Microreactor - FAQ
- Nuclear power is a crucial part of bringing sustainable energy to the world, and microreactors like these are a particularly promising way to introduce reliable, clean power to remote regions and to urban areas that currently rely on coal or other fossil fuels to generate power.
- Deployment of small, advanced nuclear energy for use by campus offers unmatched potential to accelerate the University of Illinois toward its commitment of being carbon-neutral by 2050. It will also significantly reduce energy costs because the power generated will be offset by investments from DOE and private industry supporting this first-of-a-kind application of advances in energy research.
- This microreactor would be the only of its kind in the world installed on a university campus, making it a unique resource for faculty research, education, and workforce development.
- The University of Illinois Urbana-Champaign has a long history of groundbreaking nuclear energy, power infrastructure, and operations research. In fact, the university successfully and safely ran a nuclear reactor on campus for 38 years from 1960-1998, and its fuel was safely stored on-site until 2004. That site is now in Greenfield status.
- Other grand challenge problems can be pursued with a source of high temperature, flexible, reliable, clean energy: clean water, micro-grid tech. cybersecurity, hydrogen production for transportation and energy storage, fertilizer production.
Microreactors are small scale, transportable, factory-fabricated nuclear reactors similar in size to research and test reactors. They typically leverage simple and responsive design fuel technologies, which allow the reactor to self-adjust. Importantly, many such reactors are inherently safe and cannot melt. These designs are in development by dozens of start-up companies and are poised for deployments where they are uniquely right-sized. Such applications include space, disaster response, resilient energy, isolated communities, remote projects, and developing grids.
There are a lot of differences and similarities. Existing commercial nuclear power plants in the US are all what is called Gen-II (meaning generation-two) reactors and are based on 1970s technology. This is equivalent to the emergence of the first cell phone. The proposed reactor is Gen-IV (generation-four) resulting in fifty years of advancements in nuclear engineering. The modern smart phone has some similarities to the first-generation phone, but its performance has benefited substantially from 50 years of engineering.
Similarities between the proposed reactor and existing commercial nuclear power plants is:
• Both use Uranium as the fuel
• Both are ‘thermal’ reactors.
• Both have a negative feedback from increasing temperature on reactor power
• Both can safely and reliably produce clean energy
• The fuel form (i.e., the use of silicon carbide to retain all fission products in TRISO fuel)
• The coolant in the proposed reactor is Helium gas, while the coolant in conventional reactors in the U.S. is light water
• The moderator in the proposed reactor is graphite, while the moderator in conventional reactors in the U.S. is light water
• The power level (or power density) in the proposed reactor is low enough for the decay heat to be passively removed without operator action and without any active systems. Commercial reactors in the US operate at 200 times higher power and, as a result, require large backup systems that rely on external power to keep water circulating to remove the heat and prevent fuel from melting
In short, to shape the future of nuclear research, move campus to a cleaner energy future, create unique educational opportunities for our students, and develop a skilled workforce ready to address the urgent need for carbon-free energy technologies across our country and beyond.
There are 24 other nuclear research and test reactors on campuses across the country, and in fact, we safely and successfully operated a TRIGA reactor in the heart of campus for more than 38 years, until the site was returned to Greenfield status in 2004. Rejoining our peer institutions in operating a research reactor advances the technology we need for a clean and sustainable energy future and is consistent with our land-grant mission to solve pressing societal problems.
The university is working closely with our industry partners to align the project with Department of Energy goals and near-term priorities for demonstrating new approaches to nuclear power and microreactors. The project will require support from outside investment (such as DOE) to realize the full potential of the team’s plans. Investment of university funds would need to be justified through projections in increased research, education, and training revenues, as well as the potential cost savings if the reactor is used to offset fossil fuel used at Abbott Power Plant. We will be working on these numbers as the team moves forward with further detailed planning.
Concerns about nuclear power often stem from experience with older nuclear reactor technology. People say ‘What about Fukushima?’ or ‘What about Chernobyl?’, but those are very different things entirely. The nuclear power that people know is largely based on 1960s technology; the rotary phone served us well and can still do the trick if needed, but technology has come a long way in the past half century. The same is true with microreactors. This is a significantly different technology that represents a real leap forward in safety, sustainability, reliability, and flexibility.
It is critical that the community understands where we are in the process. We are having interaction with all stakeholders so that we can share our enthusiasm about what makes advanced nuclear so revolutionary in terms of safety and sustainability, and the potential that this opportunity has to amplify the University’s mission to enhance the lives of citizens in Illinois, across the nation, and around the world. It is important to hear from the community now so that we can begin the longer conversation around the university’s role in demonstrating a clean energy future.
