How Deep Borehole R&D is Tied to Future of Advanced Reactors

By Kari Hulac

In 2022 the world saw a notable uptick in the number of countries pursuing clean nuclear energy to fight climate change and secure energy independence. In turn, more governments and next generation nuclear developers are thinking about the back end of the fuel cycle while evaluating deployment of reactors.

Among the more than a dozen contracts Deep Isolation has across three continents, our advanced reactor and small modular reactor waste disposal work includes:

*Participation in four U.S. Department of Energy (DOE) Advanced Research Projects Agency – Energy (ARPA-E) grant projects with three led by partner organizations. Deep Isolation’s scope will be to examine various aspects of how deep borehole repositories for nuclear waste can help close the nuclear fuel cycle through disposal of spent fuel and reprocessing waste streams. The total grant funding for these projects is $15.3 million, representing a significant investment from the U.S. government in support of an integrated waste management approach.

*A second contract with Fermi Energia, an energy company working on the development and deployment of small module reactors (SMRs) in Estonia. This work will build on Deep Isolation’s earlier work with Fermi Energia, a project that concluded that most of the country’s geology would be acceptable for deep borehole disposal.  This new project will research the cost effectiveness of using boreholes to dispose of waste from an SMR that would be deployed in Estonia by 2050.

Deep Isolation Head of Engineering Jesse Sloane, who is overseeing the company’s DOE grant work, funded under the ARPA-E umbrella, explains this synergy between advanced nuclear reactors and deep borehole repositories.

ARPA-E logo, Advanced Research Projects Agency – Energy
The U.S. Department of Energy’s Advanced Research Projects Agency — Energy helps fund R&D for nuclear energy and nuclear waste disposal projects such as deep boreholes repositories.

Q. We are clearly seeing more interest from the next generation nuclear reactor community in deep boreholes over the past year. What is the primary driver of this heightened consideration?

A. There are many factors contributing to the advancement of deep borehole disposal, and I think it is hard to narrow it down to only one. We are certainly seeing worldwide drivers such as the geopolitical environment and climate change concerns play key roles in the desire to find near-term solutions to the nuclear waste problem in support of carbon-neutral nuclear energy.

In the European Union, there are changes in taxonomy regulations to support investment in sustainable advanced nuclear technologies, and in the case of climate change mitigation, these are coupled with requirements to have plans for an operational disposal facility for high-level waste by 2050.  From a technical perspective, I think deep borehole disposal repository facilities are uniquely poised to be designed, licensed, constructed, and operational within that timeframe.  Borehole repositories require far less construction time than the traditional mined repositories, given they are smaller in scale, can be modular in design, and do not require workers to be underground.

In the United States, utilities that deploy advanced reactors will be required to fund the storage of the spent fuel for up to 20 years after it has been removed from the reactor.  This is a significant policy change from what is required for the existing fleet of reactors — for which the DOE is responsible for providing waste disposal services as of 1998 and is currently paying the utilities for spent fuel storage costs. Therefore, the industry seems keen to see progress in the form of innovative waste disposal technologies, including deep borehole disposal.

Q.  Of the four DOE projects, Deep Isolation is the lead on one, a $3.6 million grant in partnership with the University of California, Berkeley, Lawrence Berkeley National Laboratory and NAC International, to develop a universal canister system for advanced reactor waste streams. What are some key aspects of this project, and how does it fit into the broader picture of how deep boreholes can support advanced reactor deployments?

A. This project is funded through ARPA-E’s Optimizing Nuclear Waste and Advanced Reactor Disposal Systems (ONWARDS) program, and it specifically addresses consideration of deep borehole disposal as an alternative disposal pathway for advanced reactor waste.

There are four key parts for this project: 1.) The project team will research various advanced reactor waste forms through literature reviews, experimentation, and collaboration with other ARPA-E projects.  2.) These waste forms will be analyzed through repository performance assessments in a variety of geologic disposal configurations, including mined and borehole repositories.  3.) We will design and analyze a disposal canister that will be compatible with these waste forms and will be appropriately sized for disposal in a borehole or mined repository.  The design efforts will culminate with the fabrication of a prototype canister.  4.) We will develop generic waste acceptance criteria for waste forms to be packaged in the new canister, with differing criteria for disposal in both mined and borehole repository configurations. 

The project will provide a pathway for disposal of multiple waste forms for advanced reactor designs that have not yet been built or licensed so that a disposal pathway is identified prior to the reactors even coming online.  Future analyses can confirm if additional waste forms will be acceptable for disposal within the canister, which will allow these reactor designs to mature and progress while simultaneously planning for eventual disposal of the spent fuel.

Q. You are Deep Isolation’s Project Lead on a team that was recently selected to receive $4.9 million from the DOE ARPA-E CURIE program. The project, led by Argonne National Laboratory, is to develop and demonstrate oxide reduction technology for pyrochemical recycling of light water reactor used nuclear fuel. Deep Isolation will develop an integrated oxide reduction waste disposal plan, while simultaneously determining ideal waste acceptance parameters. Please explain the significance of this project.

A. ARPA-E’s CURIE program aims to significantly reduce the volume of light water reactor spent nuclear fuel requiring disposal by advancing various reprocessing technologies for ultimate commercial applicability.  We are partnering with Argonne National Laboratory, advanced reactor developer Oklo Inc., and Case Western Reserve University to advance oxide reduction reprocessing technology to maximize recovery of fissionable material from the existing inventory of spent nuclear fuel.  Reprocessing, whether through oxide reduction or some other means, will always result in waste forms that must be safely isolated and disposed of deep underground to protect the public from the harmful radiation emanating from those waste products.  This isolation is necessary because the waste, similar to spent nuclear fuel, contains isotopes with long half-lives (hundreds to thousands of years) that emit harmful radiation.

