UK Radioactive Waste Inventory 2022

Q: Integrated waste management

A central theme of UK radioactive waste management is the waste hierarchy. [7] The waste hierarchy sets out five steps for dealing with waste, ranked according to environmental impact. There is a preference for managing wastes at higher levels of the hierarchy. The waste hierarchy includes: Prevention of waste where practicable Minimisation where creation is unavoidable Re-use and recycling where there are opportunities to do so Disposal for wastes that can’t be managed using any other method. In 2019 the NDA published its integrated waste management strategy [8] . The strategy applies to all radioactive waste generated within the NDA estate (including materials that may become waste at some point in the future). It provides a high-level framework for flexible decision-making, to ensure safe, environmentally acceptable and cost-effective solutions that reflect the nature of the radioactive waste concerned. Diverse radioactive waste management and disposal solutions that can offer benefits over previous arrangements are part of an integrated waste management approach.

Q: Volumes by region

Figure 5 illustrates the relative contributions of radioactive waste in England, Scotland and Wales to the total reported volume in the UK. There are currently no nuclear licensed sites in Northern Ireland; only very small quantities of radioactive waste are produced there from hospitals and industry. These wastes can be incinerated or disposed of in landfill and are not within the scope of the 2022 Inventory. [25] (!!8) In terms of reported volume, approximately 91.3% of all radioactive wastes in the UK at 1 April 2022 and in estimated future arisings up to 2136 are located in England, 5.8% in Scotland and 2.8% in Wales. For England radioactive waste production is dominated by Sellafield. For Scotland most waste is from Dounreay and the legacy Magnox power station sites at Chapelcross and Hunterston. For Wales nearly all waste is from the legacy Magnox power station sites at Trawsfynydd and Wylfa. The 2022 UK Radioactive Waste Detailed Data report gives further information on waste volumes for England, Scotland and Wales, including volumes at 1 April 2022 and in projected future arisings, and for each waste category.

Question 1

The Inventory

Accepted Answer

An inventory of radioactive waste and materials in the UK is compiled every three years by the Department for Business, Energy & Industrial Strategy (BEIS) and the Nuclear Decommissioning Authority (NDA).

The inventory provides up-to-date information about radioactive waste to:

Inform policy and strategy development
Enable the UK to meet international reporting obligations
Aid radioactive waste and material management planning
Support stakeholder engagement.

The inventory is used by a wide range of stakeholders:

Government departments and agencies

Develop policies and strategies for managing UK radioactive waste and regulating nuclear operations

Supply chain organisations

Process waste and use data to support the planning, operation and performance of their facilities

Waste Planners

Ensure that radioactive waste management facilities meet local and national needs

Researchers and academics

Develop innovative technologies and processes for managing the range of radioactive waste in the UK

Members of the public

Increase in understanding about the types and quantities of radioactive waste produced in the UK

The 2022 UK Radioactive Waste and Materials Inventory (the 2022 Inventory) is the latest public record on the sources, quantities and properties of radioactive waste and materials in the UK at 1 April 2022 and predicted to arise after that date.

Question 2

Inventory documents

Accepted Answer

The 2022 Inventory comprises four reports:

Radioactive Waste Inventory - describes the sources, volume, composition and activity of radioactive waste in the UK, and a comparison with the previous inventory
Radioactive Material Inventory – summarises the quantities of UK civil nuclear materials that might have to be managed as waste in the future
Waste Detailed Data - provides further information on the radioactive waste inventory including a list of waste streams
Summary for International Reporting - gives information to meet the UK’s international reporting obligations in the field of radioactive waste and materials

As part of the commitment to openness, NDA has created a website dedicated to the Inventory, www.nda.gov.uk/ukinventory. All of the 2022 Inventory reports can be found together with other information about radioactive waste at this location.

Question 3

This report

Accepted Answer

This report provides information on the 2022 UK Radioactive Waste Inventory:

The inventory scope and process
Waste volumes, radioactivities and material compositions
Assumptions used to estimate future radioactive waste arisings (the inventory scenario)
Potential future scenarios
Uncertainty in waste volumes and radioactivities
How the 2022 Inventory compares with the 2019 Inventory
Waste disposals and overseas waste.

It also provides supporting information on the origins and categorisation of UK radioactive waste, and how the waste is managed.

More detailed data are provided in the 2022 UK Radioactive Waste Detailed Data report. This includes an analysis of waste volumes by region and from each organisation, ‘Site Information Sheets’ containing a description of the operations at each UK site that produces radioactive waste with volumes and radioactivities of the wastes, a list of waste streams in the 2022 Inventory and their volumes, the radionuclide composition of wastes, and a description of the inventory data reporting conventions.

Question 4

Origin of radioactive waste

Accepted Answer

Material that has no further use, and is contaminated by, or incorporates, activity above certain levels defined in UK legislation[1],[2] is known as radioactive waste.

Radioactive waste is the by-product of activities associated with the use of natural or man-made radioactive materials (such as uranium or irradiated nuclear fuel).

Transfer of radioactive material onto items it comes into contact with can lead to contamination and radioactive wastes being generated. Also, items that have been subjected to neutron radiation (as in a nuclear reactor) can become radioactive as a result, a process known as activation[3].

Contaminated and activated process wastes will be generated during the operation of facilities that use radioactive materials. Also contaminated and activated components will arise as radioactive waste when facilities are eventually shut down and decommissioned.

As a pioneer in the development and use of nuclear technology, the UK has accumulated a substantial legacy of radioactive waste and nuclear materials from electricity generation, defence programmes and other industrial, medical and research activities. Some of this waste is already in storage, but much of it still forms part of existing facilities and will only become waste over the next century or so as plants are shut down, decommissioned and cleaned-up. Radioactive waste continues to be produced where radioactive substances are used. More information about how radioactive waste is generated is found on the UK Radioactive Waste Inventory website.

Radioactive waste from the nuclear power industry

The civil nuclear power industry is the source of most radioactive waste in the UK. This includes waste from:

Manufacture of nuclear fuel
Operation and decommissioning of nuclear power stations
Reprocessing of spent nuclear fuel
Research and development (R&D) programmes.

The manufacture of nuclear fuels (fuel fabrication and uranium enrichment) produces wastes that have only low levels of uranium contamination.

At 1st April 2022 the UK had six operating nuclear power stations. The stations comprise ten Advanced Gas-cooled Reactors (AGRs) and a single Pressurised Water Reactor (PWR) - generating about 10% of the UK’s electricity supply.[4],[5] Eleven Magnox nuclear power stations and three AGR stations have stopped producing electricity; they are now being decommissioned.

Reprocessing of spent Magnox reactor fuel at Sellaﬁeld came to an end in July 2022. Reprocessing of spent AGR fuel in the Thermal Oxide Reprocessing Plant (Thorp) came to an end in 2018.

Nearly all of the waste from nuclear energy R&D is a legacy of government-funded programmes stretching back to the 1940s. Many test and prototype reactors were operated at research sites across the country. These reactors and associated facilities are now shut down and site operations are concerned with decommissioning, dismantling and clean-up.

Other sources of radioactive waste

Radioactive waste sources in the UK outside the civil nuclear power industry comprise:

Defence activities
Research establishments
Medical and industrial uses of radioactivity.

The main sources of defence waste are nuclear weapons production and operation of the UK ﬂeet of nuclear-powered submarines. Smaller waste quantities arise from general use of radioactive materials within the armed forces and at defence establishments.

Research into fusion reactor technology continues at Culham Centre for Fusion Energy (CCFE) with the Joint European Torus (JET) and Mega Amp Spherical Tokamak (MAST) experiments. The Rutherford Appleton Laboratory supports the work of a diverse research community using its neutron sources.

The remaining waste results from the use of radioactivity in medical diagnosis and treatment, and in industrial applications. These include sterilisation of medical equipment and food, and non-destructive testing of materials (for integrity, thickness, density). Some radioactive materials used in research, medicine and industry, which give rise to radioactive wastes, are produced in particle accelerators rather than in nuclear reactors.

Question 5

Waste producers

Accepted Answer

Figure 1 shows the main sites in the UK where radioactive waste is produced or anticipated to be produced. The waste producers are:

The NDA estate [6]
The Ministry of Defence (MoD)
EDF Energy
NNB GenCo (HPC) Ltd
The United Kingdom Atomic Energy Authority (UKAEA)
GE Healthcare Ltd
Urenco (comprising Urenco Nuclear Stewardship (UNS), Urenco UK (UUK) and Urenco Chemical Plants (UCP))
The Rutherford Appleton Laboratory (RAL).

The figure also shows the sites where radioactive waste is disposed, discussed in section 2.3.

Many, so-called, ‘small users’ of radioactive substances such as hospitals and industrial, educational and research establishments produce small quantities of radioactive wastes. Also, there are a number of supply chain organisations treating UK radioactive wastes at facilities that may produce small amounts of secondary waste. These sites are not shown in Figure 1. In the 2022 Inventory, these ‘small users’, which includes the Rutherford Appleton Laboratory are collectively referred to as ‘Minor Waste Producers’.

(!!4)

Question 6

Waste disposal

Accepted Answer

Figure 1 also shows sites at which radioactive waste is disposed. The Low Level Waste Repository (LLWR) site is the UK’s national LLW disposal facility. Its role is to ensure that the LLW generated in the UK is disposed of in a way that protects people and the environment. The National LLW Programme implements the UK LLW strategy on behalf of the NDA.

A key part of implementing the current UK LLW Strategy has been the development of alternative waste management routes. On-site disposal is also undertaken by some of the NDA Site Licence Companies Sellafield has an on-site facility capable of accepting some lower-activity wastes and Dounreay Site Restoration Ltd (DSRL) has constructed a LLW disposal facility adjacent to the site to accept LLW from Dounreay and the neighbouring MOD Vulcan Naval Reactor Test Establishment. The National LLW Programme has been successful in managing significant volumes of LLW through routes other than disposal at the LLWR site. The supply chain has developed landfill capability for the disposal of VLLW and lower-activity LLW wastes and has a critical role in providing a safe disposal route for wastes in support of the LLW National Programme.

The NDA is currently providing support to the Department for Business, Energy & Industrial Strategy (BEIS) during their review of an updated policy for Radioactive Substances and Nuclear Decommissioning. There is an expectation that a more integrated and risk-informed approach to waste management will be captured in a revised UK policy for all radioactive waste (see section 7.2 for more detail).

Question 7

Definitions

Accepted Answer

In the UK, radioactive waste is classified according to how much activity it contains and the heat that this activity produces. Categories are High Level Waste (HLW), Intermediate Level Waste (ILW), Low Level Waste (LLW) and Very Low Level Waste (VLLW). The following diagrams give the definitions and characteristics of the different waste categories.

