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.
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.
Reported volumes
Stocks
Table 1 gives the changes in the reported volumes of waste stocks compared with the 2019 Inventory.
| Waste category | Reported volume (m3) Change 2019 Inventory | Reported volume (m3) Change 2022 Inventory | Change (m3) | (%) |
| HLW (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 |
(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 2 gives the changes in total projected reported volumes compared with the 2019 Inventory.
| Waste category | Reported volume (m3) Change 2019 Inventory | Reported volume (m3) Change 2022 Inventory | Change (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.
Packaged volumes and package numbers
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 3.
| Date | HLW | ILW | LLW (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 (3) | 6,191 | 69,894 | 1,260 | 77,345 |
(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.
(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.
(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 4 gives the changes in total projected packaged volumes compared with the 2019 Inventory.
| Waste category | Reported volume (m3) Change 2019 Inventory | Reported volume (m3) Change 2022 Inventory | Change (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, 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 5 gives the changes in the total projected numbers of packages compared with the 2019 Inventory.
| Waste category | Number of packages 2019 Inventory | Number of packages 2022 Inventory | Change (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 (1) | – | – | – | – |
| TOTAL | 322,000 | 310,000 | -11,800 | -3.7 |
(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).
Radioactivities
Table 6 gives the changes in total radioactivities at 1 April 2200 compared with the 2019 Inventory.
| Waste category | Total radioactivity at 2200 (TBq) 2019 Inventory | Total radioactivity at 2200 (TBq) 2022 Inventory | Change (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 |
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.
Why does data change?
Information about waste and material streams may have changed since the last Inventory.
These changes can be due to a range of technical, commercial or policy reasons.
Data in the Inventory may change because:
- Understanding of the waste streams has increased. Some radioactive wastes generated a long time ago lack detailed records, but as these waste streams are characterised, a better understanding is gained. Find out more about how we characterise waste.
- The national strategy for managing radioactive waste materials has been updated. This may be due to more sustainable or cost-effective waste management techniques becoming available, such as new packaging, treatment or disposal options. These can affect the assumptions used when forecasting future waste arisings.
- Operational activities have affected the amount of waste in stock. The quantities of waste or materials recorded may change as waste continues to be generated, treated, conditioned and packaged.
- Baseline scenario assumptions for forecasts have been updated. Given the long period over which arisings are forecast, there are inevitably changes to future estimates, and assumptions about future forecasts and plant operating lifetimes are updated.