Meet the CEO of Freestone, a Newly Acquired Deep Isolation Subsidiary

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.

Blog by Kari Hulac, June 8, 2021

Our Podcast Celebrates its First Year

When I was hired at Deep Isolation in early 2020, I was eager to apply my experience in news, social media and renewable energy marketing to a new-to-me topic: nuclear waste disposal.

However, of the skills listed on my resume, “podcast host” was not among them. So when two weeks into my job I found out that, “Oh yes, the company was very much in need of a host for a new series about nuclear waste,” I won’t lie: I gulped.

Nuclear Waste: The Whole Story logo
Deep Isolation’s podcast was established in the spring of 2020.

But when I discovered that it would be my role to represent people similar to myself — nuclear industry outsiders mostly unaware of this hidden-in-plain-sight worldwide problem — I knew it was something I was willing to try.

The goal was for Nuclear Waste: The Whole Story to embody one of the most important elements of a successful nuclear waste disposal program: the ability to listen, to recognize, and to understand different perspectives on nuclear waste and all of its dimensions; as a former reporter and editor, those objectives were in my comfort zone.

Afterall, what better way is there to collect as much wisdom as possible on a complicated topic? Now, a year later, we have released 12 episodes with plenty more to come. We’ve also incorporated additional hosts (Liz Muller and Sam Brinton) to provide valuable insights to these conversations.

I’m happy (and relieved!) to say the podcast has earned a five-star rating on Apple, with listeners saying they appreciate its “to the point and direct vibe” and the expertise of our interviewees, who include citizen activists, nuclear industry veterans, government leaders and scientists.

I’ve learned so much from each and every one of these guests and am grateful for their willingness to speak openly about the challenges they face in their respective efforts to tackle this controversial problem.

Don’t Miss Our New Podcast Highlights Reel

There are too many highlights to mention, but we’ve assembled some of them into a short montage that I hope you’ll take a few minutes to watch or listen to.

The highlights reel includes Kara Colton, who points out that nuclear waste — often incorrectly portrayed as “green goo” ala “The Simpsons” — can be an object as seemingly innocuous as a glove or a broom.

Or there’s the episode with Judy Treichel and Steve Frishman, two “ordinary” citizens who’ve spent 30 years informing the public about the U.S. government’s plan to build a mined waste repository in Nevada. They discuss how their effort eventually led to Yucca Mt. being put on hold because, as they said the states residents believe, “Nevada is not a wasteland.”

New episodes are added monthly. Watch or listen at or subscribe via Apple, Spotify, Amazon or Google. The series is also a playlist on our YouTube channel.

Please note: Although Deep Isolation is the producer, any opinions expressed by either the interviewers or their subjects do not represent our official company position.

And as always, we’d love to hear from you! Who should interview next? What questions about nuclear waste would you like answered? Just send an email to

Blog by Liz Muller, June 1, 2021

Deep Isolation Marks Five-Year Anniversary

When Richard Muller and I founded Deep Isolation five years ago, we were inspired by a strong desire to do big things to help fight global warming.

It was evident to us that nuclear energy would have to be part of the low-carbon energy mix but that it had to be done responsibly and that it wouldn’t succeed without a waste solution.

When we realized the answer was hiding in plain sight — using advances in oil and gas drilling technology to engineer deep boreholes to safely and permanently isolate the waste — the company was born.

At the time our close friends and advisors from the nuclear industry told us we’d be better off spending our time on something that had a future. Nuclear waste disposal, they explained, could never get done. This week, in recognition of our June 13, 2016 founding anniversary, I’m pausing to reflect on how much has changed. Even though we have not yet disposed of any waste, most people in the industry now believe that we will. I am so proud of our team and what we have achieved. We have broken through barriers that many thought were impossible to overcome by assembling a strong team around a common vision.

Here are some of our most notable achievements, as well as some of my thoughts about what I hope the nuclear industry will look like by our 10th anniversary.

Deep Isolation’s Progress So Far

After we filed our first patent in 2015, Deep Isolation was officially incorporated the following year. We quietly began reaching out to environmental groups and other stakeholders across the U.S. solely to listen and learn, and we recruited our first team member (who crashed at our Berkeley, Calif., home-based headquarters!).

We knew from the beginning that a successful nuclear waste disposal initiative would never succeed without community involvement, and it remains a core company value.

