Hitting net zero on enrichment16 November 2022
Nuclear power is key to a low-carbon future, but improving the climate performance of the entire value chain is another important part of the transition. Uranium enrichment company Urenco is one of the leaders of the pack
Producing around a quarter of the world’s carbon-free electricity, nuclear is already a major contributor in the fight against climate change and the transition to net zero. But while nuclear generation is the second least carbon intensive energy source, and certainly delivers a good return on energy investment, production of nuclear fuel is still an energy intensive process with conversion and enrichment particularly energetic components. There is still carbon generated in the whole life cycle itself. This fact has led to much criticism from the environmental lobby who argue that while nuclear power may be considered low-carbon, the upstream nuclear energy business is far from green.
Recognising this, companies within the nuclear fuel supply chain are looking to improve the sustainability credentials of their businesses by moving to reduce their carbon intensity.
Taking this to its logical conclusion, uranium enrichment company Urenco has tried to lead by example by declaring its ambition to become entirely net zero compliant for scope 1 and 2 emissions by 2030. The Greenhouse Gas protocol defines Scope 1 and 2 emissions as those arising directly from business operations and those that come from purchased energy. The move represents a dramatic acceleration of its existing net zero roadmap by bringing it forward by a full decade ahead of its previously announced plans for scope 1 and 2 net zero by 2040.
“At COP26 we did announce our goal to achieve carbon net zero by 2040, 10 years in advance of the global commitments to 2050. Since that time we’ve done a lot to develop our approach and a roadmap and as a result we are planning to further substantially reduce our carbon impact by 2030,” Dave Sexton, Urenco chief operating officer, told NEi, adding: “We felt that was an important commitment to make and we’re on path to do that, but now we are planning to build off of 2040 and increase what we had originally proposed.”
Sexton continues: “Of our total carbon footprint, scope 1 and 2 constitutes about 50% so by 2030 our goal is to achieve net zero on 50% of our emissions based on our baseline year, which is 2019. Not only does that far exceed the science-based targets to limit global warming to 1.50C by 2050, but we will beat the target substantially. We are signing up to that Science Based Targets initiative (SBTi) approach because it’s the recognised way, we believe, for confirming and monitoring our progress. Furthermore, we’re committed to having these targets validated by the SBTi.”
Shifting centrifuges to sustainable energy
Today the vast bulk of uranium enrichment is performed by cascades of centrifuge machines spinning at extremely high speed. These machines separate different isotopes of uranium hexafluoride through minute (circa 1%) differences in density. First demonstrated in the 1940s, the gas centrifuge process used by Urenco has hardly changed since second-generation enrichment technology was introduced in the 1960s.
Defined in terms of separative work units (SWU), modern gas centrifuges require about 40-50 kWh per SWU and, according to the World Nuclear Association (WNA), globally some 66,700 tSWU were produced worldwide in 2020. Furthermore, centrifuges must be kept running at all times, leading to a significant power demand.
“The majority of our scope 1 and 2 emissions are from the use of electricity,” says Sexton, noting that for Urenco, the solution to the sustainability conundrum is to reduce energy use wherever possible and make a substantial shift towards low-carbon energy sources for the remaining power consumption.
“At all of our sites we are looking at shifting over time to low-carbon energy sources, which we believe does include nuclear power,” says Sexton. “Already one of our sites uses electricity solely from dedicated nuclear power,” he says, referring to the UK site at Capenhurst which already takes 100% of its supply from nuclear energy.
Urenco plans to switch all of its four sites to a low-carbon electricity supply by 2030 featuring nuclear, renewable energy or both. Under current plans the US site will switch to a low-carbon supply by 2024 and the Netherlands and Germany before 2030.
Urenco is developing on-site solar PV installations at all of its facilities where suitable space is available.
“We are looking at solar panel installations to also help offset some of the electricity demand. There’s one under construction right now at our Netherlands facility and we’re looking at them for the other three sites. Two of those three will likely be approved this year,” says Sexton. The Netherlands has installed solar panels on some of the large buildings and plans to do this in its parking area, too. These installations are expected to reduce the site’s peak electricity demand by up to 15%, resulting in an annual average reduction of 2%.
