Nuclear Waste Today

Why should I care about nuclear waste?

One out of three US citizens live within 50 miles of a nuclear waste storage facility. There are 80,000 tons of nuclear waste currently stored on site at the nuclear reactors that produced it, including decommissioned (non-operating) nuclear plants. Most of the waste is being stored in water cooling pools in buildings adjacent to the reactors. Some has been transferred to dry casks that are sitting on or near the surface of the ground within the fenced reactor facility. See Figure 1

Is nuclear waste slimy green sludge?

The waste we are concerned with in this document is “spent nuclear fuel” from commercial nuclear reactors. It consists of small (1 cm) ceramic pellets made of uranium dioxide. It is not the green sludge of science fiction, or the radioactive liquids that are held in tanks at U.S. Department of Energy (DOE) sites such as Hanford. These pellets are stored inside metal fuel rods about 14 feet long, which are in turn held in fuel assemblies about 8 to 12 inches in diameter. We will place these assemblies in steel canisters, with internal space filled with bentonite.

What is the current plan for nuclear waste?

A permanent repository is partially constructed at Yucca Mountain, Nevada, where waste will be transported and then stored in casks placed in tunnels about 1000 feet deep. No waste is currently stored at this site. The cost of completing the Yucca repository is estimated by the US Office of Management & Budget (OMB) as $96B. Licensing of the repository was halted by President Obama, but there is pending legislation to re-start the process to license the facility. However, the State of Nevada opposes these plans, and has budgeted $3.5M per year to oppose the Yucca repository on legal grounds. Even after the Yucca repository is licensed for construction, it will need another license in order to operate and actually place waste in the repository.

There are also plans for “consolidated interim storage”, with one such facility proposed in New Mexico and one in Texas. These would hold the waste above ground (or near surface) until a permanent disposal facility is operational. These proposed facilities would have 10 to 20-year licenses, with multiple renewals possible if permanent disposal continues to be delayed.

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Nuclear Waste Innovation Act 

What does the act say, in simple words?

The Act directs the U.S. Nuclear Regulatory Commission (NRC) to accept license applications from private companies, and allows the US Department of Energy to engage such companies for nuclear waste isolation and disposal.

Remarkably, current law does not allow for the consideration of innovative or less expensive options. It states that only the currently unfinished facility at Yucca Mountain Nevada could be used for disposal.

Would disposal by a private company be safe?

In order for a private company to receive a license, it would have to meet the safety criteria of the Nuclear Regulatory Commission. Standards are the same as for government-developed facilities.

How can a company maintain liability for thousands of years?

Liability would be with the U.S. government, not the private company. Just as the government will take title of the waste for the facility at Yucca Mountain, it will also take title of the waste for a privately licensed facility. The private facility would meet the same safety standards as government-licensed facilities. The main difference is that there could be additional innovations in the private-sector approach.

Currently, utilities have title for the waste created at their reactors. The Department of Energy is expected to take title when the waste is taken for permanent disposal. This would not change with the Nuclear Waste Innovation Act. The difference is that the Department of Energy could contract with a private sector license holder for the disposal of the waste.

What companies might apply for licenses?

There are many private companies in the nuclear waste disposal business, and several of them might enter the field for spent nuclear fuel. They might include Bechtel, Fluor, Orano (formerly AREVA), Holtec, Waste Control Specialists, Battelle, EnergySolutions and many more.

The Act would also open an opportunity for small, innovative startup companies in the Silicon Valley mode, similar to Deep Isolation.

Who benefits from the Nuclear Waste Innovation Act?

The Act would unleash free-market innovation to solve a critical problem. The public would be the key beneficiaries when the waste is moved from temporary locations to deep permanent isolation. Private companies could also benefit from access to a new market.

How could private companies do better than the US government?

The Nuclear Waste Innovation Act does not turn over the responsibility to private companies. It merely allows them to compete in a business that was previously a government monopoly. SpaceX currently offers launches at lower cost than NASA. FedEx transformed and improved the delivery of urgent mail and packages.

