By Cathy Milostan, Argonne National Laboratory
Nuclear power plants typically run either at full capacity or not at all. Yet the plants have the technical ability to adjust to the changing demand for power and thus better accommodate sources of renewable energy such as wind or solar power.
Researchers from the U.S. Department of Energy’s (DOE) Argonne National Laboratory and the Massachusetts Institute of Technology recently explored the benefits of doing just that. If nuclear plants generated power in a more flexible manner, the researchers say, the plants could lower electricity costs for consumers, enable the use of more renewable energy, improve the economics of nuclear energy and help reduce greenhouse gas emissions.
The new study “gives us tools to further explore potential benefits of flexible nuclear operations to work in tandem with greater shares of variable sources of renewable power generation …” — Jesse Jenkins, graduate researcher at the MIT Energy Initiative
The team explored technical constraints on flexible operations at nuclear power plants and introduced a new way to model how those challenges affect how power systems operate. “Flexible nuclear power operations are a ‘win-win-win,’ lowering power system operating costs, increasing revenues for nuclear plant owners and significantly reducing curtailment of renewable energy,” wrote the team in an Applied Energy article published online on April 24.
Audun Botterud, a principal energy systems engineer in Argonne’s Energy Systems division, is encouraged by how, for the first time, “this research evaluates and demonstrates the potential value of flexible nuclear operations in a realistic power system in the United States challenged by high variability in renewable-energy generation.”
The study helps to dispel long-held views that nuclear power plants must operate in “baseload” mode, producing power at maximum rated capacity whenever they are online. Nuclear plants can even respond dynamically to hourly electricity market prices and second-to-second frequency regulation needs, the team found. Power systems that include renewable energy must be more flexible to balance supply and demand at all times. Nuclear operators in France, Germany and other countries are familiar with this approach, but less so in the United States.
The researchers developed a mathematical representation of the physics-induced operational constraints arising from nuclear reactor dynamics and the fuel irradiation cycle in the Applied Energy article and a companion paper, published in Nuclear Technology. The interdisciplinary team then combined the new approach with power system simulation models to evaluate the overall cost of electricity generation, market prices and resulting revenues for power plants, assuming different levels of nuclear flexibility.
“Nuclear power plants are governed by a different set of principles compared to other generators, and our approach enables the representation of these relationships in the analysis of power systems and electricity markets,” said Francesco Ganda, the principal investigator of the project and a principal nuclear engineer in Argonne’s Nuclear Science and Engineering division.
By being flexible, plant operators can lower overall operating costs in the power system. For example, operators could generate less nuclear power whenever renewable energy is widely available. Nuclear plants could then exploit their spare capacity to sell valuable “operating reserves,” or the ability to quickly change power output to help grid operators rebalance supply and demand when unexpected events occur, such as power plant failures or errors in demand forecasts.
This flexibility could increase the profitability of nuclear plants by increasing revenues from electricity markets and reducing variable operating and maintenance costs. Overall, nuclear plant flexibility can also help integrate more wind and solar resources and reduce production of fossil fuel-fired energy and related carbon dioxide emissions.
Jesse Jenkins, graduate researcher at the MIT Energy Initiative, notes how the researchers’ modeling approach and study “gives us tools to further explore potential benefits of flexible nuclear operations to work in tandem with greater shares of variable sources of renewable power generation on the pathway towards low-carbon electricity supply.”
###
Of course making nuclear better, safer and adaptable to changing demand will make absolutely no difference to the greenies. They hate nuclear energy as much as they hate fossil fuels and will fight nuclear power every step of the way. It is the clearest demonstration of the gross hypocrisy going. Remember Yucca Flats storage? It may still be in litigation. I quit tracking it all when some left coast judge it was before ruled that the government had to come up with signs that lasted more than the half life of the waste stored there.
Greenies in particular and leftists in general hate anything that they don’t understand.
Which is pretty much everything.
Sadly they believe they know it all and the rest of us are the ignorant ones. I once qualified legally as an expert on several subjects. Yet regularly I had environmentalists and technocrats tell me I was not just wrong but flat wrong, lying and trying to spread propaganda paid for by someone they never defined. When I produced journal articles, data, etc they just got very angry.
