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Tritium Contaminated Water Cleaning

#0383


Creation of the Technology for Heavy and Light Water Purification from Tritium.

Tech Area / Field

  • ENV-RED/Remediation and Decontamination/Environment

Status
3 Approved without Funding

Registration date
23.02.1995

Leading Institute
Nuclear Physics Institute, Russia, Leningrad reg., Gatchina

Supporting institutes

  • SverdNIIChimMash, Russia, Sverdlovsk reg., Ekaterinburg\nNovosibirsk Chemical Concentrates Plant, Russia, Novosibirsk reg., Novosibirsk\nAO DOL, Russia, Moscow reg., Troitsk\nAll-Russian Research and Designing Institute of Complex Energetic Technology / VNIPIET (Sosnovy Bor Branch), Russia, St Petersburg\nVNIIEF, Russia, N. Novgorod reg., Sarov

Collaborators

  • British Nuclear Industry Forum, UK, London\nCanadian Fusion Fuels Technology Project (CFFTR), Canada, ON, Mississauga

Project summary

Project objective is the development of the economical and ecologically safe reprocessing technology of tritiated (contaminated by tritium) heavy and light water wastes on the base of the methods of "water-hydrogen" isotopes exchange with wetproofed catalysts, water electrolysis, low temperature distillation of hydrogen isotopes and its combinations. Work will be carried out using existing and improved at PNPI full scale assemblies. During process of the work new type of catalysts and packings and new constructions of high effective mass exchange sections for the distillation and exchange columns will be developed and studied. The various versions of the technological schemes for the water purification from tritium will be tested. It must be determined also the best conditions of the process and will be chosen the best versions of technological schemes for the reprocessing of tritiated wastes of various isotopes content.

Full scale integrating tests and studies demonstrating all aspects of the economical and ecologically safe reprocessing technology of tritiated heavy and light water wastes allow to obtain the data those are necessary for the development of project of the best economically advantageous and safety technology of tritium extraction from large and complicated nuclear systems (fission and in the future fusion reactors, spent fuel reprocessing plants, disarmed nuclear weapons and etc), its concentration and transfer it to small size compounds for the long-term and safe storage and in order to be reusable as needed.

Obtaining of heavy water or deuterium of highest quality (>99,8 % D2O) and as well as tritium will be presented in the project and this means it will be demonstrated that the reprocessing of tritiated wastes can be profitable.

Formation and accumulation of the radioactive tritium together with other radionuclides takes place during operation of the light and heavy water reactors. On a global scale the rate of the tritium accumulation at present exceeds by a factor of 10 or more the rate of tritium formation by natural way. In case of an emergency the accumulated tritium can present a severe hazard to environment and may prove deleterious on human health.

Today it is developed and introduced in practice the technologies of complete purification of heavy and light water coolants and radioactive wastes practically from any radionuclides except tritium. Technology used in the operated today detritiation plants in France and Canada allows to keep the tritium concentration in moderator and coolant of heavy water reactors at the definite level (about 70 GBq*kg-1 D2O or 2 Ci*kg-1 D2 O) but does not carry out a deep water purification from tritium.

Reprocessing of tritiated wastes is expensive due to a small tritium concentration with respect to content of other hydrogen isotopes as well as the small value of separation factors. Besides, the hydrogen isotope variations of the protium-deuterium-tritium mixture have different separation factors. It follows that the economical and safety reprocessing of tritiated wastes requires new more efficient and sufficiently flexible technologies in the field of hydrogen isotopes separation.


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