Would the passage of the Nuclear Waste Innovation Act slow progress on the Yucca Mountain facility?

No. The Nuclear Waste Innovation Act would have no impact on Yucca Mountain. The purpose of the act is to allow private-sector innovation which could apply to multiple locations. Even though the current law (the Nuclear Waste Policy Act) specifies that waste must be disposed of at Yucca Mountain, it also specifies that a second repository must be built.

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Community and Public Support

Wouldn’t communities reject disposal in their backyards?

About 1/3 of US citizens already live within 50 miles of a place where nuclear waste is stored above ground in cooling pools and dry casks. Deep Isolation would take that waste and put it a mile or so underground, protected by over a billion tons of rock. This would make the waste significantly safer than the status quo.

Deep Isolation will only work with communities and states that give their support for the permanent isolation of the nuclear waste. If a community is not interested in permanent disposal, they can still plan on shipping their waste to an interim site, or a different disposal facility, when one becomes available.

The decision process as to whether a community would prefer to transport waste to another location or dispose of it nearby is a complex one. Potential benefits of permanent isolation in their community include a timely solution to improve safety, minimizing transportation, increasing jobs, and new fees for the use of land. Only if the community decides the benefits make it worthwhile would a site be selected.

Deep Isolation will work with communities to help them make an informed decision about which option is the best fit for them. With over 60 locations in the United States that are currently storing nuclear waste, we have indications that at least a few of them are interested in exploring the option of a deep-isolation facility near them. 

What kind of consent is required from the local community?

“Informed consent” is a minimum requirement for Deep Isolation. We prefer to talk about “enthusiastic consent”, meaning that we would seek to partner with communities that have a strong understanding of the safety and other benefits that could be realized from safely isolating the waste without needing to transport it from their community.

Deep Isolation will make communities full partners in the approach to safely isolating waste in their community. Each partnership will be tailored for the specific needs and interests of the community. This partnership would impact both the design of the Deep Isolation facility, the way that the project is implemented, and the specific benefits to the community. We are not proposing a “one size fits all” solution. 

What will happen if the community is not interested?

The community could decide to leave the nuclear waste at the reactor site in cooling pools or dry casks, transport it to an interim storage site, or transport it to an alternative permanent disposal facility, should one become available. We will work only with communities who decide that Deep Isolation is preferable to these other options. 

What are the benefits to the community?

The first major benefit is safety. The nuclear waste that is currently stored in nearby above ground facilities would be safely isolated a mile deep in rock.

Additional benefits will depend on the interest of community. Because Deep Isolation would not require the full amount allocated by the Nuclear Waste Fund (currently about $40B), there could be substantial financial and other benefits to the communities that choose to license such a facility. Deep Isolation would work in partnership with the community to determine what type of benefits would work best for them. We would also want to make sure that these are sustainable for the community, perhaps setting up an annual recurring benefit or fund for future generations. 

What would a sealed Deep Isolation repository look like?

With Deep Isolation, the surface would be left essentially pristine. There is not even a need for a concrete platform; boreholes often have the platform removed when the well is sealed. The specifics of the surface would be determined in partnership with the community.

Access to the waste could not be covertly obtained. Retrieval of the waste is a highly specialized endeavor and would require sizeable equipment as a large drilling rig and would take an extended period of days.

Does the public think that the US government is the only appropriate organization to solve the waste problem?

No, quite the contrary. The public overwhelmingly believes that private enterprise should be given the chance to participate in nuclear waste innovation. A recent (2018) survey done by the highly respected firm GfK Global, was designed to reach a representative cross-section of the American public. Their poll found that 70% of Americans think the private sector should be able to propose solutions, and over 90% believed that allowing innovation in nuclear waste disposal would be a good thing to do. The complete results of the GfK poll will be made available at www.DeepIsolation.com.

Would there be jobs for the local communities?

Drilling and construction could be done by a local firm. Monitoring and inspections are expected to last up to 50 years from the emplacement of the waste, and this could also be done by local workers. The specifics of the jobs would be discussed with each community individually, as part of the partnership agreement.

