Background - assessment of new nuclear power stations

The HSE (Office for Nuclear Regulation) and the Environment Agency developed the Generic Design Assessment or GDA process in response to a request from the Government following its 2006 Energy Review.

In their contributions to the Government’s Energy Review, the HSE (ONR) and Environment Agency set out proposals to assess new nuclear reactor designs, in advance of any site-specific proposals to build a nuclear power station. The process became known as Generic Design Assessment (GDA).

GDA has a number of key benefits:

The regulators conduct their assessments using a step-wise approach with the assessments becoming increasingly detailed at each step. At the end of each step reports are published, which provide an update on the detailed technical assessment undertaken by the nuclear assessors. The reports highlight any concerns or technical issues that have been raised during the assessment. The HSE takes forward its assessment in four steps, while the Environment Agency’s process consists of a preliminary and detailed assessment followed by a consultation. At the end of the GDA process, the Regulators will decide if the proposed designs are acceptable for build in the UK.

Key Milestones

Jan 2007
HSE and EA publish guidance on the GDA process.
July 2007
Four companies make valid applications for GDA.
  • AREVA and Electricité de France's (EDF) UK EPR
  • Westinghouse Electric Company's AP1000
  • GE-Hitachi Nuclear Energy's ESBWR
  • Atomic Energy of Canada Limited's (AECL) ACR-1000
August 2007
GDA process launched (Step 1).
September 2007
Initial assessment of the designs begins (Step 2).
March 2008
HSE and the Environment Agency announce that their initial assessment of four new nuclear power stations designs found no shortfalls at this stage.
April 2008
Atomic Energy of Canada Ltd (AECL) announces that it is withdrawing its ACR 1000 design from the assessment process.
June 2008
HSE and the Environment Agency announce that they are starting the next, more detailed stage of the assessment process for the remaining three designs (Step 3).
September 2008
GE-Hitachi requested a temporary suspension from GDA. As a result, both regulators suspend assessment work on the ESBWR.
May 2009
HSE and the Environment Agency publish their first Quarterly Report (Jan-March 2009), which provides an update on their assessment work. This is the first of a series of regular updates to be produced.
July 2009
HSE and the Environment Agency, publish their second Quarterly Report (April -June 2009). This provides an update on their work to assess new nuclear power station designs.
October 2009
HSE and the Environment Agency publish their third Quarterly Report for 2009 (July-September) today. This provides an update on their work to assess new nuclear power station designs.
November 2009
HSE published Step 3 reports and announce that no show stopper, etc. The detailed Step 4 assessment begins.
February 2010
HSE and the Environment Agency publish their fourth Quarterly Report for 2009 (October – December). This provides an update on their work to assess new nuclear power station designs.
May 2010
Environment Agency will begin a public consultation, this will run until September 2010 and help inform its decision on the designs.
June 2010
HSE and the Environment Agency publish their 1st Quarterly Report for 2010 (January – March). This provides an update on their work to assess new nuclear power station designs.
June 2010
HSE and the Environment Agency publish guidance on ‘Management of GDA Outcomes. This guidance sets out the outcomes that can be expected in June 2011, when we complete our assessment of the safety case of the designs. It also simplifies and makes clear what these outcomes mean and how any outstanding GDA Issues will be managed subsequently within the GDA process.
April 2011

The new statutory corporation, Office for Nuclear Regulation (ONR), has been created and takes on the relevant functions currently carried out by the Health and Safety Executive and the Department for Transport to regulate the nuclear power industry.

Next Steps

June 2011
ONR will produce and publish Step 4 Reports which will set out its findings and final conclusion of the assessment.

Site Licencing

A site licence must also be granted before a new reactor can be built and operated on a specific site.  Before we grant a licence we will ensure that the site is safe and secure, the site is suitable for the particular design, and that the potential operator can adequately control construction, operation and maintenance of the plant to ensure safety and security.

Wider nuclear new build activities

While GDA and site-specific approval are important elements of the regulatory process, they are only a part of the wider approvals process being taken forward by the Government.  For more information visit the Department for Energy and Climate Change website.