Input to Parliamentary Inquiry
Application of Deep Isolation’s Radioactive Waste Management System for the Disposal of Australian Highly Radioactive Wastes
September 2019
Introduction and Executive Summary
On August 6, 2019, the Australian House of Representatives’ Standing Committee on the Environment and Energy resolved to conduct an inquiry into the prerequisites for nuclear energy in Australia. Deep Isolation is providing this submission addressing the question of the management of radioactive wastes from nuclear power in the event that this technology was introduced into the country.
Radioactive waste produced by nuclear power can be safely managed. The low- level radioactive waste produced by nuclear power is safely managed around the world. The transportation and storage of spent nuclear fuel has also been safely managed for decades. Recent developments by Deep Isolation have made disposal of spent nuclear fuel achievable in a safe, timely, cost-effective manner. Thus, the waste management, transport, storage and disposal aspects of nuclear power can be safely managed over the life-cycle of nuclear power.
1. Deep Isolation offers the following input specific to the disposal of nuclear waste to this matter: Australia possesses superior geology that is suitable for the disposal of radioactive wastes that would be produced by nuclear power. 2. Deep Isolation offers an inherently safe method for the disposal of Australian radioactive wastes. 3. The Deep Isolation system is environmentally superior to the development of a mined repository. 4. The Deep Isolation system allows radioactive wastes to be safely managed for a fraction of the capital outlay that is associated with the development of a mined repository.
Deep Isolation believes it is of critical importance to conduct meaningful stakeholder engagement early on. Deep Isolation integrates comprehensive, in-depth stakeholder outreach and engagement into technical planning. This philosophy is founded on the understanding that nearly every failure in the last 40 years for siting nuclear waste facilities in democracies has stemmed from the absence of a working social contract. These include prior failures to manage Australian low-level radioactive wastes. Deep Isolation senior team members have worked closely with Aboriginal leaders in South Australia and maintain close working relationships with these individuals and the people they represent, creating a basis for developing a stakeholder engagement program with this vital Australian group. In any radioactive
1 Deep Isolation input to Parliamentary Inquiry waste program, Deep Isolation will be guided by its belief in honesty, transparency and close collaboration with the local communities.
In making this submittal to the Inquiry, Deep Isolation wishes to provide confidence that the problem of managing wastes from nuclear power generation can be solved with extreme safety, cost effectively, in a timely manner and accomplished with full consideration of the concerns and interests of all stakeholders.
2 Deep Isolation input to Parliamentary Inquiry Table of Contents
Section Page
Introduction and Executive Summary 1
Table of Contents 3
Detailed Description 4
Advantages of the Deep Isolation Disposal System 5
Australian Long-Lived Radioactive Wastes 8
Best Practice and International Disposal Guidance 10
Certification/Licensing 11
Host Rock Conditions 12
Comments About Australian Professional Infrastructure 13
Community and Stakeholder Acceptance 14
Retrievability 17
Operational and Post-Closure Safety 18
Cost Profile 20
Relevant Case Studies 22
Readiness and Viability 24
Conclusions 25
3 Deep Isolation input to Parliamentary Inquiry Detailed Description
In this section, a description is provided for the Deep Isolation disposal system.
If Australia were to introduce nuclear generation as a means of electricity production, it would have to face the issue of managing long-lived radioactive wastes. Deep Isolation proposes to support the deployment of nuclear power in Australia by disposing of all intermediate-level waste and spent nuclear fuel. Deep Isolation’s patented waste disposal system leverages mature drilling technology to place nuclear waste—including spent nuclear fuel and other types of radioactive waste— underground in a horizontal drillhole within deep, highly stable geologic formations.
To implement this repository system, well understood and existing technology is used to drill a vertical access hole to a “kickoff point” (an industry term). At the kickoff point the borehole begins a gradual curve to become nearly horizontal, but with a slight upward tilt (1° to 3°). The drillhole then continues along this nearly horizontal path up to 3 km. This nearly horizontal region is the waste disposal section. A schematic representation of a deep horizontal drillhole repository is shown in Figure 1.
Once the hole is drilled, casing is FIGURE 1. SCHEMATIC OF DEEP inserted into the length of the hole. ISOLATION DISPOSAL SYSTEM The casing consists of long segments (typically made of carbon-steel, although other metals or alloys can be used) that are screwed together at the drill rig and lowered into the drillhole. The casing is typically several mm to 1 cm thick; the thickness will depend on the geochemistry found at depth. The curved path to reach horizontal is typically so gradual (a few degrees per hundred feet) that the casing bends easily around as it is lowered to the disposal section. Once the casing is in place, the standard industry practice is to push cement down the casing and back up in the gap between the casing and the rock to make a sturdy support and provide an additional rock-casing seal.
Canisters containing the nuclear waste will then be lowered into the casing and pushed (using wireline and a tractor, drill pipe, or coiled tubing) so that they are placed end-to-end within the disposal section of the drillhole. The tilt in this section provides additional isolation from the vertical access borehole, because any mechanism that transports radioisotopes in an upward direction would move up and towards the dead end of the disposal section. Once waste canisters are in place, the borehole will be backfilled with suitable material and then sealed.