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Deep Isolation Technology

What is the Deep Isolation concept, in simple terms?

Rather than use large tunnels, Deep Isolation will place nuclear waste in narrow (8 to 14 inch in diameter) horizontal drillholes in rock that has been stable for tens of millions of years. No humans need to go underground. The small diameter drillholes are markedly different than the 18 to 25-foot diameter tunnels of the planned Yucca Mountain repository.

Deep Isolation drillholes will go down about a mile vertically and then gently turn horizontal. The waste would be stored in the deep horizontal section. This approach has several key benefits. First, horizontal drillholes, especially with an upward tilt and a “plumber’s trap” can prevent radioactive material from reaching the vertical portion of the borehole, and reduce dependency on man-made barriers. Second, placing the canisters in a long horizontal borehole increases the storage room without having to drill overly deep (at which point pressure can increase cost), or to have to worry about stacked canisters being crushed by their own weight.

The drilling industry has already perfected ways to place objects in deep boreholes, and retrieve them, all robotically.

For a visual summary of a Deep Isolation borehole, see Figure 3 at the end of this document.

Can you really put three miles of continuous steel liner (a “casing”) down the drillhole (1 mile of vertical access and 2 miles of horizontal storage)? How does it get around the curved section?

Doing so has become straightforward in the drilling industry. The rig set up above the drillhole is used to support the drilling system, and also to place the continuous steel casing into the hole. In the rig, 40-foot-long sections of casing are screwed together as they are lowered into the hole. The curved region that transitions from a vertical to a horizontal borehole has typically a 700-foot radius of curvature, and the steel casing flexes easily around this bend. This has been done in over 50,000 drillholes in the US in the last two decades.

Do you pick sites that are suitable for gas and oil recovery?

The ideal geology for waste isolation has no recoverable natural resources. We prefer rock that is ductile, so it is fracture resistant. Typically, this means clay-rich, and this feature makes the rock unsuitable for fracking.

Why didn’t someone think of this before?

The Yucca Mountain tunnel repository was chosen by the US government in the 1980s, due for completion in 1998, before the new drilling technologies were highly developed. When the Yucca Mountain facility ran into physical and political problems, no alternatives could be considered because the Nuclear Waste Policy Act specified that they could not be licensed.  Our solution provides an additional disposition pathway for commercial spent nuclear fuel and DOE nuclear waste inventories and should be considered as a second disposal option.

Can all that waste fit in narrow drillholes?

Spent nuclear fuel is compact, amounting to only 2 cubic meters per year for a gigawatt (thousand megawatt) reactor. Coal waste takes over a million times as much volume. One drill hole has 1000 cubic meters of space, enough for 20-reactor years of waste, assuming that we do no repackaging of the fuel assemblies. The assemblies that hold the waste fit in long narrow canisters that can be lowered into a drillhole.

What keeps the radioactivity from reaching the surface?

The Deep Isolation design relies on both engineered and geological barriers so there is built-in redundancy to the system.

The deep geology of the Deep Isolation design is a significant barrier. If there were to be any releases, they would have to get through a mile of rock, over a billion tons, including layers that have held volatiles (methane) for millions of years.

Additional engineered barriers include the ceramic pellets themselves, the metal rods that contain them, the bentonite surrounding the rods, sealed steel canisters that hold the rod assemblies, steel casing that lines the drillhole, and the cement that fills the space between the casing and the drillhole.

For geologic times, the geology is a key barrier. The geologic formations that would be used have been stable for tens of millions of years.

Why a mile deep?

The waste is placed far below aquifers, in regions in which water has had no contact with the surface for a million years or more. We will dispose in or under geologic formations that have been stable for tens of millions of years. Typically, this means a depth of about a mile, but in some locations it could be as shallow as 3000 feet, or as deep as 10,000 feet. Drilling such holes is now routine, and the drilling industry has made over 50,000 of such horizontal drillholes over the last 20 years.

