Generic design assessment of the UK HPR1000 design - decision document summary
Published 7 February 2022
Applies to England
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Introduction
Government is responsible for the UK’s energy policy and sets out its current position in the December 2020 white paper, ‘Powering our Net Zero Future’ (BEIS, 2020). In the white paper, the government highlights the need to address climate change urgently. It sets out its strategy for wider energy systems to achieve the UK’s target of net zero greenhouse gas emissions by 2050. New nuclear power stations are an important part of this strategy to help ensure that we have secure supplies of low carbon electricity in the future.
The Environment Agency has published its own plan, ‘EA2025 creating a better place’, to guide our activities. This plan will act as our compass, enabling us and others to chart a course towards a healthier, greener and more prosperous country in 2025.
Our EA2025 plan sets out 3 main goals:
- a nation resilient to climate change
- healthy air, land and water
- green growth and a sustainable future
Our regulation of nuclear sites aligns with these goals because it helps ensure that these facilities are designed and operated in ways which minimise waste and protect the environment.
As regulators of the nuclear industry, the Environment Agency and the Office for Nuclear Regulation (ONR) are working together to make sure that any new nuclear power stations built in the UK meet high standards of safety, security, environmental protection and waste management.
Generic design assessment (GDA) is the first step in this process.
The Requesting Party (RP) for this GDA is constituted jointly by China General Nuclear Power Co (CGN), Électricité de France S.A. (EDF S.A.) and General Nuclear International Limited (GNI). General Nuclear System Limited (GNSL) is appointed by the above shareholders to act on behalf of the RP.
Both CGN and EDF are major providers of nuclear technologies, in China and France respectively. CGN has developed and is constructing new nuclear power stations in China using Hualong reactors. The UK HPR1000 power station is based on the Hualong design and has been submitted to the UK nuclear regulators for generic design assessment.
Generic design assessment allows us to begin scrutinising new nuclear power station designs well in advance of construction starting. This means that we can identify any potential design issues at an early stage and ask the RP to address them. This will help to avoid potentially costly and time consuming changes when the reactor is being built.
We have previously carried out generic design assessment on 3 different reactor designs:
- EDF-Areva’s UK EPR, completed in December 2012 and currently under construction at Hinkley Point C in Somerset and proposed for construction at Sizewell C in Suffolk
- Westinghouse’s AP1000, completed in March 2017
- Hitachi-GE’s Advanced Boiling Water reactor (ABWR), completed in December 2017
Generic design assessment of the UK HPR1000 commenced in January 2017 and we started our technical assessment in November 2017.
This document presents our final conclusions following consultation on our detailed assessment of GDA environmental aspects of the UK HPR1000 new nuclear power station design.
New nuclear power stations – the government’s view
The government has set out its strategy to help the UK achieve its target of net zero greenhouse gas emissions by 2050 as part of its response to climate change. The strategy sets out the actions government is taking on wider energy systems. It includes a continuing and future role for nuclear generation to provide reliable, clean electricity and it also sees a potential role for Advanced Modular Reactors (AMRs), which consist of new nuclear technologies. Government’s position is that additional new nuclear power stations are required and it intends to bring at least one further large-scale nuclear power station to a final investment decision by the end of the current parliament.
The nuclear regulators, the Environment Agency and ONR, developed the generic design assessment process at the request of government in 2006. It enables early assessment of safety, security and environment protection aspects of new reactor designs at a generic level, before receiving an application to consider a particular nuclear power station design at a specific location. Access to generic design assessment is controlled by government as the selection of which reactor designs should be assessed is primarily a UK strategic or commercial consideration or both.
Regulating nuclear power stations
The Environment Agency regulates specific environmental matters at nuclear sites in England by issuing environmental permits to cover site preparation, construction, operation and decommissioning. We also work closely with the Office for Nuclear Regulation, which regulates the safety and security aspects of nuclear sites.
We have split our process for assessing and permitting new nuclear power stations into 2 stages. This helps us to identify any aspects of designs that may need to be changed to meet UK regulatory requirements and expectations, early in the process. It also makes it simpler for stations of almost the same design to be built on a number of sites, for example, Hinkley Point C and proposals at Sizewell C.
The first stage is the GDA, where we assess the environmental aspects of a power station design that would be relevant to any site. At the end of GDA, we provide a statement about the acceptability of the design.
This is followed by a site-specific stage, where we receive applications for environmental permits for a specified site. We take into account all of the work we have done during GDA, so that our efforts are focused on site-specific matters, including how the operator is addressing any GDA Assessment Findings. We also carry out further public consultations before deciding whether or not to issue operational permits for a specific site and, if we do issue permits, we decide what the permits’ conditions should be.
Generic design assessment
Generic design assessment (GDA) means that we begin assessing whether the environmental aspects of a design are acceptable before an application is made to build the power station.
There are a number of stages:
- Initial assessment: we may ask the Requesting Party for further information or for design changes to be made.
