The UK Government are investigating the suitability of Newry and surrounding area of Mourne Mountains and Slieve Gullion as a potential venue for the storage of radioactive waste. It's one of four sub-regions in Northern Ireland that have been deemed potentially suitable for a Geological Disposal Facility (GDF).
Thirteen regions in total are under investigation including Northern Ireland, Northern England, Pennines and adjacent areas, Eastern England, Wales, Welsh Borderland, Central England, East Anglia, Bristol and Gloucester, London and the Thames Valley, South West England, Hampshire Basin and Wealden District.

In a Radioactive Waste Management report it explains the potential suitability of the area for Geological Disposal Facility (GDF) "There are granites and similar strong rocks around Newry, in which we may be able to site a GDF. We would need to do more work to find out whether these rocks have suitable properties and thicknesses in the depth range of interest for a GDF.""
The report adds "In the vicinity of Newry (from Slieve Gullion to Slieve Croob), the basement rocks comprise a sequence of granite masses, several kilometres deep, which were emplaced into the Ordovician and Silurian rocks about 400 million years ago. These Newry Igneous Complex rocks range from granodiorite to granite and are potential HSR host rocks."
The report was published 18 December 2018 but only just brought to light by Carlingford Lough campaigning group Love Your Lough. You can view a video and report at www.gov.uk
Explaining the theory behind geological disposal the government publication says "In geological disposal, man-made or engineered barriers work together with the geology to provide long-term safety. Placing radioactive waste deep underground puts it far beyond people’s reach, so that it is safe and secure. The rock will shield people from the radiation and, depending on the rock type, will either limit or completely prevent radioactivity from moving towards the surface when other barriers eventually degrade. Disposal deep underground will also ensure that the waste can never be exposed at the surface even in the event of a change in sea level or future ice ages."
Commenting on the investigations South Down MP Chris Hazzard said “The latest proposal in a video from the British government’s Radioactive Waste Management group that parts of Co Down and Armagh could be used as a site to dispose of nuclear and chemical waste is totally unacceptable.
“Britain cannot use the north as a dumping ground for this hazardous and toxic material.
“Not only would this have dire consequences for our environment but it would also pose a serious health risk to the population."