How do you put the fuel down there?

We put the unmodified fuel assemblies, right from the reactor (or from interim storage) into sealed canisters. They are 8 to 12 inches in diameter, and 14 feet long. These are lowered into the vertical drill hole and then pushed into the horizontal section using “coiled tubing”, a stiff form of cable widely used in the industry, and which can push as well as pull. The canister is unlatched from the tubing (again, a highly-developed technology), and then another canister inserted behind it. For retrieval, the process is reversed.

Does the fuel have to be repackaged to fit in the canisters?

No repackaging is needed. The existing fuel assemblies in nuclear reactors are 8 to 12 inches in diameter and 14 feet long. They fit easily into tracks installed onto canisters that can be lowered into the standard drillholes.

How can a vertical borehole bend to allow horizontal storage?

Directional drilling of curved drillholes is a highly developed art in the oil and gas industries. The curvature is gradual; the initial hole is vertical, and at the “kickoff” depth a gradual curvature begins; the transition to horizontal has a radius of curvature of about 700 feet. There are no abrupt turns. Even the long steel casing pipe that is inserted to line the drillhole easily make the turn. See Figure 3.


Has this drilling technology been tested?

The drilling technology has been used for over 50,000 boreholes drilled for natural gas and oil in the US in the past two decades. This is a well-developed technology, and has become a low-cost commodity. 

Can the waste be retrieved?

Yes. The drilling industry regularly retrieves objects and monitoring instruments from boreholes, and the process is standard. Once the vertical drillhole is sealed, an expert crew could still retrieve the waste, but it would take a week or possibly longer. Doing so is sufficiently complex to offer substantial security from a terrorist attempt

What if a canister gets stuck in a hole?

If there are unexpected challenges with retrieving an object, then there are specialist companies that can “fish” for uncooperative objects such as broken pipe. They regard retrieval of a canister, something that is “cooperative” (has structures purposefully built in to make connection easier), as straightforward.

If for some reason, retrieval and fishing fail, then no further waste will be placed in the hole and the hole can be monitored, and eventually sealed.

How soon can you dispose of existing waste?

The time line for disposal is set by the Nuclear Regulatory Commission licensing process, which could take 3 years or even longer. Drilling and emplacement could be done in two months or less.

Several holes could be drilled every year using no more than the interest from the current Nuclear Waste Fund. No new fees need be collected from utilities. 

Would the drilling cause earthquakes?

Drilling and storage does not cause earthquakes. We do not use the explosives employed in fracking, and we do not use high pressure water to extend fractures. The earthquakes observed near oil and gas fields come from high-pressure reinjection of produced water, and we will not be doing anything like that. Since we prefer regions that have clay rich ductile rock (which is not frackable) we would generally be miles away from fracked areas.

Is waste transportation a problem?

The Deep Isolation approach is modular, with minimally invasive repositories located around the country. If a community provides informed consent, the repository could be put close to the nuclear reactor that created the waste. Contrast that with a large tunneled repository where the waste must be transported for thousands of miles.

If putting the isolation facility near the reactor is not possible, then another location could be found within a short or longer distance, depending on what the people of the state want.

Most nuclear waste could be stored safely with the state where it was produced, or it could be shipped to a state that agrees to host the site, if that is the preferable option. The intention is to have multiple repositories, which would minimize the need for transportation.

How would you monitor the waste?

During the “performance confirmation” process, in-place monitors would record heat and radioactivity at depth. A hole parallel to the storage hole could be drilled to detect any drift of radioactivity through the rock. 

Has the concept been vetted by experts?

Yes. Former US Secretary of Energy and Nobel Laureate Steven Chu says:

“Deep isolation is adapting recently developed drilling technologies to make disposal of nuclear fuel less expensive and even safer than other approaches. This is a technology that could prove important, not only in the US, but around the world.”

Nobel Laureate Arno Penzias says:

“Deep Isolation offers an ingenious and practical approach for the disposal of spent nuclear fuel.  I believe that their technology is the key to the solution to the nuclear waste problem.”

