This forum is about wrong numbers in science, politics and the media. It respects good science and good English.
I would agree that going back to the idea of building Sizewell B-type plants would be better from a cost point of view than pursuing the proposed Hinkley C EPR design. When the Sizewell B project was given the go-ahead in 1987 (following the 1987 General Election), the intention was to build at least two further plants of that design starting in the early 1990s. But when John Major took over as PM from Margaret Thatcher in 1990, he then postponed the construction of the follow-on stations. This caused quite a bit of hassle on the Sizewell B project because equipment suppliers had submitted tenders under the assumption that three stations were going to be built, and they would have charged more if they'd known only one might be built. So the Sizewell B equipment suppliers tried to claw some money back through coming up with lots of 'contract variations'. Eventually Major cancelled the follow-on stations in 1996 and that was pretty much the end of the old UK nuclear power plant building industry.
But I doubt you would be able to build Sizewell B-type plants nowadays because of the more influential position of the UK nuclear regulator, the ONR (Office for Nuclear Regulation), formerly known as the NII (Nuclear Installations Inspectorate). In the 'rebooted' version of the UK nuclear power plant building industry, started up by the Blair government in 2005, foreign nuclear firms seem to submit state-of-the-art designs which are then assessed by the ONR. UK nuclear firms are probably out of the picture because they would be expected to finance the nuclear plant themselves, and it would be very difficult to borrow the money for that in the UK with the Green influence within the UK financial community (I think UK nuclear firms are currently talking about the idea of building small-sized reactors, which is probably all they can get the finance for).
This extract from the Wikipedia article about the ONR seems to explain how things work nowadays:
"Generic Design Assessment process
Following the 2006 Energy review the Nuclear Installations Inspectorate developed the Generic Design Assessment process (GDA), now operated by ONR, to assess new nuclear reactor designs ahead of site-specific proposals. The GDA started assessing four designs:
However the ACR-1000 and ESBWR were subsequently withdrawn from the assessment for commercial reasons, leaving the EPR and AP1000 as contenders for British new nuclear builds. Assessment of the AP1000 was suspended at Westinghouse's request, awaiting a firm UK customer before addressing issues raised by the assessment.
In 2012 Hitachi purchased Horizon Nuclear Power, announcing intent to build two to three 1,350 MWe Advanced Boiling Water Reactors (ABWR) on both of Horizon's sites. The ABWR will first require a UK GDA. The assessment was agreed in April 2013, and is likely to take about four years.
On 21 September 2015 Energy Secretary Amber Rudd announced that a Chinese designed nuclear power station was expected to be built at Bradwell nuclear power station. The reactor chosen will first require a UK GDA."
It looks to me that the ONR are now calling all the shots as to what nuclear plants get built in the UK. For example in 2006, four designs were submitted to them, and three of the designs later pulled out of the process presumably because they had to modify the design in some manner to satisfy ONR. The problem with letting the nuclear regulator decide on what gets built is they will obviously gravitate towards the 'safest' reactor design, which is also quite likely to be the most expensive and the most complicated to build. The EPR design is apparently regarded as a very safe reactor design, and has even received some praise from the "Union of Concerned Scientists" activist group.
In the old days, UK politicians had the main say in what reactor designs got built. So Labour were the champions of the UK-designed AGR from the 1960s, but the Conservatives were more sceptical about the AGR. We ended up building a PWR, Sizewell B, because the Conservatives put it into their 1979 General Election manifesto that a PWR was going to be built. I think in the 1974 Conservative General Election manifesto, the Conservatives said they would build a Canadian 'Candu' reactor, so if Ted Heath had managed to win that election we might have had a Candu reactor somewhere in the UK.
I've just noticed a couple of mistakes in my last post regarding the content of Conservative party general election manifestos in the 1970s, after checking the manifestos on the www.conservativemanifesto.com website.
The 1979 manifesto didn't mention a reactor type at all, so the Conservatives must have made the decision to build a PWR within a few months of winning the 1979 general election.
The October 1974 manifesto didn't actually specify that a Candu reactor was going to be built, it looks like it was going to be the British equivalent of a Candu, an SGHWR (steam generating heavy water reactor), described as the "British designed 'heavy water' system":
We will carry through the recently announced pilot programme of nuclear power stations based on the British designed 'heavy water' system. We believe that a larger nuclear programme must be initiated at an early date. In all nuclear matters, safety and reliability must be our paramount considerations."
To give a bit more information on why I think that £92.50/MWh figure is strongly related to the Lib Dems, I vaguely remembered that EDF were quoting a much lower figure for Hinkley Point than that a few years earlier when Labour was in power.
I searched around on the internet for the lower figure that used to be quoted, and it was actually £45/MWh in December 2008, given on this link:
But by October 2013, less than five years later, but with the Lib Dems in charge, the figure had risen to £92.50/MWh. That figure is also index-linked and applies to 2012, so it would be I reckon £98.52/MWh in 2016.
Ed Davey was given a knighthood for making these sort of arrangements for the provision of low carbon electricity for the UK. And if Chris Huhne, Davey's predecessor, hadn't fallen from grace, then he (Huhne) would presumably have got the knighthood for this.
Another big number which may come up in the near future in connection with Hinkley Point is that if the project ends up being cancelled, EDF has indicated that it wants £2.5 billion in compensation. The £2.5 billion figure presumably covers design changes they've had to make to satisfy the UK's nuclear regulator ONR, and preparatory work and site-specific work that has been carried out before the construction starts.