Storage and Disposal of Radioactive Waste
(Updated January 2023)
- Radioactive wastes are stored so as to avoid any chance of radiation exposure to people, or any pollution.
- The radioactivity of the wastes decays with time, providing a strong incentive to store high-level waste for about 50 years before disposal.
- Disposal of low-level waste is straightforward and can be undertaken safely almost anywhere.
- Storage of used fuel is normally under water for at least five years and then often in dry storage.
- Deep geological disposal is widely agreed to be the best solution for final disposal of the most radioactive waste produced.
Most low-level radioactive waste (LLW) is typically sent to land-based disposal immediately following its packaging for long-term management. This means that for the majority (~90% by volume) of all of the waste types produced by nuclear technologies, a satisfactory disposal means has been developed and is being implemented around the world.
For used fuel designated as high-level radioactive waste (HLW), the first step is storage to allow decay of radioactivity and heat, making handling much safer. Storage of used fuel may be in ponds or dry casks, either at reactor sites or centrally. Beyond storage, many options have been investigated which seek to provide publicly acceptable, safe, and environmentally sound solutions to the final management of radioactive waste. The most widely favoured solution is deep geological disposal. The focus is on how and where to construct such facilities.
Used fuel that is not intended for direct disposal may instead be reprocessed in order to recycle the uranium and plutonium it contains. Some separated liquid HLW arises during reprocessing; this is vitrified in glass and stored pending final disposal.
Intermediate-level radioactive waste (ILW) that contains long-lived radioisotopes is also stored pending disposal in a geological repository. In the USA, defence-related transuranic (TRU) waste – which has similar levels of radioactivity to some ILW – is disposed of in the Waste Isolation Pilot Plant (WIPP) deep geological repository in New Mexico. A number of countries dispose of ILW containing short-lived radioisotopes in near-surface disposal facilities, as used for LLW disposal.
Some countries are at the preliminary stages of their consideration of disposal for ILW and HLW, whilst others, in particular Finland, have made good progress. Finland's Onkalo repository is expected to start operating in 2024. It will be the first deep geological repository licenced for the disposal of used fuel from civil reactors.
The following table sets out the commonly accepted disposal options. When considering these, it should be noted that the suitability of an option or idea is dependent on the wasteform, volume, and radioactivity of the waste. As such, waste management options and ideas described in this section are not all applicable to different types of waste.
Commonly-accepted disposal options
| Option | Suitable waste types | Examples |
|---|
| Near-surface disposalat ground level, or in caverns below ground level (at depths of tens of metres) | LLW and short-lived ILW | - Implemented for LLW in many countries, including Czech Republic, Finland, France, Japan, Netherlands, Spain, Sweden, UK, and USA.
- Implemented in Finland and Sweden for LLW and short-lived ILW.
|
Deep geological disposal
(at depths between 250m and 1000m for mined repositories, or 2000m to 5000m for boreholes) | Long-lived ILW and HLW (including used fuel) | - Most countries have investigated deep geological disposal and it is official policy in several countries.
- Implemented in the USA for defence-related truansuranic waste at WIPP.
- Preferred sites selected in France, Sweden, and the USAa. Facility under construction and due to begin operations in 2023 in Finland.
- Geological repository site selection process commenced in several countries.
|
Additional ideas have also been considered and discounted in the past (see section onOther ideas for disposalbelow, and information paper onInternational Nuclear Waste Disposal Concepts).
Near-surface disposal
The International Atomic Energy Agency (IAEA) definitionb of this option is the disposal of waste, with or without engineered barriers, in:
- Near-surface disposal facilities at ground level. These facilities are on or below the surface where the protective covering is of the order of a few metres thick. Waste containers are placed in constructed vaults and when full the vaults are backfilled. Eventually they will be covered and capped with an impermeable membrane and topsoil. These facilities may incorporate some form of drainage and possibly a gas venting system.
- Near-surface disposal facilities in caverns below ground level. Unlike near-surface disposal at ground level, where the excavations are conducted from the surface, shallow disposal requires underground excavation of caverns. The facility is at a depth of several tens of metres below the Earth's surface and accessed through a drift.
The term near-surface disposal replaces the terms 'shallow land' and 'ground disposal', but these older terms are still sometimes used when referring to this option.
These facilities will be affected by long-term climate changes (such as glaciation) and this effect must be taken into account when considering safety, as such changes could disrupt these facilities. This type of facility is therefore typically used for LLW and short-lived ILW with half-lives of up to 30 years.
