Leading climate scientists have for some time been urging world leaders and environmental campaigners to reconsider their points of view on nuclear power and its expansion. Nuclear power, they argue, is a vital ingredient in a diverse low-carbon energy future and populations are ill-served by unscientific, emotional and ideological opposition.
Today, nuclear scientists believe they have the answer to anti-nuclear objections in the new generation of advanced reactors, alongside small modular reactors (SMRs), and many are now entering their testing phase.
The key common feature of these otherwise widely differing concepts is that they have passive or inherent safety features that address safety concerns based on accidents involving earlier reactor technology.
Advanced reactors will be a major focus of WNE 2020 this June in Paris. Organisers have designated one of the exhibition’s three days as SMR and Advanced Reactor Day to put exhibitors, their concepts and projects in the spotlight.
Visitors to WNE at the Villepinte exhibition centre can expect this promising sector to be prominent among the 700+ exhibits, judging by recent activity around the world in this area.
Aiming for operational status
In the US, research and development (R&D) of so-called Generation IV (Gen IV) designs – some of which are said to be aiming for operational status by the mid-2020s – has received close to $200m in grants from the Department of Energy (DoE) in the last three years. For fiscal 2021, the DoE’s budget for nuclear energy R&D has been boosted to $1.2bn, up 50 per cent from the $824m allocated for 2020.
In addition to their safety, most of the new designs are simpler and more durable than older reactors, typically targeting an operating life of 60 years. Designers clearly anticipate that these reactors will be used to generate electricity in conjunction with other low-carbon power plants, and most designs have load-following capabilities.
Last year, the DoE launched the National Reactor Innovation Center (NRIC) at the Idaho National Laboratory as a means of giving private-sector technology developers access to the strategic infrastructures and assets of the national laboratories, and in so doing to accelerate technology readiness from proof of concept through proof of operations.
Rita Baranwal, DoE Assistant Secretary for Nuclear Energy, said in an interview that the NRIC underlined the DoE’s dedication to “demonstrating new nuclear technology in the United States”.
Among those to benefit was US company Oklo, which received DoE permission to build an advanced reactor – the first non-light water design – at the Idaho site. Its Aurora design, one of several projects the company is working on, uses metallic fuel in a “fission battery” to produce electricity and usable heat, company co-founder Jacob DeWitte said.
Oklo has incorporated many well-thought-out features in the design of its Aurora powerhouse, including solar panels “to illustrate how advanced fission and renewables can work together in a high reliability, clean microgrid."
FNR technology holds promise
Elsewhere, fast neutron reactor (FNR) technology – a development on fast breeder reactors – is showing promise. These reactors, as well as producing
more fissile nuclei than they use, can operate with depleted uranium as fuel, opening a possible avenue for nuclear waste disposal.
Significant FNR research is being carried out by WNE sponsor Rosatom, which plans to have a demonstration unit of its Brest-300 design running by 2026. This design uses a closed nuclear fuel cycle that can recycle spent fuel indefinitely. Its high-density fuel does not need enrichment to high levels, resulting in what experts describe as an inherently safe reactor.
In Europe, the Danish company Seaborg Technologies is aiming to commercialise its compact molten salt reactor (CMSR) from 2027. Seaborg says it and its industrial and academic partners are “making nuclear an inexpensive, sustainable and safe technology that can out-compete fossil fuels and revolutionise energy markets.”
Its project is partly funded by the Eurostars-2 joint programme with co-funding from the EU Horizon 2020 research and innovation programme.
The CMSR’s design makes it inherently safe, less complex and cheaper than conventional reactors, says the company, and it can burn spent fuel, converting existing long-lived waste into energy. It is currently in the design, demonstration and licensing phase before building a full-scale prototype around 2025.
Heading for commercialisation
In Canada, the Gen IV integral molten salt reactor (IMSR) design of Terrestrial Energy has received the go-ahead under the new joint US-Canadian regulatory authority agreement for the next phase of its design review, leading to its licensing and first commercial operations before the end of the decade.
The Ontario-based company’s spokesman, Jarrey Adams, said a key element of the design “is that it uses a replaceable seven-year reactor core that solves material lifetime challenges often cited as impediments to molten-salt reactor development in the past.”
In the province of New Brunswick, Moltex Energy is working toward demonstrations of its “breakthrough” stable salt reactors which have been described as the most promising molten salt reactor (MSR) technology in the UK. Supported by utility funding, the Canadian-UK company and its partner Advanced Reactor Concepts (ARC) Nuclear are moving toward the vendor design review that would open the door to commercial demonstration and potential entry into service at the Point Lepreau site around 2030.
The development of advanced reactors has attracted the attention and support of Microsoft founder Bill Gates. His company is a partner in TerraPower, which calls itself a nuclear innovation company “striving to improve the world through nuclear energy and science.”
TerraPower’s main focus is on two design concepts, travelling wave and molten chloride fast reactors. It is collaborating with GE Hitachi Nuclear Energy to
design and build an experimental fast neutron nuclear reactor for the DoE, called the Versatile Test Reactor (VTR), that could start up by 2026.
Another advanced reactor design, X-energy’s pebble bed, high-temperature gas-cooled reactor, has received $3.5 million from the DoE for R&D. This funding will enable the US company to reduce construction and maintenance costs of its Xe-100 design.
This reinforces the observation of US Secretary of Energy Dan Brouillette, who said: “Advanced reactors are taking off in the United States with more than 50 U.S. companies currently developing the technology. These private-public partnerships are critical to ensure the success of the next generation of nuclear reactors by making them more affordable to build and operate.”