We knew we were being disruptive. We knew that the concept of a private company tackling a problem that has plagued the nuclear industry and governments for decades would be difficult for many to embrace. But we were galvanized by our early successes, most notably holding a public demonstration where we emplaced and retrieved a prototype nuclear waste canister from a borehole.

The 2019 demo established us as serious players in the nuclear industry, and soon after we forged partnerships and working relationships with international industry leaders including Bechtel, Schlumberger, and NAC International Inc. With these partners, plus the recently announced MOU with Dominion Engineering, Inc., we have all the elements of the fuel cycle disposal ecosystem in place.

In 2020 we announced a London-based team to serve our international market, and we landed and completed our first several paid contracts to study disposal options in specific rock formations.

Now, we are humbled to be part of the global conversation on nuclear waste. Borehole disposal, which had been studied extensively for years in the vertical formation, is seeing a resurgence in interest from governments and organizations all over the world.  Not only do I hope this continues, but that it also encourages the industry to support more innovation in disposal technologies.

And in public conversations about nuclear energy, there’s finally a more hopeful answer to the decades-old waste question. As one supporter said in an online forum recently: “As for disposal, check out Deep Isolation, a cool company thinking outside the pool on where spent fuel can go.”

Liz and Rich Founders
Liz and Rich – Founders of Deep Isolation

Five-Year Vision for Nuclear Waste Disposal

The future has never been more exciting for Deep Isolation. Our team is growing quickly, and no, no one is on our couch at the moment. We’re entering our next stage of fundraising and eyeing service contracts with multiple countries worldwide.

Here’s my vision for five things I hope Deep Isolation and the industry as a whole achieves in the coming five years.

1. All countries with waste are moving forward toward deploying a permanent nuclear waste disposal solution that is based on equitability and social responsibility and can be implemented in years not generations.

2. Countries that opt to deploy new reactors will select, site, and fund a disposal option before the reactor is built.    

3. Governments and industry will encourage new waste disposal options and allow (even encourage!) private innovation, including in approaches to stakeholder engagement and working with repository host communities.  

4. Investors and the public will understand that nuclear waste disposal technologies are pivotal in the fight against climate change.

5. Deep Isolation will have proven the cost, safety, equity and other benefits of its solution, and the company culture will continue to emphasize supporting one another, and always prioritizing what is truly important.

Blog by Jessica Chow, May 11, 2021

Demystifying Nuclear Waste: Answers to Your Questions

Nuclear waste pellets
Spent nuclear fuel comes in the form of small pellets.

The issue of nuclear waste and the history of how it has been handled in the United States and worldwide is a complicated one. When it comes to discussing the issue of finding solutions, the conversations can be difficult due to conflicting opinions and viewpoints.

Growing up, nuclear waste was not a topic that ever crossed my mind or came up in conversation. In high school, when I was deciding on my college major, a desire to help solve the global climate crisis motivated me to study nuclear engineering. Yet at the time, I didn’t have a clear understanding of the complex nature of the nuclear fuel cycle and the industry at large. 

When I started taking nuclear engineering courses at the University of California, Berkeley, nuclear waste was seldom discussed in classes or seminars. Even when I eventually took a nuclear waste technical course, the societal challenges of nuclear waste storage and disposal were barely discussed, and if they were, the issues were often dismissed because it was considered that the public’s concerns were not “based in science.”

As a student, I spent time volunteering at different science education events throughout the San Francisco Bay Area where I learned how to talk to people about nuclear science. I was and still am incredibly passionate about nuclear and broader science education.

As someone approaching nuclear science from a technical perspective, and as someone who was surrounded by peers who viewed nuclear science similarly, it was difficult to honestly understand why the public was skeptical of nuclear power and fearful of nuclear waste.  However, I have learned from listening to all sides, that the public has incredibly valid concerns and questions about nuclear power and radioactive waste, and the industry has to do a better job of understanding these concerns.  

Jessica Chow as a nuclear engineering student at the University of California, Berkeley.
Jessica Chow as a nuclear engineering student at the University of California, Berkeley.

The storage and disposal of nuclear waste is more than just a technical problem, and solving the puzzle of how to permanently dispose of nuclear waste requires a greater understanding of its intersection with our own lives and well-being.

A desire to advance this understanding is behind Deep Isolation’s decision to launch a new resource, About Nuclear Waste. (It’s also why we launched an educational podcast last year called Nuclear Waste: The Whole Story.)

As the curator for the About Nuclear Waste content, my goal is to outline the facts of nuclear science within the context of valid concerns in order to find common ground that helps our readers have more productive discussions about this important issue.

