Intermediate Level Waste (ILW) forecasts

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.5 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: ILW at 1 April 2022 and estimated future arisings
Reported volumes, masses, packaged volumes and package numbers

At 1.4.2022

Reported volume (m3) (1)

Reported mass (tonnes) (1)

Packaged volume (m3)

No of packages

Not yet packaged (2)

65,400

61,000

Already packaged

36,400

68,000

48,000

69,894(3)

Future arisings

148,000

180,000

321,000

136,000

Total (4)

249,000

310,000

496,000

282,000

(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.

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

(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).

(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.


(5) Discrete items of short-lived ILW may be suitable for near-surface disposal after a period of decay storage.