4 Deep Isolation input to Parliamentary Inquiry Advantages of the Deep Isolation Disposal System
In this section, the benefits and advantages of the Deep Isolation disposal system are presented and contrasted to other disposal approaches.
In general terms, there are three accepted approaches to disposal of long-lived waste from nuclear power. These are emplacement in a mined repository, a vertical borehole, or the Deep Isolation drillhole where the wastes are placed in a horizontal setting; see Figure 2. (Note: this is a replica of Figure 1, duplicated here for convenience.)
Broadly, disposing of reactor waste in the Deep Isolation drillhole is materially less expensive than in a FIGURE 2. SCHEMATIC OF A DEEP HORIZONTAL BOREHOLE mined repository. More importantly, REPOSITORY (NOT TO SCALE) the long-term safety case for emplacing wastes into the Deep Isolation drillhole is dramatically simplified due to features inherent in its concept. Some contributing factors to this are:
1. Disturbed rock in a disposal setting can create a potential transport pathway. Broadly, rock disturbance is approximately the radius of the opening. Hence, for a mined deep geological repository with a 7-meters diameter tunnel, the disturbed zone reaches 3.5 meters into the host rock; for a borehole with a 50-centimeter diameter, this reaches only 25 centimetres into the host rock. Minimizing the extent of disturbed rock is obviously beneficial. 2. Disposal of ILW in the Deep Isolation drillhole enables the waste to be positioned below a layer of “tight,” low-permeability cap rock with demonstrable barrier characteristics. This can be in shales or basement rock (often granites). 3. The greater depth allows for placement well below aquifers, in deep geological formations where the presence and mobility of water is extremely low. 4. The drillhole environment at depth is chemically reducing, that is, very low in oxygen. A reducing environment adds additional level of safety, as corrosion of stainless steel and other engineered barriers are dramatically reduced. 5. Very often, the density of water increases significantly with depth due to the concentrations of salts and other dissolved minerals. This density gradient
5 Deep Isolation input to Parliamentary Inquiry establishes a physical barrier to the vertical movement of radionuclides to the biosphere. 6. The sealing is easier than a mined repository since there is only one access drillhole and it has a very large length to diameter ratio. 7. The approach using horizontal emplacement of canisters eliminates the stress that results from “stacking” waste containers in vertical emplacement. Waste canisters rest on the bottom of the horizontal disposal section of the drillhole in our system.1 8. The long linear array of the canisters in the disposal section results in substantially lower temperatures than would occur if the canisters were stored more compactly. Deep Isolation drillholes dissipate heat radially along the axis of the horizontal drillhole with very limited conductance horizontally to the vertical portion of the drillhole. Moreover, emplacing the waste horizontally, well separated from the vertical access hole, means that there is no direct pathway to the surface through the disturbed zone; any driving force (such as buoyancy) that drives flow upwards will direct to the dead end of the slightly tilted disposal sector. 9. Disposal of high activity waste in the Deep Isolation drillhole will significantly reduce the cost and time for site characterisation and completion of the long- term safety case when compared to the development of a mined repository. This is because the safety case is formed around the characteristics noted above that can be rapidly verified with a limited number of exploration or pilot holes. Dating methods which require little time and cost can be used to determine the age of the brines in the proposed emplacement zone. If measurements indicate that they have had no mixing with surface waters for thousands to millions of years, then that result indicates a safe location for disposal. The isotopes used to determine such isolation include C-14, Cl-36, Kr-81 and I-129.
Key differences between a mined repository and the Deep Isolation drillhole concept are listed in Table 1 hereafter.
1 Sandia Laboratories has indicated that the weight of vertically-stacked waste containers is one of the key mechanisms by which radioactive waste canisters emplaced in a vertical borehole can be breached. Use of the Deep Isolation drillhole averts this safety issue.
6 Deep Isolation input to Parliamentary Inquiry
TABLE 1 COMPARISON BETWEEN A MINED REPOSITORY AND THE PROPOSED DEEP HORIZONTAL DRILLHOLE REPOSITORY
Deep Isolation Drillhole Feature Mined Repository Repository Depth 0.3-0.9 km 1-5 km Access Borehole 3-8 m 0.5-0.7 m Diameter Emplacement Borehole 1.5-5.0 m 0.5-0.7 m Diameter Excavation Volume Large Small Shotcrete, rock bolts, wire Ground Support Casing, liner mesh Drainage and Yes No Depressurisation Pre- and post- Ventilation None emplacement Workers Underground Yes None Local Waste and Heat High Low Density Temperature Limit ~100 C (bentonite) In situ boiling temperature Implementation Later Earlier Repository Closure Ø 50 years Immediate Retrievability Yes Yes Costs High Low
7 Deep Isolation input to Parliamentary Inquiry Australian Long-Lived Radioactive Wastes
An Australian nuclear power program would produce spent nuclear fuel (SNF) that would require long-term management. Globally, SNF is considered either to be a waste for direct disposal or a resource for the fissile material remaining after its use in a reactor.
The type of reactors being utilised would determine the physical characteristics of the SNF that needs to be managed. For example, deploying a pressurized water reactor (PWR) would generate SNF similar to that pictured in Figure 3.
