MONTHLY. Search newsstands for file 901 of the monthly Science et Avenir on the topic: “Can nuclear power be clean?”. The article below was written before the start of the war in Ukraine.
Since May 2020, the world’s first floating nuclear power plant has been operating at full capacity in the Russian port of Pevek in Eastern Siberia. This new type of plant supplies the region with electricity with two reactors of only 35 megawatts each, but enough power to supply a city of 100,000 people, in particular to replace a coal-fired power plant, which will avoid the release of 50,000 tons of CO2 per year. This 144-meter floating barge, named “Akademik Lomonosov”, is the first small modular reactor – SMR for “Small Modular Reactor” – currently in operation. Started in 2006, its construction turned out to be long and expensive. But Rosatom, the operator of the system, plans to reduce the cost of the next reactors by mass-producing them. Four other floating barges are expected to eventually anchor along the coast of Chukotka to support mining operations in the region. Rosatom will also start construction of an onshore SMR from 2024 in the remote town of Ust-Kuyga in Yakutia and has just signed a cooperation protocol with the Kyrgyz Ministry of Energy to build the same type of facilities in Central Asia. Republic. All of these reactors are based on technologies pioneered for icebreakers.
Akademik Lomonosov floating power plant in the port of Pevek. It supplies the city and this region of Chukotka with electricity and heat. Credit: Rosatom
On the other side of the planet, China is making the same bet
Thus, the Russians were the first to introduce the SMR sector. “decarbonize isolated regions, mining sites and integrate into small networks, emphasizes Michel Berthelemy, an analyst at the Nuclear Energy Agency (OECD). ABOUTOperating in the same power ranges, these reactors can be integrated into existing electrical distribution networks.” But low-power modular reactors – less than 300 MW – are also generating real enthusiasm around the world, with about 70 very diverse concepts in development. “Unlike “cathedral” power plants, the SMR sector is opting for standardization and industrial production of small reactors, explains Michel Derdeve, professor at the Institute for Political Studies in Paris. This is a breakthrough in concept that meets the notion of a delocalized economy.”
After Russia, the US has the most advanced program. Thus, in August 2020, the Nuscale project was approved by the US Nuclear Regulatory Commission. Now, on the territory of the Idaho National Laboratory, the construction of a plant of 12 modules of 77 MW each will begin. This €2.5 billion project is due to be commissioned in 2029 and will have a total capacity of 924 MW. This is another benefit of SMR: multiple modules can be combined to produce the amount of power needed for each situation. This time, the Nuscale reactors are based on reactors designed for naval power plants. The Department of Energy has already invested more than $1.2 billion since 2012 in funding a dozen projects and must double that amount in the next decade to regain its leadership in the nuclear market.
Neighboring Canada has also chosen this solution to quickly decarbonize its industrial facilities, which until now depended on energy solutions that produce a lot of CO2.
MONTHLY. Search Newsstands for Monthly File #901 Science and the future to: “Can nuclear power be clean?”. The article below was written before the start of the war in Ukraine.
Since May 2020, the world’s first floating nuclear power plant has been operating at full capacity in the Russian port of Pevek in Eastern Siberia. This new type of plant supplies the region with electricity with two reactors of only 35 megawatts each, but enough power to supply a city of 100,000 people, in particular to replace a coal-fired power plant, which will avoid the release of 50,000 tons of CO2 per year. This 144-meter floating barge, named Akademik Lomonosov, is the first operating small modular reactor (SMR) to date. Launched in 2006, its construction proved to be long and expensive. But Rosatom, the operator of the system, plans to reduce the cost of the next reactors by mass-producing them. Four other floating barges are expected to eventually anchor along the coast of Chukotka to support mining operations in the region. Rosatom will also start construction of an onshore PfP from 2024 in the remote town of Ust-Kuyga in Yakutia and has just signed a cooperation protocol with the Kyrgyz Ministry of Energy to build the same type of facility in Central Asia. republic. All of these reactors are based on technologies pioneered for icebreakers.