Deep Isolation will develop a disposal plan for the oxide reduction process waste streams. It is worth mentioning that the CURIE program has some ambitious target metrics, including a goal to maintain disposal costs in the range of 0.1¢/kWh. To reduce disposal costs, Deep Isolation will also perform an economic analysis to determine an ideal range of acceptance parameters for those waste streams. This will ensure that reprocessing technology is not only safe but economical and able to support the needs of the coming fleet of advanced reactors.

Q. In addition to the Argonne project you just discussed, describe Deep Isolation’s two other ARPA-E projects: An ONWARDS project with Oklo, Argonne National Lab and Idaho National Laboratory and a second CURIE project led by EPRI.

A. The ONWARDS project led by Oklo will develop a first-of-a-kind nuclear fuel recycling facility.  The project will advance the technical and commercial capabilities of an electrorefining facility to be deployed in support of metal-fueled advanced reactors.  Deep Isolation’s scope for the project will analyze the pyroprocessing waste streams to determine if they are suitable for deep borehole disposal.  We will also develop an integrated waste disposal plan for the project’s waste streams.

We are also fortunate to be part of another CURIE project, led by EPRI. This project, which includes an advanced reactor company, Oak Ridge National Laboratory, Southern Company, and Dominion Engineering, will develop a complete advanced reactor fuel cycle enterprise. The project will consider the use of light water reactor spent nuclear fuel as feedstock, explore optimization of various recycling processes, and will integrate with Deep Isolation’s innovative approach to efficient waste management through deep borehole disposal.

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Blog by Jessica Chow, September 28, 2022

Empowering the Next Generation of Nuclear Professionals

By Jessica Chow

The rapid growth of nuclear start-ups in the past two decades indicates the changing nuclear industry: an industry in need of innovation. This industry needs fresh perspectives from professionals excited to engage with nuclear technology, especially in the face of the global challenge of climate change. 

The nuclear start-up life was the topic of a panel I joined recently at the Nuclear Innovation Bootcamp (NIB) in Madison, Wisconsin. Also participating were Tyler Bernstein of Zeno Power Systems, Alexia Mercier of OECD Nuclear Energy Agency, and Andy Morales of FireHydrant. We delved into the intersection of nuclear technology, innovation, and team building in the start-up space. Most of the questions we received from the Bootcamp attendees focused on how to not only succeed in the nuclear start-up space but thrive. Let’s discuss that. 

What does success look like in the nuclear industry? Success looks like the further deployment of nuclear energy technology to fight climate change, continued use of nuclear material for medical purposes, and future innovation in the nuclear industry.

So how do we get there and what changes to how we approach nuclear innovation will be needed to find this success? Based on the NIB panel discussion, it seems that young professionals believe new reactor designs are key to the future success of nuclear energy. It does make sense that young industry professionals who may be unfamiliar with the complex history of nuclear power would focus on the technical aspects of nuclear. But forgoing the industry’s history misses a key opportunity for growth: to find success in the nuclear industry, especially with innovation, we need to learn from the industry’s past, especially as it pertains to its engagement with the public. 

Success for the next generation of nuclear professionals must:

Listen. Learn. Adapt. 

We can pull a great example of this from my co-panelist, Tyler Bernstein of Zeno Power Systems who said, “Something I believe we’ve done well as we’ve grown our team is balancing bringing onboard team members with decades of experience with industry newcomers — who are frequently non-nuclear engineers. We’ve seen this combination work well as those who have more experience can impart wisdom on how things have been in the past, while industry newcomers bring fresh and creative ideas to the table. In fact, our founding team is comprised wholly of newcomers to the nuclear industry; I believe a good part of our success to date is a result of my co-founders and I coming together with new perspectives on old problems.”

Recruiting a diverse team is part of creating a culture where different stakeholders are listened to in a constructive and meaningful way. A diverse team provides an organization with the ability to approach conversations from different perspectives. Many of the attendees at NIB are in the process of starting their own nuclear startups. To empower their success, we must also empower young professionals to build teams diverse in expertise, backgrounds, age, and race. 

There is so much work to be done to prepare young professionals for the complex nuclear industry, but by questioning the traditions of the nuclear industry of the past, we can learn and change to find success in the future. 

A final thank you is deserved by the organizers of the 2022 Nuclear Innovation Bootcamp, especially River Bennett of Nuclear Innovation Alliance, the panel’s moderator for the panel. It is programs such as NIB that provide much-needed resources to the young generation of the nuclear inclusive clean energy future. 

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By Dr. Ethan Bates

Deep Isolation Director of Systems Engineering Dr. Ethan Bates presented his paper, co-authored with borehole sciences expert John Midgley, titled Features, Events, and Processes Prioritization for Deep Borehole Disposal Concepts in Crystalline Rock and Shale, at the American Nuclear Society Meeting in Anaheim, Calif., earlier this month.

We sat down with Dr. Bates to learn more about these analyses.

Q: What are FEPs? Why are they relevant to the safety analysis of nuclear waste disposal?

FEPs stands for “features, events, and processes” and studying this allows us to categorize phenomena affecting nuclear waste repository performance.  Specifically, events and processes impact the features of the repository, and a screening process is needed to evaluate which of these is important to safety in the long run. This paper generally addresses FEPs for borehole concepts that Deep Isolation (and other institutions) are considering and prioritizes a subset of FEP groups to guide future collaborations. This is to support the safety and feasibility evaluation of deep borehole concepts in a wider range of geologies, including crystalline rock and shale.

Q: What was your motivation for prioritizing features, events, and processes in deep borehole disposal concepts in crystalline rock and shale?

Modern drilling technologies broaden our options for nuclear waste disposal to a wider range of sites, geological environments, depths, and configurations.  In the past, researchers (including myself) focused on crystalline rock as the host rock, but Deep Isolation has shown that equally safe repositories could be constructed in shale using horizontal drilling. This option could be very helpful in the siting process (which can be challenging) but it increases the scope of work required in the early stages of designing borehole repositories. 

To perform a comprehensive evaluation of the safety of a deep borehole repository, we need to analyze all the phenomena, initiating events, and boundary conditions affecting deep borehole repositories over 10,000 years or more.  With limited resources, it’s important to focus our efforts on the FEPs that are assessed to be of greater importance.