The following broader designations are also used in this report in the context of radioactive waste management (section 4) and waste disposals (section 12):

Higher Activity Waste (HAW): comprises HLW, ILW and a small fraction of LLW
Lower Activity Waste (LAW): comprises both LLW and VLLW.

High level waste

Definition

Wastes in which the temperature may rise significantly as a result of their radioactivity. The heat therefore has to be taken into account in the design of storage or disposal facilities.

Characteristics

HLW is generated from reprocessing spent nuclear fuel at Sellafield. It is initially produced as a concentrated nitric acid solution containing waste fission products. The 2022 Inventory includes the nitric acid solutions awaiting conditioning in the Waste Vitrification Plant (WVP), some insoluble fission products that settle in the storage tanks, tank liquor heels, the glass product of conditioning, and small quantities of contaminated plant items from the WVP (mostly metal and ceramic).

Volume

~1,470 m³ total packaged

Level of radioactivity

~14,000,000 TBq at 2100
(dominated by shorter-lived radionuclides)

Intermediate level waste

Definition

Wastes exceeding the upper boundaries for LLW, but do not generate sufficient heat to be considered in the design of storage or disposal facilities.

Characteristics

The major components are steels, graphite, concrete, cement and sand, sludges, ion exchange resins and flocculants. There is a wide range of steel items, including plant items and equipment, fuel cladding and reactor components. Most graphite is in the form of moderator blocks from final stage reactor dismantling at Magnox and AGR power stations.

The majority of waste reported as cementitious materials is cement associated with conditioned waste. The remainder is mostly higher activity concrete from the decommissioning of buildings.

Volume

~496,000 m³ total packaged

Level of radioactivity

~1,000,000 TBq at 2100

Low level waste

Definition

Wastes having a radioactive content not exceeding 4 Gigabecquerels per tonne of alpha activity or 12 Gigabecquerels per tonne of beta/gamma activity.

Characteristics

The major components of LLW are building rubble, soil and steel items. The LLW can include framework, pipework and reinforcement from the dismantling and demolition of nuclear reactors and other nuclear facilities and the clean-up of nuclear sites.

LLW also comprises miscellaneous contaminated wastes from the operation of nuclear facilities which is mainly scrap metal items, plastics and paper.

Volume

~1,340,000 m³ total packaged

Level of radioactivity

~130 TBq at 2100

Very low level waste

Definition

A sub-category of LLW. It comprises waste that can be safely disposed of with municipal, commercial or industrial waste, or can be disposed of at specified landfill sites.

Very Low Level Waste comprises:

High Volume VLLW – wastes with maximum concentrations of 4 MBq (megabecquerels) per tonne of total activity that can be disposed to specified landfill sites. There is an additional limit for tritium in wastes containing this radionuclide.
Low Volume VLLW - wastes that can be safely disposed of to an unspecified destination with municipal, commercial or industrial waste. Each 0.1 m³ of material must contain less than 400 kBq (kilobecquerels) of total activity, or single items must contain less than 40 kBq of total activity. There are additional limits for C-14 and tritium in wastes containing these radionuclides.

Characteristics

The major components of VLLW are building structural materials (principally concrete, with brick, metal and other materials) from the dismantling and demolition of nuclear facilities.

There are also smaller quantities of excavated soil from construction and demolition activities

Volume

~2,750,000 m³ total reported

Level of radioactivity

~12 TBq at 2100

Question 8

Summary of key changes

Accepted Answer

Key changes from the 2019 UK Inventory are summarised below with a further detail given in section 13 regarding reported and packaged volumes along with changes to package numbers and activities.

Key changes

The number of waste streams is 1324 compared with 1318 in the 2019 inventory. A number of streams have been removed from the 2019 inventory due to being fully consigned with other waste being reallocated to new waste streams
Inclusion of additional waste for the first time in the UK Inventory from decommissioning at Rutherford Appleton Laboratory and anticipated operational waste from the Hinkley Point C power station currently being built
The total packaged volume (4,450,000 m³) is <1% lower than in the 2019 inventory
The total HLW packaged volume (1,470 m³) has decreased from the 2019 inventory by ~2%
The total ILW packaged volume (496,000 m³) has decreased from the 2019 inventory by ~1%
The total LLW packaged volume (1,340,000 m³) has increased from the 2019 inventory by ~5%
The total VLLW reported volume (2,750,000 m³) has decreased from the 2019 inventory by ~3%
The total number of packages expected (310,000) has decreased by ~4% from the 2019 inventory.

Question 9

Overview of UK Radioactive Waste Management

Accepted Answer

Key facts:

Higher activity wastes (HLW, ILW) and some LLW unsuitable for disposal in existing facilities are being accumulated in stores.
Integrated waste management and the opening up of alternative management routes mean that LLW is well managed in accordance with the waste hierarchy.

Responsibility for radioactive waste management in England rests with the UK Government. Responsibility in Scotland, Wales and Northern Ireland has been devolved to the Scottish Government, the Welsh Government and the Northern Ireland Executive, respectively.

The management of all categories of radioactive waste involves a number of key stages:

Planning and preparation
Treatment and packaging
Storage
Disposal
Transport (between stages)

The Inventory is essential to the successful planning and preparation of managing radioactive waste. The Inventory includes information on how wastes are currently being managed and future plans such as treatment and packaging for storage and disposal of waste.

Government radioactive waste management policy is supported by a regulatory framework that aims to ensure that radioactive wastes are safely and appropriately managed in ways that pose no unacceptable risks to people or the environment.

Question 10

Integrated waste management

Accepted Answer

A central theme of UK radioactive waste management is the waste hierarchy.[7] The waste hierarchy sets out five steps for dealing with waste, ranked according to environmental impact. There is a preference for managing wastes at higher levels of the hierarchy. The waste hierarchy includes:

Prevention of waste where practicable
Minimisation where creation is unavoidable
Re-use and recycling where there are opportunities to do so
Disposal for wastes that can’t be managed using any other method.

In 2019 the NDA published its integrated waste management strategy[8]. The strategy applies to all radioactive waste generated within the NDA estate (including materials that may become waste at some point in the future). It provides a high-level framework for flexible decision-making, to ensure safe, environmentally acceptable and cost-effective solutions that reflect the nature of the radioactive waste concerned.

Diverse radioactive waste management and disposal solutions that can offer benefits over previous arrangements are part of an integrated waste management approach.

Question 11

Lower Activity Waste (LAW) management

Accepted Answer

LAW comprises both LLW and VLLW.

Government policy for the long-term management of solid LLW (including VLLW) in the UK provides a high-level framework of principles and outlines priorities for responsible and safe management of LLW. The policy addresses concerns around disposal capacity for large-scale facility decommissioning and environmental restoration being undertaken in the UK. The policy also establishes a flexible, sustainable approach for managing solid low level radioactive waste in the long term[9].

The UK-wide strategy for managing LLW from the nuclear industry has three themes:

Application of the waste hierarchy (see above) with its preference for managing LLW at upper levels (i.e. waste minimisation, reuse and recycling)
The best use of existing LLW management assets
The need for new fit-for-purpose waste management routes.

Government has also developed strategies for the management of LLW from the non-nuclear industry. There are synergies between these and the nuclear industry strategy in that they have similar strategic themes and rely on many of the same waste management routes.

Nuclear Waste Services (hence forth referred to as NWS), on behalf of NDA, leads the implementation of the solid LLW strategy on behalf of Government through the Integrated Waste Management Programme (IWMP).

The implementation of the LLW strategy has been delivered through:

The management of a significant quantity of LLW away from disposal at the LLWR through improved waste segregation and characterisation[10]
The use of alternative treatments (e.g. incineration, metal treatment[11]) and disposal routes (e.g. authorised landfill sites[12])
Opportunities for improvement and the sharing of good practices.

Low Level Waste Repository

The LLWR disposal site remains a key strategic asset for the UK’s management of solid LLW. Waste unsuitable for incineration, metal treatment or landfill disposal is immobilised in cement within mild steel International Organisation for Standardisation (ISO) containers and disposed of at the LLWR.[13] Suitable LLW is first supercompacted to minimise its volume. In this process drums or boxes of waste are compacted under high pressure of up to 2,000 tonnes per square metre.[14]

Current disposals are made in an engineered facility with concrete-lined disposal vaults. A final cap will be constructed in stages over the vaults (and older trenches) and will be completed once the last disposals are made.

Dounreay LLW facility

A shallow, engineered LLW disposal facility has been constructed next to the Dounreay site in Caithness. Waste transfers started in 2015.

The disposal facility receives LLW from decommissioning at the Dounreay site, as well as being intended for retrieved and repackaged LLW from the historical disposal pits. It will also receive waste from the neighbouring Vulcan nuclear site that cannot be recycled. Suitable LLW is first supercompacted to minimise its volume. There is a dedicated ‘Demolition LLW’ vault for waste with radioactivity at the lower end of the LLW scale.

Question 12

Higher Activity Waste (HAW) management

Accepted Answer

HAW comprises HLW, ILW and such LLW that cannot be disposed of at present.

Current practice is that vitrified HLW[15] should be stored for at least 50 years before disposal. The period of storage allows the amount of heat produced by the waste to fall, which makes it easier to transport and dispose. Most ILW is stored at the producing sites. Some wastes, however, are transferred off site to appropriate facilities (e.g. at Sellafield) when there is a clear and compelling strategic case to do so. Minor waste producers also make use of facilities at Sellafield and an ILW store at Harwell.

Treatment and packaging convert the raw waste into a form that is suitable for longer-term storage pending the development of a suitable disposal route.

The long-term management policy of the UK Government and devolved administrations for Wales and Northern Ireland is geological disposal[16],[17]. Geological disposal uses engineered barriers and hundreds of metres of rock to isolate the waste so that no harmful amounts of activity reach the surface environment. The specially-engineered vaults and tunnels deep underground that will house the waste are called a Geological Disposal Facility (GDF).

There is no GDF yet operating but the UK Government launched a site selection process in 2020 to find a volunteer host community with suitable geology[18]. The geological characteristics of the site are important for the long-term safety of the facility.

The precise layout and design of the facility will depend on the inventory for disposal and the specific geological characteristics at the site in question.

The Scottish Government policy is that long-term management of higher activity wastes should be in near-surface facilities[19]. Facilities should be located as near to the site where the waste is produced as possible. Developers will need to demonstrate how the facilities will be monitored and how waste packages, or waste, could be retrieved.

Question 13

Radioactive wastes

Accepted Answer

The Inventory includes HLW, ILW and LLW, and some High Volume VLLW (HVVLLW) where there is reasonable certainty of the total waste arisings. This is illustrated in Table 1.