There are approximately 500,000 metric tons of nuclear waste worldwide, and none of it has been permanently disposed of yet. Every year more nuclear waste is generated from nuclear power plants and nuclear industries. As the world begins to seriously explore advanced nuclear options to develop more low-carbon energy sources, nuclear waste will continue to be a problem for future generations unless an equal effort is put into finding a solution for it.

I hope you find About Nuclear Waste helpful and informative. Sharing this knowledge of what nuclear waste is will hopefully be a good step toward a shared understanding that will help build public support for a permanent disposal solution.  If you don’t find your questions answered please let us know, and we will do our best to address them in future updates to this resource.

Guest Blog by Zeke Hausfather, Apr. 8, 2021

Our Changing Climate and the Accelerating Energy Transition

On March 12 climate scientist Dr. Zeke Hausfather, Director of Climate and Energy for The Breakthrough Institute and research scientist for Berkeley Earth, was among several experts to offer testimony to the U.S. House of Representatives Committee on Science, Space, and Technology in a session titled “The Science Behind Impacts of the Climate Crisis.” This was the first time the committee addressed this topic, marking a significant milestone in the national conversation around global warming.

Zeke Hausfather Headshot
Zeke Hausfather, Berkeley Earth Research Scientist and Director of Climate at Energy, Breakthrough Institute

Since Berkeley Earth was established by Liz Muller and Richard Muller, co-founders of Deep Isolation, we are highlighting this important testimony in recognition of Earth Month 2021 and the 51st Earth Day. Deep Isolation recognizes that nuclear energy is an important means of addressing climate change, and without a nuclear waste solution, finding public support for nuclear may be challenging. The introduction to Hausfather’s testimony follows:

Good morning Chairwoman (Eddie Bernice) Johnson, Ranking Member (Frank) Lucas, and members of the Committee. I am grateful for the opportunity to join you today and the opportunity to share my perspective on the science behind the impacts of climate change. My name is Zeke Hausfather. I am the director of climate and energy at the Breakthrough Institute, an environmental think tank located in Oakland, California. I also serve as a research scientist with Berkeley Earth, and a contributor to Carbon Brief.

I am a climate scientist whose research focuses on observational temperature records, climate models, and mitigation technologies. I am also a contributing author to the IPCC 6th Assessment Report. My testimony today will draw upon my work and that of my colleagues to present a view of our changing climate and its impacts, the future warming pathways the world may take, the accelerating global energy transition away from carbon-intensive fuels, and the technologies needed to decarbonize the U.S. economy.

In many ways, 2020 was the year in which both climate change and the accelerating energy transition became impossible to ignore. On the climate front, we saw 2020 tie with 2016 as the warmest year since records began, with global temperatures around 1.3ºC (2.4ºF) above the temperatures of the late 1800s. Land areas – where we all live – were nearly 2ºC (3.6ºF) warmer. We saw devastating wildfires in California and Australia, extreme heat in Siberia, and the second-lowest level of Arctic sea ice ever observed, among other climate extremes.

This map shows how local temperatures in 2020 have increased relative to the average temperature in 1951-1980.

At the same time, the world has made substantial progress in moving away from the worst-case outcomes of climate change over the past decade. Rather than a 21st century dominated by coal that energy modelers foresaw, global coal use peaked in 2013 and is now in structural decline. We have succeeded in making clean energy cheap, with solar power and battery storage costs falling 10-fold since 2009. The world produced more electricity from clean energy – solar, wind, hydro, and nuclear – than from coal over the past two years. And according to major oil companies peak oil is upon us – not because we have run out of cheap oil to produce, but because demand is falling as consumers shift to electric vehicles.

Current policies adopted by countries put us on track for around 3ºC (or 5.4ºF) of warming by the end of the century, compared to the late 1800s. Including pledges and targets – such as those included in the Paris Agreement – brings this down to 2.5ºC (4.5ºF). We have seen a proliferation of longer-term decarbonization commitments in recent years, with countries representing around half of global emissions – including China – pledging to reach net-zero by 2050 or 2060. If these longer-term commitments are achieved, it would bring end-of-century warming down close to 2ºC (3.6ºF).

Some caution is warranted here; long-term pledges should be discounted until reflected in short-term policy commitments. And warming could well be notably higher – or lower – than these best estimates, given scientific uncertainties surrounding both the sensitivity of climate to our greenhouse gas emissions and likely changes in the ability of the land and oceans to absorb a portion of what we emit. CO2 accumulates in the atmosphere over time, and until emissions reach net-zero the world will continue to warm.