- Detailed assessment: we form our preliminary views and prepare for consultation.
- Consultation: we ask for views following detailed assessment.
- Post consultation review: we consider all responses to the consultation and complete our assessments.
- Decision and statement: this is the stage we are at now.
There may be matters that cannot be initially resolved. These are identified as ‘GDA Issues’. The assessment process can then be extended while these issues are resolved.
A GDA Issue is an unresolved issue that is significant, but resolvable, and which needs resolving before construction of the reactor starts. The company must publish a ‘resolution plan’ setting out how it will address the issue. All GDA Issues must be resolved to the regulators’ satisfaction before GDA can be completed.
There are also matters which are best resolved at the site-specific stage by the proposed operator. These are Assessment Findings. GDA Issues and Assessment Findings are identified in any statement issued.
An Assessment Finding is an unresolved issue that is not considered critical to the decision to start construction - it will need to be addressed during the design, procurement, construction or commissioning phase of any new build project.
There are 3 possible outcomes for a generic design assessment:
- we issue a statement of design acceptability (SoDA) if we are satisfied with the design
- if, after we have completed our assessments, we are largely satisfied, we provide an interim statement of design acceptability (iSoDA) that identifies the issues that must be addressed before we could consider issuing a full statement of design acceptability
- if we are not satisfied, we do not issue a statement of design acceptability or an interim statement of design acceptability
The UK HPR1000 design
There are various types of nuclear reactors around the world, with over 440 currently in operation. One of the most common types is the pressurised water reactor (PWR), of which the HPR1000 is one of the latest designs under construction. It is capable of providing around 1,180 megawatts of electricity, enough to power more than 1.5 million homes on average. The HPR1000 is currently under construction in China.
Figure 1. A simplified illustration of the UK HPR1000 reactor (image copyright of China General Nuclear)
How does the reactor work?
In the reactor core, some of the uranium atoms that make up the fuel split in a process called nuclear fission. These fissions produce energy in a continuous process called a chain reaction.
The energy created by the fissions heats water inside the reactor, which is circulated by pumps in the primary circuit to a steam generator. In the steam generator, the very hot primary circuit water is used to heat water in the separate secondary circuit, producing steam which is fed to a turbine. This makes the turbine spin and drives a generator that produces electricity.
The primary circuit of a PWR is at a very high pressure, giving this type of reactor its name.
There is a third water circuit which is used to cool the condenser of the turbine, converting the steam of the secondary circuit back to water, which is pumped back into the secondary circuit to flow through the steam generator again. In UK nuclear power stations, sea water is usually used in the third water circuit, but this can be replaced by water from rivers or estuaries or water can be cooled using cooling towers.
Find out more on how the UK HPR1000 works on the company’s website.
Our assessment
The RP submitted its UK HPR1000 design for GDA in November 2017. We completed our initial assessment and published our report in November 2018 (Environment Agency, 2018). Since then, we have been carrying out our detailed assessment. We formed our preliminary conclusions and went to public consultation between 11 January and 4 April 2021.
We are now presenting our conclusions. We have based our final findings on:
- the final versions of the GDA submission (submitted October 2021)
- technical discussions held with the RP
- consideration of the responses to our consultation
- consideration of comments submitted to the ‘GDA comments process’ website and the responses provided by the RP
We are publishing 8 updated assessment reports alongside our decision document (Environment Agency, 2022a to 2022i). We have also previously published an independent dose assessment as part of our consultation documents (Environment Agency 2021a). Our decision is based on our detailed environmental assessment reports (Environment Agency, 2022b to 2022i). These cover 8 different topics, as follows:
Management systems
We checked that the RP has the right management systems in place and enough resources to make sure the design will adequately protect people and the environment. We also checked that all appropriate information can be transferred from the RP to a future operator.
Radioactive waste management arrangements
We considered the integrated waste strategy for a generic site to ensure it is in line with UK policy and good practice.
Best available techniques
We examined the claims made by the RP about minimising waste and the impact on the environment. We considered the evidence supporting these claims in relation to good practice in the UK.
Gaseous and aqueous waste
We examined the amount of liquid and gaseous waste expected to be discharged into the environment and the proposed limits under which the power station could operate. We also considered the estimated discharges in relation to other comparable power plants across the world.
Solid waste, spent fuel and disposability
We considered the amount and type of solid waste expected to be generated, looking for potential impacts on the disposability of the waste. We looked to see that all opportunities have been taken to avoid or minimise the amount of waste generated. We also checked that UK good practice in processing and packaging the waste has been followed so it can be disposed of in the most effective way possible.
Sampling and monitoring
We considered whether the design can monitor radioactive discharges to the standard needed to comply with a future permit.
The generic site and radiological impact on people and wildlife
We reviewed the RP’s assessment of the impact of radioactivity on members of the public, plants and animals against our own independent assessment (Environment Agency, 2021a). We compared the results to the legal limit for exposure to radioactivity.