Table 1: Wastes reported in the Inventory

Category	Major waste producers	Minor waste producers
HLW		None produced
ILW
LLW	See note 1	See note 2
VLLW	See note 3	See note 4

Note 1: Some waste producers have chosen to report potentially contaminated land in the 2022 UK Radioactive Material Inventory report. This has been done until there is more certainty on the disposal route and the volumes that might arise.

Note 2: Excludes low volumes of waste that can be disposed of by ‘controlled burial’ at permitted landfill sites.

Note 3: Includes HVVLLW from facilities decommissioning and site clean-up at nuclear licensed sites. Some waste producers have chosen to report potentially contaminated land in the 2022 UK Radioactive Material Inventory report. This has been done until there is more certainty on the disposal route and volumes that might arise.

Note 4: Not reported in the Inventory. Such VLLW is of low volume and is disposed of separately, or with municipal, commercial and industrial wastes, at landfill sites.

The Inventory does not include:

Liquid and gaseous wastes containing very low concentrations of activity that are routinely discharged to the environment in accordance with statutory regulations. Discharges are made within authorised limits, usually after some form of treatment.
Small quantities of solid wastes with very low concentrations of activity typically from hospitals, universities and the non-nuclear industry (so-called ‘small users’), as well as devices such as tritium light sources and smoke detectors, that can be disposed of with domestic refuse to landfill, either directly or after incineration.
Naturally occurring radioactive materials (NORM), which accumulate as scale on pipework during the extraction of oil and gas. These scales have raised levels of activity and are treated as radioactive waste.
Estimates of waste and spent fuel from the development of new nuclear power stations in the UK until development work starts and there is greater certainty (operational waste from Hinkley Point C meets this criterion and is therefore included in the 2022 inventory for the first time).[20]

Also, the inventory does not include all secondary waste produced from waste treatment processes such as incineration and metal treatment. However, volumes are small.

Radioactive waste is divided into waste streams for the purpose of compiling the inventory. A waste stream includes waste or a collection of waste items at a particular site, usually in a particular facility and/or from a particular process or operation.

The Inventory covers radioactive wastes that existed on 1 April 2022 and those forecast to arise in the future, and for each radioactive waste stream gives its:

Identification code
Name
Waste classification
Volume in stock at 1 April 2022, and forecast in the future and the timing of these arisings
Physical and chemical composition
Radioactivity and radionuclide composition
Current or planned treatment and packaging
Current or planned disposal route.

Full information about each waste stream is contained within individual Waste Stream Data Sheets (WSDS). These are forms generated as MS Excel and Adobe pdf files, and are available on the UK Radioactive Waste Inventory website.

Question 14

Overview of the Inventory Process

Accepted Answer

Updating the Inventory is a major task which happens every three years. It involves engaging with radioactive waste producers and collecting information for over 1,300 radioactive waste streams and more than 60 radioactive material streams[21]. The Inventory process deployed in 2022 follows the approach set out below; NDA deployed a contractor to deliver the 2022 Inventory.

The process for compiling the 2022 Inventory:

Develop plan and approach

Develop and agree a plan, and the best way to work with waste producers and to record data.
Take on board lessons learned from the previous exercise and implement recommendations where these are endorsed and are achievable. Address any changes in inventory requirements.
Produce a specification and outline programme of work.

Confirm data requirements

Review data to be collected to confirm they continue to meet user needs and to ensure the UK’s international inventory reporting requirements can be met.
Maintain an inventory data improvement plan for each waste producer.
Update the inventory scenario for each site (see Section 7) before data collection.

Develop data collection tools

Develop the data collection tools; the waste producers are involved in this process.
Preload previous 2019 Inventory data for waste producers to update. Guidance and conventions are developed to help in compiling data in a consistent form.

Compile data and verify

Inventory data are obtained from a number of sources - waste sampling, measurement and calculation. Waste producers are responsible for quality checking their data before submission.
The inventory contractor processes the data and carries out independent checking. Checking confirms that data are consistent with the inventory data reporting conventions.

Publish reports and data

‘Freeze’ the inventory database once all data have been collected and checked with sites.
The inventory contractor then produces a suite of reports that are reviewed and approved by the waste producers, NDA and BEIS. Finally, the inventory is ready for publication.

Review project

After inventory publication, NDA works with all those involved to agree improvements for the next inventory cycle. This includes improvements to the process itself as well as identifying specific improvements to the data.
NDA reviews the strategy for management of inventory data and updates the strategy as needed.

Question 15

Scenarios

Accepted Answer

The Inventory scenario sets out the assumptions used by waste producers to estimate the amount of radioactive waste that will arise from their sites in future. The assumptions consider the nature, scale and timings of operations and activities at each site.

These assumptions were made at the 2022 Inventory stock date, 1 April 2022 and may change in future due to a range of commercial, policy or funding reasons, or as improved data become available.

Table 2 provides the key assumptions and programme dates used to forecast radioactive waste arisings at UK waste producing sites. Site information sheets in the companion 2022 UK Radioactive Waste Detailed Data report provide further information on the basis for estimates of future waste arisings.

Table 2: List of assumptions used to estimate future waste arisings in the 2022 Inventory

Organisation / site	Operations	Decommissioning
NDA sites:
Sellafield	Magnox reprocessing plant completed operations in July 2022	Following the end of spent fuel reprocessing the site continues to focus on high hazard reduction and environmental remediation, including waste retrieval and treatment, Post Operational Clean Out (POCO) and the decommissioning of redundant facilities. All site decommissioning activities will be largely completed by 2090. All buildings/waste stores (except product stores and supporting ancillary buildings) are assumed to be demolished by 2120
Magnox reactor sites (See note 1)	All reactors are shut down	All defuelling and Care and Maintenance (C&M) preparations completed by 2037. Final site clearance work scheduled over the period 2070-2115
LLWR	Waste forecast to 2135	Plutonium Contaminated Material (PCM) store emptied by 2025
Dounreay	All reactors and supporting facilities are shut down	All redundant facilities decommissioned by 2049[22]
Harwell	All reactors and supporting facilities are shut down	All facilities decommissioned by 2054
Winfrith	All reactors and supporting facilities are shut down	All facilities decommissioned by 2034
Springfields	Oxide manufacture to continue until 2028	All facilities decommissioned by 2045. Final site clean-up and remediation ~2100
Ministry of Defence (MOD) sites:
Atomic Weapons Establishment (AWE)	-	End of operations at 2080 (See note 3) (Notional date when all legacy and currently operational facilities are assumed to be
Dockyards	Operations continue to 2110	Rosyth - submarine dismantling activities continue until the 2030s
Submarine decommissioning	-	Includes 27 submarines currently in scope of the Submarine Dismantling Project (SDP) programme and seven existing / planned Astute boats and four future Dreadnought class boats
EDFE sites:
AGR power stations	Reactors shut down by 2028	All defuelling and C&M preparations completed by 2042. Final site clearance work scheduled over the period 2108-2123
Sizewell B PWR power station	Reactor operates to 2035	Defuelling and C&M Preparations 2035-2045. Reactor Dismantling and Final Site Clearance 2043-2053
United Kingdom Atomic Energy Authority (UKAEA) sites:
Culham	JET operates to 2024	Decommissioning 2024-2032
Urenco sites:
Capenhurst	Uranium oxide store is forecast to be maintained until 2119	Decommissioning complete 2124
GE Healthcare site:
Amersham	Manufacturing operations ceased in 2019	Decommissioning complete 2030
Rutherford Appleton Laboratory:
Rutherford Appleton Laboratory	Waste forecast to 2040
Power stations under construction:
Hinkley Point C	60 year operating life	Decommissioned after 60 years operation (See note 2)

Note 1: Stations include Calder Hall on the Sellafield site.

Note 2: Anticipated decommissioning waste from Hinkley Point C is not included in the 2022 UK RWI.

Note 3: 2080 is a notional date for planning purposes and a realistic quantification of volumes over a specific time, this is in no way an indication of the cessation of the UK’s strategic capability at a point of time in the future.

(!!5)

Question 16

Potential future developments

Accepted Answer

This section discusses potential developments that could occur in the future which could result in changes (and uncertainty) in the inventory data presented in the 2022 UK Inventory.

Opportunity routes

In addition to information on the baseline management route for radioactive waste streams, the UK Inventory process collects information on opportunities for alternative waste management routing. The objective of collecting this information is to support the identification and implementation of waste stream opportunities that align with the principle of optimised waste management as outlined in the NDA Radioactive Waste Strategy. This includes the use of the waste hierarchy, timely characterisation and segregation of waste which delivers effective waste management, and the seeking of opportunities to share treatment and interim storage assets, capabilities and learning.

If the identified opportunities become the baseline disposal and treatment options in future inventories, then it can be expected that changes will be seen in the number and type of packages destined for disposal facilities.

Site specific strategies as part of a rolling programme of decommissioning

The strategy for decommissioning Magnox reactor sites was developed over 30 years ago and involved deferring reactor decommissioning at all sites for approximately 85 years from reactor shutdown. In 2016, NDA committed to reviewing this strategy with Magnox Ltd to take account of new experience and developments in the decommissioning landscape. NDA has endorsed a site-specific approach to Magnox reactor decommissioning which will involve a mix of decommissioning strategies. Magnox Ltd has begun the process of selecting the optimum decommissioning strategy for each of the Magnox reactors. The intention is that together the site-specific strategies will result in a rolling programme of activity as the Magnox fleet is decommissioned. This will maximise the opportunity for sharing any lessons learned, developing and implementing new technologies and strengthening wider capability. As a whole, the programme will collectively be geared towards reducing risk, reducing lifetime costs and growing skills and knowledge to deliver benefits both nationally and to local communities.

If adopted in future UK Inventories, waste from reactor dismantling and the final site clearance waste from Magnox reactors may arise prior to the dates estimated in the current inventory. Differences in the properties of waste should it arise earlier will influence the selection of waste packages and disposal routes.

Risk-informed waste management

Risk-Informed Waste Management (RIWM) is a culture adopted during decision making processes, to ensure the best outcomes, where the physical risks from waste are considered across the whole waste lifecycle. At present, waste is mostly managed based on the traditional categories of HLW, ILW, LLW and VLLW, which is taken into consideration in the inventory. Changes to the management strategy could have significant consequences to both the timing and routing of waste listed in the inventory. For example, for certain waste types where the overall hazard is deemed to be low, the timing for packaging and disposal could be accelerated. This could be a result of the waste no longer needing to be stored for long periods of time before final disposal.

Examples of the potential for adoption of a more risk-informed waste management culture:

Disposal of LLW / ILW Boundary Wastes

Some short-lived ILW or wastes at the boundary of LLW and ILW may be able to be safely disposed of at the LLWR as opposed to a GDF. Disposal at the LLWR is currently restricted by limitations set in LLWR’s environmental permit and planning permission based on the definition of LLW, which limits waste disposals to solids with activity not exceeding 4 GBq per tonne of alpha activity, or 12 GBq per tonne of beta/gamma activity when averaged over a consignment. This means that wastes with e.g. slightly higher activity levels but comprising short-lived radionuclides would be assessed as non-compliant with the WAC, whereas assessment of the overall risk that the specific waste poses may find them to be low risk.