Near-surface disposal facilities at ground level are currently in operation in:
- UK – LLW Repository at Drigg in Cumbria operated by UK Nuclear Waste Management (a consortium led by AECOM with Studsvik UK, Serco, and Orano) on behalf of the Nuclear Decommissioning Authority.
- Spain – El Cabril LLW and ILW disposal facility operated by ENRESA.
- France – Centre de l'Aube operated by Andra.
- Japan – LLW Disposal Center at Rokkasho-Mura operated by Japan Nuclear Fuel Limited.
- USA – five LLW disposal facilities: Texas Compact facility near the New Mexico border, operated by Waste Control Specialists; Barnwell, South Carolina operated by EnergySolutions; Clive, Utah (EnergySolutions); Oak Ridge, Tennessee (EnergySolutions); and Richland, Washington – operated by American Ecology Corporation.
Near-surface disposal facilities in caverns below ground level are currently in operation in:
- Sweden – the SFR final repository for short-lived radioactive waste at Forsmark, where the depth of the facility is 50m under the Baltic seabed – operated by the Swedish Nuclear Fuel and Waste Management Company (SKB)c.
- Finland – an underground repository at Olkiluoto for LLW and ILW has been in operation since 1992. A similar facility at Loviisa was commissioned in 1997. The depth of these is about 100 metresd.
Deep geological disposal
The long timescales over which some waste remains radioactive has led to the idea of deep disposal in underground repositories in stable geological formations. Isolation is provided by a combination of engineered and natural barriers (rock, salt, clay) and no obligation to actively maintain the facility is passed on to future generations. This is often termed a 'multi-barrier' concept, with the waste packaging, the engineered repository, and the geology all providing barriers to prevent the radionuclides from reaching humans and the environment. In addition, deep groundwater is generally devoid of oxygen, minimising the possibility of chemical mobilization of waste.
Deep geological disposal is the preferred option for nuclear waste management in most countries, including Argentina, Australia, Belgium, Canada, Czech Republic, Finland, France, Japan, the Netherlands, Republic of Korea, Russia, Spain, Sweden, Switzerland, the UK, and the USA. Hence, there is much information available on different disposal concepts; a few examples are given here. The only purpose-built deep geological repository that is currently licensed for disposal of nuclear material is the Waste Isolation Pilot Plant (WIPP) in the USA, but it does not have a licence for disposal of used fuel or HLW. Plans for disposal of spent fuel are particularly well advanced in Finland, as well as Sweden, France, and the USA, though in the USA there have been political delays. In Canada and the UK, deep disposal has been selected and the site selection processes have commenced.
Mined repositories
The most widely proposed deep geological disposal concept is for a mined repository comprising tunnels or caverns into which packaged waste would be placed. In some cases (e.g.wet rock) the waste containers are then surrounded by a material such as cement or clay (usually bentonite) to provide another barrier (called buffer and/or backfill). The choice of waste container materials and design, as well as the buffer/backfill material varies depending on the type of waste to be contained and the nature of the host rock-type available.
Excavation of a deep underground repository using standard mining or civil engineering technology is limited to accessible locations (e.g.under land or nearshore), to rock units that are reasonably stable and without major groundwater flow, and to depths of between 250m and 1000m. The contents of the repository would be retrievable in the short term, and if desired, longer-term.
The Swedish proposed KBS-3 disposal concepte uses a copper container with a steel insert to contain the spent fuel. After placement in the repository about 500 metres deep in the bedrock, the container would be surrounded by a bentonite clay buffer to provide a very high level of containment of the radioactivity in the spent fuel over a very long time period. In June 2009, the Swedish Nuclear Fuel and Waste Management Company (SKB) announced its decision to locate the repository at Östhammar (Forsmark).
Finland's repository programme is also based on the KBS-3 concept. Spent nuclear fuel packed in copper canisters will be embedded in the Olkiluoto bedrock at a depth of around 400 metres. The country's nuclear waste management company, Posiva Oy, expects the repository to begin disposal operations in 2023. Its construction was licensed in November 2015.
The deposits of native (pure) copper in the world have proven that the copper used in the final disposal container can remain unchanged inside the bedrock for extremely long periods, if the geochemical conditions are appropriate (low levels of groundwater flow). The findings of ancient copper tools, many thousands of years old, also demonstrate the long-term corrosion resistance of copper, making it a credible container material for long-term radioactive waste storage.
