News
HSE identifies safety flaws in new nuclear reactor designs
18 December 2009
This article looks at the impact of the Health and Safety Executive's (HSE's) recent report which raised safety concerns in the designs for new nuclear power plants in the UK.
In November 2009, the Government identified ten sites as suitable for the next generation of new nuclear power plants; the intention is that the first plant will be up and running by 2018. The outcome of the HSE's latest report could lead to significant delays, meaning the UK may soon face serious energy shortfalls.
The HSE's role
The HSE has developed a new 4 step process called Generic Design Assessment (GDA) to assess the proposed reactor designs. This involves the HSE looking at the design issues separately from other factors such as whether the location for the site is suitable, or whether the potential operator is competent. This enables the HSE to assess new nuclear power station designs before an application for a specific site licence has been received. The intention is that the process should be consistent and transparent. Crucially, as the process only needs to be carried out once for each design it should speed up the subsequent site-licensing process, and offer more certainty to investors at an earlier stage.
The HSE has set out the following 4 steps to determine whether a design can achieve "Design Acceptance Confirmation":
Step 1: Discussions with the requesting party
Step 2: Fundamental safety review (3-6 months)
Step 3: Overall design safety review (6-12 months)
Step 4: Assessment for design acceptance (2 years)
Current stage in the GDA process
The HSE started the GDA process in July 2007 by carrying out Step 1 for the following four designs:
• Atomic Energy of Canada Limited's (ACEL) ACR-1000
• AREVA and Electricité de France's (EDF) UK EPR
• GE-Hitachi Nuclear Energy's ESBWR
• Westinghouse Electric Company's AP1000
Step 1 involved preliminary discussions and initial reviews of the formal submissions together with starting the public involvement process. Step 1 was completed in August 2007.
Step 2, the fundamental safety review, commenced in August 2007. Before this was completed two of the original design companies withdrew from the GDA process. In April 2008, AECL announced that it would focus its resources on the Canadian market and in September 2008, GE-Hitachi temporarily suspended its design from the process. However, recently GE-Hitachi has suggested it may re-enter the UK market.
The Step 2 process was completed for the two remaining design companies, EDF/AREVA and Westinghouse, in March 2008. The HSE found no safety shortfalls which were "so serious as to rule out the construction of the designs on licensed sites in the UK".
The HSE published Step 3 reports for EDF/AREVA and Westinghouse on 27 November 2009. Both reports raised health and safety concerns. The HSE report "identified a significant number of issues with the safety features of [both] design[s] that would first have to be progressed. If these are not progressed satisfactorily then we would not issue a ‘Design Acceptance Confirmation' at the end of GDA Step 4." The HSE recorded, "It is too early to say whether they can be resolved solely with additional safety case changes or whether they may result in design modifications being necessary."
The HSE expressed "significant concerns" about the lack of separation between the safety protection and control systems on EDF/AREVA's EPR reactor design and its structural integrity. The HSE has criticised Westinghouse's design saying the safety case on internal hazards has "significant shortfalls" and that there is a "lack of detailed claims and arguments" to support various assertions.
Some of the concerns raised echo those relating to the Olkiluoto Nuclear Power Plant in Finland. Various issues in the construction of this AREVA EPR designed reactor have led to costly delays and the Finnish nuclear regulator has expressed doubts about the reactor's safety. The Olkiluoto reactor was intended to start generating electricity in May 2009. However, the plant is at least three and a half years behind schedule and more than 50% over-budget.
Commercial Impact of the HSE's Report
The Government's proposals for the next generation of new nuclear power stations depends upon HSE "Design Acceptance Confirmation" being secured. There has been some speculation that the HSE will come under commercial and/or government pressure to approve the designs. The capital costs involved are very significant and concerns have been expressed that any delays (including GDA confirmation) would potentially lead to companies making alternative investments in other markets.
The next step
Following the Step 3 report, both Westinghouse and EDF/AREVA must address the concerns the HSE has raised. Step 4 involves a much more detailed safety analysis.
The HSE's assessment work is due to be completed by June 2011 but concerns remain that this is a highly ambitious target.