If adopted, future UK Inventories could show an increase in waste packages destined for the LLWR and a reduction in waste routed to a GDF.

Packaging Reactor Core Graphite Waste

Reactor core graphite contains a range of radionuclides each posing different radiological risks. Graphite with beta/gamma activity greater than 12 GBq per tonne is managed as ILW despite some of the radionuclides being not readily released from the graphite matrix. The baseline plan for large volumes of activated graphite from Magnox reactor cores is disposal to a GDF. From a risk perspective, some of the safety features offered by disposal to a GDF are not required. Disposal at facilities with a lower level of engineering could be safe and much more cost effective to the taxpayer.

If adopted, future UK inventories could show a reduction in waste routed to a GDF and with more waste routed to new types of disposal facilities.

Question 17

Waste Volumes

Accepted Answer

Key facts:

At 1 April 2022 the total reported volume of waste is 137,000 m³.
Future waste arisings volume is estimated to be 4,450,000 m³.
Over 94% of the total waste volume is of low activity (LLW and VLLW).
About 73% of the total waste volume is at Sellafield.

Radioactive waste quantities are reported by waste producers as:

Stocks - waste at 1 April 2022 comprises radioactive materials that had been declared as waste and were being held at this date
Future waste arisings - estimates of waste that will be generated based on assumptions about the nature, scale and timing of future operations and activities.

Waste quantities in this section are presented in terms of reported volume and mass, packaged volume and the number of packages:

Reported volume	For stocks, the volume that waste occupies in tanks, vaults, silos, drums etc. in which it is contained. Some wastes are being conditioned directly in suitable containers for long-term management as they arise and others have been retrieved from stores and conditioned; for these wastes, the reported volume at 1 April 2022 is also the conditioned volume.[23]. For future arisings, the projected volume in general reflects current waste management practice. For most future arisings the reported volume is that for untreated or partly treated waste. For those waste streams where fresh arisings are being conditioned the reported volume is also the conditioned volume.
Reported mass	The mass of the waste corresponding to the reported volume.
Packaged volume	Packaging is the loading of waste into a container for long-term management. The packaged volume is the total volume taken up by the waste, any immobilising medium and the waste container. It represents a ‘final’ waste volume.
Number of packages	The number of waste containers corresponding to the packaged volume.

Question 18

Summary for all wastes

Accepted Answer

To determine total radioactivity in waste at 1 April 2022, the radioactivities of all relevant waste streams are summed. This is valid, because the radioactivities of waste at 1 April 2022 refer to a particular point in time. For selected future dates, the total radioactivity of accumulated wastes is calculated by taking account of the radioactive decay of each waste stream. The period of decay for wastes that existed at 1 April 2022 is from that date, and for waste generated after 1 April 2022 is from the time that the waste is generated.

The radioactivities given in Table 8 are those for all wastes at 1 April 2022, 2050, 2100 and 2200. The values show that most of the activity is in HLW.

Table 8: Total activity of all wastes

Waste category	Total radioactivity (TBq)
	At 1.4.2022	At 1.4.2050	At 1.4.2100	At 1.4.2200
HLW	82,000,000	45,000,000	14,000,000	1,900,000
ILW	3,800,000	1,900,000	970,000	430,000
LLW	35	170	130	81
VLLW	0.06	4.8	12	14
Total	86,000,000	47,000,000	15,000,000	2,300,000

Although the majority of radioactivity is associated with HLW, this waste category represents a very small volume relative to other categories in the 2022 Inventory. In contrast, very little radioactivity is associated with LLW and VLLW although these waste categories represent most of the waste volume in the 2022 Inventory (see Figure 3). Figure 9 below illustrates this relationship between radioactivity and volume for each waste category.

(!!12)

(!!13)

There are a number of aspects to note:

Total radioactivities of HLW and ILW initially decrease slightly as a result of the reduction in radioactivity from the decay of accumulated arisings being greater than the additional radioactivity in projected future arisings. In contrast total radioactivities of LLW and VLLW increase; this is because stocks at 1 April 2022 are relatively small and projected future arisings over the next 100 years are considerably larger (see Figures 7 and 8)
Once all projected waste has arisen, total radioactivities fall in a manner that reflects the decay of the major radionuclide species. No HLW is projected to arise after 2031 and there are no further arisings of ILW, LLW and VLLW beyond 2136. By this time, the final stage decommissioning of existing power reactors, the dismantling of all other nuclear plants and site clean-up activities are forecast to be complete
The total radioactivities of HLW and ILW exhibit decreases of many orders of magnitude over time as radionuclide components with shorter half-lives decay
LLW shows a markedly smaller decrease in radioactivity over time from its peak level than either HLW or ILW. This is because a relatively high proportion of the radioactivity at the time of generation is from uranium, which has a very long half-life
There is an initial rise in the radioactivity of VLLW because large quantities of waste are generated over the next 100 years. Thereafter the radioactivity of VLLW is dominated by uranium and its daughter products.

Question 19

Volumes by region

Accepted Answer

Figure 5 illustrates the relative contributions of radioactive waste in England, Scotland and Wales to the total reported volume in the UK. There are currently no nuclear licensed sites in Northern Ireland; only very small quantities of radioactive waste are produced there from hospitals and industry. These wastes can be incinerated or disposed of in landfill and are not within the scope of the 2022 Inventory.[25]

(!!8)

In terms of reported volume, approximately 91.3% of all radioactive wastes in the UK at 1 April 2022 and in estimated future arisings up to 2136 are located in England, 5.8% in Scotland and 2.8% in Wales.

For England radioactive waste production is dominated by Sellafield. For Scotland most waste is from Dounreay and the legacy Magnox power station sites at Chapelcross and Hunterston. For Wales nearly all waste is from the legacy Magnox power station sites at Trawsfynydd and Wylfa.

The 2022 UK Radioactive Waste Detailed Data report gives further information on waste volumes for England, Scotland and Wales, including volumes at 1 April 2022 and in projected future arisings, and for each waste category.

Question 20

Volumes by waste category

Accepted Answer

Tables 4-7 give the reported waste volumes and corresponding masses at 1 April 2022, and the volumes already packaged at 1 April 2022 with corresponding numbers of packages for each waste category. The tables also give figures for future radioactive waste arisings that are projections made by the organisations operating the sites. These projections are based on assumptions about the nature, scale and timing of future operations and activities at their sites (see section 7). The 2022 Inventory includes forecast radioactive wastes from future operations and activities up to 2136.

High Level Waste

At 1 April 2022 the reported volume of HLW at Sellafield was about 1,990 m³.

HLW is being safely stored at Sellafield pending the availability of a disposal route for this waste category. The quantity of packaged HLW being stored is increasing as waste, which is initially managed in a liquid form known as Highly Active Liquor (HAL), undergoes an evaporation process before vitrification into glass blocks within stainless steel canisters. At 1 April 2022 there were 6,191 packages of conditioned HLW in long-term storage.

Table 4: HLW at 1 April 2022 and estimated future arisings

Reported volumes, masses, packaged volumes and package numbers

		Reported volume (m³) (See note 1)	Reported mass (tonnes) (See note 1)	Packaged volume (m³)	No of packages
Stocks at 1.4.2022	Not yet packaged	1,060	1,300	-	-
Stocks at 1.4.2022	Already packaged	929	2,500	1,210	6,191
Future arisings		See note 2	See note 2	See note 2	See note 2
Total		1,670	3,500	1,470	7,520

Note 1: Volume and mass “not yet packaged” are for HAL; volume and mass “already packaged” are the conditioned volume and corresponding mass for waste that has been encapsulated in glass.

Note 2: From 1 April 2022 there will be a net decrease in the reported volume and mass of HLW. This is because accumulated HAL is being conditioned, which reduces its volume and mass by about two-thirds. It is also because vitrified HLW is being exported to overseas customers.

Reported volumes of HLW will fall in the future. There are two reasons for this. Firstly, and most significantly, due to evaporation and vitrification (the vitrified glass blocks are roughly one-third of the volume of the original HAL). Secondly future arisings of HLW are net of exports to overseas reprocessing customers (see section 14 for more information).

Further vitrified wastes will arise during the subsequent Post Operational Clean Out (POCO) phase which is expected to continue until 2032. Total HLW generated is forecast to be 7,520 waste packages (1,470 m³ packaged volume).

Intermediate Level Waste

At 1 April 2022 the reported volume of ILW was about 102,000 m³, of which about 76,300 m³ (75%) was at Sellafield. Most of the other ILW was at the Magnox and AGR power stations (10,700 m³ and 3,570 m³ respectively), Dounreay (4,840 m³), Aldermaston (4,590 m³) and Harwell (895 m³).

ILW is also being safely stored pending the availability of a disposal route for this waste category.[26] At 1 April 2022 there were 69,894 packages of ILW in long-term storage facilities. Of these 60,980 (87%) were at Sellafield.

Table 5: ILW at 1 April 2022 and estimated future arisings

Reported volumes, masses, packaged volumes and package numbers

		Reported volume (m³) (See note 1)	Reported mass (tonnes) (See note 1)	Packaged volume (m³)	No of packages
Stocks at 1.4.2022	Not yet packaged (See note 2)	65,400	61,000	-	-
Stocks at 1.4.2022	Already packaged)	36,400	68,000	48,000	69,894 (See note 3)
Future arisings		148,000	180,000	321,000	136,000
Total (See note 4)		249,000	310,000	496,000	282,000

Note 1: Volume and mass “not yet packaged” are for untreated or partly treated waste. Volume and mass “already packaged” are the conditioned volume and corresponding mass e.g. conditioned in a cement-based material.

Note 2: ILW “not yet packaged” includes 1,440 m³ reported volume that is expected to be disposed of as LLW.

Note 3: ILW package numbers include 1,938 1803-type mild steel drums. These drums are expected to be overpacked in larger capacity boxes (6 drums per box).

Note 4: ILW includes 12,600 m³ of waste that is expected to become LLW as a result of decontamination or decay storage. This comprises 1,440 m³ at 1.4.2022 and 11,200 m³ for future arisings.

The reported volume for forecast future arisings of ILW is about 148,000 m³. About 71,600 m³ (49%) is from Sellafield. Most of the other ILW is from Magnox power station sites (42,500 m³) and AGR power station sites (20,200 m³).

About 117,000 m³ (79%) of all forecast future arisings are from decommissioning of existing reactors and other facilities. The remainder are from ongoing plant operations.

