The 13th International Conference on Environmental ... - Events

Abstracts
hyperalkaline groundwaters. Although not included in this calculation to date, the CSH phases identified are completely
consistent with reaction of clays with hyperalkaline groundwaters, as seen at other sites worldwide.
At the Bigbiga site, an active hyperalkaline groundwater/bentonite reaction zone (at the base of the bentonite
deposit) has recently been drilled and samples are currently undergoing analysis. A comparison of the data sets from both
sites will be included in the presentation. <strong>The</strong> paper will also outline the potential future programme of research at these
sites.
6) 40063 – Natural Analogues of Cement: Overview of the Unique Systems in Jordan
Gento Kamei, JAEA (Japan);
W Russell Alexander, Bedrock Geosciences (Switzerland); Ian D. Clark, University of Ottawa (Canada);
Paul Degnan, IAEA; Marcel Elie, Shell (UK); Hani Khoury, Elias Salameh, University of Jordan (Jordan);
Antoni E. Milodowski, British Geological Survey (UK); Alister F. Pitty, Pitty Consulting (UK);
John A.T. Smellie, Conterra (Sweden)
In L/ILW repository designs, cement-based materials are expected to dominate – for example, the proposed Swiss
repository will contain over 1.5 million tonnes of cementitious material. Models of cement evolution predict that leaching
of the cement in the repository by groundwater will produce an initial stage of hyperalkaline (pH~13.5) leachates,
dominated by alkali hydroxides, followed by a longer period of portlandite and CSH buffered (pH~12.5) leachates. It has
also been predicted that the hyperalkaline porewater leached out of the near-field will interact with the repository host
rock (and, where applicable, bentonite buffer and backfill). This could possibly lead to deterioration of those features for
which the host rock formation and bentonite were originally chosen.
Here, the safety assessment implications of the novel data from the Jordan Natural Analogue Study, which looked
into interaction of natural cementitious hyperalkaline leachates on repository host rocks and clays, are presented. Several
sites across Jordan have been studied, but the focus here will be on two particularly contrasting sites:
• Maqarin in northern Jordan – this represents repository host rocks with advective groundwater systems.
Hydrogeological, hydrochemical and structural data collected on the fractured rock at the site have been used to
assess the likely implications of hyperalkaine leachate interaction on the long-term flow conditions in similar
repository host rocks (e.g. granites, fractured sediments) and this will be discussed in detail
• Khushaym Matruk in south-central Jordan – this represents repository host rocks with diffusive groundwater
systems. Here, hyperalkaline leachates have diffused through an impermeable, clay-rich sediment, so providing
information on the likely controls on leachate interaction in tight repository host rocks (e.g. claystones)
In addition, data are provided on the nature of the secondary phases produced following interaction of the leachates
with clays present at the sites. <strong>The</strong>se clays include mixed-layer illite/smectite and so are particularly good analogues of
reaction of cement leachates on the bentonite buffer which is an integral part of the EBS in some L/ILW repository
designs. This work will be contrasted with that presented by Fujii et al (this conference) which is focussed on bentonite
reaction in leachates from low alkali cements. <strong>The</strong>se cements are under consideration for use in repositories where
bentonite and concrete will be placed together as they produce lower pH leachates (pH 10 to 11) which are believed to be
less aggressive to bentonite than the higher pH leachates from OPC which are discussed here.
SESSION D4: Panel "Applying Lessons Learned from Past D&D Activities"
Abstract Not Required
SESSION R2: Environmental Remediation
1) 40261 – Reclamation of Three In Situ Uranium Mines - Innovative Techniques
Wallace Mays, W M Mining Company (USA)
RECLAMATION OF THREE IN SITU URANIUM MINES IN TEXAS-INNOVATIVE APPROACHES By:
Wallace Mays, President of IEC, Chairman and COO of Powertech Uranium, President W M Mining Company From
1990 through 2010, Wallace Mays has been restoring the ground water and reclaiming the surface of three In Situ Leach
Uranium Mines in south Texas; the Lamprecht, Zamzow and Pawnee In Situ Leach Mines located in Bee and Live Oak
Counties in south Texas. <strong>The</strong>se mines were operated by Westinghouse Corporation subsidiary Wyoming Minerals and by
Intercontinental Energy Corporation (IEC). <strong>The</strong>se were among the first In Situ Mines operated and utilized high levels of
ammonia carbonate, which complicated the ground water reclamation project. IEC was acquired by Oren Benton, who
declared bankruptcy in 1995 in the middle of the ground water restoration process. Westinghouse had set up an annuity
to fund their reclamation obligations. W. Mays formed a company, Cima Energy to contract to manage the reclamation
and to finance the funding of the working capital to be reimbursed. <strong>The</strong>se ISL mines posed very difficult ground water
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