Borehole FEPs Graphic
This graphic shows some of the FEP groups that our paper studied for a horizontal repository in shale and a vertical repository in crystalline rock.

Q: What are the high-priority FEPs, and how were they determined?

To streamline the prioritization process, a smaller subset of FEP groups was created. Then, an expert panel (including those from a leading national laboratory) was convened to assess the relative importance of the FEP groups.  The FEP group related to radionuclide transport through the host rock barrier, which varies with depth, was deemed high-priority because in the deep borehole disposal concept this barrier strongly impacts the safety of the repository. Ultimately, three high-priority FEP groups were identified:

  • radionuclide transport through the host rock and overlying geologic units;
  • seal and plug degradation; and
  • radionuclide transport through the disturbed rock zone.

Further evaluation of these FEPs will advance the generic feasibility and safety assessment of deep borehole disposal concepts.

Q: What are the big takeaways from this work?

Early findings on the high priority FEP group related to host rock transport properties show that deep borehole disposal enables wider access to host rocks where diffusion of radionuclides (extremely slow and predictable, relative to advection) is the dominant transport mechanism.  Imagine having a sugar cube at the bottom of a glass of water: With diffusion, the water is not moving and it takes a very long time for the sugar to dissolve into the water.  Having advection is equivalent to stirring the glass and allows for much more rapid transport of the sugar.

Q: What are the next steps?

High- and medium-priority FEPs were identified in this paper to better understand the long-term performance assessment of deep boreholes for nuclear waste disposal. Although a preliminary analysis was conducted on the high-priority FEP group related to host rock properties, additional work is needed to draw general correlations about the depth variation of clay properties.  Future work on the other high priority FEP groups such as transport through the disturbed rock zone and seal and plug degradation might eventually show these FEPs to have a lower significance in the safety case than initially thought, for example, by showing that the repository performs safely even when these features and barriers are conservatively assumed to be degraded. Additional efforts will also go toward the medium priority FEPs such as gas generation in the emplacement zone, transport and dilution in the biosphere, and matrix diffusion, which can act as an important delay mechanism in crystalline rock.

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*Deep Borehole Expert Joins Deep Isolation

*Sealing of a Deep Horizontal Borehole Repository for Nuclear Waste

By Kari Hulac

At Deep Isolation we are all here for one reason: To solve a decades-old environmental problem that most people never even think about.

Yes, that is as difficult as it sounds. It’s so difficult, in fact, that most governments around the world have yet to solve it while ratepayer dollars allotted for a permanent disposal solution collect dust in the coffers, and taxpayer dollars pay for interim storage.

Unless you personally live near one of the 93 commercial nuclear reactors operating in the United States at 55 locations in 28 states, you probably rarely think about nuclear energy or spent nuclear fuel, which is radioactive and requires specialized handling and containment for thousands of years.

Most of those who do live near a plant, where waste is temporarily stored in very large concrete casks, aren’t too worried because it is safe where it is.

While spent nuclear fuel is safe in these storage casks, this was never intended to be permanent. The international scientific consensus for decades has been that the BEST place for spent nuclear fuel and other high-level radioactive waste is in deep geologic disposal, where it’s protected from the elements and can’t be tampered with by humans. In the U.S. disposal in a mined repository is required by law.

We believe governments have a moral and legal obligation to move forward with permanent waste disposal. We think this is more important now than ever:

*To reduce opposition to clean nuclear power and fight climate change;

*And to increase energy independence as a national security priority.

As a company we’ve internally struggled with how to raise public awareness and gain public support for solving a problem that is (mostly) out of sight and thus, out of mind. How do we persuade the government that doing nothing is not a solution?

So, a small group of us got together and embarked on a mission to: Find out what people think about waste and nuclear energy; provide factual information in hopes of inspiring others to feel more inspired to solve this problem; and finally, give those newly inspired folks a way to make their voices heard by those with the power to make change.

Solve Nuclear Waste Project

First, we took the public’s temperature to make sure we were on the right track. We launched a nationally representative U.S. poll last summer and found that 70 percent of those surveyed agree that it’s the government’s job to solve this problem. We also found that people would be more likely to support nuclear energy if the waste was in safe disposal.

Once we gathered the poll data, we gut-checked our progress with a focus group of nearly 20 stakeholders and environmental community advocates. We took their suggestions to heart, and the Solve Nuclear Waste website was born.

The webpage features facts about nuclear waste in the U.S. and a pledge that concerned citizens can sign as a rallying cry to hold government accountable to solve this issue now. (If we’re successful, we certainly hope to expand our efforts worldwide.)

We see this pledge as an important initial step to talk more openly about nuclear waste and earn support for action needed by decision makers who can help drive progress on this long-standing environmental issue.

Once we collect a critical mass of signatures, we plan to share this information with decision makers to demonstrate that the public DOES care about nuclear waste disposal and wants this problem addressed now.

We hope you’ll visit the new webpage and consider signing our pledge today.

Solve Nuclear Waste Website Screenshot

By Betsy Madru

In 2012, the U.S. Blue Ribbon Commission on America’s Nuclear Future was formed by the Secretary of Energy to conduct a comprehensive review of policies for managing the back end of the nuclear fuel cycle. One of the Commission’s recommendations was to use consent-based siting approaches to determine a location for a facility to store and dispose of nuclear waste. 

In 2017 the United States Department of Energy developed and requested public comment on the “Draft Consent-Based Siting Process for Consolidated Storage and Disposal Facilities for Spent Nuclear Fuel and High-Level Radioactive Waste.” The incorporation of consent-based siting in DOE’s nuclear waste work is moving the nation’s nuclear waste program in the right direction. 

The DOE has revived its efforts by recently issuing a Request for Information on “Using a Consent-Based Siting Process To Identify Federal Interim Storage Facilities.” This means interested entities had an opportunity to submit their thoughts on how such a process should be conducted to ultimately help the U.S. progress toward a solution. 

