Euradwaste '08 - EU Bookshop - Europa

Dr Peter Blümling of Nagra in Switzerland imparted some insights from the FUNMIG project, describing
the disturbed and damaged zones around underground openings caused by construction and
thermal loading. ‘Alterations, fractions, stress, redistribution, shear and spalling are problems
common for all rock types,’ he explained, adding, ‘If you go in deep mines you see similar processes.’
The visualisations of Dr Blümling’s presentation certainly provided some food for thought. Tunnelling
causes fracture propagation, heating can increase swelling, and fissures apertures change
with the seasons. This is where the value of ‘plastic’ clays as a host environment comes into play:
the self-sealing and self-healing properties have been well studied and are well-known processes.
The same processes are not apparent in crystalline rock and are more complicated in industrial clay
or shales; the implication was that these are areas where future research efforts might do well to focus.
Dr Tiziana Missana of CIEMAT in Spain spoke about migration of radionuclides in crystalline host
rocks, concluding, ‘Realistic conditions are very important to assess the real role of colloids in radionuclide
transport. This is important for future experiments.’ ‘Studies in realistic, dynamic conditions
are needed,’ she added, noting that evaluation of overlooked processes such as microbiological
aspects is also important.
From basic research to repository engineering
Mr Wolf Seidler of ANDRA in France presented the achievements of the ESDRED project, which
aimed at demonstrating, at an industrial scale, the technical feasibility of developing, manufacturing
and testing equipments and components necessary for the construction, operation and closure of a
deep geological repository, for which there are no industrial equivalents anywhere. He explained
that all the demonstrators had met or exceeded the design specifications. Making a parallel with
Henry Ford’s first industrial car more than one hundred years ago, which paved the way to uninterrupted
improvement in car mass production, he added that ‘technical solutions for the emplacement
of waste packages, the backfilling and the sealing of cells and drifts are now at hand’.
The safety case
An enormous amount of data has clearly come out of FP6 research programmes, in all areas of nuclear
waste management. The big challenge is to put it all together, and to create multiple models
on different scales that can be used to validate conclusions.
To that end, the development of a safety case is one of the main goals of the industry at large. ‘A
safety case is a book,’ explained Dr Jörg Mönig of GRS in Germany. ‘Everyone who starts later
can benefit from previous programmes because of the publication of safety cases. A safety case
uses multiple scales to show that a case is reasonable.’
Speaking from the perspective of performance assessment, Mr Johnson of Nagra said, ‘If you look
at it all, you’ve got a whole lot of information but there is no good way to really put it all together.
Future synthesis studies will be helpful for integrating results. A larger effort to bring the story together,
to explain some of these observations, would be helpful.’
The application of knowledge generated by the FP6 projects in the safety case necessitates digesting
the large amount of data, tools and knowledge generated. Because of the sheer amount of data and
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