Multi-barrier disposal concept (Image: Posiva)
Deep boreholes
As well as mined repositories, which have been the focus of most international efforts so far, deep borehole disposal has been considered as an option for geological isolation for many years, including original evaluations by the US National Academy of Sciences in 1957 and more recent conceptual evaluations. In contrast to recent thinking on mined repositories, the contents would not be retrievable.
The concept consists of drilling a borehole into basement rock to a depth of up to about 5000 metres, emplacing waste canisters containing used nuclear fuel or vitrified radioactive waste from reprocessing in the lower 2000 metres of the borehole, and sealing the upper 3000 metres of the borehole with materials such as bentonite, asphalt or concrete. The disposal zone of a single borehole could thus contain 400 steel canisters each 5 metres long and one-third to half a metre in diameter. The waste containers would be separated from each other by a layer of bentonite or cement.
Boreholes can be readily drilled offshore (as described in the section below on sub seabed disposal) as well as onshore in both crystalline and sedimentary host rocks. This capability significantly expands the range of locations that can be considered for the disposal of radioactive waste.
Deep borehole concepts have been developed (but not implemented) in several countries, including Denmark, Sweden, Switzerland, and the USA. Compared with deep geological disposal in a mined underground repository, placement in deep boreholes is considered to be more expensive for large volumes of waste. This option was abandoned in countries such as Sweden, Finland, and the USA, largely on economic grounds. The borehole concept remains an attractive proposition for the disposal of smaller waste forms including sealed radioactive sources from medical and industrial applicationsf.
An October 2014 US Department of Energy (DOE) report said: “Preliminary evaluations of deep borehole disposal indicate a high potential for robust isolation of the waste, and the concept could offer a pathway for earlier disposal of some wastes than might be possible in a mined repository.” In January 2016 the DOE commissioned a team led by Battelle to drill a 4880-metre test borehole into crystalline basement rock in North Dakota, but the project was later scrapped following local opposition.
In 2021 the US company Deep Isolation contracted with Slovenia’s radioactive waste management organization ARAO to conduct a feasibility study on the use of deep boreholes to dispose of the country’s spent research reactor fuel. It has conducted feasibility studies also for Fermi Energia in Estonia and the Electric Power Research Institute in USA.
As part of a pilot study, the IAEA have provided technological and engineering support for the construction and implementation of borehole disposal facilities in Malaysia and Ghana. Preparatory work for the start of construction of the Malaysian borehole is in its final stages, with the facility expected to be operational in 2023. The facility is situated at Nuclear Malaysia's main complex in Selangor. Ghana is also in the advanced stage of implementing its borehole project, with construction expected to begin as soon as the licensing review process is completed. The site will be managed by Ghana Atomic Energy Commission and based in the Accra region. The IAEA hope that these projects will provide a model for other countries to follow.
Mined repositories – development examples
Boom clay & Opalinus clay, Europe
The Belgian disposal concept proposes that spent fuel and HLW is placed in high integrity steel containers and then emplaced in excavated tunnels 230 metres deep within a ductile (self-sealing) clayg– the Boom clay. The very low permeability of the clay leads to virtually no groundwater flow over long time periods. Waste would be backfilled with excavated clay or, alternatively, could be emplaced into unlined secondary tunnels where the clay would be allowed to 'creep' into contact with the waste containers. Similar systems have been proposed in the Netherlands and, using less plastic clays, in France and Switzerlandh (Opalinus clay). Clay is generally suitable for heat-generating HLW, and the OECD Nuclear Energy Agency has a‘Clay Club’researching this.
The French radioactive waste disposal agency, Andra, is designing a deep geological repository in clays near Bure in eastern France. This will be for disposal of vitrified HLW and long-lived ILW. The repository is designed to operate at up to 90ºC, which is likely to be reached about 20 years after emplacement.
Yucca Mountain, USA
At the end of 1987, the Nuclear Waste Policy Act was amended to designate Yucca Mountain, located in the remote Nevada desert, as the sole US national repository for spent fuel and HLW from nuclear power and military defence programs. An application by the US DOE to construct the repository was submitted in June 2008.
The repository would exist 300 metres underground in an unsaturated layer of welded volcanic tuff rock. Waste would be stored in highly corrosion-resistant double-shelled metal containers, with the outer layer made of a highly corrosion-resistant metal alloy, and a structurally strong inner layer of stainless steel. Since the geological formation is essentially dry, it would not be backfilled but left open to some air circulation. Drip shields made of corrosion-resistant titanium would cover the waste containers to divert possible future water percolation and provide protection from possible falling rock or debris. Containment relies on the extremely low water table, which lies approximately 300 metres below the repository, and the long-term durability of the engineered barriers.
