A final report on whether nuclear submarine waste breached annual radiation limits at the Drigg repository in Cumbria will not be available until the summer, the Environment Agency disclosed this week.
The Engineer revealed last month that the wastes from the Devonport naval dockyard might have exceeded Drigg’s annual limit for the isotope Carbon-14 on up to four occasions during the first half of the 1990s (News, 5 March).
DML, the dockyard’s owner, came to this conclusion based on 17 samples taken from one submarine. The Environment Agency (EA) asked DML to carry out a comprehensive study and stopped shipments to Drigg.
An agency spokeswoman said AEA Technology, the independent specialist which is conducting the sampling, would not complete the work until the end of May.
It is then likely to take the EA several weeks to assess the findings before it decides whether shipments from Devonport to Drigg could resume.
DML refused to divulge results of the more detailed investigation to date, but said it was unlikely Drigg’s annual limit was breached on more than one occasion – and then by a factor of 1.6, rather than over four times, as first feared.