FIGURE 3. PWR ASSEMBLY
A PWR SNF assembly such as is pictured above is approximately 4 m in length. It is approximately 20 cm square. It weighs approximately 600 kg and contains approximately 450 kg of uranium. The original uranium loading contained a mix of U235 (fissile uranium) and U238. After discharge from a reactor, it also contains small quantities of plutonium, other heavy metals and a considerable amount of fission products. After an approximately 3-year cycle in a PWR, the SNF assembly is intensely radioactive and requires active cooling for about 5 years.
Australia might deploy several different types of nuclear reactors. These could include boiling water reactors (BWRs), a midsized “small modular reactor” (SMR), or even a microreactor, one that might be suitable for deployment at Australian Defence facilities in lieu of diesel generation. Each of these reactor types generate SNF. Like the PWR fuel, the SNF contains uranium, plutonium, heavy metals and fission products.
In the event that Australia decided to recycle the uranium and plutonium in the SNF, the resulting FIGURE 4. CSO-U CANISTER OF high-level waste (HLW) is similar to that which VITRIFIED HLW
8 Deep Isolation input to Parliamentary Inquiry Australia possesses from the processing of ANSTO’s HIFAR fuel, pictured in Figure 4. The HLW would be a glass form, referred to as vitrified.
In addition to the disposal of SNF and/or HLW, Australia would generate waste that is referred to as intermediate-level waste (ILW). Such material is generally intensely radioactive and will remain so for several centuries. The characteristics of the ILW are such that it is inappropriate for disposal in a low-level radioactive waste disposal facility, similar to the one being pursued in South Australia.
Australia currently possesses at least two types of waste that must be managed in a manner similar to nuclear power plant wastes. These are, as mentioned above, the vitrified ILW deriving from the HIFAR fuel processing. It should be noted that in the future, more of this vitrified ILW will be generated from the operation of the current OPAL reactor at ANSTO. In addition, ANSTO anticipates producing SYNROC ILW resulting from the production of the medical isotope, Mo99, as is pictured in Figure 5. 2
FIGURE 5. SYNROC CANISTER Every type of highly radioactive waste currently in the Australian inventory and that can be anticipated from the development of a nuclear power program can be managed by the Deep Isolation system.
2 K. Fernando, D. Gregg and J. Shatwell, “Strategy for Processing and Disposal of Intermediate Level Waste From Mo-99 Production”, presented at the Technical Meeting of the International Predisposal Network and International Low Level Waste Disposal Network on The Management of Radioactive Waste Streams that Present Specific Challenges, Vienna, Austria, 28 November – 2 December 2016.
9 Deep Isolation input to Parliamentary Inquiry Best Practice and International Disposal Guidance In this section, comments are provided on how the Deep Isolation disposal system meets and exceeds international best practice standards. Deep geologic disposal has traditionally meant having a large mined repository that is ~500 meters below surface. This requires extensive excavation as well as workers to be underground. Over the past few years, an alternative deep geologic disposal solution using boreholes drilled thousands of meters deep has received extensive research. This approach does not require extensive excavation nor are workers underground. Initial thinking was that boreholes had to be vertical and deep enough to allow waste to be ‘stacked’3 from the bottom up. This vertical approach presents problems – particularly related to stacking nuclear waste containers on top of one another and the presence of a thermal gradient that can become the driving mechanism to move radionuclides from their emplacement location to the biosphere. Disposal of high activity waste in a Deep Isolation horizontal drillhole addresses the problems associated with vertical boreholes by creating a horizontal emplacement site at a depth that is geologically isolated from the surface. All waste is disposed in the horizontal portion – safely away from the vertical hole. Use of a vertical borehole for disposal results in a potential direct vertical path to the surface through the filled hole itself and the surrounding disturbed zone. With a horizontal disposal section, particularly with a slight upward tilt towards the dead end, the isolation of the waste is significantly increased. The International Atomic Energy Agency (IAEA) has published a Specific Safety Guide for Borehole Disposal Facilities for Radioactive Waste (SSG-1). (IAEA SSG-1 is focused on sealed sources, but it has application for long-lived ILW and HLW waste streams.) Disposal of ILW in a Deep Isolation drillhole meets or exceeds all of the best practice guidelines in IAEA guidance.
3 Waste containers would not be stacked directly on top of other containers in a vertical borehole configuration. Rather, spacers would be placed between the containers and a mechanism would be created that attempts to keep the vertical load from being transmitted onto the lower containers.
