Atomic education20 February 2019
From the early days, the UK has been at the forefront of nuclear science and technology. Paul Norman, director of the UK’s longest-running nuclear degree programme, looks at how the industry and higher education have evolved.
THE STORY OF FISSION BEGAN back in the 1930s when, following the discovery of the neutron by James Chadwick in 1932, experiments began on bombarding different materials with neutrons.
Two experimentalists were Otto Hahn and Fritz Strassmann, who observed interesting effects when bombarding uranium. They observed by-products that behaved like barium and other elements, and Hahn wrote to Lise Meitner describing what he thought could be a “bursting” of the nucleus. It was actually Meitner and her nephew, Otto Frisch, who pieced together the details of the process, tying in the energy release with the semi-empirical mass formula and Einstein’s famous E=mc2. They realised that the process was more along the lines of the nucleus dividing than bursting, and Frisch called it “nuclear fission” in analogy with cell fission in biology. By this time Europe was on the brink of World War 2 and many scientists were moving or doing research into military related applications.
Frisch came to Birmingham in the UK to work with Rudolph Peierls, an eminent theoretical physicist, for what Frisch thought would be a brief spell in England in 1939. The outbreak of World War 2 resulted in him staying longer, however, and the use of nuclear fission began being turned into a more militaristic direction.
Previously, even Einstein had thought that, although some sort of device exploding with vast energy release could be possible it would be so massive that only a huge ship could possibly carry it. The step that Frisch and Peierls made at Birmingham was that if one enriched the uranium, so a higher proportion was useful U-235, then the amount needed to sustain a chain reaction decreased massively. It could become a practical device that could be dropped from a plane onto a target. Their Frisch-Peierls memorandum which was typed up at, and signed off by, the University of Birmingham laid out the principles of constructing the atomic bomb, and also went into detail about the blast itself, the radioactive fallout that would follow, etc. This was also the basis of the British “tube alloys project” to build an atomic device in the UK to help win the war. British findings were sent to the USA, but did not initially reach the right people. It was only when Mark Oliphant, head of physics at the University of Birmingham at the time, went to the USA and spoke to key figures such as Ernest Lawrence that the findings were taken more seriously and acted upon. With much greater resources, and not being at war at the time, the USA was able to make much swifter progress in developing the bomb, and key figures such Frisch, Peierls and Oliphant joined a “British Mission” to work on the Manhattan Project. Many of them played key roles. Frisch was head of critical assemblies, during which he famously “tickled the dragon’s tail” in playing with lumps of uranium that almost caused him to be blasted by a fatal dose of radiation.
Following the development of the two atomic bombs, Little Boy and Fat Man, and the subsequent bombings of Hiroshima and Nagasaki, the emphasis on nuclear technology thankfully turned towards Atoms for Peace.
The world’s first commercial nuclear power station was opened in 1956 by the Queen at Sellafield in the UK, and was of the Magnox reactor type. The USA followed a year afterwards at Shippingport, with a pressurised water reactor (PWR). The USA had identified the PWR as a useful technology, partly due to Captain Rickover (later to become Admiral Rickover) noting that its use was well suited to submarine propulsion.
Whilst light water reactor systems always require enriched fuel to operate, this was not a problem in the USA following the end of WW2. It had enrichment facilities and quantities of enriched uranium. The UK, in contrast, was playing catch-up. Much of the collaboration with the USA ceased after WW2 and the UK initially needed a reactor type that could run with unenriched (natural) uranium. The Magnox system suited this purpose. The French initially followed along fairly similar lines to the UK, before years later embracing the USA’s PWR technology.
Japan’s first reactor was a Magnox reactor (Tokaimura 1) built in collaboration with the UK. Various other designs were tried in various countries, including boiling water reactors (BWRs), fast reactors, molten salt reactors and high temperature reactors (HTRs). Many of the advanced and next generation systems being designed today come under these categories, and trace their early origins to those pioneer designs.
The situation today
The present day sees an interesting picture in the UK and around the world. All of the UK’s first generation of Magnox power stations are now undergoing decommissioning.
Their successors, the advanced gas-cooled reactors (AGRs) are still operating, and were an evolution of the Magnox design that still used a graphite moderator and CO2 coolant but were designed to operate at higher temperatures. This was achieved by changing the cladding from Magnox to steel, and the fuel from uranium metal to uranium dioxide. They required enriched fuel, but by this stage that was no longer a problem for the UK.
These reactors achieve thermal efficiencies comparable to fossil fuel plants and are world leading in a number of aspects (including the record for most days of continuous operation for a nuclear plant). However, most of the world’s reactors are PWRs or BWRs, with the next most common design being the Canadian heavy water “Candu” systems.
The Chernobyl nuclear accident in 1986 was one factor that saw a decline of nuclear build. In the UK, for example, the only new reactor project to have been completed since then is Sizewell B (the UK’s only civil PWR). A number of other countries saw a similar tailing off, so in many places the current nuclear fleets are already some time into their operational lives. This raises the question of where things will go from here.
Clearly, if no new systems are brought in to replace the old when they retire then the capacity will soon be lost (we are still talking about reactors here, but the same can be said of personnel).
As nuclear is arguably the only large-scale electricity producer which is low carbon, this has implications for climate change targets. The nuclear workforce in many nations follows the same trend observed by the power plants themselves. In the heyday of nuclear new-build the industry attracted significant numbers, and of the brightest and best minds. As nuclear new-build dwindled, so did the new blood in the industry, and this creates manpower issues now when those experienced workers are approaching retirement.
