One wing good, two wings better
90 years ago, the Air Ministry dismissed monoplanes as fighter aircraft on the grounds that biplanes had served us well in World War 1 and biplanes were what our world-beating aircraft industry built. The fact that monoplanes were breaking airspeed records and winning international races merely indicated their suitability for amateurs. It should have been no surprise, come 1939, that British “string bags” proved no match for the Luftwaffe’s monoplanes. Luckily, and just in time, the private sector had rebelled and put the Spitfire, and then the Hurricane, into production. MIT Professor Eric von Hippel has long demonstrated that “user innovation” is more successful than that by bureaucracies.
The Department for Business, Energy and Industrial Strategy (BEIS) exhibits the same “two wings better”. It is widely accepted that a zero carbon 2050 means that most electricity by then will have to be generated by renewables and, because the wind does not always blow, nuclear. BEIS is committing us to the third generation of pressured water reactors (PWRs) like Hinkley Point and Sizewell C. They expect those to be followed by Rolls Royce which is “planning to build 16 Small Modular Reactors [SMRs], and says the first one could be on the grid by 2031.” There are a number of other types of nuclear plant that BEIS could be evaluating but the most attractive looks to be Molten Salt Reactors (MSRs). However, BEIS does not want to consider those before the 2040s.
There is no BEIS analysis today, e.g. in the White Paper, of the best options. PWRs roll on because that is what we have done before. PWRs purchased from EDF, described by Alistair Osborne, The Times Business Editor as “the cost-overrun and late-delivery specialists behind the consumer-fleecing £22.5 billion Hinkley Point C.” What with flood risks, ecological damage and nuclear waste disposal, these are unpopular and virtually banned in Germany. Seven of the existing eight UK plants need decommissioning by 2030 and it would seem that we can expect more of the same out-moded PWRs.
The case for the Rolls Royce SMRs rests on Rolls Royce being British. If any performance or cost comparisons have been made, they have not been published. The case for MSRs rests on safety, size, cost, and rapid deployment. We should look at those in turn.
“The basic idea is to dissolve the nuclear fuel in a liquid – a molten salt at 600-700 degrees C – that is continuously circulated through the reactor core. In the core, the liquid-carrying channels are surrounded by neutron-moderating material (mainly graphite), which provides the conditions for fission chain-reactions to occur in the dissolved fuel. Leaving the core at a higher temperature, the fluid runs through a heat exchanger, transferring the extra heat energy to a secondary circuit. It is then recirculated back to core.” I am not sure that explanation leaves me much the wiser. Let’s just say, it is high tech and it works.
MSRs operate at low pressures without the need for large containment structures. Radioactivity declines as they heat up with no risk of radioactive isotopes escaping. They are small, built on a factory production line and delivered by road. They can also be mounted on special barges and moved close to where electricity is needed. They do not need large quantities of cooling water which means that they can be located inland.
Capital cost estimates are in the range £1.5m to £2.5m per megawatt (MWe) of output. This is significantly lower than the capital cost per MWe of output of Hinkley Point C (currently around £6.6m per MWe) and would make electricity from molten salt reactors cheaper than electricity from gas fired power stations.
Total costs (including running costs) are compared using the ‘Levelised Cost of Electricity’ (‘LCOE’). The LCOE for molten salt reactors is in the range $40 to $50 per MWh. For comparative purposes, the LCOE for conventional nuclear is in the range $118 to $192 per MWh. Offshore wind is estimated at $111 to $115 per MWh.
MSRs were successfully tested in the USA in the 1960s. The Seattle-based USNC expects to get approval for a demo plant in Ontario in 2022 and commercial operations are due to start in 2026. At the end of 2021, the Washington State based ThorCon will begin the first stage of construction of its 500MWe demo plant for installation in Indonesia by the end of 2024. Most of their plant will be built in a Korean shipyard. Using rapid modern shipbuilding techniques, they will be able to build most of a plant in a year. ThorCon started as outsiders in the industry – but so was Elon Musk and he is now well ahead of the traditional car makers. Moltex and Terrestrial Energy, both with offices in Canada, the US and the UK, have received large financial backing from both the US and the Canadian Governments. USNC, Terrestrial and Moltex are the front runners to produce cheap electricity for the Provinces of Ontario and New Brunswick by 2029. Those companies estimate dates for deployment of full-scale MSRs in 2024 (Indonesia), 2027-2029 (Canada, USA & Denmark) and 2030 (China).
It really is remarkable that BEIS should ignore international developments and fail to cost or compare the options available. Some people might consider that unprofessional. Unless Kwasi Kwarteng wakes up soon, the UK will be 20 years behind other leading nations.