This is the brutal math of climate change, and it means that the full decarbonization of our economy is not a matter of if but when. Cost declines in clean energy go a long way toward making deep decarbonization more achievable at a lower cost than appeared possible a decade ago. Low-cost renewables can provide a sizable share of our energy needs in modern grid-integration models. In the near term, however, America’s cheap and abundant supplies of natural gas will play a key role in filling in the gaps as we build out more wind and solar and keep existing clean energy sources like nuclear online.

In the longer term, there is a growing recognition of the need for both complementary technologies – such as grid-scale storage and long-distance transmission – as well as clean firm generation like advanced nuclear, enhanced geothermal, and gas with carbon capture and storage to wean the system off natural gas. Studies have consistently shown that low-carbon power grids with a sizable portion of clean firm generation are a lower cost option than wind, solar, and hydro alone.

Debates around climate mitigation are often framed as a choice between the technologies we have today and future innovations. In reality, we need to do both; to deploy what is cost-effective today, and to invest in the range of solutions needed to tackle the hard-to-decarbonize parts of the economy. The recent omnibus bill takes an important step in this direction, authorizing billions of dollars for investments in clean energy, vital energy R&D, and grid modernization. It shows that there is real potential for bipartisan energy solutions that both reduce emissions and create jobs.

If we want to ensure that the rest of the world follows the U.S. lead in reducing CO2 emissions, there is no better step that we can take than making clean energy technologies cheaper than fossil fuel alternatives. Making clean energy cheap can set the U.S. up to be a leader in developing and selling these technologies to the rest of the world while building new industries and creating jobs at home.

Find a link to the full testimony and a video of the hearing here.

In December 2020, the peer-reviewed journal Energies published a new paper by the Deep Isolation technical and geo-science team that explores what might happen if a deep borehole repository for nuclear waste had an improperly sealed access hole connecting the disposal section of the repository to the Earth’s surface.

In a recent blog post, Deep Isolation lead hydrogeologist Stefan Finsterle summarized the results of a paper titled “Sealing of a Deep Horizontal Borehole Repository for Nuclear Waste.” This new paper is a continuation of a more extensive safety study released a year ago that examines the overall safety of deep borehole repositories.

In a public webinar set for March 30 and 31, Stefan and other Deep Isolation team members will present the results of this updated safety report and field your questions and comments.

Get to know Stefan better through this Q&A.

Stefan Finsterle Headshot
Lead Hydrogeologist, Stefan Finsterle

Q. Hydrogeology is defined as a branch of geology that deals with the distribution and movement of groundwater in the soil and rocks, including aquifers of the Earth’s crust. Why is this so critical to understand for nuclear waste disposal?

A. Groundwater is the main vehicle by which radionuclides could be transported from a breached waste canister through the rocks, aquifers and soil to the land surface, where they may find their way to people, either directly through drinking water or more indirectly through other exposure pathways. It is therefore crucial to understand how water moves through rocks, how dissolved radionuclides would migrate within the groundwater, and what natural or repository-induced driving forces may exist in the deep subsurface. Geologic layers considered suitable to host a repository for nuclear waste are very tight, that is, groundwater flows extremely slowly through the small pores of the rocks, effectively isolating the waste for very long times. I hope this clarifies why understanding hydrogeology — the interaction of water and rock — is essential when trying to find a suitable site and for assessing the safety of a nuclear waste repository.  

Q. Tell us about your background as a hydrogeologist who studies deep geologic repositories for nuclear waste. What interests you most about this work?

A. As an environmental engineer, I want to understand the natural environment, protect it, or at least help minimize or mitigate the potentially negative impacts of our intrusions. Hydrogeology has always been fascinating to me because the deep subsurface is both vast and difficult to observe, requiring innovative methods to understand and characterize it, with the response of the groundwater to our testing being the most telling messenger. Nuclear waste disposal is obviously a multifaceted challenge; the fact that answering hydrogeological questions is key to finding a viable solution is certainly a great motivation for me. Moreover, I find the idea of borehole disposal intriguing because this concept indeed minimizes the interference of the repository with its host rock and the fluids that flow through it.

Q. This latest study looks at what the consequences would be for an improperly sealed borehole containing nuclear waste. Why was this important to study?

