How The ‘Generic Design Assessment’ Has Failed

The Generic Design Assessment (GDA) is a process which was set up in order to examine the designs for new power stations and iron out any flaws in them before the power stations are constructed. Allowing the regulators to get involved with designers at the earliest stage was supposed to ensure an open and transparent process resulting in several competing designs with all significant design issues fully resolved.

The GDA was carried out by the Health and Safety Executive between 2007 and 2012. It was was undertaken in order to prevent the construction problems that have plagued the two reactors currently being built in Europe from being repeated in the UK. The two European Pressurized Reactors (EPR’s) are being built by Areva, a company which, like EDF, is largely owned by the French State. One of the reactors is at Olkiluoto in Finland, the other is at Flamanville in France. The original date for completion of the Olkiluoto reactor was May 2009, but in February 2013 it was announced that the reactor would not be finished until 2016. the cost has escalated from an original estimate of €3 billion to a whopping €8.5 billion. This has led to legal tussles over who is to blame for the delays as Areva has a fixed price contract to build Olkiluoto for €3 billion. According to some estimates, the Olkiluoto reactor will be the 5th or 6th most expensive structure in the world, even more expensive than the Large Hadron Collider in Switzerland. Similar cost overruns and delays have dogged the EDF owned Flamanville reactor which is now projected to cost about 8 billion euros, almost three times the original price.

In November 2010 Stephen Thomas, a Professor of Energy Studies from the University of Greenwich authored a report1 which stated that The EPR design is “in crisis” to such a severe extent that it is likely to be an economic failure. He said:

“The two sites in Europe where EPR is under construction, Olkiluoto and Flamanville, have gone dramatically wrong from the start of construction. It might have been argued that the problems at Olkiluoto were due to the lack of experience of the utility and the inexperience of Areva NP in carrying out the architect engineering. However, the fact that EDF, the most experienced nuclear utility in the world seems to be doing no better at Flamanville suggests the main problems are more related to the build-ability of the design itself than to specific issues at Olkiluoto.”

He was also concerned about the cost-

“As early as 1995 and again in 1997, there were concerns about the cost of the EPR .., it seems unlikely that EPR will be affordable except where huge public subsidies are offered and/or there is a strong likelihood of full cost recovery from consumers, no matter what the cost is.”

The fundamental cause of the escalating costs and delays is due to problems with the design which have come to light during the course of the construction.

In October 2010 The Royal Academy of Engineering published a report2 called ‘Engineering the Future Nuclear Lessons Learned’ in which they analysed factors to deliver reactors on time and to budget. The primary lesson from Olkiluoto and Flamanville is that the design must be finalized before construction

“New stations should be based on the application of proven technology and established design. This must be complemented by a high level of design completion in advance of construction?

“…design development does involve risk of delay and price escalation and should be resisted. There must be a rigorous, efficient and auditable design change process in place, indeed this is a requirement of the nuclear site licence, and a culture established that recognises that even seemly small changes can have unexpected implications and therefore require formal review.?

The government insists that we urgently need new nuclear power in order to replace the coal, gas and ageing nuclear plants that are scheduled to be closed within the next few years. In order to make the claim that nuclear power will plug the energy gap credible, the time frame that was imposed on the GDA process was strict. EDF proposed to begin construction of the first of the power stations in January 2013. In order for this to be feasible, it was planned that an Interim Design Acceptance Confirmation (I-DAC) would be granted in 2011, and a Final Design Acceptance Compliance (F-DAC) would be granted by December 2012

From the outset of the GDA process, reports indicate that the HSE was understaffed and that the information requested from EDF on the details of the design was not provided on time and was often of poor quality, which made it very difficult for the HSE to reach its targets. In a review of the GDA process in May 20103 , the review board discussed the issue of what to do in the event of being unable to meet the deadline:

“One further key issue… concerns ‘the end of GDA’, and particularly the outcomes of that process and the transition from Phase 1 (GDA) into the site-specific licensing work of Phase 2. In this respect, we were surprised and concerned at the level of uncertainty that now appears to have grown within ND (Nuclear Directorate) about these issues and at the potential damage that such uncertainty is likely to create to both the momentum of the work on the new build programme and to the credibility of GDA in particular.?

The Board went on to say:

“The final Step 4 of GDA has been scheduled to finish in June 2011 but, at the time of our review, we noted debate within ND as to whether or not, if a DAC (Design Acceptance Confirmation) were to be issued with ‘issues’, the GDA timetable should be extended until such time as these had been satisfactorily resolved. Doing so would, of course, turn what had originally been envisaged as a defined and time-limited process into a more open-ended one, with all the attendant risks of such open-endedness. The alternative approach that we learned had also been under consideration in ND would be to stick to the original finish time for GDA (in June 2011) and instead deal with any unresolved and outstanding generic issues as part of Phase 2 – the licensing process.?

Ironing out all the generic design problems before issuing the site licences (which allow construction to begin) was the very reason for setting up the GDA. Here the review body admits that if the generic issues are not solved, the licences could be granted regardless.