Here is an excerpt from Deep Isolation’s RFI response:

“The Department of Energy should lay out a comprehensive plan for development of an entire waste management system that provides flexibility in the strategy and approach for storage, transportation, and disposal. An essential part of any fully integrated plan is continuation of generic work that will be required regardless of the final destination of the material, such as work being done under 180(c) of the NWPA to provide technical and financial training to local state and tribal public safety officials whose jurisdictions are on major transportation routes. Initiating a consent-based siting process for interim storage is an important first step of the Department’s overall plan, but it must be developed against the larger backdrop of a comprehensive system that is grounded in sound science and built on a platform of public trust and confidence.”

“Progress on establishing one or more permanent disposal facilities is critical to efforts to develop an interim storage facility. … If it is assumed that potential interim storage sites will be pursued using a consent-based process, then the hosts of those sites must have reasonable confidence that the sites will, in fact, be “interim” and not become permanent by default. The only way to maintain that balance and assurance is to have a robust integrated waste management system that includes both types of facilities as well as the accompanying safety and regulatory structure to enable success.”

“New regulations for geologic disposal must be built on a solid technical foundation of safety analyses and performance assessments, and must establish regulatory certainty at the outset…. Clarity and certainty about the regulatory process will provide a necessary underpinning for conversations about the siting of disposal facilities.  This will in turn provide greater confidence that interim storage will not become permanent and will allow more open dialogue with prospective host communities and states that is built on a platform of transparency and trust”

Now that responses to the RFI have been submitted, the Office of Nuclear Energy and the U.S. Department of Energy will use the 220 responses submitted to inform development of a consent-based siting process, overall strategy for an integrated waste management system, and possibly a funding opportunity. The DOE has consolidated all the responses and is planning to issue a report of all the findings in the coming months and 

To learn more:

Social Scientist Explains Community Consent

Keeping Nuclear Waste Transportation Safe

Editor’s note: This is an excerpt of an article that was originally published in the March edition of Nuclear Engineering International’s magazine, which is available via a subscription here. You can view our paper, “Implementing Deep Borehole Disposal: Study of International Stakeholder Views from Regulatory, Policy & WMO Communities,” presented at the March Waste Management Symposia, here.

By Chris Parker

Deep Isolation EMEA Ltd, Managing Director

New research affirms that there is growing interest worldwide in the advancement of deep boreholes as an option for the disposal of nuclear waste.

Deep boreholes offer a scalable, modular, and more economical disposal solution for spent nuclear fuel and high-level waste, particularly for countries with smaller waste inventories that may make the safety case for a mined facility costlier to demonstrate.

A study Deep Isolation conducted last year analyzed international stakeholder views across 18 countries in the Americas, Europe and the Asia-Pacific region to determine perceptions about deep borehole repositories for nuclear waste disposal. The results show that those surveyed agree overwhelmingly that the next best step for learning more about this solution is an end-to-end technology demonstration.

The deep borehole opinion research, which was preliminarily shared at the IAEA 2021 International Conference on Radioactive Waste Management and was presented in full at Waste Management Symposia 2022, is based on interviews and surveys with members of the regulatory, policy and waste management organizations. The majority of those surveyed said they believe boreholes potentially have a significant role to play and cited benefits including choice and flexibility thanks to a reduced physical footprint coupled with cost and time savings compared to centralized mined repositories. 

Given that proposed changes to the EU taxonomy would dictate that nuclear waste and decommissioning funds must be in place and that there must be operational facilities for the disposal of low and intermediate-level waste streams, with a plan in place for a high-level waste disposal facility to be operational by 2050, the benefits of being able to potentially deploy a borehole repository in a fraction of the time of a mined repository could make this option even more attractive. Deep boreholes also could potentially be co-located with a mined repository if needed.

Research followed rigorous 7-step qualitative and quantitative process

The target research group was senior-level stakeholders with specific responsibilities for geological disposal of higher activity radioactive waste disposition, selected from the following six categories: National government policymakers; waste management organizations; nuclear and environmental regulators; international agencies that influence national policies; university researchers; and national laboratories and other research institutions specifically focused on radioactive waste disposal.

Following a seven-step qualitative and quantitative research methodology, 37 people completed an online survey, with 10 also participating in in-depth interviews; two additional subjects completed in-person interviews only.

The study was conducted by Deep Isolation internal experts as well as one external researcher, Prof. Neil A. Chapman of the University of Sheffield. Chapman is a leading expert in the geological disposal of radioactive wastes, with four decades of experience in environmental, strategic and waste management in the international nuclear industry.

“After years of seeing largely unstructured commentary on the potential role of deep borehole disposal in national waste management programs, this work has at last focused light on what a wide range of policy and decision-makers really think,” Chapman said. “The general consensus that (deep borehole disposal) could be incorporated into a suite of safe disposal solutions, considerably improving strategic and economic flexibility, ought to encourage countries to get together now and support an early multi-national demonstration project. This is becoming increasingly important as the world moves closer to a low-carbon nuclear power future.”

Graphic on International Stakeholder Perspectives on Deep Borehole Disposal of Nuclear Waste
Graphic on International Stakeholder Perspectives on Deep Borehole Disposal of Nuclear Waste

Benefits of deep boreholes

Survey participants were queried about the key potential opportunities and benefits that they believe deep boreholes can offer; and the policy/regulatory, technical/operational and societal challenges that remain to be addressed.

When it comes to benefits, 74 percent of respondents tended to “agree” or “strongly agree” that deep boreholes have a potential role to play in ensuring the safe geological disposal of the world’s higher activity radioactive waste.

The benefits highlighted by those surveyed included: Increased choice and siting flexibility, including the reduced physical footprint compared to traditional mined repositories; the potential for cost reductions across national waste disposal programs; potentially attractive features from the perspective of community consent; and potential for economies of scale when it comes to regulatory processes.