10 Deep Isolation input to Parliamentary Inquiry Certification/Licensing In this section, the approach to securing a licence for the Deep Isolation disposal system is discussed. Sandia Laboratories has published a study4 that speaks to the ability to license the disposal of ILW in the Deep Isolation drillhole. In this report, pre- and post- emplacement safety was considered for the emplacement of the US ILW Cs-Sr capsules produced at the Hanford site. The study considered emplacement of this ILW waste in a deep crystalline basement rock formation between 4,500 and 5,000 m in depth. Disposal was considered in vertical boreholes. It should be noted that these wastes are similar to the ILW that Australia will have to manage and give a good analogue to how spent nuclear fuel may be act, hence their discussion here. A detailed generic analysis of the post-closure safety was completed by Sandia. The conclusion was that the transport of radionuclides up the borehole was limited to less than 100 m over a ten-million-year timeframe. This result was significantly better than the public safety standards of the US Nuclear Regulatory Commission and the US Environmental Protection Agency. Experts at Deep Isolation are actively working through licensing matters and preparing for eventual submittal of a license application to the U.S. Nuclear Regulatory Commission or international regulators. The Sandia report is a template for this work, but also provides significant confidence that Australian ILW and SNF disposal in a Deep Isolation drillhole can meet all applicable safety standards. It is noteworthy that the Sandia assessment of vertical borehole disposal presents its safety conclusions in the context of multiple, highly engineered seals in the borehole. Cement and bentonite dominate these. The seals are an essential part of the vertical borehole disposal system because of the presence of a thermal driver that can cause radionuclides to move vertically up the disturbed zone of the borehole. For disposal in the Deep Isolation drillhole, there is no mechanism present to move radionuclides laterally from a hypothetically breached waste container to the vertical portion of the system, and then there is no mechanism to drive radionuclides vertically up the borehole. Consequently, it is concluded that the Deep Isolation drillhole is inherently safe and does not rely upon engineered seals and barriers to protect human health and the environment. Regardless, the Deep Isolation drillhole will have robust engineered seals and barriers in the vertical portion of the drillhole because of the primacy of protecting human health and the environment.
4 Deep Borehole Disposal Safety Analysis, G. Freeze, E. Stein, L. Price, R. MacKinnon and J. Tillman, Sandia Laboratories, September 2016, Publication SAND2016-10949R.
11 Deep Isolation input to Parliamentary Inquiry
Host Rock Conditions
In this section, comments are provided about the compatibility of the Deep Isolation system with Australian geology.
Deep Isolation has developed a unique approach for determining the suitability of a host formation for the disposal of radioactive waste. The method involves measurements of Cl-36, Kr-81 and I-129. By measuring these isotopes at various locations in a vertical profile, Deep Isolation is able to confirm the age of water in the formation. This, in turn, informs the safety assessment by inferring the speed of travel of water from the emplacement depth. While other methods of characterisation will be employed (e.g., geophysical, geochemical and hydrogeological testing), the isotopic measurements are fundamental to Deep Isolation’s determination of suitability of a host rock formation.
There are few if any other limitations to the selection of a host geology. A Deep Isolation drillhole can be developed in sedimentary, metamorphic or igneous rock. The drilling industry has vast experience at developing boreholes in all three rock types. The oil and gas sector has developed over 50,000 horizontal boreholes that serve as the template for a Deep Isolation drillhole. Deep Isolation has relationships with global oil and gas drilling companies that can be used for the development of drillhole repositories in Australia.
Drilling horizontally through a basement rock such as granite is more challenging but based on discussions with oil and gas drilling company experts, this is achievable and cost-effective compared to a mined repository.
Work done in South Australia in the 1990’s near Roxby Downs confirmed that ideal geological conditions exist in Australia for the safe disposal of long-lived radioactive wastes. This work confirmed that large tracts of geology in Australia are hydrologically static, that water has not moved either vertically or laterally in over 1 million years. Emplacing reactor wastes into a Deep Isolation drillhole in such an environment is ideal in that there is no native nor induced physical means to move radioactive materials from the disposal location into the biosphere.
12 Deep Isolation input to Parliamentary Inquiry Comments About Australian Professional Infrastructure
Australia is fortunate to have three world-class institutions that could be called upon to support the development of a nuclear power industry in Australia.
The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) is the nuclear regulator. Any well-founded nuclear industry must have a strong and independent regulator to provide the public with confidence that safety is paramount in the ongoing operation. ARPANSA fills this role ably. It is recognized throughout the world has a tough and objective nuclear regulator.
The Australian Nuclear Science and Technology Organisation (ANSTO) is a world- class nuclear group. ANSTO has operated a nuclear reactor a Lucas Heights for many years – including the now-decommissioned HIFAR reactor and the current OPAL reactor. ANSTO attracts leading nuclear specialists from throughout the world.
The Commonwealth Scientific and Industrial Research Organisation (CSIRO) has brought world-leading insights into Australia for decades. More recently, CSIRO has taken the lead role, with support from ANSTO, to develop a disposal system for Australian ILW, including the vitrified waste returned from Europe from processing HIFAR and OPAL fuel, as well as SYNROC waste from Mo99 production.
Deep Isolation has had the pleasure of working with both CSIRO and ANSTO.