Much of these issues have been mirrored in the academic sector. By the 1990s the number of UK university courses in civil nuclear power had shrunk to just one – the MSc in Physics & Technology of Nuclear Reactors (PTNR) at the University of Birmingham. Prior to the current incumbent, the course had only been run by three other people. The most recent was taught nuclear physics by Frisch, his predecessor was an engineer taught mathematical physics by Rudolph Peierls, and the course founder referred to them as “Rudi and Bobby” (due to Frisch’s middle name being Robert).
Course numbers, rarely high on a postgraduate Masters course, also dwindled during the late 1990s.
Thankfully, the British industry rallied around the course to keep it afloat when it was in danger of closure, and a steering group composed of key UK nuclear companies provided support to the programme to keep it going – support that continues, with some changes of company members, to this day. Things also started to turn around in the outlook for new nuclear in the UK following a government white paper and then Prime Minister Tony Blair’s remark that nuclear was “back on the agenda” in the UK in 2006.
Student numbers started to grow on the MSc course so typical yearly numbers were about three and a half times the average over the previous half century. The average has been maintained for about 13 years.
Other initiatives have sprung up, both at Birmingham and elsewhere, as other universities seek to help meet future skills needs. Programmes elsewhere offer slightly different emphasis to the Birmingham course, such as catering more towards part-time or industrial students, or delivering a larger focus on other aspects such as policy.
A few universities have also started a nuclear engineering undergraduate programme (either as Bachelors or undergraduate Masters) and Birmingham currently delivers the biggest of these in the UK, utilising the expertise built up over many years of running an MSc course. It has also recently been running an MSc in Nuclear Decommissioning & Waste Management, in recognition of the growing need for people in the decommissioning sector.
This is currently the only specific decommissioning course in the UK. Indeed, there are few decommissioning- focused courses worldwide, despite what will obviously be a pressing need for many nations. Significant numbers of graduates with some form of nuclear qualification are now graduating every year from British universities, so this is a good sign for the future workforce.
Supporting a nuclear future
What is the future outlook for nuclear in the UK and worldwide? The Fukushima accident in 2011 put a halt to a number of countries’ aims for possible nuclear new-build. In places with new-build underway at the time, Fukushima delayed the process and all countries required a careful review of plant safety and procedures. (The UK regulator published a report on this, informally dubbed “The Weightman report” in honour of Mike Weightman, the Chief Inspector at the time).
However, Fukushima did not stop all new-build ambitions. In the UK the support for new nuclear did not dwindle, and in fact according to surveys done by Ipsos MORI the UK saw (after an initial slight blip) a small increase in public support.
Now there is new-build in a number of countries. As well as the USA, France, UK and Finland, the majority of new-build is in China, the UAE and elsewhere in the middle and far east. These projects are moving more smoothly than their western counterparts, where issues such as financing, significant company changes, and delays have been more prevalent. The UK currently has a twin EPR system being constructed at Hinkley Point in Somerset. This is a project with EDF as the main company and Chinese company China General Nuclear (CGN) as a minority stakeholder.
These units are, at the time of writing, on schedule. So it is hoped that lessons learned at the previous EPRs under construction at Olkiluoto 3 and Flamanville 3 may ultimately keep Hinkley Point C to schedule.
The other most immediate new build possibility in the UK is Horizon Nuclear Power (owned by Hitachi), which is aiming to build Advanced Boiling Water Reactors (ABWRs) at the Oldbury and Wylfa sites. A decision on the first of these, at Wylfa, is due within the next year. This could be a key milestone for new-build in the UK, because construction at multiple sites will begin to build momentum behind what would then start to be shaping up towards a new fleet of reactors to replace those closing.
Additional plans are for Horizon to eventually follow the Wylfa Newydd project with twin ABWRs at Oldbury, and for the EDF-CGN partnership to build twin EPRs at Sizewell C. As part of the deal with CGN, EDF plans to support CGN with build of their HPR1000 or “Hualong One” reactor system at Bradwell in Essex. In this case, ownership of the project will be flipped with respect to Hinkley and Sizewell, with CGN the main company and EDF the minority stakeholder.
The UK’s regulator has a rigorous Generic Design Assessment (GDA) process for scrutinising and approving reactor designs for their safety and suitability for deployment in the UK. Both EPR and ABWR have completed the GDA process and the HPR1000 is currently in stage three of the GDA at the moment.
The Westinghouse AP1000 had also been in GDA with plans at one stage to build up to three units at Moorside near Sellafield. Sadly, recent financial developments at Westinghouse/Toshiba have now cast this project into doubt and any eventual progress on the Moorside site will now probably have to come from new companies and investors, who will likely bring their own technology in place of the AP1000.
Possibilities for this could include Korea Electric Power (Kepco), or perhaps CGN again, but at the time of writing the future for Moorside is uncertain.
In the longer term, other possible technologies being explored and developed worldwide include of course fusion power, and also next-generation fission reactors. In the USA, which traditionally has a history of LWRs, there is some emerging interest in gas-cooled reactors. In France, there is an interest in exploring how fast reactors can be coupled with the PWR fleet for more efficient and improved nuclear fuel cycles.
Research into small modular reactors (SMRS) in a number of nations, including the UK, also hints at some promising possibilities for a nuclear future. Whilst these have to be made in significant numbers to create any savings compared to larger systems, the worldwide emphasis on cutting carbon emissions should point towards greater desire for multiple low-carbon units in many parts of the world. It is interesting that UK new-build is by companies from other countries; at present France (EDF), Japan (Hitachi) and China (CGN).
Compared to the early historical content discussed at the beginning of this article, nuclear has come almost full circle – going from a secretive technology, closely guarded and not widely disseminated, to one which is crossing borders, forging international collaborations, and being shared to countries which, in some cases, previously had no nuclear. With this evolving picture, and the desire for increasing amounts of low-carbon energy, the nuclear future could be bright.
Author information: Paul Norman, Director of Education for Birmingham Centre for Nuclear Education & Research (CNER)