The project has experienced many delays since its inception and following the 2009 presidential election the Barack Obama administration decided to cancel iti. However, in June 2010 the Nuclear Regulatory Commission's Atomic Safety and Licensing Board (ASLB) rejected the DOE's motion to withdraw the licence application, and in August 2013 the federal Appeals Court ordered the NRC to resume its review of the DOE's application for a licence to construct and operate the Yucca Mountain repository. The final volumes of the NRC’s safety evaluation report were published early in 2015, which contain the agency's technical review of safety of the repository. In May 2016 the NRC released its final supplement to the US DOE's environmental impact statement on the proposed Yucca repository. Both the environmental impact assessment and the NRC's experts established that the repository design would prove safe for one million years.
Disposal in layered salt strata or domes
Geological salt environments have a very low rate (perhaps even an absence) of groundwater flow and feature gradual self-sealing of the excavations due to creep of the salt, which is plastic. Salt is generally suitable for heat-generating HLW, and the OECD Nuclear Energy Agency has a‘Salt Club’researching this.
The Waste Isolation Pilot Plant (WIPP)j in New Mexico for defence transuranic wastes (long-lived ILW) has been operational since 1999. For this repository natural rock salt is excavated from a Permian layer several metres thick, between other types of rock, 650 metres below ground level. The wastes placed in these excavations contain large volumes of long-lived ILW, usually in steel drums. These are then placed on pallets and stowed in excavated rooms or caverns. The salt is plastic and will eventually seal the wastes and isolate them permanently. Containment of the radionuclides in the wasteform mostly relies on the almost complete absence of water flow in the salt. To date over 90,000 cubic metres of ILW has been disposed of at WIPP.
Salt environments are also available in northern Germany and the Netherlands although these are salt domes rather than bedded formations. In Germany, the former salt mines at Asse and Morsleben have been used for LLW and ILW disposal though this has now been suspended. The decommissioning process is now being investigated to determine the method for backfilling and sealing the repository.
Following an exhaustive site selection process the state government of Lower Saxony in 1977 declared the salt dome at Gorleben to be the location for a German national centre for disposal of radioactive wastes. Some €1.5 billion was spent over 1979 to 2000 researching the site. Work then stopped due to political edict, but resumption of excavation was approved following a change of government in 2009. Following a new law in early 2017, Gorleben was then considered one possible site for geological disposal of HLW. However, in September 2020 Germany launched a new search for a disposal site, naming 90 possible locations (but not Gorleben).
Nirex Phased Disposal Concept, UK
The UK's Nirex Phased Disposal Concept (or Phased Geological Disposal Concept) has been developed for relatively large volumes of ILW and LLW, usually cemented into stainless steel containersk. These containers would be emplaced into a repository in a host rock environment below the water table. The waste would be monitored and remain retrievable and the groundwater managed to prevent contact with the wastes, until such a time that the repository is sealed. When this happens, the waste will be surrounded (backfilled) by specially formulated cement and the repository allowed to resaturate. The cement would provide a long-lasting alkaline environment that contributes to containment of the waste by preventing many radionuclides from dissolving in the groundwater. Similar cement-based schemes for ILW disposal have been proposed in France, Japan, Sweden and Switzerland.
Multinational repositories
Not all countries are adequately equipped to store or dispose of their own radioactive waste. Some countries are limited in area, or have unfavourable geology, and therefore siting a repository and demonstrating its safety could be challenging. Some smaller countries may not have the resources to take the proper measures on their own to ensure adequate safety and security, or they may not have enough radioactive waste to make construction and operation of their own repositories economically feasible.
It has been suggested that there could be multinational or regional repositories located in a willing host country that would accept waste from several countries. They could include, for example, use by others of a national repository operating within a host country, or a fully international facility owned by a private company operated by a consortium of nations or even an international organization. However, for the time being, many countries would not accept nuclear waste from other countries under their national laws. National policies towards radioactive waste management are listed inNational Radioactive Waste Management Appendix 2: National Policies & Funding and the information paper onInternational Nuclear Waste Disposal Concepts.
Deep geological repository projects
Construction Underway
| Location | Commissioning date | Organisation Responsible | Stage of process |
|---|
| Onkalo, Finland | 2024 | Posiva | Constuction in process. Licence application for operation under review. |
Planned projects with selected site
| Location | Commissioning date | Organisation Responsible | Stage of process |
|---|
| France, Cigéo | 2035 | ANDRA | In July 2022 the French official journal published the decree recognising the public utility of Cigéo.