13 Deep Isolation input to Parliamentary Inquiry Community and Stakeholder Acceptance
In this section, Deep Isolation’s approach to gaining community and stakeholder acceptance is discussed. Deep Isolation recognizes that the successful disposal of long-lived may only be accomplished through a collaborative, productive and lasting partnership with the host community and other stakeholders. In this context, the term “partnership” is worthy of special attention as it provides the guiding theme for all our projects and is the defining concept for meeting community and stakeholder expectations. In particular, Deep Isolation’s partnership strategy is comprised of three components: cultural competency, process transparency and legitimacy, and the creation of shared outcomes. I. Cultural Competency Understanding the context and culture of a community is the fundamental prerequisite to meaningfully engage in partnership. To that end, Deep Isolation has put together a team of professionals with decades of proven experience in working effectively with the complexities of community dynamics. With this experience and our appreciation of the ways in which host communities respond to the challenges and opportunities associated with hosting a waste management facility, we have become experts in crafting productive stakeholder engagement programs. More importantly, this institutional understanding provides the critical platform for ongoing and productive dialogue with the goal of creating mutually crafted community partnerships. Through the experience of the Deep Isolation team in Australia and in the Aboriginal community, the ability to identify and engage a strong and sensitive advisory team is dramatically enhanced. II. Process Transparency and Legitimacy It is widely recognized that a solid understanding and appreciation of community and cultural dynamics is a fundamental prerequisite to any radioactive waste disposal solution. That knowledge, however, is only useful if it may be purposefully applied to engagement processes that create lasting and productive stakeholder partnerships. Deep Isolation’s experience in building these productive partnerships is rooted in the elements of transparency and legitimacy. From a transparency perspective, Deep Isolation creates engagement platforms and mutually reinforcing communication programs that attract and sustain stakeholder participation because they are accessible, easily internalized and resonate with target audiences. Deep Isolation’s engagement processes are designed in a collaborative manner in order to realize the level of trust and “buy-in” that any agreement and partnership will require. Deep Isolation also tailors a two- way dialogue to incorporate the cultural nuances that are inherent in every host community. This initial investment in process transparency, with an equal
14 Deep Isolation input to Parliamentary Inquiry commitment to collaboration, creates the opportunity for the community to make the informed decisions that will be needed for a durable agreement. In parallel, and building from this commitment to transparency and collaboration, Deep Isolation establishes the essential framework of process legitimacy. Due to the fact that stakeholders have had a clear and deliberative role in designing the engagement process, they are increasingly likely to view both the process and ensuing outcomes as legitimate and worthy of their trust. This added level of legitimacy gets to the root of a successful facility siting effort by creating the foundation for mutual trust and the development of shared outcomes: the hallmark of any successful waste facility siting effort. Deep Isolation also recognises that a part of the effort to be transparent and gain legitimacy is to engage with the academic community in a very open way. Within the Deep Isolation team, for example, lies significant experience in establishing open, public dialogue with the academic community in national and international conferences. Deep Isolation, CSIRO and ANSTO could explore facilitating a regular conference in Australia to explore the academic developments and uncertainties related to the use of drillholes for long-lived waste disposal. Such events could be organised by the Australian Institute of Nuclear Science and Engineering (AINSE) thereby directly engaging its member universities. The international flavour of such an initiative would be realistic given the number of countries around the world exploring the use of borehole disposal. The broader stakeholder engagement process is enhanced with open, academic discussions. III. Shared Outcomes Through the combination of cultural competency with expertise in process transparency and trust- building, the foundation for creating shared outcomes from a siting and hosting process becomes possible. These outcomes are at the core of any working relationship with a host community as they set the overall goals and objectives for an ensuing disposal project. It is, however, important to recognize that these outcomes are not the same as the technical goals of a disposal effort. Shared outcomes define the macro, community-based objectives that may be supported by a disposal program and are defined in metrics that are created by, and resonate with, a particular host community. The disposal project is simply the means by which these outcomes may be achieved. Shared outcomes are generally defined in terms of Community Well Being (CWB) metrics and divided into the following general categories: economic, social, cultural and political. The combination of these four dimensions helps define the overall well-being of a particular community and its ability to sustain itself and meet the needs of its residents.
15 Deep Isolation input to Parliamentary Inquiry Deep Isolation finds that CWB is often useful to assess the effects of a proposed long-lived waste disposal facility on a community. To that end, the first step in the shared outcomes process is to build upon the process and relationship legitimacy discussed previously and to work with community stakeholders to define a baseline CWB definition. With this sense of the present established (through the CWB process), Deep Isolation’s stakeholder engagement team then works to define and establish a host community’s CWB aspirations: essentially giving voice to, and quantifying through CWB metrics, its plan for the future. After having worked collaboratively to create a clear definition of the present and a desired future scenario, Deep Isolation would then work to incorporate the ways in which a disposal facility may help or hinder the desired options for achieving CWB goals. In particular, Deep Isolation would work with community leaders and stakeholders to explore how economic, social, cultural and political decisions about a disposal facility may advance overall CWB objectives. In doing so, Deep Isolation would place the presence of a radioactive waste facility at the heart of the larger discussion about collaboratively achieving a community’s CWB aspirations. By developing trusted partnerships, formed through collaboration and transparency and informed by cultural competency, Deep Isolation builds a model for the pursuit of Community Well Being. This design increases additional incentive for successful project siting and hosting by aligning national radioactive waste management goals with those of the host community. The results of such an approach may be summarized in the following quote from a local elected official who spoke as part of a recent Deep Isolation community engagement process:
“We are very fortunate to have this facility here in our county. We appreciate Deep Isolation and welcome them any time.”5
5 Richard Watkins, Milam County Commissioner, 2019.
16 Deep Isolation input to Parliamentary Inquiry Retrievability
In this section, retrievability is discussed.