A. There are two main reasons why it is important to analyze the safety effects of an improperly sealed borehole. First, building a repository invariably perturbs the otherwise impermeable host rock. The access hole and the disturbed rock around it are often considered the weakest elements of the repository system, as they pose a risk for radionuclide leakage. Second, even if the borehole is carefully sealed and tested as part of the repository closure activities, it is difficult to demonstrate that the seals will remain tight for the long time periods over which the safety of the repository must be assessed. Rather than studying the effectiveness of different sealing methods, we decided to examine the impacts of a poorly sealed borehole (or a seal that has degraded over time) on safety, to better understand how much we will have to rely on the long-term integrity of the seal. It is important to note that the design of a Deep Isolation repository includes proper sealing of the boreholes.

Q. The results seem to imply that a tight seal is not really necessary. Yet, Deep Isolation plans to install an impermeable sealing barrier. Given the results of your study, why spend the time and resources to do so?

A. There will always be irreducible uncertainties in predicting the long-term behavior of both the engineered and natural barrier systems. It simply makes good sense to install plugs at strategic locations and to backfill the access hole, specifically since such safety measures are relatively inexpensive. For example, installing a sealing plug at the beginning of the horizontal disposal section or another point along the access hole within the host rock would be very effective in retarding axial radionuclide transport. Special attention should also be given to the uppermost section of the vertical access hole. A suitable backfill would reduce the near-surface hydrological disturbances that propagate along the borehole into the repository, specifically pressure drawdowns caused by climate change effects or groundwater pumping. It would also directly protect the aquifer and inhibit inadvertent or malicious human intrusions into the repository. Hydraulic feed or thief zones identified during drilling and borehole logging can be plugged, and the drilling-disturbed zone around the borehole can be grouted at certain intervals. Sealing of boreholes and abandoned wells is required by regulation in other areas of engineering, specifically oil and gas production, energy storage, and geologic carbon sequestration systems. Similar requirements are expected for a borehole repository for nuclear waste. Nevertheless, it is certainly reassuring to know that a deep borehole repository does not need to rely on the long-term integrity of its backfill materials and sealing methods.

Q. What do you see as next steps or a follow-on study to this one?

A. I’m looking forward to engaging in discussions that further probe our assumptions about potential axial driving forces, the dissipation of pressure and dispersion of radionuclides into the overburden, and the overall arguments about the inherent, passive safety afforded by the geometry of the borehole repository. The topic of sealing will definitely need to be revisited for each potential repository site, as the site-specific geology and design adjustments will influence the effectiveness of the seals as well as alter seal degradation processes. In summary, extending the current, generic study to a site-specific performance analysis will be the next step in further examining the sealing of a deep borehole repository.  

Two sessions of the webinar “Safety in Depth Part 2: Sealing of a Deep Horizontal Borehole Repository for Nuclear Waste” will be offered. Click here to register for the 10:30 a.m. PST March 30 session. Click here to register for the 3:30 p.m. March 31 CET session. Both sessions will feature a live question-and-answer period following the presentation.

Q&A Blog, Mar. 3, 2021

Getting Prepped for #WMSym 2021

Next week, two Deep Isolation company leaders, Chief Operating Officer Rod Baltzer and Director of Partnerships Jim Hamilton, will be presenting at Waste Management Symposia 2021, an annual conference that provides an opportunity for education and information exchange among those in the radwaste industry.

For this year’s event, featuring the theme “Reducing Risk Through Sound Technical Solutions,” Baltzer will highlight the results of a recently published EPRI report in his session, “Disposal of Radioactive Wastes from Advanced Reactors in Horizontal Boreholes.” The session is part of the High-Level Radioactive Waste, Spent Nuclear Fuel/Used Nuclear Fuel track, 7 a.m. to 10:10 a.m. PST on March 11. Hamilton will participate in the panel session, “Stakeholder Involvement in Consolidated ISF Storage, Disposal, and Transportation Initiatives,” 7-8:30 a.m. PST, also on March 11.

To help conference attendees get to know Baltzer and Hamilton, we sat down with them for a short Q&A.

Rod Baltzer Headshot
Chief Operating Officer, Rod Baltzer
Jim Hamilton Headshot
Director of Partnerships, Jim Hamilton

Q: Let’s get to know you both a bit. Why did you choose careers in something as challenging as nuclear waste disposal? What keeps you inspired each day?

Rod:  I think nuclear waste chose me.  I got a degree in accounting and agricultural economics.  After working in public accounting, I worked for a company that owned a nuclear waste company.  It was fascinating, and I really enjoyed working on the issue and have been in the nuclear waste industry ever since. 