Construction licence submitted in January 2023. |
| Russia, Krasnoyarsk | tbc | NORWM | Underground Research Laboratory under construction. Construction of DGR will begin after research period. |
| Sweden, Forsmark | 2030-2032 | SKB | Licence application for construction approved in September 2022. |
| Switzerland, Nördlich Lägern | 2060 | Swiss Nuclear | General licence applications to be submitted to the federal government in 2024. Approval, expected around 2030, subject to an optional referendum. |
Proposed projects
| Location | Commissioning date | Organisation Responsible | Stage of process |
|---|
| Canada | 2040+ | NWMO | Site selection by late 2024, two sites under consideration. Construction License by 2032. |
| China | 2050+ | CNNC | Construction process of URL to test the suitability of Besuha region. If successful, an underground repository will be built near the laboratory by 2050). |
| Czech Republic | 2065 | SÚRAO | Site selection by 2030. |
| Germany | 2050 | BGR | Site selection by 2031. |
| Hungary | 2030 | PURAM | Site selection process is expected to be completed by 2032. |
| India | tbc | AEC | Plans are focused on the northwest Rajasthan region |
| Japan | 2035 | NUMO | Site selection in process in Hokkaido prefecture (Suttu town or Kamoenai village). Expected to be complete by 2025. |
| Slovakia | tbc | JAVYS | Two sites are undergoing detailed site investigations - expected to be complete in 2023. |
| United Kingdom | 2040 | NDA | Site selection in England or Wales launched in 2018. |
| USA | Suspended | USA DOE | A solution to the permanent disposal of spent nuclear fuel (SNF) in the United States is currently stalled. |
Interim waste storage and transport
Specially designed interim surface or sub-surface storage waste facilities are currently used in many countries to ensure the safe storage of hazardous radioactive waste pending the availability of a long-term disposal option. Interim storage facilities are generally used for ILW and HLW, including used nuclear fuel from reactors.
Storage ponds
Storage ponds at reactors, and those at centralized facilities such as CLAB in Sweden, are 7-12 metres deep to allow the racked fuel assemblies to be covered by several metres of water. The fuel assemblies are typically about 4 m long and standing on end. The multiple racks are made of metal with neutron absorbers incorporated in it. The circulating water both shields and cools the fuel. These pools are robust constructions made of thick reinforced concrete with steel liners. Ponds at reactors may be designed to hold all the used fuel for the life of the reactor, but usually the design assumes some removal of cooled fuel for reprocessing or to dry storage.
Central Interim Storage Facility (CLAB), Sweden. Image: SKB
Dry storage
Some storage of fuel assemblies which have been cooling in ponds for at least five years is in dry casks or vaults, typically with air circulation inside concrete shielding. Dry storage has been used at US nuclear power plants since 1986, and at least one-third of the total US used fuel is now in dry storage casks. Facilities are at most of the nuclear power plant sites (including some closed ones). As of the end of 2019, 3203 casks had been loaded at 72 interim spent fuel storage installations (ISFSIs) in the USA. Transfer from wet storage to dry casks at a power plant site may use special shielded transfer casks, which are less robust than those used for transport beyond the site. Casks may contain a sealed canister which can be transferred from one kind of cask to another.
Multi-purpose canisters
Sealed multi-purpose canisters (MPCs), also called dual-purpose canisters (DPCs), each holding up to 89 fuel assemblies with inert gas, are commonly used for transporting, storing and eventual disposal of used fuel. MPCs are contained inside robust overpacks – metal for transport, or mainly concrete for storage. Each MPC, constructed using 13 mm welded stainless steel with a secure lid and internal fuel basket to hold and keep the fuel assemblies separate, is designed for up to 45 kW heat load. MPCs have standard external dimensions and the number of fuel assemblies actually loaded into one depends on their characteristics. Some are double-walled (DWC), with helium in between the layers. Once an MPC is loaded the contents should never need to be handled again.
The IAEA publishes radioactive material transport regulations – notablyRegulations for the Safe Transport of Radioactive Material,IAEA Safety Standards Series No. SSR-6 (Rev.1).
Holtec’s MPC contains a 68-cell fuel basket for BWR fuel, a 24-cell flux-trap, or a 32-cell non-flux trap fuel basket for PWR fuel. Some have neutron-absorbing Metamic-HT fuel baskets and liners with high thermal conductivity, enabling relatively-hot three-year-old spent fuel to be placed in them. Since 2013 Holtec also makes double-walled canisters (DWCs) for the UK and Ukraine, with the same standard external dimensions.