For a variety of reasons, there is a generally-accepted need for radioactive wastes emplaced in a repository to be retrievable for a specified period of time.
Recovery of wastes emplaced in a Deep Isolation drillhole is possible but becomes more complex over time, as noted below:
A. Before the drillhole is sealed (i.e. filled with rock, bentonite, cement, and other materials), the metal casing is expected to be intact for 50 to 300 years. The basic recovery operation for canisters under this condition has been demonstrated by Deep Isolation at a test facility in Texas, using conventional oil and gas “fishing” technology. B. If the vertical access hole has been sealed and retrieval is mandated, then it must be re-drilled. This can be done by bringing a rig on site and boring out the access hole. Technology can do this, although it will be more expensive (several million USD) than for option A. C. Deep Isolation’s waste canisters are designed to be robust for thousands of years. Recovery of such canisters after the borehole has been sealed for hundreds or thousands of years would require entering the hole in which the casing (made of carbon-steel) has corroded. Although doing this has not been tested, modern oil and gas field drilling techniques can easily find the canisters and should be able to remove them intact.
As will be discussed later in this document, Deep Isolation has done two retrievability demonstrations at a test facility in Texas. In these tests, a small canister was lowered down a borehole and then conveyed horizontally some distance from the vertical axis. The canister was released and the drillstring removed from the site. The canister was then successfully retrieved.
17 Deep Isolation input to Parliamentary Inquiry Operational and Post-Closure Safety
In this section, Deep Isolation’s approach to operational and post-closure safety is discussed.
I. Operational Safety
In operations, the key operations are the transfer of disposal containers from the transport cask to the on-site transfer cask, and the emplacement of the waste disposal container into the disposal position. As outlined elsewhere in this document, these activities are well proven. The site operator6 would secure an operating licence from ARPANSA. This licence would describe each element of operations and the measures that would be employed to ensure the safety of workers, the public and the environment. An example of this document is the licence prepared by ANSTO for the operation of the on-site facility for the storage of the vitrified ILW.7 Activities at the disposal site are comparable to those on the ANSTO facility. Operational safety is assured by the commitment of the site operator, the strict adherence to safe procedures by all workers, through excellence in design, and through constant monitoring and inspection. The key point is that operational safety is within the current practice of the nuclear industry in Australia, under the regulation of a competent and independent regulator.
II. Post-Closure Safety
At present, ARPANSA has not promulgated post-closure safety standards. Most countries subscribe to a long-term, probabilistic safety standard for the disposal of ILW. Standards like those that exist in the US (10CFR63) establish a maximum radiation dose that the public may receive as a result of disposal operations for periods of between 10,000 and 1 million years. The Deep Isolation disposal concept is designed to meet and exceed these public safety requirements.
The principal safety advantage of disposing of Australian ILW in a Deep Isolation drillhole is that the qualification requirements for the site are stringent. These requirements mandate that the water (actually brine) at the extreme disposal depth be ancient, demonstrating that there has been no communication between waters in the biosphere and the emplacement geosphere.
Another dominant safety factor is the emplacement of the ILW in the horizontal portion of the Deep Isolation drillhole, a considerable distance from the vertical
6 The site operator could be a private entity such as Deep Isolation or could be a unit of the Government, with operations undertaken by a site contractor.
7 See “Interim Waste Store Operating Licence – Arrangement for Operating the Facility”, document IWS-O-LA- DOP, prepared by ANSTO, October 2014.
18 Deep Isolation input to Parliamentary Inquiry borehole. For the site to meet the Deep Isolation acceptance criteria, no pathway can exist that would cause radionuclides to migrate from the emplacement zone to a receptor that results in exposures over the regulatory limit.
Emplacing the wastes in the horizontal position creates another safety barrier when compared to disposal in a vertical borehole. In vertical disposal, the total mass of the waste canisters can impose a crushing load onto the lower containers. Utilising the Deep Isolation drillhole emplacement, the disposal containers are not loaded onto each other. Consequently, there is no crushing load present. Further, there is no need to rely on an engineered spacer system to prevent crushing.
Disposing of the Australian long-lived radioactive waste in a Deep Isolation drillhole may add another preventive barrier through the corrosion resistance of the disposal container. In specifying the container materials, Deep Isolation will select a corrosion resistant material that will assure thousands of years of containment prior to corrosion by groundwater.
Earlier in this document, the Sandia borehole safety analysis was discussed. That 2016 analysis of the post-closure safety of the disposal of US ILW in a hypothetical vertical borehole in granite showed that the stringent safety standards of the US Nuclear Regulatory Commission were met. Disposal of Australian long-lived wastes in a Deep Isolation drillhole exceeds the safety projections of disposal in a vertical borehole because it removes a direct vertical potential pathway and because it removes the principal mechanism by which containers might be breached – a crush load imposed by vertically stacked waste containers.
