Untersuchungen zur rückhaltung von tritium in HTR-brennelementen

In a nuclear reactor tritium is produced by ternary fission and a number of further neutron-induced nuclear reactions. The liberation of the tritium so produced from the ceramic fuel of a high temperature reactor was examined. Fuel particles with pyrocarbon coatings are able to retain tritium to a large extent under reactor operating conditions. The amounts of tritium found in reactorirradiated fuel particles correspond within the limits of error with the calculated concentrations. The activation energy of the liberation factor for tritium from fuel particles is 106 kcal/mol in the temperature range 1400–1900°C. The release of the tritium found according to ${}^6\text{Li (n, α)}{}^3\text{H}$ from a reactor graphite was measured and the concentration of tritium in graphite samples from the AVR nuclear power station was determined.