In order to stick to the schedule and issue the final design confirmation in December 2012, the HSE regulators introduced a process of ‘Assessment Findings’. Assessment Findings were unresolved concerns with the design which, though they were deemed to be important to safety, were not considered critical to the decision to start construction. Between December 2011 and November 2012, 240 Assessment Findings were raised. These were in addition to the 484 Assessment findings raised during the three year period up to the issue of the Interim-Design Acceptance Compliance (I-DAC) in December 2011

It has been strongly argued that a great number of the unresolved design issues that have been shunted off into Assessment Findings(AF’s) are in fact major elements of the design. A report4 examining the GDA process compiled by John Large a respected nuclear engineer concluded that:

“In effect, this AF deferral approach has lacked transparency at the time of the F-DAC grant and, moreover, in terms of nuclear safety the final performance of the plant (functionality, risk, effectiveness of protection, etc) will not be finally settled until well into the construction and, quite possibly, commissioning phases of the first EPRs scheduled for Hinkley Point. The existence of such uncertainties together with the quite obvious incompleteness of the plant design and development, particularly in the generic safety critical areas of Fault Studies and Control & Instrumentation must have, surely, rendered the GDA process itself incomplete and inconclusive?

1 The EPR in Crisis, Steve Thomas, 2010, (

2 Engineering the Future. Nuclear Lessons Learned, The Royal Academy of Engineering, 2010, (

3 Third Report of the GDA Process Review Board, HSE 2010, (

4 Final Report On The ONR Generic Design Assessment, Large and Associates 2013, (


4 Responses to “How The ‘Generic Design Assessment’ Has Failed”

  • Oliver says:

    Just to say the EA has just competed phase 1 of GDA for PBWR:
    28 August 2014

    Regulators complete initIal GDA assessmenT step for uk ABWR

    The Office for Nuclear Regulation (ONR) and the Environment Agency have completed their first high level assessment step of Generic Design Assessment (GDA) for Hitachi-GE’s UK Advanced Boiling Water Reactor (UK ABWR).

    The regulators have not at this stage identified any fundamental safety, security or environmental issues that are so significant that they would prevent this reactor design from being constructed in the UK.

    The Environment Agency and Natural Resources Wales (NRW) are working closely together on GDA; the Environment Agency and NRW are the principal environmental regulators for nuclear power stations in England and Wales respectively. ONR’s responsibilities include safety and security at nuclear sites in the UK.

    The regulators expect to begin the next step of GDA involving more detailed assessment of the UK ABWR in September 2014. GDA’s process includes the Environment Agency and Natural Resources Wales consulting on their findings from detailed assessment. The regulators are targeting completing GDA in December 2017; this is subject to Hitachi-GE submitting timely and acceptable submissions.

    Horizon Nuclear Power Ltd is developing proposals to use the UK ABWR at its two sites, Wylfa (on Anglesey) and Oldbury (in South Gloucestershire).

    In addition to Wylfa and Oldbury any developer may propose to build this nuclear reactor design at any of the sites included in the Government’s Nuclear National Policy Statement.[1]

    The regulators have published reports of their initial high level assessments.

    The overall conclusions of our initial assessment for the UK ABWR nuclear power station design are:

    • The submission does not adequately address all of our information requirements (as set out in our process and information document (P&ID) (Environment Agency, 2013). Hitachi-GE has committed to providing the required information on a timescale that, subject to the information being of adequate quality, should enable us to maintain our indicative target of four years for completing a meaningful GDA.

    • We have not at this stage identified any matters addressed by the submission that are obviously unacceptable.

    • We have not at this stage identified any significant design modifications that are likely to be required.

    • Hitachi-GE has an appropriate management system in place to control the content and accuracy of the information it provides for GDA.

    • The annual radiation impact of the UK ABWR design on people would be below the UK constraint for any single new source.

    • Based on the information we have at present, it is likely that radioactive discharges would not exceed those of comparable power stations.

    • The generic site description is broadly consistent with the potentially suitable coastal sites identified in the nuclear national policy statement.

    Further or modified conclusions may be developed once Hitachi-GE has provided all the required information and we have carried out our detailed assessment.

    Getting involved

    · We welcome your feedback on our proposed approach to public and stakeholder engagement published earlier in the summer.

    · You can submit a question or make a comment about the UK ABWR using Hitachi-GE’s comments process. Your question will be answered by Hitachi-GE and both your question and Hitachi-GE’s response will be seen by the regulators and used to help inform their assessments.

    · The Environment Agency and Natural Resources Wales will consult on their findings from detailed assessment of the UK ABWR design around spring 2016.

    Further information

    To receive our GDA quarterly reports please register for our ebulletin at
    View our websites at:

    Contacting us

    Write to us at:
    Phone the Environment Agency general enquiries line: 03708 506 506 (Mon to Fri, 8am to 6pm). Minicom (for the hard of hearing) 03702 422 549. Details of call charges can be found on the GOV.UK website.
    For enquiries about GDA in Wales, or to speak in Welsh please contact NRW on 01248 484013

  • heinbloed says:

    About the EPR in Olkiluoto:

    News is just out that the project won’t be fished before 2017

    From Finland

    From Austria

    The situation of the site and the proposed data of going on-grid has to be reported to the grid authority every year, the last notification data (31.12.12013) Areva did let pass without giving a reason.
    The Finish press speculates that the EPR might never be finished.

  • Pete Pete says:

    This post is cited in ‘The Ecologist”. However, it was not written by me but by Emma –

  • […] I have just seen a posting that must be shared with all interested parties.Visit Peter Lux’s Blog […]

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