Deep Isolation’s borehole designs have potential for providing additional siting flexibility because they leverage directional drilling and geo-steering techniques to emplace disposal canisters in either vertical, inclined, or horizontal orientations in stable rock formations that have been isolated from the biosphere for millions of years.

The great majority of those interviewed said boreholes would likely be “suitable” or “highly suitable” for small waste inventories of spent fuel, for example fuel from research reactors, and/or for vitrified high-level waste that could be disposed of at or near a nuclear power plant.

As one regulator stated: “Some countries have to deal with wastes that are long-lived and hazardous for a long time, but maybe don’t have a major nuclear program and volumes are relatively small…. [borehole disposal] would be an attractive option because building a mined repository for relatively small volumes can seem unfeasible.”

But borehole disposal is not only an option for small inventory countries. More than half of the respondents believe that it is likely to be suitable, at least to some extent, for both small and large inventories.  As one survey respondent said, “There’s a lot of work that demonstrates that potential usefulness is there for the U.S.A, for Germany — and therefore obviously for all nations.”

All told, 8-of-10 stakeholders said they want to see greater international collaboration on borehole disposal, with the No. 1 priority being a full-scale (non-radioactive) demonstration.

“Even if you had a hundred percent confidence that it would work as designed, I don’t think people would be comfortable until it actually has been used,” said one study participant. “So I think you would have to actually demonstrate the technology in order to gain acceptance by the entire community.”

Demonstrating technical readiness

Although spent fuel handling and deep drilling technologies are mature, Deep Isolation understands there are aspects of the deep borehole technology that will require additional technology maturation prior to industrial-scale deployment. 

Deep Isolation recently completed its first preliminary technology readiness level assessment, and borehole expert Dr. Ethan Bates, Deep Isolation Director of Systems Engineering, presented a paper on this topic at Waste Management Symposia.

Overall, the technical assessment concludes that spent nuclear fuel handling above ground is the most mature technical industry process and that demonstrating borehole stability and canister emplacement is the highest priority in terms of technology development planning. 

Other processes such as pre-closure monitoring, canister retrieval, and borehole sealing may also require additional development and demonstration, but the extent will depend on regulatory and risk-informed engineering requirements that are still being developed.

Given the readiness levels of Deep Isolation’s technology and processes, the company agrees with stakeholder study participants that an end-to-end demonstration should be a top priority.

We are committed to working with the international community to launch the planning process for a long-term collaborative permanent borehole demonstration.

Working with industry partners and government research institutions, we hope to assemble an independent, science-driven, non-profit task force of experts and citizens to oversee the effort. It would be the first ever public-private partnership devoted to researching how deep boreholes can be used to permanently and safely dispose of spent nuclear fuel and other types of high-level radioactive waste.

The goal of the project is to advance the technical readiness levels of deep borehole disposal in a progressive, cost-effective and strategic manner, accelerating the preparation for global deployment of this as a licensed disposal technology.

Since Deep Isolation was founded more than five years ago we’ve sought to assemble an advisory board that includes preeminent experts, Nobel laureates, leaders in nuclear energy science, technology, and policy, and entrepreneurs who value innovation.

In addition to those leadership qualities, inclusion and diversity is also important to us as a company. We were co-founded by and are led by a woman — historically not the norm in nuclear — and last year we launched an internal Inclusion and Diversity Committee to help support and educate our employees. So we were pleased to recently welcome an expert in this field, Monica Mwanje, to our advisory board.

Mwanje entered the nuclear sector in 2003 and in 2015 founded a consultancy company, Liverpool, England-based MM Creative Services, to provide strategic consultancy services for organizations seeking growth and transformation in nuclear and other regulated sectors. Specializing in inclusion and diversity, she works with multi-disciplined technical teams, boards, and leadership teams, advising them on how to develop, implement and maintain inclusive working cultures.

We posed a few questions to her to learn more about her experiences and what advice she shares with companies as well as those beginning their careers in nuclear.

Q. You started out as a chemical engineer, doing graduate work at Sellafield, the former nuclear energy plant in England. What was it like working at a decommissioning plant, and how did your experience influence the development of your career in nuclear?

It was very interesting and informative. I had the opportunity to work on facilities projects and go to view them too. This gave me a better appreciation of the realities and challenges associated with implementing and deploying designed solutions into those sorts of environments.  I was able to draw on this experience as my career advanced and keep it in mind when I was working on design projects or facilitating technical workshops.

Q. As of 2019, women only comprised 22.4 percent of the nuclear workforce, according to the IAEA, so you were clearly a trailblazer when you got your start 18 years ago. What challenges did you personally face when it came to feeling included in the workplace? How did those experiences inspire you to teach employers to provide a more welcoming work environment for people who may be in the minority due to their race, gender or sexual orientation?

I have a lot of admiration and respect for those from minoritized groups who entered the nuclear sector before me and who broke down some barriers. They were the trailblazers. Being honest, my experiences are very mixed when it comes to feeling and being included in the workplace. Early in my career I faced challenges around my race, gender and age. Knowing what it’s like to feel and be excluded, seeing peers experiencing exclusion at times, too, and being frustrated by limited (sometimes non-existent) progress on the matters, inspired me to see what I can do to help improve experiences for others.

Monica Mwanje Headshot

Q. Last summer your consultancy service MM Creative Services co-organized the third annual Inclusion & Diversity in Nuclear conference, which Deep Isolation attended for the first time. What were your goals in founding this event and perhaps share some highlights and what you’ve learned from it so far.

When I first proposed we hold a conference, my goals were simple. I wanted to bring people together so we could talk, understand issues, share and learn from one another. Without this feedback, how would we know what people are experiencing, or what they need, or what organizations are doing well that should be amplified? Personally, I also wanted to learn from the experts we engaged to speak and lead workshops, and further broaden and deepen my knowledge so I can be a more inclusive colleague when working in and with different teams. Highlights were all the different keynote speakers we have had, the different panelists we’ve engaged, and the speakers who shared their lived experiences. The workshops I attended were also really informative and prompted me to reflect and think about what I will do differently.  Different parts of each conference stick out for me. I go back and rewatch recordings from the conferences ( ) as I pick up on different things each time. A conversation I remember from the first conference in 2019, was during some networking, two individuals formed a connection and agreed to share best practices and exchange information around inclusion policies. It was really good to see people talking and helping each other out.

