Comparing VVR-M reactor fuel assembly heat technological capabilities

Translated from Atomnaya Énergiya, Vol. 67, No. 2, pp. 97–100, August, 1989.     

Design and experience of HEU and LEU fuel for WWR-M reactors

Thin-walled WWR-M5 fuel elements were designed and manufactured and have been used successfully for 16 years; they contain twice as much uranium-235 as the WWR-M2 and WWR-M3 fuel elements. The fuel elements have been optimized with regard to their neutron physics and thermal-hydraulic parameters and fuel consumption has been minimized. The mean specific power in the core of the WWR-M reactor was raised to 230 kW l⁻¹, the measured maximum volume thermal specific power was 900±100 kW l⁻¹ and the surface specific power was 136±15 W cm⁻². The WWR-M5 fuel elements enable the power of the WWR-M pooltype reactor to be raised to 30 MW while simultaneously increasing the number of cells in the core available for experimentation by a factor of approximately two and reducing fuel element consumption. Reactor tests of WWR-M fuel elements with reduced fuel enrichment (36 and 21%) were carried out for a meat uranium density up to 2–3 g cm⁻³. Conversion of WWR-SM-type reactors to these fuel elements did not lead to a loss in reactivity and enabled their power to be increased to 20–30 MW.     

Estimation of the coordinates of radiation source taking into account receiving points location definition error in radio systems with minimal amount of carriers moving around

There are represented the algorithms of estimation of radiation source in angular-measuring and differential distance-measuring radio systems with minimal amount of carriers moving around, taking into account the errors of receiving points location on a basis of adaptive filtering with method expanded state vector split. There are represent the results of static simulation.     

Production of low-pour diesel fuels by hydroisomerization of middle distillates from eastern medium-sulfur crudes

Summary Processes have been developed for catalytic hydrotreating and isomerization of n-paraffins to produce wintergrade diesel fuels from middle distillates.In the single-stage process on sulfur-resistant hydrotreating catalysts promoted with halogens, thorough drying of the feedstock and the hydrogen-rich recycle gas is required, along with promotion of the catalyst with the halogen and protection of the equipment against hydrogen halide corrosion.The yield of winter-grade diesel fuel conforming to specification GOST 305-62 (solid point –35C, cloud point –25C) is 85% by weight.In the two-stage process, the first stage is a thorough hydrotreating operation, the second stage hydroisomerization of the n-paraffins. The yield of winter-grade diesel fuel conforming to the requirements of GOST 4749-49 (solid point –45C, cloud point –35C) is 70% by weight. Also formed in the process is some 21–24% naphtha cut with a clear octane number of 76 by the motor method.Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 9, pp. 22–25, September, 1973.