“In the United States, which we are still investigating, the current proposal there is to install solar on a piece of land that we own that is not physically located on the site property. It depends on the site and the availability of space and if were able to put solar on top of the buildings, but we’re moving down that path for all of them,” Sexton adds.
“Our German site is looking into this as well, but the largest install will likely be our Capenhurst site in the UK where we have quite a bit of land space that we’re proposing to use solar on,” he says.
The proposed project has been estimated to provide 15MWp, enabling up to 75% of peak demand at the UK site to be generated through on-site solar. Overall, this would meet around 6% of the site’s total annual electricity demand.
However, even once fully installed the solar capacity available at all the sites will not be sufficient to fully meet the power demand from enrichment services, a point acknowledged by Sexton: “I don’t believe that in any case it will be a complete offset of our energy use for any of our sites, but we believe that everything we do to invest in this is a step in the right direction”.
In addition to building on-site solar, Urenco will also be contracting low-carbon energy supplies including nuclear to meet its electricity needs. While gross electricity use is one major element, the company is also looking to electricity use reductions as part of its overall net zero strategy.
“Part of it is direct solar installs, part of it is low-carbon energy purchases over time, part of it is energy reduction,” he says.
Tackling all aspects of energy use
One area where Urenco has succeeded in reducing energy demand in its enrichment process is by reducing the voltage in the power supply for its gas centrifuge equipment when in energy saving mode. This approach has achieved a reduction of 547 MWh in 2021 at its UK site and an estimated 1,745 MWh per annum in future years. It also installed speed-controlled motors to pumps, saving 501 MWh in 2021, and an estimated 2,589 MWh per year in future years, also in the UK. “We’ve learned how to reduce the voltage that we need to run our plants, which is also a significant saving at all of our facilities, and we improved on last year,” says Sexton.
Urenco is also targeting other diverse areas of energy use such as heating, transport and even employee travel.
Among a wide range of measures the company is adopting to curb emissions, it has switched to LED lighting at its facilities in the UK and USA. Emergency lighting upgrades to LEDS in 2021 brought savings of 600 MWh for the UK site, while LED lighting that was installed in the Security Building in the USA at the end of 2021 is saving an estimated 178 MWh/year.
Other projects include upgrades to a chilled water system in the USA which is estimated to save 1,441 MWh a year and which is planned to be substantially complete by the end of 2022. At the Netherlands site a project has begun that will reduce the natural gas consumption at the Recycling Centre to zero. Natural gas is currently used to generate steam for air conditioning in the ventilation system. This system will be replaced with a new one using waste heat from the enrichment plant, saving 90,000 m3 of gas per year.
Urenco is also looking at transport, installing dozens of EV charging points at its sites, for example. “We already use a lot of hybrid and electric vehicles at our sites and continue to look into those and of course even employee travel is another element to look into. We transport material internationally with trucks and shipping and we are looking at synthetic fuels and, down the road, hydrogen-based shipping and truck systems will clearly have to be a future part of it,” Sexton explains.
Reflecting on the overall picture, Sexton says: “There are a whole range of measures, which is why it’s probably going to take about 10 years to get all those things here but there’s no specific tech breakthrough that’s going to really make this happen, it is small steps that have a cumulative effect,” he adds, noting: “We feel confident enough with what already exists in terms of technology and what our commitments are that we can achieve it. We also are installing more smart monitoring our plants to really understand our electric demands.”
Investing in sustainability
Given the wide range of measures being pursued, Sexton emphasises the importance of board-level support in terms of investment. “We’ve already built some of those costed elements and projects into our long-term business plan. We actually project our capital expenditure needs on a 10-year basis because of the nature of our industry and sustainability is a category in and of itself within our financial modelling. I’m very pleased that we have full support of our board and our executive committee to do these things. Every sustainability investment that has come forward from our sites has been approved. We are committed, we’ve assigned dedicated resources at all of our physical locations and they are in the process of developing their carbon reduction plans,” he says, adding: “I feel confident that we can make the investments necessary to achieve it by 2030. We also believe that we need to demonstrate some leadership. I have yet to find anybody in our company that disagrees. The whole company is on that same journey and that is a very important part.”