Q. As a consultant to nuclear companies, what does it take to succeed in this industry? Can you share some wisdom that you try to impart upon your clients?

I recommend patience and being prepared that it may take a while before things come to fruition. Like any industry, it’s important to understand the market and any requirements or qualifications needed that will enable a client to place a contract with your organization. I like to conduct reviews with my clients so we can understand their current status and identify and implement an action plan to close any gaps and put them in an improved position to win those contracts.    

Q. Knowing what you know now, what career advice would you give your younger self?

Seek mentors and a career sponsor sooner.

Q. Following up on that, what advice do you give nuclear industry employers seeking to diversify their workforce?

Check how inclusive your organization currently is and be honest about retention issues and any feedback you’ve received from marginalized or minoritized employees. Work on improving that element of performance and improving the work environment so that everyone feels included and able to do their best work. Hiring people into an environment that isn’t welcoming, will likely result in any hiring gains being undone, due to people leaving and going to work elsewhere.

Q. And finally, what advice can you give to those starting out in their careers, when it comes to navigating an industry that lacks diversity.

Develop your network and don’t be afraid to ask for help. For me, having some peers in my network who understood some of the challenges I faced, because they faced some of them, too, helped me work out ways around or through some of the barriers. Seek mentors and sponsors who are supportive of you, your development and your career goals. If your organization has an inclusion and diversity plan and you’ve not heard about nor seen any progress reported, if you have the confidence to — ask for an update.  

Can recruiting an ace volleyball player lead to a 17-year business partnership? Apparently so, says Steve Airhart, CEO of Freestone Environmental Services, the newly acquired wholly-owned subsidiary of Deep Isolation.

Airhart, who studied geology at the University of Montana and launched a career in environmental consulting at the Pacific Northwest National Laboratory, was playing in a city volleyball league in the early 1990s when he heard that local environmental scientist Dan Tyler had just moved to town and had played college volleyball at Purdue University. He figured Tyler would be a great addition to the league team, so he didn’t waste time to make an introduction and invited him to a tryout.

Tyler, who founded Freestone Environmental Services in 1998, lived up to his volleyball reputation and joined the roster. Soon he and Airhart began collaborating off the court on waste management projects. As Freestone took on additional contract work at the Department of Energy’s Hanford nuclear weapons clean-up site, it made sense to become business partners in 2004.

These days Tyler serves in a high-level advisory role while Airhart leads the day-to-day operations. The recently announced acquisition of Freestone by Deep Isolation marks the next chapter in Freestone’s 23-year history, so we sat down with Airhart to learn more about his passion for environmental services and nuclear waste management.

Q. What intrigues you most about your role as an environmental consultant?

A. Environmental consultants provide a broad range of services to ensure compliance with the myriad of complex federal and state regulations. I focused my early career on the characterization and remediation of contaminated sites which allowed me to apply my science and geology background. Contaminated site characterization is particularly intriguing because it involves unraveling the mystery and interconnections of the site geology, hydrology, and geochemistry. That’s what makes our job interesting and challenging. When the location involves a contaminant release, we have to overlay our understanding of the subsurface to determine how the contaminant has moved and how to remediate it to reduce the risk it poses. Our work incorporates science and technology to understand the problem, the risk, and the regulatory framework that governs the cleanup. The final objective and reward is to remove a problem that otherwise would pose an ongoing risk to humans, biota, and the environment. It’s very satisfying.

Q. It sounds like your expertise fits nicely with Deep Isolation’s mission — to permanently dispose of nuclear waste in deep boreholes.

A. Interestingly I studied geologic disposal of radioactive waste at the University of Montana. Digging tunnels in granite for mined repositories intrigued me at the time, and later through my connections, I got into the work at Hanford. I’ve worked around many borehole drilling operations, though not to the depth that Deep Isolation’s looking at and for different purposes.

Q. What are some particularly interesting projects you’ve worked on?

A. Although I’ve been fortunate to work on complex clean-up projects at Hanford, some other notable projects involved smaller clean-up projects that I conducted independently as a private consultant.  These involved cleaning up after fuel-truck and railroad spills in remote locations in eastern Oregon. The logistics of managing the cleanup and ultimately receiving approval from the regulators was very gratifying.  Also, I’ll never forget working in the Alaskan Pribilof Islands where a group of us provided site characterization work on behalf of the National Oceanic and Atmospheric Administration (NOAA). That project tested our abilities to work in a very remote and challenging environment.  Invariably, remote projects involve unexpected complications requiring creative field troubleshooting solutions — which at the time can be stressful but also become the most memorable and rewarding.  

Hanford-Freestone Boat
Freestone conducting field work in the Columbia River near the Hanford Nuclear Site in eastern Washington.

Q. What excites you about being acquired by Deep Isolation?

A. While sometimes acquisitions lead to one company being absorbed by another, that’s not the case here. The goal is for each company to leverage the other’s strengths. Freestone will continue operating independently but will have opportunities to share technical experience to inform Deep Isolation projects. For example, our geologists could provide useful insights into Deep Isolation’s feasibility studies, where they study how a deep borehole repository for nuclear waste will work in certain types of rock deep underground. And certainly our experience with government contracts — we also have a prime contract with NOAA and previously held a prime contract with the U.S. Army Corps of Engineers  — could help inform Deep Isolation’s future contracts. On the Deep Isolation side, they’ve gained worldwide recognition for their solution in a very short timeframe, and we foresee this giving Freestone an opportunity to expand its footprint beyond Washington state.

Q. Speaking of government contracts, your primary customer is the U.S. Department of Energy’s Hanford site, where you provide scientific and regulatory support to the prime contractors. How would you characterize Freestone’s role with this project?

