Page 125 - Neutrons for Sciences and Society

Chapter 5: The construction of the reactor and the scientific groups
Fig. 5.7: The detritiation facility in 2004. On the left the monitor circuit and in the background the exhaust circuit for the tritium gas.
The deuterium in heavy water has a capture cross-section
about 1000 times smaller than that of hydrogen, but it cannot
be ignored. Capture leads to the formation of the radioactive isotope of hydrogen, tritium, which has a half life of 12 years.
If not removed the heavy water of the reactor would reach equilibrium with a radioactivity of 80 curies per litre. In these conditions even a modest leakage of heavy water could have
very serious consequences for the environment, and would also make maintenance interventions on the heavy water circuits more difficult. The institute included a detritiation facility (Fig. 5.7). For a long time this prototype installation has remained unique in the world. It comprises a stage with catalysed exchange between the heavy water vapour and deuterium gas, followed by liquefaction
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