Akademik Lomonosov floating power plant in the port of Pevek. It supplies the city and this region of Chukotka with electricity and heat. Credit: Rosatom
On the other side of the planet, China is making the same bet
Thus, the Russians were the first to introduce the PRM sector. “decarbonize isolated regions, mining sites and integrate into small networks, emphasizes Michel Berthelemy, an analyst at the Nuclear Energy Agency (OECD). ABOUTOperating in the same power ranges, these reactors can be integrated into existing electrical distribution networks.” But low-power modular reactors – less than 300 MW – are also generating real enthusiasm around the world, with about 70 very diverse concepts in development. “In contrast to the “cathedral” power plants, the PfP sector is opting for standardization and industrial production of small reactors, explains Michel Derdeve, professor at the Institute for Political Studies in Paris. This is a breakthrough in concept that meets the notion of a delocalized economy.”
After Russia, the US has the most advanced program. Thus, in August 2020, the Nuscale project was approved by the US Nuclear Regulatory Commission. Now, on the territory of the Idaho National Laboratory, the construction of a plant of 12 modules of 77 MW each will begin. This €2.5 billion project is due to be commissioned in 2029 and will have a total capacity of 924 MW. This is another advantage of PRM: several modules can be combined to produce the amount of power needed for each situation. This time, the Nuscale reactors are based on reactors designed for naval power plants. The Department of Energy has already invested more than $1.2 billion since 2012 in funding a dozen projects and must double that amount in the next decade to regain its leadership in the nuclear market.
Neighboring Canada has also chosen this solution to quickly decarbonize its industrial facilities, which until now depended on energy solutions that produce a lot of CO2. “Canadian mining operations run on diesel generators, which cost several hundred euros per MWh. analyzed by Michel Berthelemy. PRMs represent an interesting solution to reduce the carbon footprint of their operations and are also of economic interest.” The country is particularly supporting molten salt reactors developed by startups such as Moltex and Terrestrial Energy and will now build the first demonstration project in Ontario.
On the other side of the planet, China is making the same bet, having developed six PRM models to date, including five with pressurized water. The latter, more innovative, produced its first watts on December 20, 2021 at the Shidao Bay power plant (200 MW generated by two modules) under construction since 2012 on the coast of the Yellow Sea. This so-called “very high temperature pebble bed” reactor was developed in Germany from 1966 to 1988. Its technology is based on the use of graphite pebbles instead of steam to cool reactors and very hot semi-inert gas (helium, nitrogen, CO2) to drive turbines. This technology provides more efficient energy transfer and less intense consumption of radioactive material.
Artist’s impression of a nuclear power plant project with small American Nuscale reactors. Credit: Nuscale.
“The goal is to be able to shut down the reactor without human intervention”
Europe, for its part, has no common project; but several Member States are developing their own PRM models, including France with the Nuward and Naarea projects. The first consists of two 170 MW conventional pressurized water reactors developed by a consortium including EDF and CEA. This nationally funded project is a type of reactor designed for our nuclear submarines. In contrast, startup Naarea, on the recommendation of several CNRS physicists among others, is proposing a molten salt solution enriched with the radioactivity of mining and nuclear waste.
Another innovation that the Naarea project — and many others, especially Americans — are exploring is 3D printing, a major asset in the industrialization of the sector. A solution of molten, liquid salts imposes “The new restriction on materials, explains Axel Loro, physicist at CNRS. This requires tight welds, which is now possible with this new technology. Now it is possible to manufacture more complex reactor shapes in one piece which will increase heat exchange with the environment. This will also allow, for example, to include silicon carbide heat shield, difficult to weld material.” Subject to confirmation of the resistance of materials to radiation and corrosion, these tests are still ongoing.
The emergence of PRM is in some way a return to the origins, since “The nuclear industry started with small light water reactors in the late 1950s, explains Michel Berthelemy. Then, to increase their power and achieve economies of scale, the size of the reactors was increased. The return to small reactors today is aimed at making the series effect a priority.” At the same time, the increase in combustion rate also made it possible to produce more power with less fuel. But this excess of energy required an increase in the cooling infrastructure. This does not apply to PRM. “Low power contributes to safety, as it allows the use of passive heat dissipation systems in case of a problem.notes Karin Erviu, head of the department for the safety of nuclear installations and systems at the Institute for Radiation Protection and Nuclear Safety. The goal is to be able to shut down the reactor without human intervention. After all, the smallest reactors of a few MW, like the French Naarea, are cooled only by natural convection, namely the surrounding air! This should allow them to be installed on cargo ships or aircraft in the future.