(!!9)

Figure 6 illustrates the pattern of future ILW arising volumes. Forecast annual arisings of ILW average about 1,680 m³ in the period up to about 2045. The arisings are largely from legacy waste conditioning and facilities decommissioning at Sellafield. From 2045 to 2070 the annual arisings are largely from decommissioning at Sellafield. Final dismantling and site clearance at Magnox and AGR stations between 2070 and 2123 gives rise to higher but changeable annual volumes over this period.

Low Level Waste

At 1 April 2022 the reported volume of LLW was about 32,100 m³, of which about 20,500 m³ (64%) was at Dounreay. Most of the other LLW was at Sellafield (3,350 m³), Magnox stations (2,010 m³) and Aldermaston (1,330 m³). Most LLW at 1 April 2022 was in temporary storage awaiting recycling if suitable, or disposal to landfill or the LLWR.

Table 6: LLW at 1 April 2022 and estimated future arisings

Reported volumes, masses, packaged volumes and package numbers

		Reported volume (m³) (See note 1)	Reported mass (tonnes) (See note 1)	Packaged volume (m³)	No of packages
Stocks at 1.4.2022	Not yet packaged (See note 2)	25,800	30,000	-	-
Stocks at 1.4.2022	Already packaged	6,280	12,000	7,600	1,260
Future arisings (See note 3)		1,550,000	1,900,000	1,320,000	18,900
Total		1,580,000	2,000,000	1,340,000	19,900

Note 1: Volume and mass “not yet packaged” are for untreated or partly treated waste. Volume and mass “already packaged” are the conditioned volume and corresponding mass e.g. conditioned in a cement-based material.

Note 2: “Not yet packaged” includes 1,230 m³ reported volume of mixed LLW/VLLW at Springfields.

Note 3: LLW includes 323,000 m³ reported volume of mixed LLW/VLLW at Springfields.

The forecast future arisings of LLW are about 1,550,000 m³ including about 323,000 m³ of mixed LLW/VLLW from Springfields that can be routed to landfill.

About 464,000 m³ (30%) of all forecast future LLW arisings are from Magnox power station sites (excluding Calder Hall). Much of the other LLW is from Sellafield (464,000 m³ - including 35,100 m³ from Calder Hall), Springfields (323,000 m³), AGR power stations (108,000 m³), and Dounreay (86,500 m³).

Approximately 1,310,000 m³ (85%) of all forecast future arisings of LLW are from the decommissioning of reactors and other facilities, and from site remediation. Only 236,000 m³ (15%) are from plant operations; about 86,200 m³ of which is from Sellafield.

Final stage decommissioning of reactors and ancillary plants at Magnox and AGR power stations is forecast to produce 477,000 m³ and 61,000 m³ of LLW. Decommissioning of uranium processing and fabrication facilities at Springfields is forecast to produce 224,000 m³ of LLW. Decommissioning of facilities at Sellafield is forecast to produce about 343,000 m³ of LLW.

(!!10)

Figure 7 illustrates the pattern of future LLW arisings volumes. Forecast annual arisings decrease from about 31,000 m³ to about 12,000 m³ over the period up to 2039. The decrease is the result of a number of factors including:

The completion of Magnox and oxide fuel reprocessing operations at Sellafield
The completion of C&M preparations at Magnox stations
The closure of AGR power stations
Defuelling and C&M preparations at AGR power stations
Lower volumes of general waste at Springfields
The completion of decommissioning activities at Winfrith.

From 2040 up to 2049, forecast annual arisings are higher as a result of the decommissioning of uranium processing and fabrication facilities at Springfields. From 2050 up to about 2073, average annual arisings are lower at about 5,300 m³. Much of this waste is from facilities decommissioning at Sellafield. Final dismantling and site clearance at Magnox and AGR stations between 2070 and 2123 give rise to higher but changeable annual volumes over this period.

Very Low Level Waste

At 1 April 2022 the reported volume of VLLW was about 1,490 m³. 1,030 m³ of this was at Harwell and 261 m³ was at Hinkley Point A. All VLLW was in temporary storage awaiting treatment or disposal.

Table 7: VLLW at 1 April 2022 and estimated future arisings

Reported volumes, masses, packaged volumes and package numbers

		Reported volume (m³) (See note 1)	Reported mass (tonnes) (See note 1)	Packaged volume (m³)	No of packages (See note 2)
Stocks at 1.4.2022	Not yet packaged	1,490	1,300	-	-
Stocks at 1.4.2022	Already packaged	0	0	0	-
Future arisings		2,750,000	2,800,000	2,610,000	-
Total		2,750,000	2,800,000	2,610,000	-

Note 1: Volume and mass “not yet packaged” are for untreated or partly treated waste.

Note 2: As VLLW can be disposed to appropriately permitted landfill sites, no package numbers are collated for this waste category in the inventory.

Figure 8 illustrates the pattern of future VLLW arising volumes. The forecast future arisings of VLLW are about 2,750,000 m³. About 2,680,000 m³ (97%) of this volume is attributable to waste from the decommissioning of reprocessing and associated plants, waste storage and treatment plants, and site service facilities at Sellafield. However, there is a large uncertainty about how much of this will be managed as radioactive waste; current expectations are that about 70% of the material, which comprises concrete, brick and metal from building structures, may be out of scope of regulatory control. As decommissioning projects at the site are progressed and opportunities for further characterisation arise, the projected amounts of radioactive waste will continue to be refined. Forecast annual arisings of VLLW are on average about 10,200 m³ in the period up to 2049. Thereafter they increase due to planned decommissioning projects at Sellafield.

(!!11)

Question 21

Radioactivity in Wastes

Accepted Answer

Key facts:

Radioactivity in LLW and VLLW is significantly lower than that in HLW and ILW.
Total radioactivity at 1 April 2022 (86 million TBq) is mainly in HLW.
Total radioactivity reduces over time - by 2200 total radioactivity will be more than 36 times lower, in 1,000 years it will be 400 times lower and in 100,000 years it will be more nearly 5,600 times lower.

Information on radioactivity is important for managing the safe handling, storage, transport and disposal of radioactive wastes.

Waste producers report the radioactivity concentration of waste in stocks at the inventory reference date of 1 April 2022 or, for future waste arisings, this is reported at the time that the waste will be generated. Activities (in TBq) given in this section have been derived from reported radioactivity concentrations (in TBq/m³) and volumes (in m³) for each waste stream.[27]

The radioactivity of waste reduces over time as it undergoes radioactive decay. This means that the total radioactivity of all wastes in the 2022 Inventory will change as new wastes arise and existing wastes decay. Hence, we can only determine the total radioactivity of wastes by selecting reference points in time and calculating the radioactivity at those dates.

Total radioactivity is made up of the sum of the radioactivities of radionuclides (or radioisotopes) present in the wastes. The waste origin determines the types of radionuclide present (called a ‘fingerprint’). Information on 114 radionuclides relevant to understanding the safety performance of disposal facilities is collected.

In the 2022 Inventory there are about 80 waste streams where radioactivity concentration is not quantified because characterisation work has yet to be completed. These streams have been reviewed, and the overall impact on total radioactivity and individual radionuclide activity estimates will be small. This is because these streams have relatively low volumes and/or are expected to have relatively low radioactivity.

Because radioactivities in wastes can cover a wide range, it is sometimes necessary to use scientific notation in tables of data. For example, 16,000 TBq is expressed as 1.6E+04 TBq and 0.00016 TBq is expressed as 1.6E-04 TBq.

Summed waste stream radioactivities reported in this section are rounded to two significant figures.

Information on the radionuclide composition for each waste category and how this composition changes over time as a result of radioactive decay can be found in the 2022 UK Radioactive Waste Detailed Data report.

Question 22

Radioactivity at 1 April 2022

Accepted Answer

The total radioactivity of all wastes at 1 April 2022 was about 86,000,000 TBq. Figure 11 shows the relative contributions of HLW, ILW, LLW and VLLW to this total.

Most of the radioactivity was contained in HLW. The total radioactivity in ILW was lower, while the radioactivity contents of LLW and VLLW were comparatively very small. HLW is produced from spent fuel reprocessing at Sellafield.

(!!14)

Figure 12 illustrates the origin of radioactivity in ILW at 1 April 2022. The major contributor to ILW is from spent fuel reprocessing at Sellafield, where radioactivity is present in fuel cladding and process wastes. The AGR and PWR power stations are the other major source of radioactivity. Most of this radioactivity is generated as activation products in fuel element and reactor core components that have been subjected to neutron irradiation.

(!!15)

Most LLW is held in storage on the site of arising for a short period before being consigned to disposal, recycling, or management through metal treatment or incineration routes. VLLW is similarly managed.

Question 23

Waste Composition

Accepted Answer

Key facts:

Radioactive wastes arise in a variety of chemical and physical forms.
HLW is processed into a glass waste form.
ILW comprises a number of different forms, with graphite and PCM making up ~42% by volume.
LLW is ~76% by volume miscellaneous contaminated materials and concrete & rubble.
VLLW comprises almost 90% by volume of concrete & rubble.
The total mass of all wastes at 1 April 2022 and for future arisings is 5,100,000 tonnes.

In the UK, materials with radioactive properties are used for a wide range of purposes, including nuclear power generation and a variety of medical, industrial and research activities. The radioactive wastes that are produced from these activities take many different forms and have varying physical, chemical and radiological properties. Waste can range from large solid items that are relatively inert to chemically reactive sludges and liquids.

These different forms of waste may need separate management arrangements. This could include particular conditioning and packaging solutions appropriate for their properties. The different forms of waste are assigned to 24 individual waste groups. The assignment is done to facilitate an explanation of the different forms that are generated and how these forms are to be processed and stored. The 2022 UK Radioactive Waste Detailed Data report provides a list of the waste groups.

Subsections 10.1-10.3 below describe the composition of ILW, LLW and VLLW in terms of the volumes of these waste groups. HLW has its own single waste group because it is all vitrified, meaning that it is processed into a glass waste form.

Section 10.4 gives a separate breakdown of the wastes in terms of their component material masses (metal, organic and inorganic species).

The mass of conditioned HLW at 1 April 2022 was 2,500 tonnes. A further 1,300 tonnes of liquid waste remained to be conditioned. Once all waste at 1 April 2022 and projected future arisings of liquid waste and contaminated scrap items are conditioned the total mass will be about 3,500 tonnes. This mass does not include HLW that will be exported.

Question 24

Intermediate Level Waste

Accepted Answer

Figure 13 illustrates the waste groups that make up the total reported volume of ILW.

(!!16)

The two largest waste groups – graphite and Plutonium Contaminated Material (PCM) – account for over 41% of the total ILW reported volume. Most graphite is associated with Magnox and AGR cores and will arise during final stage decommissioning of the reactors. PCM is mainly from spent fuel reprocessing and future facilities decommissioning at Sellafield as well as plutonium plant decommissioning at Aldermaston.