Why not buy seven microreactors and get rid of all the natural gas used on campus? Would either of the two possible locations allow for expansion of the number of reactors subsequent to the first one, to permit an even greater reduction in our carbon footprint in the future?
Though we would be able to use the microreactor that we have proposed to reduce the campus’ carbon footprint, it is important to remember that this a research project. The technology is not yet commercially available. We are certainly interested in continuing the conversation about the role nuclear power can play in a sustainable future and in campus’ carbon-neutrality commitments –whether the expansion of this type of micro-reactor or other appropriate technologies.
This reactor type, called a high temperature gas-cooled reactor (HTGR), is technically feasible at higher levels of output. But one of its key positive features is its small size. That size makes it extremely safe. It also means that, unlike the vast majority of other reactors that can supply power and steam, the micro-reactor can be built in a factory and delivered to a site by truck or train. That ease of installation is a big upside in remote areas or in urban areas that want to convert away from coal or natural gas. Small is good in the case of microreactors.
Most current Research and Test Reactors are primarily focused on the study of radiation interaction with matter and production of medical isotopes. But we want to enable a much broader research portfolio, focused on synergistic technologies for a clean and sustainable energy future. We have already identified many opportunities across campus, including work on clean water, instrumentation and control, micro-grid technology, cybersecurity, hydrogen production for transportation and energy storage, and fertilizer production. The number of world-changing projects that this micro-reactor could make possible over the coming years is incredible. It would be a win for nuclear-related research campus wide, and campus sustainability efforts.
Students and researchers will learn at the cutting edge of advanced clean energy technologies, and the integration of those technologies. The reactor will enable a breadth of education, training, research, and outreach around interconnection of various clean energy strategies already being demonstrated on campus (solar, wind, geothermal, biomass). The facility will enable advancement and demonstration of clean hydrogen production and other high-value energy-intensive products. Central to nuclear power technology, this facility will enable education, training, and research in advance instrumentation and monitoring systems, new reactor control methodologies, and improve our modeling and simulation tools for better predictive capability of the reactor system. Unlike other university-based research reactors which focus primarily of exposing the reactor’s radiation to materials, this facility will focus more on the critical and synergistic technologies that must be developed for microreactors to be an economically viable option for a clean energy future.
The reactor has a rated power of 15MW and can provide that power continuously for 20 years without any refueling. This facility’s primary purpose is for education and research but the energy it produces will be available for integration into Abbott Power Plant's operations. Abbott Power Plant produces between 40 and 70MW for campus depending on the time of year. Abbott’s primary responsibility is to produce steam for building heating (and other functions: cleaning, steam driven chillers, etc.) and also produces electricity as a byproduct. The microreactor can offset the carbon fuels necessary to produce this steam where other clean energy power generation technologies can not.
Existing plants are critical to bridging the clean energy gap until advanced reactors can be commercially available.
Many other nuclear reactors that are located on college campuses (like TRIGA) include irradiation facilities for experiments (like neutron activation). Given that this reactor will be producing power, do you expect that it will not be used as a neutron source for these types of experiments? Will it be used primarily for training and power production?
Core and beam-line access is not currently planned for the initial demonstration of this reactor. The reactor vessel is designed to be sealed for the full core life which limits access to the core and provides substantial safety benefits. Production and training are major pieces of our vision but we also have identified an extensive portfolio of research to enable a clean and sustainable future.
How much research has gone into using the hydrogen produced by this reactor to power campus vehicles and CUMTD buses? If this is truly a possibility, are we ready to maximize the hydrogen as fuel and make this transition?
This is currently being studied through a separate DOE grant awarded to the NPRE department.
As early as 2015, the campus utility master plan assessed the feasibility and promise of various energy technologies with respect to the University’s decarbonization goals. In that public document, small nuclear was noted as promising and worth consideration as a developing technology that could replace existing fossil steam production.
Similarly, in the 2020 Illinois CarbonAction Plan, the Energy SWA Team recognized that the promise of micro-reactor technologies hold promise for steam production and recommended evaluation of their deployment on campus. These campus-level goals have underpinned our team’s interest in establishing technology criteria, conducting preliminary research, and seeking out supporting opportunities.
Financing, stakeholder support, regulatory review, contracting, siting, and construction—we are at the start of a very complex process.