19 Deep Isolation input to Parliamentary Inquiry Cost Profile
In this section, Deep Isolation discusses the costs to test and deploy its disposal system. Utilising Deep Isolation’s disposal solution using horizontal drilling techniques allows for an optimum allocation of funds. The largest costs are not incurred until the disposal drillhole is developed and disposal canisters are manufactured. Cost areas include pre-licensing activities, license application development and pursuit, drilling, waste handling facilities, intellectual property licences, and project management costs. Pre-licensing activities include identifying a suitable site, engagement and ongoing communication with stakeholders and the local communities, preliminary characterization activities and development of waste inventory for disposal. Many of these activities may be done in parallel. License application development includes detailed site characterization, writing a license application in accordance with applicable regulations, submitting the license application to the appropriate regulatory authority and pursuing the issuance of a licence with the regulator. Note that community and stakeholder engagement will continue during this phase of the project and throughout the life of the project. Drilling activities would commence after a licence was issued. The number and sizes of the wells will be determined based on the detailed waste inventory and any license conditions. Deep Isolation expects that one or more characterization wells drilled in the license application phase could be enlarged to function as disposal wells to reduce costs and increase certainty of the disposal zone. Drilling is expected to take approximately two months and costed at a day rate. Waste handling facilities include the necessary facilities for waste handling, repackaging and transportation to the disposal drillhole. This will also include shielded transfer casks and other equipment to meet radiation safety and license conditions for safe operations. These costs could be minimized if the waste inventory is already packaged to meet disposal criteria or if existing facilities could be used for these activities. Intellectual property (IP) license costs are for the use of Deep Isolation IP. This covers the IP related to the general concept of using a horizontal drillhole to dispose of hazardous or radioactive waste, disposal canister designs and other aspects. Project management costs include the overall project management, overhead and back-office related activities. Deep Isolation will provide these services and include periodic reporting and face-to-face updates. There are many variables and uncertainties that make difficult the projection of costs for either the development work or the full deployment of the Deep Isolation system.
20 Deep Isolation input to Parliamentary Inquiry There are some indicative figures, however, that provide illumination on the relative costs.
Characterising a site for a Deep Isolation drillhole repository involves a $4 - 10 million program. This work focuses on collecting and dating the water at various depths. The dating focuses on the relative concentrations of naturally occurring radioisotopes to demonstrate the isolation of the proposed disposal horizon. Traditional geophysical methods would also be employed. This contrasts with the extensive characterisation program needed for a mined repository, which is significantly more costly and lengthy.
Once qualified (characterised and licensed), the Deep Isolation drillhole is completed. Without knowing the depth, geology and diameter, the cost could cover a broad range. Further, the site’s location relative to existing drilling equipment capable of completing the Deep Isolation drillhole is another significant variable. However, it is expected that a Deep Isolation drillhole could be completed for less than $20 million, perhaps significantly less. This drillhole would be capable of receiving SNF from 10-15 years operation of a large PWR, or the entire production of SNF from smaller reactors.
Once the Deep Isolation drillhole is completed, there are routine capital cost items needed at the site. The two specialty items would be a permanent overhead crane and associated downhole equipment, as well as the on-site cask.
In Deep Isolation’s experience, security will dominate the cost of operating the long- lived waste disposal facility. Such waste will be received and emplaced at a pace that will allow a single shift crew to manage operations. Security, on the other hand, will have to be provided on a 24 hour, 7 days per week basis.
The location of the disposal facility may also impose an inherent cost component by its remoteness from an existing population and infrastructure. There is extensive experience in Australia for developing and operating such remote, fly-in-fly-out operations with on-site dormitories and meal facilities as may be required for a very remote facility.
21 Deep Isolation input to Parliamentary Inquiry Relevant Case Studies
In this section, information is presented about relevant case studies that support the deployment of the Deep Isolation disposal system.
The most compelling demonstration of the technology was done by Deep Isolation in Cameron, Texas earlier this year. A prototype waste canister (see Figure 6) was lowered over 600 m into a borehole in a drilling equipment training and testing facility in Texas. The canister was then moved laterally approximately 130 m and released as if emplaced for disposal. The wireline was then removed from the borehole. Afterwards, the canister was retrieved and brought back to the surface (see Figure 7).
FIGURE 6. PROTOTYPE ILW CANISTER FIGURE 7. PROTOTYPE ILW CANISTER BEING LOWERED IN TO DRILLHOLE RETRIEVED
This work demonstrated that oil and gas technology that is extremely mature is directly applicable to the disposal of some forms of radioactive wastes. It further demonstrated that retrievability is possible from an engineering standpoint.
There are many other elements of Deep Isolation’s disposal approach that have been individually demonstrated. Some of these are listed below:
22 Deep Isolation input to Parliamentary Inquiry • In the US, the Environmental Protection Agency has issued permits on approximately 180,000 “Class II” wells.8 Twenty percent of these wells require characterisation to identify aquitards – zones within the earth that restrict the communication between aquifers. This work is the starting point of Deep Isolation’s identification and qualification of a disposal site. • It is estimated that 50,000 gas recovery wells, similar to a Deep Isolation drillhole, have been developed in the US. These have been completed to depths of up to 5 km, some with diameters of up to 700 mm, and many with horizontal extent of up to 4 km. • On-site handling and storage of highly radioactive materials has been accomplished throughout the world, including in Australia. Technology for transferring wastes into storage or disposal positions have been demonstrated at work such as the Climax demonstration9 in the US and routinely at nuclear power plants worldwide (see an example in Figure 8).