Other technical endorsers (quotes available upon request) include Per Peterson, a highly-regarded nuclear engineer and member of the US President’s Blue Ribbon Panel on the future of nuclear power; and Bob Budnitz, former director of nuclear waste research at the Dept. of Energy, and advisor to the Director of the Yucca Mountain Facility.

Will an encasement feel warm to the touch when it has fuel in it?

Yes. The initial fuel is hot; that’s why it is kept in cooling pools. After several years, it has cooled below the boiling point of water, and calculations show that the canister and the surrounding rock (to a depth of a few meters) will be about 40°F warmer than the natural rock in the first 30 years of the deposition. Then the temperature will drop (as the radioisotopes of Sr-90 and Cs-137 disappear by radioactive decay).

These temperatures are much lower than those in dry casks, for the simple reason that the fuel is not as concentrated. A typical dry cask has 37 fuel assemblies sitting next to each other cooled by gas flow, whereas a Deep Isolation canisters has the fuel assemblies strung out in a line, each one surrounded by rock that conducts the heat away.

What kind of steel will be used and how thick?

The casing is typically made of carbon steel, but other materials could be used. The space between the casing and the drillhole is filled with cement. The canister can be made of steel or corrosion-resistant material, but the ultimate safety of the disposal, for thousands of years, is provided primarily by the deep highly impermeable geologic formations.

Will there be an oxidizing or reducing environment in the Deep Isolation disposal?

In the Deep Isolation solution, the spent fuel canisters will be in contact with a reducing environment.

The concentration of oxygen in the waters determines the oxidizing power of the environment, high oxygen means an oxidizing environment where as low oxygen means a reducing environment. Concentrations of oxygen in the horizontal disposal section are extremely low.

Corrosion depends upon the combination of the corrosion resistance of the metal and the corrosivity of the environment.  Steel corrodes in oxidizing environments and has low corrosion rates in reducing environments but corrosion resistant alloys (CRA) have extremely low corrosion rates in either oxidizing or reducing environments.  Deep Isolation will be using corrosion resistant alloys.

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Safety

How much radioactivity will be emitted by the spent fuel before the repository is sealed? How much after the drillhole is sealed?

Until it is sealed, a potential leakage path is the vertical access drillhole. No leakage is expected through this path, because the engineered barriers offer substantial protection. Nevertheless, radioactivity will be closely monitored in the borehole to assure that this is the case.

At all times, the drillhole will be in compliance with regulations for the release of radioactive isotopes and radioactive dose to the public. The release of radioactive isotopes has been specified by law and regulations. These laws and regulations are written in highly technical language, but generally speaking, they assure that no human-harmful levels of radioactivity will reach the surface for tens of thousands to millions of years. The geology of the repositories is chosen in formations that have been stable for tens to hundreds of millions of years. Ultimately, it is the geology that provides the long-term confinement.

How will workers and the environment be protected during insertion?

Methods for moving the waste have been highly developed by the nuclear industry. They have already been implemented for the transfer of waste from the nuclear reactor to the cooling pools, and for transport of waste from the pools to dry casks at locations on the reactor site. The transfer of waste involved lifting the assemblies into transfer canisters, transport, and then lowering them into storage casks. The entire process is monitored, and personnel are kept at safe distances and their exposures are monitored. The safety record for this technology is excellent.

Will you be removing waste from dry casks and if so what are the process and safety issues?

The transfer of fuel assemblies from pools to dry casks takes place at the reactors using cranes and other equipment. Similar facilities and equipment can be used to transfer the fuel assemblies from dry casks to disposal canisters; these canisters will be placed in reinforced transfer casks for transport to the disposal site.

The Department of Energy has designed procedures for such transfer; the difference, for Deep Isolation, is that the transportation will be local, often within the perimeter of the nuclear power plant, or only a few miles from the plant. In contrast, transport to the proposed centralized tunnel facilities, such as the Yucca Mountain repository, would have to take place over thousands of miles of US roadways and railways.