The U.S. has long been a world leader in nuclear research (the first human-made fission chain reaction happened right here in Illinois, at the University of Chicago). Recognizing both that history and the opportunity to advance safe, modern nuclear power technologies, Congress recently passed bipartisan legislation to stimulate industrial innovation in technologies that win on safety, waste reduction, and reliability.
With a successful licensing by all governing bodies, including environmental assessments, safety assessments, and operational approval, the project team expects to be on-line with the new system in 2027.
There are several decision makers:
- The Department of Energy makes decisions about funding, fuel supply, the suitability of our programming, the quality of our industry partners, and ultimately, the value of the proposed research to the country.
- The U.S. Nuclear Regulatory Commission and Illinois Emergency Management Agency assess safety and risk to the public.
- Campus leadership and the Board of Trustees assess how the microreactor aligns with our institutional mission.
- All of these entities will consider public sentiment and the best interests of the community in their decision-making processes.
Our timeline does include all of the NRC licensing and siting processes. A detailed schedule of the various aspects of that is a central piece of our proposal to DOE. In Canada, the licensing process for this reactor design is already underway, in preparation for their first deployments at the Canadian Laboratories in Chalk River.
With or without this DOE opportunity, USNC is on schedule with their deployment in Canada The small reactor system does not have the long fabrication and construction timeline of past reactor deployments.
The use of steam is typically limited to within a few mile radius of its generation due to large losses and the infrastructure expense. Clinton could be an attractive future site for electricity production onto the grid if the economics are favorable once the technology is available commercially.
Preliminary site selection has focused on locations adjacent to Abbott Power Plant in order to utilize the heat generated in the reactor and demonstrate the ability of these systems to integrate with existing power generation infrastructure. Substantial education, training and research opportunities are enabled through connection of the reactor with Abbott Power Plant. Through the NRC licensing process, the environmental impact and safety analysis is reviewed in detail to ensure no danger to the public or environment. The project team is confident that safety concerns of the reactor deployment can be addressed through understanding the design of the reactor and the inherent safety considered in the governing physics and safeguards.
Safety and Radiation
The safety of the technology comes from three primary design features:
1. Small kernels of fuel (0.8mm in diameter) are encased in silicon carbide to prevent the possibility of any radioactive material produced in fission from leaving the fuel pellet. Silicon Carbide has superior mechanical and chemical properties even under extreme temperatures (temperatures far exceeding temperature possible in the reactor).
2. Negative power feedback with increasing temperature: built into the reactors design, through the physics of the fission process, as the temperature of the reactor increases the fission process becomes harder to sustain itself. If the temperature gets too high, fission can't continue, and the power drops.
3. Removal of residual power after shutdown through passive, natural heat transport processes. The very small power of the reactor (15MW compared to 3,000MW in conventional nuclear reactors) means that the decay heat present in the system after shutdown can be removed by natural heat transport processes to the surrounding structures without the need for any backup cooling systems (like those found in existing commercial nuclear power plants). Loss of these backup cooling systems were to blame for the Three Mile Island and Fukushima fuel melting. With the small power, the reactor can cool without an intervention from an operator or any active cooling system.
All nuclear reactors at universities are regulated by the US Nuclear Regulatory Commission (NRC) who is charged with ensuring the safe use of nuclear material for beneficial civilian purposes while protecting people and the environment. The project team is at the beginning of a multi-year process with NRC to acquire a construction permit followed by operating license. During this initial period, all aspects related to the microreactor’s safety, environmental impact, and proposed operation is reviewed by the NRC. Additionally, the project team interacts regularly with the Illinois Emergency Management Agency (IEMA), who also has some jurisdiction on the operation of nuclear facilities in the state. The operation of the reactor will be dictated by the terms of the license and oversight from these federal and state agencies. The University of Illinois had nearly 40 years of experience in the safe operation of a reactor under this type of license. Once operational, the reactor requires onsite personnel who have a license from NRC to operate the reactor.
The microreactor will be installed below ground. Once the reactor is installed and turned on, it cannot be stolen. It would be a major engineering challenge to move a reactor while, or shortly after, it is operational. We are also required to comply will all security requirements as outlined by state and federal authorities. Universities are home to many cutting-edge advancements and have highly trained emergency responders.
No. The reactor is sealed for the full life of the material. It would cause fatal harm to steal the reactor contents of an operating reactor or a recently operated reactor. The nuclear material in this reactor is much less accessible than all other Research and Test Reactors on university campuses, and the fuel form (silicon carbide surrounding layers) make it much less attractive for bomb fabrication.
