailed assessment of the effects of our discharges on non-human species in four habitats that are in the vicinity of the site. These habitats, which were chosen because they represent the range of eco-systems present, are: Terrestrial. An area close to the site predominantly impacted by gaseous discharges to the atmosphere. Marine. Bridgwater Bay and associated mudflats impacted by liquid discharges to the sea. Coastal. Bridgwater Bay and associated mudflats impacted by liquid discharges to the sea and gaseous discharges to the atmosphere. Freshwater. Freshwater pond fed by run-off from the terrestrial habitat. The conclusions of our assessment are that the impact will be very low for all of the different habitats in the Hinkley Point area. We have also explored the cumulative impacts on the environment from Hinkley Point A, Hinkley Point B and Hinkley Point C. Our conclusion is that the impact will remain very low with only a slight increase of the dose to non-human species from Hinkley Point C. Our assessments assume that we will make discharges at the limits that we are proposing in this application. This conservative approach means that our actual impacts will be significantly lower than those calculated in our assessments. 6.3 Our Impacts on People People living near Hinkley Point C may be exposed to very low levels of radioactivity from our discharges and disposals of radioactive waste. We have defined a set of characteristics for a hypothetical group of people whose lifestyles and diets would result in them being the most exposed to any radioactive discharges from Hinkley Point C. This approach allows us to develop a conservative estimate of the impacts on people from our discharges and disposals of radioactive waste. In reality, we expect that the impacts on members of the public will always be significantly less than estimated. We have determined impacts for four scenarios which are representative of the way we will operate our power station at Hinkley Point C: Annual discharges. The impacts from discharges at the limits we are proposing in section 4 Short term discharges. The impacts from short-term peaks in discharges that may occur from occasional activities such as start-up, shut-down and plant maintenance. Environmental build-up. The impacts of radioactivity that accumulates in the environment to ensure that future populations are afforded the same degree of protection as current populations. NNB-OSL-REP Page 20 of 27

21 Collective Dose. The total impacts on people for up to 500 years from all of the discharges that will be made during the lifetime of Hinkley Point C. We are required by law to demonstrate that our the impacts of our discharges are below the source constraint of 0.3mSv per year for Hinkley Point C and the site constraint of 0.5mSv per year for all of the nuclear facilities at Hinkley Point. The data presented in the following sections demonstrate that we will be well within this requirement. Full details of the radiological impact assessment undertaken are presented in Chapters 12 and 13 of the main submission document. Impacts from Annual Discharges The hypothetical group of people who would be most exposed to our annual discharges and disposals of radioactive waste from Hinkley Point C is a farming family who live in one of the closest properties to the site and who consume foodstuffs produced on their property. They are exposed to radiation from beach sediments and the inhalation of sea spray whilst spending time recreationally on beaches near the power station. They also consume locally sourced sea foods. We have assumed that the discharges are at the limits we are proposing in section 4. We have estimated the impacts to this hypothetical group and the results are presented in table 5. For completeness we have also included the doses for Hinkley Point A and Hinkley Point B. The impacts are well below both the source and site constraint indicated above. The annual impacts from discharges from our power station at Hinkley Point C are the equivalent of 1 or 2 dental X-rays. Table 5 Annual doses to hypothetical group Family Member Hinkley Point C (msv per year) Hinkley Point B (msv per year) Hinkley Point A (msv per year) Adult Child Infant The source dose constraint of 300 Sv y -1 is the maximum dose to people that may result from discharges from a single new source. The critical group the doses to adults, children and infants are respectively 2.7, 2.5 and 4.5 μsv y -1 for Hinkley Point C. The doses to this group are much lower (approximately 1.5%) than the source dose constraint of 300 Sv y -1. The estimated dose for discharges at proposed limits is below 10 μsv y -1. This is the level at which the UK Government in its statutory guidance to the Environment Agency [19] has indicated that it would not seek further progressive reductions in discharge limits as long as the application of best available techniques continues to be implemented. The graph below illustrates the contribution of the impact from Hinkley Point C discharges to the average dose to a member of the public in the UK. It equates to approximately 0.2% of the total annual average exposure. NNB-OSL-REP Page 21 of 27