During insertion into the drillholes, the transport canisters will be placed above the drillhole and the canisters lowered. The main safety concerns are the people working at the site. The operations will be conducted remotely using well-developed procedures for monitoring and safety.

Will the encased spent fuel be as safe as dry casks?

It should be enormously safer, largely because of the billion-ton (cubic mile) of stable sedimentary rock that separates the two-mile-long repository from the surface. Dry casks are meant for temporary “interim” storage only. The US National Academy of Sciences and the President’s “Blue Ribbon Panel” concluded that ultimate disposal of spent nuclear fuel should be done deep underground in stable geologic formations.

Is it safeguarded from terrorists?

Deep geology provides a barrier that gives significant protection against a terrorist attempt to obtain spent nuclear fuel. Contrast the deep isolation storage location to either temporary storage in pools or in dry cask interim storage on or near the surface.

Although the fuel is retrievable, doing so requires setting up a rig, removing 5000 feet of bentonite sealant, and operating a fishing system to pull up canisters one at a time. That is a process an experienced crew can accomplish but the cost and difficulty does not lend itself to a surreptitious terrorist attack. Moreover, spent nuclear fuel is not readily useable in a radiological or other nuclear weapon and requires specialized equipment and expertise to handle the radiation to do so.

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Cost

What does a Deep Isolation repository cost?

The drilling costs are low, since drilling is a mature and competitive industry. A two-mile-long repository can be constructed for under $10M, and hold 300 tons of waste, so the cost is under $130,000 per ton. Contrast this with the cost of a tunnel facility. The US OMB estimates completion of Yucca will cost $96B to hold 70,000 tons of waste, at a cost of $1.4M per ton, over 10x higher than the cost of the Deep Isolation solution.

The larger cost is that of obtaining the license, including environmental impact and performance confirmation studies. Even so, it is reasonable to assume that Deep Isolation would be substantially cheaper than putting the same waste in Yucca Mountain.

How could multiple drilled repositories a mile deep be less expensive than a second tunnel repository that is only 1000 feet deep?

The lower cost for Deep Isolation directly reflects the fact that our drillholes have much less volume. Drilled repositories make much more efficient use of space. The Yucca repository will have 40 miles of tunnel, typically 18-25 feet in diameter; the waste occupies less than 0.4% of the volume. For a drilled repository, the waste occupies about 20% of the volume, making it much more space efficient. The lower volume of rock removed, compared to tunnel disposal methods, also minimizes the disruption to the rock.

Equally important, no humans go underground for a drilled repository, and that saves the need to have ventilation or below ground human-safety certification. The waste is emplaced using flexible coiled tubing, a technology that has been highly developed by the oil and gas drilling industry. 

Would US government financial support be required?

It is anticipated that all the costs could be carried by the applicant companies and their investors. Upon completion, the companies would be paid from the Nuclear Waste Fund.

To ensure reasonable use of the Nuclear Waste Fund, the DOE might only allow solutions to be contracted that are lower-cost than Yucca Mountain. Because repositories can be small and modular, the threshold to enter the field is relatively small, much less than the cost, for example, of a new nuclear reactor.

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Figures

Figure 1 (below). A typical nuclear fuel assembly. The one shown below is a common design for a Boiling Water Reactor (BWR). The fuel pellets for Pressurized Water Reactors are the same size, but placed in somewhat larger fuel assemblies, about 11 inches, and contain more rods.   The fuel assembly would be placed in canisters that fit conveniently down drillholes.

Fuel Assembly, Fuel Rod, Pellet, Boiling Water Reactor (BWR)

 

 

 

 

 

 

 

 

 

 

 

Figure 2 (below). Above ground dry cask nuclear waste storage at the decommissioned Diablo Canyon Nuclear Power Plant in California.

Dry Casks

 

Figure 3. The Deep Isolation drillhole waste repository concept. The horizontal drillhole has about an 8 to12 inch inner diameter.

Deep Isolation Waste Repository Concept

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