Dry retrieval
During the 1990s, UKAEA carried out a number of studies to develop a plan for the future management of the waste contained in the shaft.
On March 31, 1998, the UK government announced its approval of the selected strategy based on dry retrieval, treatment and on-site storage of the ILW until a national strategy for the long-term management of ILW was developed.
Dry retrieval is based on lowering the water level inside the shaft so that operators can identify individual items to be retrieved.
As the shaft is not lined, however, the volumes of water that would have to be removed were up to 300 cubic metres per day, all of which would need to be treated as ILW.
This would have required a new liquid treatment plant that would have cost approximately £300m to build and operate.
As a result, the control of groundwater into and around the shaft was seen to be essential to the successful implementation of waste retrieval operations.
Following a number of studies and a period of public consultation, grouting of the rock around the shaft was identified as the best groundwater control option. To read the full report, click here
Inside the silo
The waste inside the shaft
Waste inside the silo
