Page 15 - PR 2014 2016 11 Nuclear Safety

Nuclear Safety | Progress Report 355

Figure 7 – TENORM waste
treatment with micro-
wave technology

Assessment of cement durability active sources. In the environment of a deep
in repository environment borehole for this waste, the aging hydrated
cement material is exposed to the radiolytic
Cementitious materials made with Portland effects of the radiation field of the sources,
cement are widely used in the management the high temperature determined by the geo-
of radioactive waste, particularly as immobi- thermal degree of the disposal site and the
lization matrix of low- and intermediate-level disposal depth, and is possibly exposed to
waste and as structures in the engineered aggressive chemical species dissolved in the
barriers of repositories. As any other engineer- ground water. Presently, the assessment of the
ing barrier, the cementitious materials must long-term behavior of cement materials can
perform as required for the period of service only be done by accelerated tests in laboratory
life in the disposal facility. However, Portland and modeling. The GRR’s work in this field is
cement is a relatively new engineering mate- combining both methods, taking advantage of
rial and its behavior in the period of hundreds the availability of the Multipurpose Irradiator
or thousands of years is still mostly unknown. to irradiate cement specimens cast in labora-
tory with the expected integrated radiation
The GRR is performing a research work in dose delivered to the material until the sources
order to contribute to the assessment of the are decayed. The effects of the radiation, tem-
durability of cementitious materials in a deep perature and chemical species in the cement
borehole for disposal of disused sealed radio- specimens are evaluated by X-Ray Diffraction