Two other waste groups – conditioned and contaminated metals - each contribute more than 10% of the total ILW reported volume. Conditioned includes all conditioned wastes in the inventory, most comprising waste in a cement-based matrix. The majority (77%) of conditioned waste is at Sellafield, including fuel cladding (Magnox, AGR and Light Water Reactor (LWR)), PCM and Enhanced Actinide Removal Plant (EARP) flocculant. The majority of contaminated metals arise from plant decommissioning at Sellafield.

Question 25

Low Level Waste

Accepted Answer

Figure 14 illustrates the waste groups that make up the total reported volume of LLW.

(!!17)

Two waste groups - miscellaneous contaminated materials and concrete & rubble – account for about 76% of the total LLW reported volume. Miscellaneous contaminated materials are mainly from routine operations, demolition and excavation projects at Sellafield and the decommissioning of uranium processing and fabrication facilities at Springfields. Concrete and rubble arise mostly from the decommissioning of Magnox reactors, while most contaminated metals are from decommissioning and arise across the inventory.

Question 26

Very Low Level Waste

Accepted Answer

Figure 15 illustrates the waste groups that make up the total reported volume of VLLW.

(!!18)

Almost 90% of VLLW is comprised of concrete & rubble, with smaller quantities of contaminated metals, miscellaneous contaminated materials and soil. Most VLLW is from the decommissioning of reprocessing and associated plants, waste storage and treatment plants, and site service facilities at Sellafield. Sellafield’s best estimate, albeit based on limited decommissioning experience, is that about 70% of this waste may be exempt from regulatory control.

Question 27

Waste component masses

Accepted Answer

Table 9 gives the total masses of material components in HLW, ILW, LLW and VLLW. This includes wastes at 1 April 2022 that had already been conditioned as well as future arisings that are reported as conditioned waste.

Table 9: Mass of materials by waste category

Material	Mass (tonnes)
	HLW	ILW	LLW	VLLW
Metals:
Stainless steel	6.3	31,000	160,000	22
Other steel	-	64,000	370,000	1,100
Iron	-	3,200	42,000	3,700
Magnox/magnesium	-	5,900	210	0.11
Aluminium	-	2,200	22,000	11
Zircaloy/zirconium	-	1,300	10	0.11
Copper & alloys	-	590	15,000	250
Nickel & alloys	69	89	1,100	-
Uranium	-	920	830	30
Other metals	-	1,800	47,000	140,000
Organics
Cellulosics	-	1.300	77,000	40,000
Plastics	-	4,700	100,000	310
Rubbers	-	1,200	19,000	50
Ion exchange resins	-	790	1,300	0
Hydrocarbons	-	74	5,800	800
Other organics	-	370	34,000	17,000
Inorganics:
Asbestos	-	120	25,000	27,000
Cementitious materials	-	66,000	800,000	2,000,000
Graphite	-	82,000	15,000	-
Sand, glass & ceramics	2,600	1,300	21,000	150
Ion exchange materials	-	3,200	16	-
Brick, stone & rubble	-	1,000	93,000	420,000
Sludges, flocculants & liquids	800	29,000	13,000	9.1
Other inorganics	-	890	340	26,000
Soil	-	27	100,000	120,000
Unspecified materials (See note 1)	-	9,600	12,000	210
Total	3,500	310,000	2,000,000	2,800,000

Note 1: Includes wastes for which no material breakdown or only a partial breakdown is reported.

The breakdown includes only the major contributors to radioactive waste mass; there are many other minor components present in the wastes. For waste streams where characterisation data are uncertain, waste producers may have reported no material composition or only a partial composition. The unspecified materials mass is shown in the table.

Question 28

Uncertainty in the Inventory

Accepted Answer

Key facts:

The greatest uncertainties are in radioactivities on the upper side of current best estimate values.
Currently a small number of waste streams make a large contribution to uncertainty in volumes and radioactivities. These can be targeted as priorities for data improvement.
Uncertainties will reduce in the future as decommissioning experience feeds into improved inventory estimates and waste is packaged for long-term management. Effective characterisation will drive lower uncertainties of radioactivity levels.
The size of nuclear new build will impact on future inventories.

There are a number of reasons why there is uncertainty in UK Inventory data:

Much waste is in situ (e.g. activated reactor structures) and hasn’t been fully characterised
Waste producers’ plans for their future activities, including plant operating lifetimes, can change
Waste management strategy can change
New waste treatment solutions and packaging technologies may be developed.

There is the highest level of confidence in the volumes, material composition and activity of waste streams that have already been packaged for long-term management because they have been well characterised. The greatest uncertainties rest with future arisings of waste. This uncertainty is particularly from facilities decommissioning and site clean-up where past operational experience is less relevant and future strategies may not yet be confirmed. As decommissioning projects progress through initial scoping studies, detailed planning and then implementation, and as land contamination surveys are extended and refined, waste volumes can be estimated with greater certainty.

Legacy waste streams generated many years ago may lack detailed contemporary records. As these waste streams are retrieved from storage and characterised, the uncertainties on the amounts and compositions are greatly reduced.

Consequently, waste estimates can change from one inventory to the next (section 13 provides a comparison of the 2022 Inventory with the previous 2019 Inventory). Furthermore, the NDA maintains an inventory Data Improvement Plan for each waste producer to support a programme of continual UK Inventory improvement.

Question 29

Volumes

Accepted Answer

The 2022 Inventory includes information on the confidence levels in reported waste stream volumes. Where lower and upper uncertainties on the reported best estimate volumes can be quantified, waste producers have provided appropriate factors. These data have been used to calculate lower and upper waste volume estimates for each waste category (see Table 10).

Table 10: Estimated uncertainties in reported volumes for each waste category (See note 1)

Waste category	Best estimate (m³)	Lower estimate (m³)	Upper estimate (m³)
HLW	1,670	1,580	1,730
ILW	249,000	195,000	382,000
LLW	1,580,000	1,070,000	2,600,000
VLLW	2,750,000	996,000	3,980,000
Total	4,580,000	2,260,000	6,960,000

Note 1: The 2022 Inventory includes numerical lower and upper volume uncertainty factors on the best estimate volumes for waste streams covering more than 99% of the total reported waste volume.

The uncertainties in the HLW volume are relatively small, as spent fuel reprocessing ended in July 2022 and the HAL vitrification process are well defined.

For ILW, the calculated lower volume estimate is 54,500 m³ (22%) less than the best estimate volume. The calculated upper volume estimate is 132,000 m³ (53%) more than the best estimate volume.

A large percentage of the uncertainties in the ILW volume can be attributed to a small number of waste streams. The major contributors are shown in Figure 16. (A list of waste streams is given in the 2022 UK Radioactive Waste Detailed Data report). They comprise:

Operational PCM arisings and plant decommissioning wastes at Sellafield (2D streams)
Operational PCM arisings and plutonium plant decommissioning waste at AWE Aldermaston (7A streams).

Volume uncertainties for the major contributing streams are higher on the upper side.

Figure 16: Waste stream percentage contribution to the change in reported best estimate volume associated with lower and upper volume uncertainty for ILW

(!!19)

For LLW, the calculated lower volume estimate is 516,000 m³ (33%) less than the best estimate volume. The calculated upper volume estimate is 1,020,000 m³ (65%) more than the best estimate volume.

A large percentage of the uncertainties in the LLW volume can be attributed to a small number of waste streams. The major contributors are shown in Figure 17. They include:

Plant decommissioning wastes and miscellaneous wastes contaminated by aerial discharges at Sellafield (2D and 2X streams)
General waste for Clifton Marsh and Decommissioning waste at Springfields (2E)
Radioactive contaminated land at AWE Aldermaston (7A)
Concrete decommissioning waste at Calder Hall (2A).

Volume uncertainties for the major contributing streams are higher on the upper side.

Figure 17: Waste stream percentage contribution to the change in reported best estimate volume associated with lower and upper volume uncertainty for LLW

(!!20)

Most VLLW reported in the Inventory is generated from future decommissioning projects at Sellafield. The best estimate of Sellafield VLLW volume is 2,750,000 m³, but there is a large uncertainty in the potential arisings. Improved inventory assessments have refined the likely lower and upper bounds to be 1,000,000 m³ and 4,000,000 m³. Also, Sellafield has stated its current best estimate volume, based on limited decommissioning experience, is that approximately 70% of the waste may be exempt from regulatory control.

Strategies for site end states can differ; hence some sites might generate much more VLLW from land remediation work than others.

Radioactive land contamination and radioactively contaminated subsurface structures at certain sites have not been included in the Radioactive Waste Inventory where clean-up plans have not been confirmed and there is significant uncertainty over the management route and waste quantities. Volume estimates can be found in the 2022 UK Material Inventory report. As land contamination surveys are extended and refined, and there is more certainty on management routes, waste volumes can be determined with increasing confidence.

Question 30

Radioactivities

Accepted Answer

Table 21 gives the changes in total radioactivities at 1 April 2200 compared with the 2019 Inventory.

Table 21: Changes in radioactivity between the 2022 and 2019 Inventories

Waste category	Best estimate (m³)	Lower estimate (m³)	Upper estimate (m³)
HLW	1,670	1,580	1,730
ILW	249,000	195,000	382,000
LLW	1,580,000	1,070,000	2,600,000
VLLW	2,750,000	996,000	3,980,000
Total	4,580,000	2,260,000	6,960,000

The principal reasons for changes are:

For HLW, activity data have been recalculated using a new improved tool and updated nuclear libraries
For ILW and LLW, the decrease in radioactivities is largely the result of a reassessment of specific activities.

Question 31

Waste Disposals

Accepted Answer

Key facts:

Annual disposals are at historical lows at the LLWR with other disposal routes such as disposal to landfill continuing to be utilised.
Disposals are being made to the Dounreay LLW facility from decommissioning at the site.

The UK Inventory compiles data on waste producers’ waste disposal plans. Disposal routes for HLW, ILW, LLW and VLLW in the 2022 Inventory are illustrated in Figure 20. All HLW and nearly all ILW will be disposed to a GDF. Small fractions of ILW are to be managed using NWS’s waste services framework for metal treatment, incineration or disposal at the LLWR where it is appropriate to do so. A small proportion of ILW is declared as being routed to landfill, this ILW is all subject to decay and segregation from higher activity waste to appropriate levels.

Figure 20: Projected disposal routes for radioactive wastes in the 2022 Inventory
(% of reported volumes)

(!!23)

There is greater certainty in how lower activity wastes (LAW) will be managed in the near term.

