In the nuclear reactors using uranium as fuel and heavy water as moderator, after a while, due to increased tritium concentration as result of neutrons capture on deuterium nucleus, we have to establish a set of measures to decrease the tritium concentration. The amount of tritium obtained in a CANDU reactor is about 2,4 KCi/MW. The experimental plant realise the separation and extraction of tritium from tritiated heavy water at 30 Ci/kg (for a higher concentration will be diluted at that level). The tritium request in the USA was 4*10(6) Ci in 1980; in Romania was 2*10(4) Ci in 1990, 3*10(4) in 2000 and will continue to increase. On present times the price for tritium is estimated at about 2$/Ci([1]) on international market and increasing. This is due to growing and continues diversification of application fields; nuclear medicine, nuclear fusion, research labs. The experimental Pilot plant for tritium and deuterium separation, part of National Research and Development Institute for Cryogenics and Isotopic Technologies - ICSI Rm. Valcea, as principal target have to establish the technology of the water-hydrogen catalyzed isotopic exchange and cryogenic distillation for mixtures of hydrogen and his isotopes diatomic species. The main target of the experimental pilot plant is to establish the detritiation technology of CANDU reactor moderator and to certify the equipments specific for cryogenic domain and tritiated mediums. The most important part of the experimental Pilot plant for tritium and deuterium separation is module 300(cryogenic distillation of hydrogen/deuterium/tritium mixture). The principal goals on to that module are: a) to insure and maintain the proper temperature for hydrogen condensation in the head of the distillation column, b) to elaborate the high efficiency contact elements on hydrogen isotopes separation. Therefore, to accomplish the task presented at the point (a)), the hydrogen distillation column condenser is cooled within a hydrogen cryogenic cycle which is insuring a level of temperature within 20-30 K, corresponding to the working pressure of the distillation column. Also, it has to be mentioned the special character both for dynamic and static equipment as for entire measurement and control systems with are parts of technological outflow working under liquid nitrogen temperature. The tasks of experimental techniques effectuate within experimental Pilot plant for tritium and deuterium separations into module 300 are: establishing the working parameters in different states of nitrogen cryogenic cycle. functioning checkout for dynamic and static equipments (turboexpanders, compressors, etc.) control and measurement equipments specifically for cryogenics liquids operations. overlooking the materials comportment at cryogenic temperatures booth in steady state and in transition states.
