Radiation Shielding Concrete on the Base of Depleted Uranium Dioxide
Production and Testing of Heavy Concretes Including Depleted Uranium Dioxide Concerning their Use as Shielding Materials in Constructions of Casks for Spent Nuclear Fuel
Tech Area / Field
- ENV-RWT/Radioactive Waste Treatment/Environment
- MAT-ALL/High Performance Metals and Alloys/Materials
8 Project completed
Senior Project Manager
Tocheny L V
VNIIEF, Russia, N. Novgorod reg., Sarov
- VNIIKhT (Chemical Technology), Russia, Moscow\nAll-Russian Scientific Research Institute of Non-Organic Materials named after A. Bochvar, Russia, Moscow
- Oak Ridge National Laboratory, USA, TN, Oak Ridge
Project summaryThe purpose of the Project is to investigate:
- characteristics of radiation shielding concrete developed in ORNL, used as shielding of casks designed for spent nuclear fuel (SNF) and radioactive wastes (RW) transportation, storage and disposal;
- potential applications of sintered depleted uranium dioxide as an aggregate for the radiation shielding concrete.
It is proposed to introduce depleted uranium dioxide into concrete composition in order to provide required radiation shielding characteristics. There are examples in world practice of uranium usage as an aggregate in order to modify properties of the source materials. In particular, there are well-known technologies of shielding glass production; such glass contains uranium oxides (UO2, U2O5). Introduction of these components in the glass composition provides additional shielding features, in particular, ability to absorb ultraviolet radiation, which damages paper, paint, textile materials, etc.
Use of depleted uranium dioxide in metal-concrete casks will allow one to provide required degree of gamma shielding and fast neutrons slowdown, which will allow one to capture these by thermal neutrons absorbers. This property is unique for high-density shielding materials.
There is one more reason making attractive the idea on depleted uranium use as a concrete component. The reason is that a possibility arises to reclaim the substance being not engaged into economic turnover up to now and created problems connected with its storage, control and etc.
Use of especially hard and especially heavy concrete as structural and radiation shielding material in casks for SNF storage demands to meet the whole series of contradictory requirements. Save cheapness and availability of components, it should have high strength, sufficient density (being generalized indicator of ionizing radiation absorption degree), satisfactory heat conduction, thermo-, radiation and corrosion resistance, longevity and waterproof.
While creating material with such characteristics, the main problem is to provide necessary chemical resistance and granulometric composition of depleted uranium dioxide acting as fill in the concrete under development.
Uranium dioxide which is supposed to be used as a fill in the concrete, is powdery substance with particles size from 0.01 µm up to 400 µm (depending on technology of production). Such fractional composition makes practically impossible use of traditional technologies of radiation shielding concrete for SNF casks with rather high fraction of depleted uranium dioxide in concrete composition. In this connection, to provide suitable quality of the concrete it is necessary preliminary coarsening (granulation) by backing of depleted uranium dioxide particles up to required size.
Within the framework of the Project the following work is to be performed:
- study of potential application of sintering dioxide of depleted uranium as an aggregate of radiation shielding concrete;
- study of radiation shielding concrete properties with an aggregate based on sintering dioxide of depleted uranium;
The work is suggested by Oak-Ridge National Laboratory (USA).
The Project is of practical interest for all countries having atomic power and dealing with the problem of SNF handling.
Researches planned to be fulfilled within the framework of the Project and their results belong to category of applied research.
After the Project completion, in the case of coming to positive decision on possibility of us of backed uranium dioxide as a component of radiation shielding concrete, a long-term prospect arises for further researches connected with practical development and bringing industrial technologies of large-size items for shielding casks to commercial level, as well as with development of actual constructions of such casks.
Results of investigations being conducted within the framework of the Project will be taken up:
- in the field of material sciences (new materials and technologies of its production);
- in the field of ecology and environment protection (safe handling of SNF and RW, RW disposal).
The project suggested meets ISTC goals and objectives namely, will give scientists and specialists involved into development and manufacturing of nuclear weapon an ability for science and research activity in peace fields, will allow one to support applied research and development of new technologies in the field of ecology and environment protection. The results of the Project will make for solution of international technical problems connected with utilization (burial) of ecologically hazardous radioactive materials.
The Project has a commercial potential and its realization will make for development of market system in Russia. The Project contributes to engage specialists of nuclear-weapon complex into international science community in interests of the world science and engineering development.
During the Project implementation science and engineering potential will be used as well as vast experience of highly qualified specialists of RFNC-VNIIEF, VNIIKhT, and A.A. Bochvar VNIINM in the field of uranium and its compound material science, who are engaged in development of uranium materials production technologies including these for shielding casks, as well as in investigation of nuclear-physical, chemical, mechanical and other properties of uranium and materials on its base.
Works on the Project will be carried out using science and research experimental bases being in possession of organization-participants, free of additional general fitting-out, using certified equipment and setups, instrumentation and experimental methods meeting modern science and engineering requirement and approaches to solution of problems set by the Project.
It is planned to use a number of original methods and patented inventions while conducting investigation.