I suspect nuclear flexibility is not going to be as easy as this author is anticipating. I think nuclear and renewables are in conflict and nuclear is the better choice. A while back, I ran into his disturbing piece:
https://www.euractiv.com/section/electricity/news/german-nuclear-damage-shows-atomic-and-renewable-power-are-unhappy-bedfellows/
The real question that articles like this never ask nor answer is “Why would you force a large generator that operates at a 97% capacity factor to vary its output to “generation-follow” a source with a 20% capacity factor?”
If you use nuclear generation, whatever do you need wind or solar for?
Truth, I’d be all for nuclear energy. The marching brooms won’t ever let it happen.
Oh no! Don’t design it 8n to new nuke.
Alasdair
April 26, 2018 at 5:30 am
“Why, on earth we are not investing in the development of of these is beyond comprehension.”
Because it’s a bad idea, in spite of what the book you read told you.
Let me explain these studies. There is a welfare system for our national labs and university systems. We need to keep them busy when there is no cold war work to do. So do not worry too much about it
All US commercial and naval LWR are designed to load follow (change power output). It is an operational necessity even if we rarely use it. It is part of safety analysis models. We validate models during startup testing. It is no big deal.
If fact all steam plants can load follow. That how we do it if hydro is not can not be used.
Even at the level of simply dumping excess heat into a vast pond of water, nuclear can be throttled back.
But e.g. smelting aluminium with the surplus is also a good plan.
In the US, FERC now requires new large power plants to keep running even if there is a loss of transmission capability. This way power can be restored faster when the transmission problem is resolved.
None of the plants I worked at had a large enough steam dump capacity to handle a complete loss of offsite power.
The EPR is designed with 100% steam dump capability followed by a controlled down power to house loads. This a much less severe thermal transient than a scram to hot standby.
I did the calculation for the US design (60 hz). Since the US grid is much more stable than Europe, we have 35 million less transients associated with maintaining grid voltage and frequency.
And BTW, there is no such thing as “renewables”.
It’s spelled “weather dependent production unit”.
I truly wish that well reasoned sites like this one would stop giving credence to the “,believers” by using the term “renewable energy” . There is no such thing. For instance: How does humanity “renew” the wind? The Sun?
Here is how consumption tracking is followed (instant, hour, day, week, etc.) at the production level, with nuclear and hydro operating mostly, in France. Text is in French but all the different settings and actions on how to pilot nuclear reactors, plants, and the whole network is described:
http://www.sauvonsleclimat.org/images/articles/pdf_files/communiques/Acket-Nucleaire_et_suivi_reseau.pdf
In 2 words: nuclear has enough built-in flexibility to sustain any kind of network demand at any time-scale provided the nuclear plants are rather homogeneously located.
My Senior Reactor Operator training is 60 years old, so I’m more than a little rusty; however, one problem with cycling reactors is when you reduce power, fission products that we used to call “poisons” built up in the reactor. The isotope that has the biggest affect when power is reduced is Xe-135. (https://en.wikipedia.org/wiki/Iodine_pit) As soon as the reactor power is reduced or the reactor is tripped, Xe-135 increases for about 15 hours. When you want to increase power again, there has to be sufficient reactivity in the reactor to burn out the Xe-135 and achieve/maintain criticality or the desired power level. If the reactor cannot be immediately restarted after a trip, it takes about 30 hours for the Xe-135 to decay sufficiently to enable restart. If the power is being varied, each increase has to use some of the reactor power to “burn out” the Xe-135. Anyway, there’s a built-in nuclear inertia with reactors that complicates using them for load following. ‘Never read anything on how this might affect plant efficiency.
Thanks for this review of the study. Nuclear and renewable can, and should, work together to provide the best carbon-neutral energy sources for the country and the world. While the industries are often siloed, hopefully this can signal the beginning of them working together, both technologically and in terms of the politicking that (unfortunately) is needed for real change in the energy space. Obviously a carbon tax would benefit both industries, and their collective power might be enough to take on the fossil industries of the world.
The problem is that, when viewed from a cost/benefit analysis, nuclear alone can accomplish that goal. Solar is no more than a ‘niche’ need filler.