In a nuclear fission reactor, heat is generated by splitting the atoms of fuel with neutrons. When the atoms split, smaller atoms are left over. Sometimes, though, instead of splitting, the fuel absorbs a neutron and becomes a larger atom. This will happen a countless number of times over the 20-year lifetime of the reactor.
The waste – or spent fuel – refers to some of these newly formed atoms. In the case of the microreactor contemplated in our proposal, the spent fuel remains encased in the reactor for its entire 20-year lifespan.
In a TRISO fuel particle, these atoms can remain contained within the silicon carbide while the atoms decay to a stable, non-radioactive state. Alternatively, the TRISO particles can be processed to separate leftover fuel atoms from the unwanted bi-product atoms.
Continued research on this waste is something we are excited to conduct, in the hopes of making a green technology even greener.
If the project is awarded, the full safety basis for the reactor system and siting will be submitted to the US Nuclear Regulatory Commission during the project period. These systems have been designed to eliminate any question of their safe response to internal and external events. This is done through three important features: temperature feedback – as the fuel heats up, the nuclear chain reactor slows down; low operational power –residual power produced after shutdown is easily managed through passive heat transfer processes; fuel robustness – the fuel can retain all nuclear material even under extreme temperatures well beyond any hypothetical accident.
Power Production and Operation
Gas-cooled reactors have a rich operational and testing history. This reactor leverages this past performance at a smaller scale to deliver an ‘ultra-safe’ system. If our proposal is awarded and the project is successful, the reactor at UIUC would be the third deployed by USNC, following the two deployments planned in Canada.
In the proposed project, UIUC would be the owner and operator of the reactor as required by the Research and Test Reactor license and consistent with all other Research and Test Reactors on campuses across the country. Close integration of F&S throughout the reactor deployment and a comprehensive workforce development program included in the proposed work scope prepare the university for long-term operation.
This proposed system has an intermediate molten salt thermal storage system between the reactor helium loop and abbot power plant steam cycle. Molten salt is an elevated temperature fluid that can store thermal energy. This intermediate system provides substantial flexibility by 1) decoupling the reactor and Abbott Power Plant operations, 2) allowing the storage and dispatch of energy as needed without needing to change the reactor power, 3) provide a source of high temperature source for research, 4) couple the system to other production streams such as clean hydrogen.
This system proposed has an intermediate molten salt thermal storage system between the reactor helium loop and abbot power plant steam cycle. Molten salt is an elevated temperature fluid that can store thermal energy. The power from the reactor is not needed for Abbot Power Plant’s production of steam and electricity (or other research needs), this molten salt system can be used to store the energy until it is needed.
The reactor can be shutdown actively by the reactor operators through the insertion of materials that absorb the neutrons, preventing the fission chain reaction from continuing. Alternatively, the reactor will shutdown without any operator intervention if the fuel temperature becomes too large (which is still far below the fuel melting temperature). Physical laws that govern the fission process and subsequent power generation dictate that once the temperature exceeds a certain temperature there will not be enough neutrons available to sustain the chain reaction and the reactor must shutdown.
Details of the reactor fuel can be found on USNC’s webpage for FCM Fuel.
Many new advanced reactors, including the one considered in our proposal to the DOE, use TRISO fuel. Unlike fuel used in current reactors, these are not “rods” but rather small “balls” of fuels. Remarkably, this fuel is considered to be “melt proof” and intrinsically safe.
How is that possible?
TRISO fuel begins like a grain of sand (0.5mm in diameter –like the diameter of the ‘lead’ in a 0.5 mechanical pencil). These grains of fuel are then coated by several carbon layers, including a final layer of Silicon Carbide, which is only slightly less durable than diamond. Silicon Carbide melts at nearly 5000 degrees Fahrenheit, with high thermal conductivity, meaning that it easily transfers its heat away without melting, thereby maintaining containment of the fuel.
In this application, particles are then embedded into a larger Silicon Carbide matrix. The double-layered protection with the ultra-hard Silicon Carbide ensures that no radioactive fission products can escape small grains of fuel.
The reactor is pre-fueled for its entire 20-year lifespan, so refueling is not required, and no additional fuel is needed to be kept on campus for refueling purposes.
Fuel for university research reactors are provided under a lease agreement with the federal government. The fuel remains owned by the US Department of Energy (DOE) throughout its life. Once a university is done with the fuel it is returned to one of DOE’s national laboratories for additional research, storage, reprocessing, or disposal. For the proposed microreactor facility, upon completion of the fuel’s life, the fuel would be returned to DOE. From there, we expect that the fuel would be used across the country for research to study the fuel’s properties and its performance before its final disposal at an existing DOE spent fuel repository.