Sexton also highlights the importance of independently verifying the company’s progress on meeting sustainability targets. “We have a commitment to have our 2030 near term targets validated by the SBTi, to evaluate progress. Our annual disclosure to [the Carbon Disclosure Project] CDP demonstrates our evolving commitment to net zero and performance against targets. We’ve done quite a bit of work already, but we are formally committing to really driving and accelerating our targets well beyond 2050 and even 2040,” Sexton says. The company currently has a B-rating from CDP for its 2020 performance, the second highest of four levels. Urenco has also asked independent sustainability ratings organisation EcoVadis to assess the organisation in terms of overall sustainability.
The company’s scope 1 and 2 emissions currently account for about half the total associated with the production of enriched uranium but Urenco is also working within its supply chain to help achieve reductions in scope 3 emissions too. “We also recognise, obviously, scope three, that is our supply chain and the carbon emissions of our vendors and suppliers. We are working with them and part of that same commitment is to reduce our scope 3 emissions by 30% by 2030,” says Sexton.
Alongside its scope 1 and 2 ambitions, Urenco is targeting about a 30% reduction in its scope 3 supply chain sector by 2030 with a view to hitting net zero in its scope 3 contribution by 2040. Where Urenco makes direct purchases of uranium ore, feed, or other materials this will be counted entirely within those Scope 3 emissions. When the feed comes from a Urenco customer, the third party will account for it in their Scope 3 emissions. Indeed, Urenco is now putting in sustainability as one of the selection criteria for their supply chain.
Progress on Scope 3 emissions and sustainability will also be assessed by EcoVadis which is working with Urenco suppliers and getting them up to speed and monitoring them on emissions and overall sustainability.
“They are a very strong partner in helping us to identify, primarily, our scope three goals and objectives, working with us and with our vendors. I think that’ll help us positively engage our supply chain as well, in terms of our scope 3 emissions, as they are another set of eyes and ears to monitor the performance of companies.”
Reaping the benefits of climate leadership
Urenco is taking a clear lead in sustainability among enrichment companies but other companies within the sector are also setting out carbon reduction targets. Orano, for example, has established a target to reduce the “equivalent” carbon footprint of its business in line with the Paris Agreement by cutting its scope 1 and 2 emissions by 40% compared with a 2015 reference year and a 20% reduction of emissions across scopes 1, 2 and 3 compared with a 2019 reference year over the same period. It aims to achieve these goals by 2025.
Orano says it has already been implementing new industrial processes and modernising its asset base enabling its environmental footprint to be reduced. Among the projects it has developed, Orano built the Georges Besse II plant which has been running since 2016. More than 10 projects have been studied to date, with a potential reduction of 80,000 tonnes of CO2. For instance, it has switched to electricity from fuel oil for the production of steam at its used fuel recycling plant at la Hague. Orano also recently signed a 10-year power purchase agreement for the output from a 5 MW solar farm in Nambia that will power the company’s Erongo Desalination Plant.
Other enrichment companies such as Centrus, Tenex and CNNC have also nodded towards greater sustainability as part of their business strategy but haven’t gone as far as publicly announcing any targets on carbon reduction or net zero so far.
As Sexton observes: “We believe it’s important to the nature of what we do, our business, our industry – which is a low-carbon energy source for the world and is a critical part of achieving the goals for climate reduction – that since we are supplier it’s important for us to also be a leader in achieving those targets but we don’t view this as our journey alone. It’s the journey of ourselves with our vendors or partners or customers, as well as the industry in general.”
Nonetheless, Sexton sees value in being a responsible corporate citizen: “With sustainability we’re finding interestingly that all of those investments have a return. Some of them perhaps longer out than what we would normally expect, but that’s not stopping us.”
He also believes that a competitive advantage is also emerging from having an edge on sustainability. “Our customers are primarily utilities, they generate electricity and of course they all have their own goals and commitments. I would like to believe that if I was a utility making a choice of a scope three supplier, the ones that are being aggressive about this and addressing it, it’s that much less than utilities have to deal with in their scope 3. I truly believe that there is a benefit to sustainability and carbon reduction as a business benefit. It’s critical that we contribute and we take a more aggressive leading role where we can.”