Other environmental regulations
We considered whether the design can comply with environmental legislation other than regulation of radioactive substances activities, for example, control of major accident hazards (COMAH), combustion activities and non-radioactive surface water discharges.
Our consultation
We have deliberately made this assessment open, clear and consultative, subject to commercial and security sensitive constraints, because this helps to inform our decision and build confidence in us and the process. We consulted on our preliminary conclusions, following our detailed assessment up to the start of consultation, for 12 weeks, from 11 January to 4 April 2021 (Environment Agency, 2021b).
We are confident that we did all we should do to properly consult and that this consultation was accessible to, and clearly targeted at, the people and organisations it was intended for. We are grateful to all who took the time to respond or contribute to our consultation events.
More detail on the consultation events can be found in section 2.5.3 of our decision document (Environment Agency, 2022a).
Our decision following consultation
At consultation, we highlighted 6 potential GDA Issues (Appendix 1) related to 4 Regulatory Observations (ROs) and 2 other open issues. The RP has since submitted the additional information required to close out the 4 related ROs (RO-UKHPR1000-036, RO-UKHPR1000-037, RO-UKHPR1000-041 and RO-UKHPR1000-044). In addition, information was received from the nominated fuel supplier on the storage conditions required for spent fuel. Also, ONR has not raised any GDA Issues associated with the demonstration of ALARP, that is the demonstration that safety risks are ‘as low as reasonably practicable’ that could result in a need for a re-evaluation of the best available techniques (BAT) information presented to us. Further information on the closure of the 6 potential GDA Issues is given in Appendix 1.
There are no unresolved GDA Issues.
We have identified 45 Assessment Findings (AFs) in our assessment reports (Environment Agency, 2022b to 2022i). These are also presented in our decision document (Environment Agency, 2022a) and in Appendix 2 of this report. We will expect a future operator to address these at the appropriate stage in the life cycle of the plant.
Subject to the Assessment Findings (Appendix 2), the design would be acceptable for permitting at any coastal site consistent with the generic site as defined by the RP. The characteristics of this generic site envelop the sites included in the national nuclear policy statement NPS EN-6 (DECC, 2011a and 2011b), but detailed assessments specific for any proposed site would be required as part of application.
We do not believe that any of the Assessment Findings are so fundamental that they are unlikely to be resolved satisfactorily before or during site-specific permitting.
We have also considered whether the additional information received since our consultation has significantly changed the basis of our consultation. We believe that there have been no changes to the design or submissions that would impact on the information presented at consultation.
Our overall conclusion is that we can issue a statement of design acceptability (SoDA) for the UK HPR1000. This is valid only for a site that meets the identified generic site characteristics and subject to any future determination of a site-specific permit application.
This statement is provided as advice to the Requesting Party, under Section 37 of the Environment Act 1995. It does not guarantee that any site-specific applications for environmental permits for the UK HPR1000 will be successful.
Our full decision document and updated assessment reports are available on GOV.UK.
Alternatively, you can request a copy by email at nuclear@environment-agency.gov.uk.
Next steps
Any company that wants to build and operate a new nuclear power station must obtain a number of important site-specific permissions from regulators. These include a nuclear site licence and relevant consents from ONR, environmental permits from the Environment Agency, and planning permissions from the Planning Inspectorate.
Bradwell B Power Generation Company Limited (Bradwell B) is proposing to build the UK HPR1000 at its site at Bradwell in Essex.
Environmental permits
Bradwell B will therefore need to apply for a range of environmental permits relating to building and operating a nuclear power station and for relevant ‘associated developments’ such as workers’ accommodation. This includes permits for radioactive discharges, cooling water discharges and operating combustion plant, such as emergency diesel generators.
If we receive permit applications, we will decide whether permits should be granted and, if so, what conditions should apply. When making decisions about site-specific permit applications, we will take account of the work done during GDA. We will also carry out further public consultation before deciding whether to issue operational permits for a specific site.
Nuclear site licence
Any organisation that wants to carry out prescribed nuclear activities must apply to ONR for, and be granted, a nuclear site licence, before it starts building a nuclear safety-related plant. Granting a nuclear site licence is a significant step, but, on its own, does not give permission to start nuclear-related construction. That requires a regulatory permission from ONR.
Planning permission
A new nuclear power station of this size needs a Development Consent Order (DCO) from the Secretary of State, who makes a decision having received a recommendation from the Planning Inspectorate.
References
BEIS, 2020
Department for Business, Energy & Industrial Strategy: Energy white paper: Powering our net zero future.
DECC, 2011a
National Policy Statement for Nuclear Power Generation (EN-6): Annexes - volume I of II.
DECC, 2011b
National Policy Statement for Nuclear Power Generation (EN-6): Annexes - volume II of II.
Environment Agency, 2018
Initial assessment of General Nuclear System’s UK HPR1000 design: Statement of findings.