High-capacity MPCs are able to hold 37 PWR or 87-89 BWR fuel assemblies. Others take only 12 PWR or 32 BWR fuel assemblies. With some small canisters – 4 PWR/9BWR – four can be fitted into a standard transport cask. Orano has a large canister design holding 21 PWR or 44 BWR fuel assemblies.
Storage casks and systems
For storage, each MPC is enclosed in a ventilated storage module or overpack made of concrete and steel. These are commonly standing on the surface, about 6 metres high, cooled by air convection, or they may be horizontal in banks, or vertical and below grade, with just the tops showing. The modules are robust and provide full shielding. At a nuclear power plant, a shielded transfer cask is used to move the MPC from the used fuel pool to a storage module. Holtec’s transfer casks for onsite use are called HI-TRAC.
A free-standing above-ground system is Holtec’s HI-STORM 100, which accommodates a variety of sealed stainless steel MPCs vertically inside ventilated concrete and steel overpacks standing on a concrete pad. The 165-tonne overpack has 65 cm of concrete inside steel casing for shielding. This system is used at many US plants. A below-ground variant is HI-STORM 100U, and a more sophisticated version of this is Holtec’s HI-STORM UMAX storage system, which is already deployed at two US nuclear power plant sites, and proposed for the HI-STORE CIS facility in New Mexico (see below). HI-STORM UMAX stores the canisters containing used fuel in ventilated vertical steel and concrete cavity enclosure containers 5 metres high below ground, with massive lids at ground level. The containers are set up in a 7.6 m deep excavation and low-strength concrete grout is backfilled around them. The final half metre of fill is a reinforced concrete pad. Seismic tolerance is about 2000 Gal.
An above-ground horizontal system is Orano’s NUHOMS HSM-H system, used by 20 of the 67 ISFSIs at US nuclear plants. The used fuel is sealed in 15 mm thick stainless steel dry storage canisters which are then moved in horizontal shielded transfer casks to large horizontal storage modules, with each hole 5 m long and 2 m diameter. Orano claims better heat distribution in these than vertical systems, using conduction more than convection, and also points to no gaps between modules being very safe seismically (1500 Gal) and radiologically. Each canister holds 32-37 PWR fuel assemblies or 61-69 BWR assemblies, in helium. Orano plans to have a US-licensed transport cask for NUHOMS by 2020, and meanwhile it has one for high burn-up fuel. NUHOMS horizontal storage can accommodate a variety of canister designs, and the Orano NUHOMS canisters are compatible with other,e.g. Holtec, vertical storage systems.
In July 2017 the US Nuclear Regulatory Commission granted Orano TN certification for its NUHOMS Extended Optimized Storage (EOS) dry used fuel storage system. The system is designed for high burn-up fuel management and reactors in shutdown phase. The large NUHOMS EOS dry shield canisters hold 37 PWR or 89 BWR fuel assemblies. These can be transferred in the EOS TC series transfer cask and stored in NUHOMS EOS HSM concrete modules.
Germany’sGesellschaft für Nuklear-Service mbH (GNS), set up in 1977 and owned by the country's four nuclear utilities, is both an operator of waste storage and supplier of two types of cask. The main type are CASTOR casks, more than 1000 of which are used in Germany alone for transport and interim storage of spent fuel and HLW. The cask body provides full shielding and allows loading after very short cooling times of high burn-up fuel, and they are closed with two lids. GNS’s CONSTOR casks are similar but with concrete in the walls and designed for cooler fuels.
A large canister HI-STORM FW storage module is a flood- and wind-resistant version with high seismic tolerance – 1.2 Gal. It holds 37 PWR assemblies, or 89 BWR ones, or 31 VVER-1000 ones, with maximum heat load 46 kW. The HI-STORM 190 is the VVER version of the HI-STORM FW. These canisters can hold damaged fuel in special failed fuel containers.
A new large storage cask is HI-STORM MIC (mega-impact capable) designed with EDF Energy in the UK and having a 100-year design life. It uses a double-walled MPC, and is heavily shielded.
According to theInterim Storage Partners (ISP) website, there were over 460 NAC and 1265 Orano TN casks storing spent fuel at both operating and decommissioned US nuclear plants as of June 2019.
A collection of casks or modules comprises an independent spent fuel storage installation (ISFSI), which in the USA is licensed separately from any associated power plLS
