Briefing Paper:
Generic Design Assessment
Wylfa Newydd, Horizon Nuclear Power
The UK’s growth in nuclear new build is increasing rapidly. In 2006, as a result of the
Government’s Energy Review, the nuclear regulatory bodies, the Office for Nuclear
Regulation and the Environment Agency developed the Generic Design Assessment
(GDA) process.
GDA is unique to the UK and is recognised globally as a robust, independent process to assess new nuclear reactor
designs before they are built. The process is not a legal requirement, however it is an essential step to deliver safe,
secure and environmentally acceptable nuclear new build in the UK.
The Office for Nuclear Regulation (ONR) is an independent organisation responsible
for regulation of nuclear safety and security across the UK.
The Environment Agency (EA) is the environmental regulator in England. Natural
Resource Wales (NRW) and the Scottish Environment Protection Agency (SEPA) have
similar responsibilities in Wales and Scotland.
REGULATORY JUSTIFICATION
Justification is the first step in the regulatory process for new reactor designs. It is required by EU law and can be
undertaken in parallel with the GDA process.
The Government must assess whether the social, economic or other benefits outweigh the health detriment of
ionizing radiation.
The Secretary of State for Business, Energy and Industrial Strategy is the sole Justifying Authority and any
decision will be UK-wide.
WHAT IS THE GDA PROCESS?
GDA is a step-wise process consisting of four stages to assess generic design of a specific
reactor type. At each step the ONR undertakes an increasingly detailed assessment of the safety
and security aspects for the reactor design.
GDA is not a legal requirement but it aims to give a clear indication of whether the design would
meet UK regulatory requirements. The GDA process takes around four years to complete.
ONR assesses the reactor design and operator in three steps, after an initial preparation step.
The EA’s process consists of a preliminary and detailed assessment followed by a consultation.
Briefing Paper:
Generic Design Assessment
ONR and EA publish end of step reports with any issues identified.
At the end of the GDA process ONR will grant a Design Acceptance Confirmation and the EA will grant a Statement
of Design Acceptability only if the design and operators meet the high safety and security standards.
BENEFITS OF GDA
The GDA process is recognised internationally as a gold-standard of regulation for nuclear new build. The benefits
include:
Regulatory influence at the earliest stage before the construction of the reactor starts.
Providing advice to the designers and operators about any issues ONR and the EA identify so they can
be resolved in the design phase. This increases efficiency and reduces the financial and regulatory risks.
Focusing on the assessment the design, rather than the specific site related issues.
Completing the GDA process once for each design, it can be built across a number of different sites.
Working in an open and transparent manner, publishing assessment reports and public consultations.
LICENSING AND ENVIRONMENTAL PERMITS
A company planning to build and operate a new nuclear power station must obtain a
number of site specific permissions from the regulators and Government.
A site licence assesses the characteristics of the site and ensures the reactor design
can be constructed and operated safely and securely over its lifetime. This must be
granted by ONR before construction at a nuclear site in the UK.
Environmental permits for any new nuclear site must be obtained from the Environment
Agency or Natural Resource Wales.
CURRENT AND POTENTIAL REACTOR DESIGNS
Several reactor designs have either completed the GDA process or are currently progressing through:
Company
Site
Type
Capacity
GDA Status
NNB GenCo
Hinkley Point C, Somerset
Sizewell C, Suffolk
UK-EPR (PWR)
2 x 1670 MWe
2 x 1670 MWe
Completed 2012
Horizon Nuclear Power
Wylfa Newydd, Anglesey
Oldbury B, Gloucestershire
UK ABWR (BWR)
2 x 1380 MWe
2 x 1380 MWe
Step 4 – target
completion Dec 2017
NuGeneration Limited
Moorside, Cumbria
AP1000 (PWR)
3 x 1135 MWe
Target completion
March 2017
China General Nuclear
Bradwell B, Essex
HPR1000
Hualong One
(PWR)
TBC
Step 1 – start Jan
2017
PWR = Pressurised Water Reactor, BWR = Boiling Water Reactor
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