Figure 21 shows the disposal routes for LLW forecast to arise over the next six years (2022-2027 inclusive). Only about 8% of the reported volume is expected to be disposed of at the LLWR. All other LLW is expected to be disposed of at the Dounreay LLW facility or alternative disposal and treatment routes such as appropriately permitted landfill sites, or metal treatment or incineration. Almost all VLLW in this period is expected to be disposed of at appropriately permitted landfill sites or sent for metal treatment.

A small volume of ILW (1,630 m³) forecast to arise over the next six years is expected to be managed as LAW. The majority of this waste (1,190 m³) is expected to be suitable for disposal at the LLWR.

(!!24)

Table 12 provides an analysis of projected disposal routes for LLW and VLLW in the 2022 inventory, comprising stocks at 1 April 2022 and all forecast future arisings. The arisings are projected far into the future and so have higher uncertainties associated with them than the nearer term arisings. The table shows that about half of all LLW by volume is expected to be disposed of at off-site landfill facilities, with less than 10% expected to be disposed of at the LLWR.

The 2022 Inventory data show that increasing amounts of LLW are expected to be managed through landfill disposal, on-site disposal, metal treatment or incineration compared with previous inventories.

Most VLLW is consigned for disposal at suitably authorised and permitted landfill sites. Smaller amounts are disposed at on-site landfill facilities or sent for metal treatment or incineration.

Table 12: Projected routing of LLW and VLLW - wastes at 1 April 2022 and estimated for future arisings

Expected waste route	LLW		VLLW
	Reported volume (m³)	Reported volume (%)	Reported volume (m³)	Reported volume (%)
LLWR	150,000	9.5	0	0
Off-site landfill facilities	780,000 (See note 1)	49.3	2,560,000	93.3
On-site disposal facilities (See note 2)	160,000	10.1	47,600	1.7
Dounreay LLW facility	105,000	6.6	0	0
Metal treatment	207,000	13.1	137,000	5.0
Incineration	91,800	5.8	606	0.02
Recycled / reused	11,200 (See note 3)	0.7	12.0	0.0004
Out-of-scope (See note 4)	63,700 (See note 5)	4.0	107	0.004
Unconfirmed	14,000	0.9	0	0
Total	1,580,000	100	2,750,000	100

Note 1: About 310,000 m³ is concrete from final stage decommissioning of Magnox site reactors and 312,000 m³ of mixed LLW/VLLW from Springfields.

Note 2: Comprises the Calder Landfill Extension Segregated Area (CLESA) facility at Sellafield.

Note 3: Includes 11,200 m³ of mixed LLW/VLLW at Springfields.

Note 4: Following treatment or characterisation, waste is expected to contain activity below regulatory levels.

Note 5: Includes 56,900 m³ from miscellaneous wastes contaminated by aerial discharges at Sellafield.

Consignments to the LLWR over the past thirteen years have totalled about 42,600 m³ (see Table 13). Annual consignment volumes have reduced, driven primarily by application of the waste hierarchy, and by use of alternative treatment and disposal routes.

Table 13: Consignments to the LLWR 2009 to present

Year (See note 1)	Total volume (m³) (See note 2)	Year (1)	Total volume (m³) (See note 2)
2009	6,190	2016	3,350
2010	5,700	2017	1,810
2011	6,070	2018	1,720
2012	5,000	2019	693
2013	4,170	2020	436
2014	3,650	2021	533
2015	3,320

Note 1: For period 1 April to 31 March.

Note 2: Volume is for waste and its primary containment and represents volumes of waste received with the intent for disposal.

Consignments to the Dounreay LLW facility started in 2015. Total disposals to date are given in Table 14.

Table 14: Consignments to Dounreay LLW facility 2015 to present

Year (See note 1)	Total volume (m³) (See note 2)
2015	2,050
2016	1,900
2017	643
2018	0
2019	375
2020	195
2021	0
2022 (See note 3)	0

Note 1: For period 1 January to 31 December.

Note 2: Volume is for packaged waste.

Note 3: Up to 31 March 2022.

Table 15 gives a projection of total waste consignments to the LLWR and Dounreay disposal vaults over the next few years. The values are packaged volumes for waste streams that are identified in the 2022 Inventory as expected to be consigned to the LLWR or for disposal at Dounreay.

Table 15: Projected future consignments to disposal facilities

Year (See note 1)	Total packaged volume (m³) (See note 2)
	LLWR	Dounreay LLW facility (See note 3)
2022	2,440	2,550
2023	2,600	1,970
2024	2,540	1,540

Note 1: For period 1 April to 31 March.

Note 2: Volume is the packaged volume and reflects the effect of both waste compaction and containerisation.

Note 3: Provisional volumes.

Question 32

Comparison with the 2019 Inventory

Accepted Answer

Key facts:

A number of waste streams show changes in volume as inventories have been updated.
Package numbers in stock have increased as progress continues in conditioning HLW and ILW for long-term management.

This section summarises the changes in the 2022 Inventory compared with the previous 2019 Inventory.

Information about radioactive wastes may change from one inventory to the next due to a range of technical, commercial or policy reasons:

Understanding of the waste streams has improved. Some radioactive waste streams generated many years ago lack detailed contemporary records. As these waste streams (often referred to as legacy wastes) are characterised a better understanding of amounts and compositions are gained.
The waste stream category has changed. Opportunities may arise to optimise the waste lifecycle where waste streams are close to the boundary between categories. For example, decay storage or decontamination of ILW to LLW or of LLW to VLLW.
The strategy for managing wastes has been updated. This may be due to more sustainable and cost-effective techniques being used such as new treatment, packaging and disposal options.
Operational activities have affected the amount of waste. Volumes of waste recorded may change as waste continues to be generated, treated, conditioned and packaged.
Forecasts of future amounts have been updated. Waste arisings are projected over many decades. Because of this, there will be inevitable changes in future estimates and updated assumptions underpinning the forecasts and plant operating lifetimes.

As part of the continuing process of UK Inventory development and improvement, the inventory data fields were reviewed by the data providers and key inventory data users. A number of additional data fields were included in the 2022 Inventory covering information on:

The carbon-14 bearing materials within waste streams
The option for specification of individual density by treatment/disposal route
Whether the waste packages are currently exportable
Landfill Directive waste classification codes for hazardous and non-hazardous waste.

Question 33

Reported volumes

Accepted Answer

Stocks

Table 16 gives the changes in the reported volumes of waste stocks compared with the 2019 Inventory.

Table 16: Changes in stocks reported volume between the 2022 and 2019 Inventories

Waste category	Reported volume (m³)		Change
	2019 Inventory	2022 Inventory	(m³)	(%)
HLW (See note 1)	2,150	1,990	-162	-7.5
ILW	102,000	102,000	-233	-0.2
LLW	27,400	32,100	+4,730	+17.3
VLLW	1,040	1,490	+451	+43.2
Total	133,000	137,000	+4,780	+3.6

Note 1: For HLW the reported volume is for conditioned waste.

The principal reasons for changes are:

For HLW, decreases in liquid waste from fuel reprocessing and an increase in conditioned waste from continuing vitrification
For ILW, the reported volume in stock is effectively unchanged
For LLW, the increase is from LLW at Dounreay and includes uncompacted drums that will be supercompacted before disposal in half-height ISOs (HHISOs) and encapsulated LLW in HHISOs that are in temporary storage awaiting disposal
For VLLW, the increase is from land remediation waste at Harwell.

Total

Table 17 gives the changes in total projected reported volumes compared with the 2019 Inventory.

Table 17: Changes in total reported volume between the 2022 and 2019 Inventories

Waste category	Reported volume (m³)		Change
	2019 Inventory	2022 Inventory	(m³)	(%)
HLW	1,390	1,670	+284	+20.4
ILW	247,000	249,000	+1,970	+0.8
LLW	1,480,000	1,580,000	+106,000	+7.2
VLLW	2,830,000	2,750,000	-82,300	-2.9
Total	4,560,000	4,580,000	+25,900	+0.6

The principal reasons for changes are:

For HLW, revised estimates of arisings from reprocessing operations and transfers to the Waste Vitrification Plant for final vitrification.
For ILW, inclusion of additional waste for the first time in the UK Inventory from decommissioning at Rutherford Appleton Laboratory and operational waste from Hinkley Point C
For LLW, a reassessment of future arisings across the Dounreay site and a re-evaluation of general waste arisings at Springfields intended for disposal to the Clifton Marsh landfill site
For VLLW, revised estimates at Sellafield due to changes in planned future facilities and reassessment of the volumes of excavated soil and putrescible waste based on previous / remaining disposal volumes.

Question 34

Packaged volumes and package numbers

Accepted Answer

Most wastes in stock at 1 April 2022 are in an untreated or partly treated state. However, increasing amounts of legacy wastes are being retrieved from stores and packaged for long-term management. Progress in the packaging of wastes is indicated by the accumulation in the number of waste packages over time, illustrated in Table 18.

Table 18: Numbers of waste packages accumulated (See note 1)

Waste category	Best estimate (m³)	Lower estimate (m³)	Upper estimate (m³)
HLW	1,670	1,580	1,730
ILW	249,000	195,000	382,000
LLW	1,580,000	1,070,000	2,600,000
VLLW	2,750,000	996,000	3,980,000
Total	4,580,000	2,260,000	6,960,000

Note 1: The table gives the numbers of packages accumulated at various Inventory reference dates. As VLLW can be disposed to appropriately permitted landfill sites, no package numbers are collated for this waste category in the inventory.

Note 2: LLW package numbers exclude those in short-term storage before consignment for disposal. Packages at 1.4.2007, 1.4.2010 and 1.4.2013 include those held in vaults at the LLWR and which were not classed as disposed under existing environmental permits. Most of the packages reported at 1.4.2007 were subsequently classed as disposed.

Note 3: At 1.4.2022 HLW packages were at Sellafield, ILW packages were at Sellafield, Dounreay, Harwell, Chapelcross, Berkeley, Bradwell, Oldbury, Trawsfynydd, Wylfa and Hunterston A, and LLW packages were mostly at Dounreay and Winfrith.

Table 19 gives the changes in total projected packaged volumes compared with the 2019 Inventory.

Table 19: Changes in total packaged volume between the 2022 and 2019 Inventories

Waste category	Packaged volume (m³)		Change
	2019 Inventory	2022 Inventory	(m³)	(%)
HLW	1,500	1,470	-28.3	-1.9
ILW	499,000	496,000	-3,140	-0.6
LLW	1,280,000	1,340,000	+65,800	+5.1
VLLW	2,690,000	2,610,000	-78,900	-2.9
Total	4,470,000	4,450,000	-16,300	-0.4

The principal reasons for changes are:

For HLW, there has been an increase in the volume of liquid waste that will be loaded into a HLW canister for waste that has not yet been vitrified (2D02 High Level Liquid Waste)
For ILW, a decrease at Sellafield is due to updated packaging data for a number of waste streams
For LLW, a reassessment of Springfields operational and decommissioning wastes for landfill disposal and the inclusion of waste for the first time in the UK Inventory from Rutherford Appleton Laboratory decommissioning and anticipated Hinkley Point C operations
For VLLW, revised estimates at Sellafield due to changes in planned future facilities and reassessment of the volumes of excavated soil and putrescible waste based on previous/ remaining disposal volumes.