A. We have been very fortunate to establish ourselves as a go-to small business among the Hanford prime contractors.  We don’t take our responsibilities to our clients lightly, because ultimately their clean-up decisions must be effective and compliant and meet the expectations of their client, the U.S. Department of Energy, as well as a large number of stakeholder groups and regulators.  The Hanford site encompasses 586 square miles.  It is considered the largest environmental cleanup in the nation, involving a complex 50-year history of chemical storage and operations. Our work at the site varies and involves support to subsurface characterization activities, environmental data verification, and data management, site characterization reports, and preparation of regulatory planning and permitting documents.  Due to the variety of work we support, we work with staff with a variety of technical backgrounds and levels of experience. 

Q. Running a small business can be challenging. Describe your growth philosophy and what you see for your future.

A. To use a baseball analogy, our business philosophy is more in line with a small ball approach, where we emphasize slow incremental growth similar to advancing one base at a time.  We do this so as to not sacrifice our commitments and reputation with our current clients to achieve a more rapid gain. Over the years we have succeeded in maintaining a balance between maintaining our current client commitments while pursuing opportunities to diversify and grow. Something that we are less known for is our technology development. Using assistance from a series of Department of Energy-sponsored Small Business Innovative Research (SBIR) grants, Freestone developed a sensor to measure hexavalent chromium in groundwater. We hope in the next five years to have the opportunity to deploy multiple sensors to provide continuous real-time monitoring of the diminishing hexavalent chromium groundwater plumes near the Columbia River. Last but certainly not least, in light of our recent acquisition by Deep Isolation, we are excited to collaborate to support nuclear waste disposal demonstration projects and look for new government and commercial contract opportunities. 

Blog by Sam Brinton and Jessica Chow, November 22, 2021

Solving the Nuclear Waste Problem Removes Barrier to Nuclear

At COP26 earlier this month, the glaring absence of nuclear energy as a central discussion topic highlights the uphill challenge this clean energy source has in being recognized as a key player in fighting global warming.

Right before COP26 started, the International Atomic Energy Agency’s Director General Rafael Mariano Grossi stated, “Nuclear energy provides more than a quarter of the world’s clean power. Over the last half-century, it has avoided the release of more than 70 gigatons of greenhouse gases. Without nuclear power, many of the world’s biggest economies would lack their main source of clean electricity.”

Media headlines lately have touched on California, Germany, and the U.K. struggling with skyrocketing natural gas prices and projected increases in power demand while simultaneously shuttering or considering closing their nuclear power plants.

Additionally, it’s not just first-world countries that are grappling with transitioning to a carbon-neutral energy base; as energy demand increases worldwide, all clean energy sources should be utilized to combat the climate crisis.

In another COP26-related article, Matt Bowen of Columbia University’s Center for Global Energy Policy said, “(Climate change)  will be much more daunting if we exclude new nuclear plants — or even more daunting if we decide to shut down nuclear plants altogether… Nuclear waste needs to be dealt with, (but) with fossil fuels, the waste is pumped into our atmosphere, which is threatening us from the risks of climate change and public health impacts from air pollution.”

So, if nuclear energy is seen as a way to fight climate change, why does it have such a bad rap? The reasons are many: fear of nuclear accidents, the potentially high costs and long construction timelines, and perhaps most relevantly, the fact that no country has yet to permanently dispose of its spent nuclear fuel.

Nuclear waste disposal isn’t as easy (or fun) to talk about as the deployment of renewable energy sources, but it is just as important. Because the ultimate disposal of nuclear waste proves to be a barrier to the deployment of new nuclear power plants, solving the nuclear waste disposal problem will help governments address public concerns about building new plants.

Although nuclear energy has its challenges and is often hampered by issues of public perception and deployment, it is still an incredibly necessary low-carbon energy source that can help reduce emissions that lead to global warming. While nuclear may not have been officially discussed enough by top decision-makers at COP26, we believe that solving the problem of nuclear waste will get the world one step closer to its climate goals.

Blog by Kari Hulac, July 28, 2021

Deep Borehole Expert Joins Deep Isolation

Deep Isolation is pleased to welcome its newest team member: Ethan Bates, Director of Systems Engineering.

Dr. Bates, a nuclear engineer who received his doctorate from MIT in 2015, is an expert in reactor safety and nuclear systems integration and has worked for more than five years with leading advanced nuclear companies. In 2014 he co-authored a short paper for the Energy Policy journal published by Elsevier titled “Can Deep Boreholes Solve America’s Nuclear Waste Problem?” The highly cited paper looked at how disposal in deep boreholes could ease siting issues, provide modularity, and lower costs.

At Deep Isolation Dr. Bates is responsible for systems engineering-based product development for the operations of the company’s deep borehole repository concept.

In this Q&A get to know Dr. Bates and learn about his passion for deep boreholes.

Q. What inspired you to choose nuclear engineering as your career path?

After growing up in Singapore and participating in Model United Nations in high school, I became familiar with international issues needing massive institutional and technological advancements. The one that concerned me the most and which I felt could benefit the most from my quantitative skills was climate change.  I applied to Massachusetts Institute of Technology (MIT) and was admitted along with my twin brother Richard, who shares my passion for preventing climate change. We saw a flyer for a new freshman class called “Energy, Environment, and Society” and were intrigued by its project-based format.  I chose a project analyzing ways to recover thermal energy from MIT’s 5 -megawatt research reactor and became increasingly fascinated by how elegant, clean, efficient, and compact nuclear reactors are.  Combined with the realization that nuclear power was one of — if not the only — mature clean energy technology that could be expanded rapidly to grid-scale, I dedicated my studies and career to advancing the technology.

Dr. Ethan Bates touring SKB’s Äspö Hard Rock Laboratory (HRL), a spent fuel repository demonstration facility near Oskarshamn, Sweden.
Dr. Ethan Bates touring SKB’s Äspö Hard Rock Laboratory (HRL), a spent fuel repository demonstration facility near Oskarshamn, Sweden. He is standing next to a display model of a KBS-3 repository concept copper canister, designed to corrode less than 1 mm in 100,000 years.

