Nuclear power | Generator clutch Valve
Clean fuel plant
HP/IP
A – SSS® B – SSS®
LPST clutch engaged clutch disengaged
Small modular reactor
process steam Industrial To grid
Electrical demand Local and/or grid. Local
Hot water accumulator
incineration Waste Possible use cases for the SSS clutch in tandem with an SMR. Source: SSS
supply that data centres need to support AI,” says Faith Birol, Executive Director of the International Energy Agency (IEA). “According to our analysis, there is a role for established technologies such as renewables and natural gas, as well as emerging technologies like small modular nuclear reactors (SMRs) and advanced geothermal.” The IEA reports that there are plans to build up to 25 GW of SMR capacity associated with supplying the data centre sector worldwide. The first projects are expected around the end of this decade. Holtec, for example, is working on the recommissioning of the Palisades nuclear facility. In parallel, it is planning to add SMRs to the site. “We plan to open the first two SMRs within the Palisades complex by 2031,” said Patrick O’Brien, Director of Government Affairs at Holtec. Siemens Energy and Rolls-Royce, too, have signed an SMR partnership. Siemens Energy will supply steam turbines, generators, and auxiliary
systems for Rolls-Royce Generation 3+ modular nuclear power plants. Some might be as big as 470 MW.
“We are currently experiencing a global renaissance of nuclear energy,” said Karim Amin, a member of the Siemens Energy Executive Board. “Numerous countries are turning to nuclear technology to produce low-emission electricity, and small modular reactors will play a key role.”
SMRs for flexibility
Nuclear pinion turning gear with an SSS clutch. This provides a fail-safe mechanism to rotate the large steam turbine shaft during the cool down phase to prevent distortion. Source: SSS
Some see SMRs as being the best way to add low carbon power to the grid in a reasonable time frame. Others are looking at how to expand their use cases. Applications might include energy storage, hydrogen steam reforming, process steam, district heating, or sea water desalination, and more. Hydrogen, for instance, has been held back due to the high cost of energy required for electrolysis. If a steam reforming plant was positioned beside an SMR, it could benefit from less costly and more efficient heat supply. The hydrogen could then be blended with natural gas at nearby power plants to lower the carbon footprint. Another use case attracting interest is CHP. This could even act a bargaining chip for communities that might be quick to protest an SMR popping up in their vicinity. By promising cheap electricity for the community, or the delivery of cheap steam to the local utility to be used for district heating, residents might be more willing to consider a new facility. It will be important in these cases to emphasise to the community that the steam they would receive from the power plant would NOT be the steam from the reactor itself and that there are heat exchangers between the reactor and the fluid that is sent to homes, ensuring that it is as safe as any traditional natural gas CHP process. Alternatively, certain industries might be keen to have an SMR nearby to provide their process
16 | June 2025|
www.modernpowersystems.com
steam needs as well as power for the facility. Some might be willing to invest in such a CHP plant to provide themselves with a reliable source of steam and power. Oil and gas production or refining operations use steam in many ways including polymerisation of plastics. Car manufacturers use steam to dry paint on cars. Chemical plants need steam for enzymes, carbon black, paint, glassware, rubber, and more. These are just a few possible examples.
Flexible output from an SMR would not require any redesign to the reactor island but would necessitate a minor redesign of the steam turbine. By adding an SSS clutch, the low-pressure (LP) section of the steam turbine can switch between electrical generation mode and supplying heat and steam. This concept is proven across many CHP plants and provides the added benefit of full utilisation of the steam and lower losses compared to other options.
“The flexibility of the steam turbine allows the reactor to operate at a continuous output, whilst the secondary island can switch between different operating modes,” says Morgan Hendry, President of SSS Clutch.
SSS Clutch has a track record in the nuclear industry dating back to the 1960s. Its main turning gear technology is being implemented at Hinkley Point C, which is currently under construction in the UK, and is employed at other projects, including Flamanville in France, Akkuyu in Turkey, El Dabaa in Egypt, and Taishan in China.
Some SMR facilities might be flexible enough to base output on market rates. If electricity prices are high, the SMR can provide maximum power to the grid. If rates drop, the price for steam in industrial processes might prove more profitable. Alternatively, the plant could operate with a certain percentage of output going to power and the remainder to steam.
Local demand
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45