FIGURE 8. WASTE TRANSFER WITHOUT A HOT CELL
8 See https://www.epa.gov/uic/class-ii-oil-and-gas-related-injection-wells
9 “Spent-Fuel Test – Climax: An Evaluation of the Technical Feasibility of Geologic Storage of Spent Nuclear Fuel in Granite”, by W. C. Patrick, Lawrence Livermore National Laboratory, UCRL-53762, September 1986.
23 Deep Isolation input to Parliamentary Inquiry Readiness and Viability
In this section, Deep Isolation summarises its readiness and commercial viability relative to the Australian program. Collaboration on nuclear waste disposal can be done in several parts depending on the needs, desired timeframes and budget. The demonstration can generally be broken down into drilling operations and surface operations, which include nuclear material handling. Drilling operations include drilling the well, installing the casing, emplacement of disposal canisters and, if needed, retrieval of canisters. Deep Isolation has agreements in place to provide turn-key testing of the drilling equipment and tools at a commercial oil & gas facility in the USA. We have already engaged with the local community leaders near the testing facility and several of them participated in the January 2019 demonstration of our technology. Our approach to that community and stakeholder engagement can be part of the process in Australia. Our partner drilling company is a large multi-national that can provide drilling rigs and services in Australia with advanced notice. We would like to discuss the location, and any community and stakeholder engagement that should be done in advance of a demonstration of our concept in Australia. Surface operations include the packaging of waste into disposal canisters and the transport of the disposal canisters from the current storage location to the drillhole site. We have had strategic negotiations with several internationally known nuclear companies to provide services in this area. Deep Isolation has patented canister designs and other resources that could be deployed to demonstrate our surface handling capabilities. A better understanding of the Australian waste inventory, including waste package dimensions, would allow Deep Isolation to customize a disposal solution. Deep Isolation is ready to review contract terms and determine if any adjustments to our insurance programs or other corporate aspects are needed to meet the requirements.
24 Deep Isolation input to Parliamentary Inquiry Conclusions Deep Isolation has a proprietary approach for disposing of spent nuclear fuel and other long-lived radioactive waste in Australia. In this presentation, Deep Isolation has presented the following: 1. Deep Isolation has developed an extensive conceptual engineering basis for managing the Australian long-lived radioactive waste. This basis embraces spent nuclear fuel from some future nuclear power program as well as existing long-lived waste challenges in Australia for disposal of the vitrified ILW packaged in the CSD-U canister as well as the soon-to-be-produced Synroc waste form. 2. Deep Isolation has presented the advantages to utilizing its disposal approach over utilization of a mined geological repository. While vertical borehole disposal may be acceptable, Deep Isolation has presented the advantages offered by disposal in a horizontal orientation that will simplify licensing, increase safety, and reduce costs. 3. Disposal of Australian long-lived radioactive waste in a Deep Isolation drillhole meets or exceeds all of the best practice guidelines in the IAEA guidance. 4. Deep Isolation has presented a qualitative foundation for licensing the disposal of Australian long-lived radioactive waste in a Deep Isolation drillhole. The work done by Sandia, referenced in this business proposal, provides confidence in the ability to meet and exceed the ultimate disposal standards of ARPANSA. 5. Deep Isolation is convinced, based upon the vast experience accumulated in the drilling sector in the past two decades, that a Deep Isolation disposal drillhole can be established in any geology that meets Deep Isolation’s stringent qualification criteria. 6. Disposal of existing and possible long-lived Australian radioactive waste is entirely suitable in a Deep Isolation drillhole. 7. Deep Isolation has commented on retrievability of Australian long-lived radioactive waste disposed of in a Deep Isolation drillhole. Deep Isolation’s conclusion is that the wastes are readily retrievable for a period of up to 300 years, and thereafter are retrievable with increasing levels of effort as a function of time. 8. Deep Isolation has commented on the superior professional resources available to Australia through ANSTO, CSIRO and ARPANSA. 9. Deep Isolation has presented the qualitative basis for operational and post- closure safety and is entirely confident that it will exceed the safety standards of ARPANSA. 10. Deep Isolation has commented on the CAPEX and OPEX associated with deploying its technology for the disposal of Australian long-lived radioactive waste.
25 Deep Isolation input to Parliamentary Inquiry 11. Deep Isolation has presented its early 2019 Texas demonstration as one relevant case study that shows the maturity of the technology. In addition, Deep Isolation has referenced other routine activities in the oil and gas, as well as nuclear sectors, to demonstrate that almost every aspect of the Deep Isolation system is mature and ready to be deployed. 12. Deep Isolation has provided an extensive summary of the value and priority it places on community and stakeholder engagement before and during the deployment of the Deep Isolation system. This is a core value of the company and an essential element of success. 13. Deep Isolation asserted that it is viable and ready to be deployed.
26 Deep Isolation input to Parliamentary Inquiry