Q. After earning your nuclear science and engineering degree from MIT, you earned your doctorate there in which you developed a computational thermal and geologic model to simulate and optimize the design for a deep borehole waste disposal/spent nuclear fuel repository. Tell us how you became interested in deep boreholes and share some highlights of your doctoral research.

I saw an intriguing handwritten and photocopied flyer in the nuclear engineering department asking for an undergraduate researcher to conduct experiments on new concepts of emplacing nuclear waste in a deep borehole repository.  I discovered the flyer was composed by Professor Michael Driscoll, who had been pioneering borehole research (among other areas) for decades and had developed a reputation for tackling highly complex problems with elegant solutions he derived with pencil and paper.  This seemed like a great way to get more hands-on experience in a laboratory and to contribute to solving the nuclear waste problem.  Inspired by my advisors (Prof. Michael Driscoll and Prof. Jacopo Buongiorno), I made the research the focus of my bachelor’s and master’s degrees, which received an award from the Department of Energy in 2011 and led to a scholarship from the American Nuclear Society in 2013.

My doctoral research led to a published paper on sealing materials for borehole repositories.  I also investigated new filler materials for the canister and canister-to-borehole wall gap.  I realized that to quantify the benefit of these advancements, I’d need to develop an integrated safety and cost model.  This allowed me to provide justified answers to even more fundamental and unexplored questions of deep borehole design, such as the limits of waste loading and borehole spacing.

One of my favorite experiences was collaborating with accomplished scientists from national laboratories and having the chance to visit the Waste Isolation Pilot Plant in Carlsbad, New Mexico.  It gave me a true sense of geologic time scales and proved to me that siting, building, and operating a deep borehole repository is possible.

A key finding of my research validated my initial draw to nuclear as a compact and efficient energy source.  I estimated that for the same amount of electricity, geologic disposal of nuclear waste will require up to 10,000 times less land area compared to the alternative of building advanced natural gas plants with carbon capture and sequestration into similarly isolated geologic formations.

Q. You also published a short paper examining whether deep boreholes could provide a means to address the nuclear waste problem. What did this paper conclude?

The primary conclusion is that deep boreholes provide access to stable rocks that have

been isolated from flowing groundwater and surface processes for millions of years.  This increases the number of potential sites where geologic disposal is possible, easing one of the biggest challenges to the nuclear industry.  The concept relies more on the natural barriers and features whose behavior can be extrapolated into the future more confidently compared to man-made and engineered barriers.  Since boreholes are modular (i.e., capacity can be expanded as needed), they’ll create less programmatic risk and could be valuable to countries with smaller inventories.

Q. You worked at two advanced nuclear reactor companies before coming to Deep Isolation. Please tell us about these experiences and why you’ve chosen to focus on the back end of the fuel cycle.

I had the rare opportunity to work at both TerraPower and Oklo and attended MIT alongside the founders of Transatomic.  In this way, I’ve lived the dream that a young engineer might have after watching the movie, “A New Fire,” a compelling and inspiring documentary about these three advanced nuclear companies.

I was strongly drawn to TerraPower’s vision of bringing bright nuclear engineers together to design and deploy an advanced sodium-cooled nuclear reactor in the near term.  There I analyzed the safety of their reactors and focused on validating the accuracy of accident simulation codes.  The most rewarding part of my time there was traveling to the International Atomic Energy Agency (in the real, not “model” United Nations) to present the findings of the work I had started as an intern.  That led to an invitation to present our findings at a conference in Yekaterinburg, Russia, where I was the only American in attendance and toured their sodium-cooled fast reactors. 

The challenge of nuclear waste disposal is shared by many countries and should be solved soon if there is to be a significant (and much needed) expansion in nuclear power.  Advanced nuclear reactors will still produce significant amounts of waste, and the front-runner concepts are not positioned to rapidly deal with the existing and growing inventory of spent fuel.  Thus, although I had opportunities to continue in the advanced nuclear industry, I ultimately decided to refocus on disposal.  I believe I can benefit the industry the most (and thus help combat climate change) by designing, testing, and deploying a borehole repository.  I was also attracted by the rewarding sense of empowerment, mutual respect, and mission of the Deep Isolation team.

Q. Any Deep Isolation accomplishments you’d like to highlight so far? What would success look like to you moving forward?

I’ve been able to pick up where I left off with my MIT research and begin fulfilling my goal of bringing it to reality.  Over the past five years, Deep Isolation has made great advancements in borehole design and performance analysis. By applying systems engineering principles, I’ve structured these efforts within an overarching concept of operations.  Breaking the large complex problem into organized and manageable pieces enables us to prioritize them and build more a detailed and robust technology commercialization pathway.  I’m also leading our collaboration with external industry experts to improve the deep borehole community’s collective understanding of long-term safety analysis assumptions.

Moving forward, success requires continuing development of technical partnerships, customer relationships, and government funding sources across the globe. We’ve assembled excellent teams to lead each of these areas and our progress so far is encouraging.

In the near term, techno-economic models which reveal performance trade-offs and limits as a function of various host rocks, waste types, loadings, and other design assumptions will enable optimization of design configurations.  Using these methods, we can also generate site selection criteria specifying where and under what conditions deep borehole repositories can be safely built.  Combining this with customer-specific requirements, the design can be refined, and a complete set of technical requirements can be established.

In parallel, a well-planned and executed demonstration program would be a major success for the industry, building broader confidence, establishing trust, and signaling that the technology will be ready to commercialize and scale.

Q. Tell our readers something about yourself that they might not expect to know about a nuclear engineer.

Most people wouldn’t associate nuclear engineers with music or dancing, but I really enjoy playing guitar and dancing Argentine tango.  Musically, I’d say my style is blues-rock with an infusion of jazz.  I performed for many years as a student at MIT’s “Battle of the Bands,” have danced in tango festivals all over the U.S., and even taught a series of tango classes at a university.

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