Table 20 gives the changes in the total projected numbers of packages compared with the 2019 Inventory.

Table 20: Changes in total number of packages between the 2022 and 2019 Inventories

Waste category	Number of packages		Change
	2019 Inventory	2022 Inventory	(number)	(%)
HLW	7,660	7,520	-144	-1.9
ILW	292,000	282,000	-9,300	-3.2
LLW	22,300	19,900	-2,390	-10.7
VLLW (See note 1)	-	-	-	-
Total	322,000	310,000	-11,800	-3.7

Note 1: As VLLW can be disposed to appropriately permitted landfill sites, no package numbers are collated for this waste category in the inventory.

For LLW, the decrease in package numbers as opposed to the increase in packaged volume is because more waste is being sent to appropriately permitted landfill sites (the inventory does not compile data on packages numbers disposed to landfill).

Question 35

Wastes from Overseas Materials

Accepted Answer

Key facts:

Waste from reprocessing overseas spent fuel is returned to the country of origin.
About 1,780 canisters of vitrified HLW and smaller quantities of other wastes will be exported.

A proportion of the waste from the Thorp and Magnox reprocessing plants at Sellafield results from reprocessing overseas spent fuel. All reprocessing contracts with overseas customers signed since 1976 include a provision to return packaged wastes or their equivalent (by internationally agreed substitution arrangements) back to the country of origin.

Government policy is that wastes resulting from the reprocessing of overseas spent fuel should be returned to the country of origin. This policy also means that HLW should be returned as soon as practicable after vitrification. The policy allows “waste substitution” arrangements that ensure broad environmental neutrality for the UK. Waste substitution is the process whereby an additional amount of HLW from reprocessing would be returned, which is smaller in volume but equivalent in radiological terms to customers’ ILW and LLW from reprocessing that would otherwise be returned.

Exports of vitrified HLW started in January 2010 and are planned to be completed by around 2025. In total about 1,780 canisters of vitrified HLW (about 267 m³) are planned for export, and this volume assumes that substitution arrangements are implemented.

Future arisings of HLW reported in the inventory are net of exports to overseas reprocessing customers, so that the total volume/ number of containers reported represents only the HLW that is a UK liability.

During the 1990s materials test reactor fuel was reprocessed at Dounreay for customers in Belgium, Germany, the Netherlands and Australia. The contracts and regulatory authorisations required that the radioactive wastes produced be returned to the countries of origin within 25 years of reprocessing. The contracts are backed by inter-governmental letters. A total of 123 containers of cemented waste were returned to Belgium between 2012 and 2014. In 2012 the Scottish and UK governments agreed in principle to allow waste substitution, with such arrangements currently being at various stages of implementation.

[1] Radioactive Substances Act 1993 (as amended), 27 May 1993.

[2] Statutory Instruments 2016 No. 1154. Environmental Permitting (England and Wales) Regulations 2016, 11 December 2016.

[3] Activation can also occur as a result of irradiation of materials with other particles (e.g. protons in the ISIS facility at the Rutherford Appleton Laboratory).

[4] Department for Business, Energy & Industrial Strategy, Digest of United Kingdom Energy Statistics 2022, July 2022.

[5] Hinkley Point B stopped generating in August 2022.

[6] includes Sellafield Ltd, Magnox Ltd, Nuclear Waste Services – Low Level Waste Repository, Dounreay Site Restoration Ltd and Springfields Fuels Ltd

[7] The Waste Framework Directive (2008/98/EC), which is the primary European legislation for the management of waste, establishes the requirement on Member States to apply the waste hierarchy.

[8] Nuclear Decommissioning Authority, Integrated Waste Management Radioactive Waste Strategy, September 2019.

[9] Application of the waste hierarchy is central to the UK-wide strategy for managing LLW from the nuclear industry and a move away from the past focus of managing waste through disposal.

[10] Similarly, improved characterisation is resulting in the recategorisation of some waste from ILW to LLW (e.g. Magnox FED, Magnox reactor fuel skips).

[11] Recovered material can be released back into the scrap metals market for a variety of uses.

[12] Some LLW and VLLW can be disposed of at suitably authorised and permitted landfill sites. There are controls on the amount of radioactive waste that can be disposed at these sites.

[13] Some LLW may require geological disposal.

[14] Between 1959 and 1995 drummed, bagged and loose waste was disposed in a series of seven clay-lined trenches at the LLWR. As a result of compaction, the waste in the trenches occupies a volume of about 500,000 m³. The trenches have been covered by an interim soil cap; a final cap will be constructed over the trenches and vaults as part of site closure engineering.

[15] Vitrification is the process used at Sellafield to convert liquid HLW produced during spent fuel reprocessing into a borosilicate glass.

[16] Department of Business, Energy & Industrial Strategy. ‘Implementing Geological Disposal – Working with Communities. An updated framework for the long-term management of higher activity waste’, December 2018.

[17] Welsh Government, ‘Welsh Government Policy on the Management and Disposal of Higher Activity Radioactive Waste’, 2015.

[18] https://www.workinginpartnership.org.uk/

[19] The Scottish Government, ‘Scotland’s Higher Activity Radioactive Waste Policy 2011’, January 2011.

[20] The UK Government supports the building of new nuclear power stations. A number of organisations are pursuing plans for new nuclear power stations in the UK. It is not yet clear how many reactors and of what design might be constructed. It is for these reasons an estimate of radioactive waste from all potential nuclear new build is not included in the 2022 Inventory.

[21] Radioactive waste producers also maintain their own inventories to support their ongoing site activities.

[22] Adopted for strategic planning purposes and modelling and will be subject to revision in the next lifetime plan.

[23] The conditioned volume is the volume of the waste form (waste plus any immobilising medium) within the waste package.

[24] Springfields generates low activity wastes that have a range of activity concentrations spanning the LLW/VLLW boundary. The wastes are not separated into the two categories as they can be routinely disposed of to the landfill site at Clifton Marsh. The Clifton Marsh landfill site has a permit to accept radioactive wastes up to 200 Bq/g (i.e. comprising VLLW and LLW at lower ends of its activity range).

[25] Some redundant radioactive sources are transferred for storage in the Miscellaneous Beta/Gamma Waste Store (MBGWS) at Sellafield and so are included in the Inventory.

[26] Discrete items of short-lived ILW may be suitable for near-surface disposal after a period of decay storage.

[27] For conditioned waste streams the radioactivity concentration and volume reported are those for the conditioned product

Date	HLW	ILW	LLW (See note 2)	Total
At 1.4.2001	2,281	21,654	23	23,958
At 1.4.2004	3,037	31,557	123	34,717
At 1.4.2007	4,319	40,797	8,527	53,643
At 1.4.2010	5,108	47,662	1,288	54,058
At 1.4.2013	5,626	55,326	2,549	63,501
At 1.4.2016	5,781	60,407	648	66,836
At 1.4.2019	6,101	67,307	1,324	75,694
At 1.4.2022 (See note 3)	6,191	69,894	1,260	77,345

Waste category	Reported volume (m³)	Reported mass (tonnes)	Packaged volume (m³)	Number of packages
HLW (See note 1)	1,670	3,500	1,470	7,520
ILW	249,000	310,000	496,000	282,000
LLW	1,580,000 (See note 2)	2,000,000	1,340,000	19,900 (See note 3)
VLLW	2,750,000 (See note 4)	2,800,000	2,610,000	See Note 5
Total	4,580,000	5,100,000	4,450,000	310,000

Waste type	At 1.4.2022 (TBq)			At 1.4.2200 (TBq)
	Best estimate	Lower estimate	Upper estimate	Best estimate	Lower estimate	Upper estimate
HLW	82,000,000	55,000,000	120,000,000	1,900,000	1,200,000	4,100,000
ILW	3,800,000	1,100,000	21,000,000	430,000	110,000	2,800,000
LLW	35	8.3	250	81	12	710
VLLW	0.06	0.02	0.32	14	0.32	140
Total	86,000,000	56,000,000	140,000,000	2,300,000	1,300,000	6,900,000

Waste category	Total radioactivity at 2200 (TBq)		Change
	2019 Inventory	2022 Inventory	(TBq)	(%)
HLW	1,500,000	1,900,000	+440,000	+30.3
ILW	460,000	430,000	-27,000	-5.9
LLW	89	81	-7.61	-8.6
VLLW	14	14	+0.2	+1.5
Total	1,900,000	2,300,000	+410,000	+21.7

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Preface

Conditions of Publication

Feedback

Introduction

The Inventory

Government departments and agencies

Supply chain organisations

Waste Planners

Researchers and academics

Members of the public

Inventory documents

This report

Sources of Radioactive Waste

Origin of radioactive waste

Radioactive waste from the nuclear power industry

Other sources of radioactive waste

Waste producers

Waste disposal

Categories of Radioactive Waste

Definitions

High level waste

Definition

Characteristics

Volume

Level of radioactivity

Intermediate level waste

Definition

Characteristics

Volume

Level of radioactivity

Low level waste

Definition

Characteristics

Volume

Level of radioactivity

Very low level waste

Definition

Very Low Level Waste comprises:

Characteristics

Volume

Level of radioactivity

Summary of key changes

Key changes

Overview of UK Radioactive Waste Management

Key facts:

Integrated waste management

Lower Activity Waste (LAW) management

Low Level Waste Repository

Dounreay LLW facility

Higher Activity Waste (HAW) management

Scope of the Radioactive Waste Inventory

Radioactive wastes

Table 1: Wastes reported in the Inventory

Overview of the Inventory Process

Develop plan and approach

Confirm data requirements

Develop data collection tools

Compile data and verify

Publish reports and data

Review project

Scenario for Future Waste Arisings

Scenarios

Table 2: List of assumptions used to estimate future waste arisings in the 2022 Inventory

Potential future developments

Waste Volumes

Key facts:

Summary for all wastes

Table 3: Total wastes at 1 April 2022 and estimated for future arisings

Volumes by region

Volumes by waste category

High Level Waste

Table 4: HLW at 1 April 2022 and estimated future arisings

Intermediate Level Waste

Table 5: ILW at 1 April 2022 and estimated future arisings

Low Level Waste

Table 6: LLW at 1 April 2022 and estimated future arisings

Very Low Level Waste

Table 7: VLLW at 1 April 2022 and estimated future arisings

Radioactivity in Wastes