Jim:  In the literature, nuclear waste is described as a “wicked problem.”  Any attempt at a fix requires balancing technology, policy and pragmatism combined with a deep appreciation of the societal issues surrounding nuclear energy.  It also requires forming collaborations and partnerships across sectors, cultures and disciplines.  Sure it’s not for the faint of heart, but I find it fascinating and feel lucky to be working toward a solution.

Q: If I’m a first-time WM Symposia attendee, what should I expect? What are some highlights, learnings etc. from past conferences?

Rod: I can’t imagine attending WMS for the first time in a virtual format.  I’ve attended the conference for the last 15 years, and I’m not sure what to expect this year.  Typically, you have about 3,000 people from around the world in a large exhibit space with hundreds of exhibitors. There’s really good content and intriguing new ideas and discussions. The best part is randomly meeting new people and then seeing them every year after that. 

Jim: I agree with Rod. The real learning comes from the interactions in the hallways, meeting new people, then building on those relationships in the future.

Q. When you think of this year’s theme, “Reducing Risk Through Sound Technical Solutions,” what’s top of mind for you in terms of your respective roles at Deep Isolation?

Rod: Deep Isolation believes that fitting the right disposal solution to the right situation can allow disposal to be accomplished sooner and more cost-effectively.  Borehole disposal — whether vertical or horizontal — may provide a safe, cost-effective solution to reduce risk and make progress on waste disposal. 

Jim: I’m a bit of a contrarian. Yes, we need sound technological solutions. Nobody will argue with that.  But technology by itself is only half the issue. In parallel, we need to earn public trust and support.

Q. Let’s give conference attendees a couple of reasons to attend your sessions. Can you share a few high-level goals for what you’d like attendees to learn in your presentations?

Rod: Well, first off, we’re having a swag giveaway for my office hours session. (Sorry, Jim!) So if you show up, you can enter a drawing for your choice of a cool portable speaker or a nifty set of earbuds.

Other than that, I think a discussion about costs for disposal for advanced reactors is very timely. 

Jim: Ok, Rod. Well, I can’t top you on the swag, but I’ll do my best here. I can promise my session will give an update on how we view stakeholder engagement and its importance in supporting our overall mission.

Q. Aside from your sessions, is there a session that you’re particularly looking forward to attending? Tell us why.

Rod: I like the Plenary sessions and am looking forward to a session on the cleanup of Fukushima in Japan.

Jim: I’m a fan of the student poster sessions.  It’s always invigorating to see new ideas and innovations coming from national and international research institutions.

The virtual Waste Management Symposia is set for March 8-12. Register or learn more about sessions and speakers. See Swag Bag Giveaway contest rules here.

A paper on the impact of poor borehole sealing on repository performance written by Stefan Finsterle, Cal Cooper, Richard A. Muller, John Grimsich and John Apps, has been published in the peer-reviewed journal Energies. The paper is available online and for download.

A deep horizontal borehole repository offers strong isolation of nuclear waste. The safety afforded by waste isolation at depth relies largely on the natural barrier provided by the horizontal section of the borehole. A potential for vulnerability may be with the vertical section of the borehole that needs to be drilled to build and access the repository. It is important to measure and ensure that the vertical access hole does not provide a direct path through which radionuclides escape from the repository to the land surface. While the borehole will be backfilled and plugged after waste emplacement, it is difficult to assure that the engineered sealing barrier will remain effective over the very long time period for which the waste must be safely isolated.

To investigate the importance of borehole sealing on repository safety, we calculated the radiological exposure dose assuming that the backfill material is of poor quality or has lost its ability to inhibit water flow and radionuclide transport. Our computer simulations indicate that the release of radionuclides through the poorly sealed access hole is small, even if an earthquake destroyed the waste canisters and pushed water along the borehole and into faults. The estimated maximum dose from the release of radionuclides during these adverse events does not increase significantly compared to the nominal scenario and is two to three orders of magnitude lower than a 10 mrem dose standard.

Given that the long-term effectiveness of borehole sealing is difficult to assess or predict, it is reassuring that a deep horizontal borehole repository does not need to rely on the long-term integrity of its seals and backfill material.

Sealing Paper Image
Computer simulations of water flow and radionuclide transport in a deep horizontal borehole repository indicate that the waste remains sufficiently isolated even if a strong earthquake occurs and the access hole is poorly sealed.

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Berkeley, CA 94704