Introduction

The international search for suitable sites for deep geological disposal follows well-established geological criteria. This could also be said of the UK up till 2007, when 'voluntarism' became the dominant criterion.

The UK is now out of line with international guidelines and practice. Furthermore, the government misleadingly suggests that voluntarism is the successful approach in other countries. This is not true; elsewhere the geological search invariably precedes the approach to the communities involved.

UK guidelines before 'voluntarism'

In the mid 1980s generic geological environments were developed for use in the UK by Chapman and co-authors, geologists at the British Geological Survey (BGS) and Nirex. These criteria were then applied by BGS, which undertook a national search in the late 1980s.

After the Sellafield public planning inquiry verdict in 1997 a commercial company, Pangea Resources International, was set up to try to find a global solution for high-level waste disposal. The principal shareholder in Pangea was BNFL, which in turn was government-owned. Although the aim of the company was scientifically laudable - to find the best possible site internationally - it was politically inept. Having chosen the desert of West Australia, the company found great opposition from the Australians. Pangea was wound up in 2002 and replaced by a non-commercial association, Arius.

Pangea's requirements for a good site were summarised as follows:

• Stable geology (needed because of the long isolation times aimed at)

• Flat topography (reduces driving forces for advective groundwater flow)

• Near-horizontal sedimentary strata (simpler to explore and extrapolate)

• Stable, arid climate with little erosion (eases problem of extrapolation into the

• Low permeability (reduces groundwater movements in host rocks)

• Old and saline groundwater (indicates slow natural circulation; non-potable)

• Stratified salinity (counteracts thermal buoyancy effects)

• Reducing geochemical conditions (reduces solubilities of radionuclides)

• Absence of complex karst systems (simplifies hydrogeologic modeling)

• Low population density (reduces intrusion risks)

• No significant resource conflicts (reduces intrusion risks)"

As late as 2006 the BGS was saying, specifically about the UK:

[We] "Ideally need:

Physical stability (constructability/operational safety);

Long groundwater return time;

Relatively simple, predictable groundwater flow regimes;

Slow groundwater movement/low hydraulic gradients;

Long term stability;"

- and, furthermore, the BGS was still using the environments as classified by Chapman and co-authors in 1986.

“Fundamental criteria include, for instance, long geological stability, low hydraulic gradients and permeabilities, low geochemical and other potentials, etc. In other words, a geological system is sought out that exhibits in its natural state a low potential for change and very slow rates of change.”

The Nirex Planning Inquiry Inspector made frequent reference to the 1994 IAEA paper, which was referred to in the Inquiry documents as GOV/507. His comments based around it are still valid, since it remains the current guidance. The paper itself is rather abstract, as it is meant for general worldwide application; it is easier to read the Inspector's words on it, in the real-world context of a proposed repository in West Cumbria.

As I understand it, the international guidelines are a general framework for individual countries to use in developing their own disposal strategies. So in the UK case, the generic geological environments developed by the BGS in the 1980s, and mentioned above, still apply. They cannot simply be discarded.

Current practice in other countries

Two absolutely fundamental requirements for a safe repository are:

A - simple geology (predictable)

B - low relief (little energy to drive groundwater).

This table shows how these requirements are fulfilled elsewhere, as compared with West Cumbria:

There are other requirements, as mentioned, for example, in Pangea's list above, but they need not be mentioned further here since practically any site in the UK would satisfy them.

There is a suggestion that sites within suitable thick clays may be the most fruitful way forward, as shown by the list. The hard rock coastal sites chosen by Sweden and Finland are encountering problems because the rocks are actually complex and faulted - it is inaccurate to refer to these sites as 'granitic', as is often done.

Voluntarism in other countries

The UK government has held up Finland and Sweden as examples of two countries where voluntarism has (allegedly) worked in the search for deep waste disposal sites. Of the former, Defra stated (2007):

"In 1983 TVO (a nuclear power operator which had responsibility for siting a radioactive waste disposal facility) drew up a list of 101 potential sites and undertook a consultation process with the affected communities. This resulted in the identification in 1985 of 5 potential ‘volunteer’ sites at which more detailed investigations were carried out."

and it described Sweden thus:

"SKB (Swedish Nuclear Fuel and Waste Management Company) ... has been using a staged, volunteer process to identify potential sites since the beginning of the 1990s. After the first attempt to find volunteers failed SKB re-launched the initiative, including proactively approaching existing nuclear communities. This resulted in 8 volunteer communities (5 nuclear communities and 3 communities from next to nuclear communities) coming forward, at which feasibility studies were conducted to assess the suitability of the areas in question."

Both these statements misleadingly imply that voluntarism has succeeded where other methods of search failed. Geology is not even mentioned. The implication is, of course, that such an approach will also work in the UK. But both countries differ from the UK in that most of their bedrock is fairly (or even very) suitable; nevertheless the geological search did come before the approach to communities. I have analysed this in more detail [here - in preparation]. I qualify the voluntarism success story with 'allegedly', because both the deep HLW repositories now being constructed are encountering technical problems because of the geology, as the table above suggests.

Funding for genuinely independent peer review

[Summary] Such funding is available in Sweden and Canada, but not in the UK.

Conclusion

The UK is pursuing a unique strategy in seeking volunteer communities before the geology is considered. Ironically, this has led to the volunteering of the very district which has already been thoroughly investigated, but which failed the test of a planning inquiry.

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