22 The site dose constraint of 500 Sv y -1 is the maximum dose to people that may result from discharges from a site and applies to the cumulative dose from the discharges from all sources at a single location. The cumulative doses due to discharges to adults, children and infants are respectively 6.8, 7.3 and 17.2 μsv y -1 for Hinkley Point site. The doses to this group are much lower (approximately 3.5%) than the site dose constraint of 500 Sv y -1. Comparison National annual average exposure in UK compared to Dose to most affected group from Hinkley Point C disposals 99.8% UK Average Radiation Exposure Hinkley Point C exposure 0.2% Figure 5 - Comparison of impacts from Hinkley Point C discharges to UK national average exposure Impacts from Short Term Discharges The hypothetical group of people who would be most exposed to our short term discharges is the same as for annual discharges and disposals. We have only considered discharges to atmosphere in our assessment because liquid discharges are more evenly spread over time and people are not exposed until after the waste has been dispersed in the environment. We have assumed that short term discharges will be the equivalent of a twelfth of the annual discharge limit (a month s worth) and will be released into the atmosphere over a period of 24 hours. We have also assumed that a short term release will only be made from one of our UK EPR units at any one time. The estimated impacts on the hypothetical group are presented in table 6. The doses to this group are less than 0.2% of the source dose constraint of 300 Sv y -1. NNB-OSL-REP Page 22 of 27

23 Table 6 Doses to hypothetical group from short term discharges Family Member Hinkley Point C (msv) Adult Child Infant Impacts from Environment Build-Up We have assessed the impacts from the accumulation of radioactivity in the environment on and around Hinkley Point C. This is to determine the implications for legitimate land use during and after our operations at the site. It also contributes to calculating the impacts from annual discharges and collective impacts. Current advice on radiological protection objectives for contaminated land is that restrictions on future land use would be applied if the dose from accumulated radioactivity was above 0.02mSv per year. We have calculated that for Hinkley Point C, the total associated dose for future use of the land and sea are msv per year and msv per year respectively. For the Hinkley Point site, the total associated dose for land and sea are msv per year and msv per year respectively. Impacts from the environmental build-up of radioactivity in the environment from the Hinkley Point C station, as well as the Hinkley Point site as a whole are lower than the guidance value of msv per year. Therefore, there would be no restriction on future use of the land. Collective Impacts The collective dose is the sum of doses from a given practice or situation to all affected individuals, now and in the future. It is the result of the summation of very small individual doses to a very large number of people over a long period of time, typically 500 years. Thus, although the resultant collective dose may be numerically large, from the perspective of the individual the risks from the exposure may be very, very low. The summation approach also means that the collective dose for the World is larger than the collective dose for Europe, which in turn is larger than the collective dose for UK. The collective doses for discharges from Hinkley Point C are presented in table 7. The unit of collective dose is the mansievert (mansv) which expresses the impact in terms of societal risk. Table 7 Collective dose to the UK, European and World populations from HPC discharges UK Collective Dose (mansv) Europe Collective Dose (mansv) World Collective Dose (mansv) Discharges to Atmosphere Discharges to Sea Total NNB-OSL-REP Page 23 of 27

24 The collective dose due to discharges from Hinkley Point C are all dominated by the long lived radionuclide, carbon-14, present in gaseous discharges. Carbon-14 accounts for the vast majority if the collective doses for all of the populations considered. However, these are all much lower than that from naturally occurring carbon-14. For example, the collective dose from naturally occurring carbon-14 to the UK population is about 480 mansv per year. 6.4 How we calculated the impacts We used a number of assessment tools to model the way that our discharges of radioactive waste will behave when they enter the environment and for determining impacts on humans and non-human species. The development and application of these tools are subject to stringent quality assurance processes. The main tools used were: Dispersion Modelling. This models the movement and concentration of pollutants in the environment from our discharges. We use both atmospheric and marine models. PC-Cream. We have made estimates with this tool which was developed for the European Commission by the UK Health Protection Agency to assess the impact of radioactive discharges from routine releases to air and sea. ERICA Integrated Approach. Developed by the European Commission to determine the impacts on non-human species. It is a three-tier approach that uses data from a range of scientific literature and field studies organised around different wildlife groups. Environment Agency R&D Methodology 128. This allows the impacts on wildlife from noble gases, which are not covered by ERICA, to be determined. It uses data on the movement of radionuclides in the environment and provides a number of approaches to determining exposures. NNB-OSL-REP Page 24 of 27