Julianne Antrobus

UK & Europe

Julianne is responsible for developing the strategic direction of Atkins’ nuclear division across the core markets of the UK, Middle East and the US, with consideration of other emerging markets.

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We’ve talked about small modular reactors (SMR) before, looking at what they are and what the benefits and potential drawbacks of the technology are. Since then, industry around the world has been working hard to push forward the development of SMRs ready to bring to market.

The development of SMRs gives UK plc the opportunity to develop home grown intellectual property, create skilled jobs and to be an exporter of technology which can be sold around the world. Whilst it remains largely theory at the moment, two different categories of SMRs are now leading the way in development and we took the opportunity to discuss the pros and cons of each at the recent Nuclear Industry Association (NIA) SMR conference. Atkins is taking a leading role in working with government and industry to push forward the SMR development agenda, and our engineering experience across the energy sector puts us in a great position to assist developers find an engineering solution that will work to bring SMRs to reality.

The more developed designs coming forward are integral pressurised water reactors (IPWR), often referred to as third generation (GEN III). Made of the same four major components that make up a standard large scale light water reactor (LWR) or pressurised water reactor (PWR): the reactor, stream generators, pumps and the pressuriser. Integral is the key word: in the integral SMR, there is one vessel and all of these four components are either inside or directly part of the SMR vessel, removing all of the complicated pipe work that connect the components within a large nuclear reactor. So effectively it’s similar to what we have now, just scaled down with a new configuration.

The problem with these reactors is that they share complexity with the larger PWRs and it now appears unlikely that light water SMRs will be able to significantly reduce the cost of generation compared with larger reactors using the same technology due in part to the inability to reduce the complexity of the required safety control systems and diseconomies of scale in site operations.

However, IPWRs are based on proven technology in a new configuration, they are well advanced in design and some in regulatory approval, and they offer a least risk pathway to early deployment (by 2030). They are generally compatible with UK nuclear infrastructure but offer less opportunity for UK technical development.

The other group of reactors in development is are the “advanced” reactors or non-IPWR’s, commonly referred to as GEN IV. This category groups together some different technological approaches and includes a number of less well developed technologies that may offer significant cost and other advantages but with commensurately higher technical risks.

Non-IPWRs include high-temperature gas-cooled reactors, sodium-cooled reactors and molten salt reactors, amongst others. Some believe that this technology is too far away – it is possible that none could be deployed before 2030 and some significantly later than that date – as there are more uncertainties in both the technical and cost aspects of advanced reactors. Some GEN IV vendors are claiming they could be available only just behind the GEN III designs but these claims have yet to be substantiated.

However, there is the potential for a true price breakthrough because of the simplicity of the design of some of the GEN IV options. For example, they could have intrinsic safety which would reduce risk and control and operation requirements, but this is not yet proven. If you can get this, you remove a lot of the complexity therefore making it simpler, smaller and cheaper. These advanced technologies also offer the potential for greater UK technical development.

The dilemma facing the SMR initiative is: Can GEN III deliver at a globally competitive power price that would create a true mass market? Or is it worth taking the risk on GEN IV which may be able to offer a true safety and price breakthrough a few years after GEN III?1The development of SMRs is moving at different paces in different parts of the world and it remains to be seen who will get there first, and which technology will be able to provide cost competitive and commercial scale power. SMRs could play a major role in a broad energy mix and in theory SMRs could help reduce cost, secure domestic supply of electricity and reduce greenhouse gases, whilst at the same time – with the right competition, the right support and the right approach – the SMR opportunity for the UK could be a major wealth creator.

UK & Europe, North America, Middle East & Africa, Asia Pacific,

When we think about generating nuclear power, the immediate image that springs to mind is of a large nuclear reactor, always somewhere near the coast, producing between 1,000 and 2,000 megawatts (MW) of power – enough energy to power millions of homes.

High capital cost is one of the reasons why it is becoming harder to finance and invest in new large scale nuclear plants and that, in many people’s eyes, makes large scale nuclear difficult to justify as competitive with other forms of generating power. Another argument is about time. The last nuclear power station to be built in Britain – Sizewell B – was finished over 20 years ago and although we’re closer than ever to a new one getting underway, it’ll be into the 2020s before a new nuclear power plant will be up and running.

Small modular reactors, more commonly known as SMRs, could therefore play an important role in the future of nuclear.

Defined by the International Atomic Energy Agency (IAEA) as under 300MW, SMRs are by their nature, smaller and more flexible to site. As well as decreased site infrastructure construction and cost reductions because of their modular nature, staggering construction of units could mean a more gradual level of investment as the capacity builds up module by module, better matching capacity to requirement.

The other major benefit of a modular reactor is that they can be deployed at a wider range of sites than large scale nuclear reactors – assuming the SMR gains all the necessary consents and licenses – and has applications as an alternative energy source in regions where grid capacity is weak or non-existent, remote locations with sparse populations, or larger energy-using industrial applications such as for the chemical industry or at desalination plants.

Much less water is needed to cool an SMR than a conventional large scale reactor, and this has potential applications as heated water from an SMR can be pumped into district heating schemes.

This begs the sixty-four million dollar question: why haven’t we built any yet?

Economies of scale have meant that for larger power plants the pound per megawatt ratio is reduced the bigger the plant gets. For SMRs, scale would be found in economies of mass production as they are turned out in factories in large numbers, but the technology would still have to prove it can generate electricity at a reasonable price. Technical challenges about how to exactly do that is something developers are still working on.

There are some examples from around the world that show development of demonstration projects well under way – from Russia, Korea, China and the USA (although there’s been a bit of a stumble in the latter due to the impact of the shale gas boom), many companies are working on many different designs.

In the UK, Atkins has for some time been involved in work to help make the SMR a reality including our contribution to a recent Energy Technologies Institute study on the role for nuclear within a low carbon economy. Our country’s nuclear pedigree and desire to regain our position as a pioneering nuclear nation has led to some interesting designs and developments of our own. Several UK based companies, and the government, are either conducting feasibility studies or developing micro-reactor concepts and we’re excited to see where the next stages of work will take the industry.

Aside from regulatory hurdles, perhaps the biggest issue with SMRs really lies around acceptability. Support for nuclear power varies wildly from country to country. In the UK, support hovers at around 40% (source: The Guardian) and is much higher at 68% in the USA (source: World Nuclear News), whilst a return to nuclear power in Japan is staunchly opposed by 70% of people there (source: Washington Post). So would the public be open to having a small nuclear reactor in their backyard providing direct power and maybe also heating to their community? Do we want one in the basement of our office block? Are there moral implications of putting small nuclear reactors into remote communities?

If these and other questions can be answered, there may be a big future for small nuclear.

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