United kingdom Nirex limited is a company owned by the nuclear industry and was set up to dispose of intermediate and low level radioactive waste.
These wastes include:
At present most of the waste is currently disposed of at the Drigg site in Cumbria operated by British Nuclear Fuels.
Nirex has been investigating the possibility of building a nuclear repository near the Sellafield site since 1989.
Before a repository could possibly be built, Nirex had to investigate the maximum possible lifetime that the repository could have, and a whole load of other possible life reducing factors. To do this they proposed to build a rock laboratory, plans for which were recently rejected.
The aim of the Rock Lab was to help work out if and how radioactivity could get to the surface. Radioactivity fades with time. So one could assume that intermediate-level waste, surrounded by cement, then placed in a steel drum, would be fairly safe. And if the drums are placed in hard rocks deep under the ground and more cement is poured around them, surely this must be safe not just for now but for thousands of years? Yes one would certainly hope so.
There are tiny amounts of water in most rocks - it is possible these may move some of the radioactivity back to the surface over thousands of years. Gas will be released and this could also be a route back to the surface over many centuries. Therefore it is vital that Nirex has as much information as possible on the rocks at a potntial site. One way of building up a picture is with deep bore holes.
Much of the technical information would be fed into computers which could be used to predict how the repository would operate over many thousands of years.
The rock lab would be built in three phases:
PHASE 1
PHASE 2
PHASE 3
It would be easy to provide a repository system that would be safe for 100, 200 or 300 years - the steel drums containing the radioactive waste alone would see to that. But Nirex's task was much bigger - the repository would have to meet some of the most stringent safety requirements in the world; the target was that the annual risk for an indidvidual from the repository would not exceed one in a million.
To help contain the radioactivity and in preparation for disposal, the waste is packed in stainless steel drums (or boxes), with cement poured almost to the brim. About 3,000 cubic metres has already been packaged and stored at Sellafield and other sites. The waste, in its special packaging, can be kept safely in interim storage for decades if necessary. But to maintain safety over many thousands of years, the waste containers should be placed in rock caverns deep underground. More cement would be poured around the gaps and the repository would then be sealed. So there is not just one but a number of barriers:
Intermediate level waste will be immobilised in cement in stainless steel drums or boxes.
Four drums will be placed in stillage(or frame).
The frames will be stacked in caverns excavated in hard rock.
Cement backfill will be pumped around the stillages.
The purpose of the development was to carry forward the investigations which Nirex began in 1989 into the potentiality of the site as a location for the disposal of intermediate level radioactive waste. The planning application under appeal was not for such a repsoitory. Nirex have made no decision to propose a repository at Sellafield. Their decision whether to propose a repository at this location would depend upon the information they would have extrapolated from the Rock Lab.
Whilst, in Nirex's view, the site holds good promise for a repository, they cannot and do not claim the the Rock Lab (RCF) will produce information which will lead to a decision to propose a repository at Sellafield. They only claim from their present understanding that the site holds sufficient promise to justify further investigations through an RCF.
The main opposition against building an RCF is cost, why spend £195 million on a project that may show Sellafield to be an unsuitable repository site.
But Nirex argue that even though an RCF may show Sellafield to be an unsuitable site, it also may not, there is chance in everything. As well as finding out whether or not Sellafield is a suitable site, Nirex claim that an RCF would vastly increase their knowledge and understanding of long term deep repositories, and if say, Sellafield was an unsuitable site then they could use their new found knowledge to help pick a better site.
Another argument against an RCF is the visual impact , large ugly buildings, drilling gear etc. But Nirex have thought around this by designing cunning disguises for the equipment and by making the buildings less like those found on large industrial estates, and in any case much of it would be underground, so the visual impact would be minimal.
One other concern was the effect an RCF would have on the local wildlife and animal habitats. Again Nirex are certain this effect would be absolutely minimal.
Other concerns include noise level, vibration, air quality, impact on agriculture, soil quality and an increase in traffic on the local roads due to the new RCF.
But the argments for the RCF seem to outshine those against, as the effects on all of the above would almost certainly be minimal, and the building of an RCF would definetly be advantageous, in that it would provide over 140 jobs for local people and if in the future a repository were to be built at Sellafield over 1000 jobs would be created.
But the main advantage of an RCF being built at Sellafield is that it would provide Britain and perhaps in the future other countries (with less knowledge of radioactive waste disposal) key information for the "SAFE" disposal of radioactive waste, not just for the present but for many thousands of years into the future.
The sum of national, regional and local benefits is shown clearly to out weigh any harm or risks to the local and wider environment.
By Nick Topp... References: Nirex homepage: http://www.nirex.co.uk : Nirex BGS Research://www.nirex.co.uk : '97 News Releases://www.nirex.co.uk