Nuclear Energy

Viscount Hanworth Excerpts

Thursday 7th September 2023 Lords Chamber

[Viscount Hanworth (Lab)]

Britain is experiencing an energy crisis. Despite its commitment to staunch the emissions of carbon dioxide, it remains heavily reliant on fossil fuels to power its industries and, more significantly, to power its transport and its electricity generation. The electricity generation is increasingly dependent on renewable sources of wind and solar energy. These sources are intermittent and require to be supplemented by other means of generating electricity which depend, mainly, on gas purchased on the international markets at prices that are subject to extreme fluctuations. We would not be in our present position of vulnerability to international markets if we had maintained our nuclear industry.

At the beginning of the Cameron-Clegg coalition Government in 2010, it was proposed that contracts should be offered for building eight new nuclear power stations. Whereas the existing nuclear power stations had been financed by central government, it was decided, in accordance with the philosophy of the Conservative Party, that the new power stations should be financed by private capital. It would be tedious to recount the history of the repeated failures of the Government’s nuclear policy. Over the succeeding 13 years, only one semi-nationalised enterprise, EDF, has undertaken to build a nuclear power station in Britain.

Politicians appear to have woken up, belatedly, to the crisis in our energy supply. A body called Great British Nuclear—GBN—has been established, which will be charged with overseeing the revival of our nuclear power industry. Its first activity will be to oversee a competition in which the favoured design of a small modular reactor—an SMR—will be chosen. This process is shrouded in secrecy, which inhibits a rational discussion of the options. It looks as if there will be a three-horse race, in which the competitors will be Rolls-Royce, GE Hitachi and X-energy, which are one British enterprise and two American enterprises.

It is galling to recall that Britain was the first nation to establish a civil nuclear industry. The world’s first civil nuclear power station was opened at Calder Hall, in Cumbria, in 1956. The domestic and geopolitical circumstances at that time determined the nuclear technologies that have prevailed to this day. A covert purpose of the nuclear industry was to manufacture the plutonium that would be deployed in nuclear weapons. The first two reactors that were erected at Windscale, adjacent to Calder Hall, were devoted entirely to this purpose. The Calder Hall reactor, which was a gas-cooled Magnox reactor, was entirely devoted to the civil purpose of electricity power generation. Britain continued to pursue technological advances in this area. This led to the advanced gas-cooled reactors which power all but one of Britain’s nuclear power stations. It also gave rise to a so-called pebble bed gas-cooled reactor, the Dragon reactor, in Winfrith, in Dorset, which operated from 1965 to 1976. Another experimental reactor was the sodium-cooled fast breeder reactor at Dounreay, which was capable of consuming the excess stocks of plutonium.

There were other developments in the United States. A leading proposal for a civil nuclear reactor was a thorium molten salt reactor that was advocated by Alvin Weinberg, of which a prototype was realised at the Oak Ridge laboratory. Weinberg encountered fierce opposition from Admiral Hyman Rickover, who was in charge of the American nuclear fleet. Rickover favoured a pressurised water reactor for submarines. The consequence was that such reactors have come to dominate both in civil nuclear power stations and in military applications in submarines and aircraft carriers.

The pressurised water reactor was favoured for submarine propulsion because it appeared to be light and compact. An irony is that, in its civil applications, it has spawned massive nuclear power stations that are burdened with safety devices designed to overcome the dangers of a pressurised nuclear meltdown, of the sort that we witnessed at Three Mile Island, Chernobyl and Fukushima.

This account of the available nuclear technology provides a backdrop to the British competition for a design of a small modular reactor. Rolls-Royce should be a front-runner in view of its experience with pressurised water reactor technology and in view of the fact it is a British enterprise. Its reactor would generate 470 megawatts. This exceeds the 300 megawatts which is the conventional limit of a small modular reactor. GE Hitachi is offering the tried and tested technology of a pressurised water reactor, packaged as an SMR and rated at 300 megawatts. This amounts to a small power station. Perhaps one would be more excited if GE Hitachi were to offer its fast sodium-cooled PRISM reactor, which would be capable of burning the plutonium of which there is an abundant stock at Sellafield. X-energy is proposing a pebble-bed reactor that is cooled by helium and which weighs in at 80 megawatts. It looks complicated. Among the complications are, first, the manufacture of the fuel pebbles; secondly, the deployment of the helium coolant; and, thirdly, a mechanism for the active control of the reaction. If this reactor were to be favoured, Britain would be importing from the United States a technology that it already pioneered in the 1960s via the Dragon reactor.

Other options are available to us which we are in danger of overlooking. Foremost of these is a British design for a molten-salt reactor, described as the MoltexFLEX reactor. This reactor has an inner core in the form of a collection of fuel rods that contain a salt-uranium reagent. Its cooling circuit, which transfers the power to a heat exchanger, also contains molten salt at a temperature of 750 degrees centigrade. The outer cooling circuit is powered solely by convection, with an absence of valves or pumps. The reactor is inherently safe. If, for some unimaginable reason, the reactor were to rupture, the escaping salt would quickly crystallise at a temperature of 550 degrees centigrade. A single MoltexFLEX reactor would produce 40 megawatts of energy; and it could be deployed on its own in an industrial application, which might use its heat, or a combination of heat and electricity generated by steam, using turbines. An electrical power station might contain a battery of 32 such reactors.

The MoltexFLEX prototype could be up and running before 2030. Therefore, it seems unaccountable to me that it has not also been considered as a front-runner. I have difficulty in understanding this. I presume that, in the minds of the civil servants, the advantage of the X-energy reactor, with which the MoltexFLEX might be compared, is that it is receiving funding from the United States Department of Defense and from the Department of Energy. Also, if the X-energy reactor were to be adopted in the UK there would be some inward financial investment, but these are insufficient reasons for failing to sponsor a native design; yet I believe that they are typical of the thinking of the Civil Service and of the Government.

Three distinct purposes could be served by the various designs of nuclear reactors. First, we need nuclear power stations that contribute electricity to the grid. Various reactors are on offer for this role, which are mainly pressurised water reactors. At one end of a spectrum are the EPR reactors, rated at 4,500 megawatts thermal power, which are to be deployed in the mega power stations of Hinkley C and Sizewell C. At the other end of the spectrum are the small modular reactors of Rolls-Royce and GE-Hitachi. We should persist with Hinkley C and Sizewell C: but they should be succeeded by a fleet of SMRs from Rolls-Royce, which could be distributed widely throughout the country.

Secondly, there is the need for a much smaller reactor for powering industrial processes. The MoltexFLEX reactor should be chosen on the grounds of its simplicity and robustness.

Thirdly, there are fast reactors that are capable of burning the stocks of plutonium and of consuming other kinds of nuclear waste. The GE Hitachi PRISM reactor, which is finding favour in the USA, could be an appropriate choice.

I must ask the Minister to reveal the Government’s appraisal of these opportunities and I seek an assurance that they will take steps vigorously to support our native endeavours, which include the Rolls-Royce SMR and the MoltexFLEX reactor.