PREPRINTS

Preprint IBRAE-98-01

Demyanov V.V., Kanevski M.F., Savelyeva E.A., Timonin V.A., Chernov S.Yu. 

The work deals stochastic cosimulation of ⁹⁰Sr and ¹³⁷Cs soil contamination after the Chernobyl fallout. Cosimulation is to model spatial variability and uncertainty of the spatial distribution. Cosimulation results are significantly improved by additional data on the secondary variable ⁹⁰Sr, which has more measurements than ⁹⁰Sr. Cosimulations are compared with sequential Gaussian simulations of single ⁹⁰Sr. All the modelling is applied to real data on the Chernoby fallout. 

Bibliographical reference

Demyanov V.V., Kanevski M.F., Savelyeva E.A., Timonin V.A., Chernov S.Yu. STOCHASTIC COSIMULATION OF SPATIAL VARIABILITY AND UNCERTAINLY OF ⁹⁰Sr AND ¹³⁷Cs. Preprint IBRAE-98-01. Moscow. Nuclear Safety Institute. January 1998. 27 p. — Refs.: 11 items.

Preprint IBRAE-1997-21

New mathematical methods are presented allowing for the times of about 1~sec to prognosticate at PC~IBM type the special changes of full--scale filds of neutrons, power density, moderator temperature, etc. resulting from the local insertion of reactivity into the reactor core (displacements of shim rods, overloading of channels, etc.). Computation speed of proposed algorithms allow to use them for the development of mathematical support of simulators, programs of “operator adviser” type and other system of operator support.

Bibliographical reference 

Arutyunyan R.V., Afanasyev A.M., Afanasyeva A.A., Bolshov L.A. Code package “PROGNOZ” - smart system to support decision making by the operator of the RBMK Reactor. Preprint IBRAE-97-21. Moscow: Nuclear Safety Institute, December 1997. 25 p.

Preprint IBRAE-97-20

Bogachyov A.V. 

Natural phenomena of potassium and ¹³⁷Cs migrations in the system “soil—plant” are examined. Particular attention has been given to the causes of inter-season and inter-annual fluctuations in specific radioactive contamination of plants as well as to those of interspecific differences in this index. 

Bibliographical reference

Bogachyov A.V. MIGRATIONS OF ¹³⁷Cs AND POTASSIUM IN THE SYSTEM “SOIL—PLANT”. FACTUAL DATA, NATURAL PHENOMENA, HYPOTHESES. MANUAL. Preprint IBRAE-97-20. Moscow. Nuclear Safety Institute. December 1997. 35 p. — Refs.: 138 items.

Preprint IBRAE-97-19

Aksenova А.Е., Vasilev A.D., Varenkov V.V., Volchek A.M., Krylov S.F., Pakhomov E.P., Pervichko V.A., Popkov A.G., Strizhov V.F., Chudanov V.V. 

The paper contains a description of a program code for the modeling the interaction of a high-temperature molten metals and zirconium dioxide concrete. The concrete is considered as a perspective refractory material to use in the ex-vessel core retention devices (core catchers). The models of thermal and chemical interactions, model of metal-inductor system coefficient are considered. The results of numerical modeling the metal melts and zirconium dioxide concrete are presented. The influence of main parameters of the problem has been investigated: power released, temperature of melting of concrete and metal, heat conductivity, emissivity, latent heat. Temperature distribution in the melt and concrete, evolution of the temperature in given points, dynamics of the heat fluxes are obtained. The comparison against experimental data are performed. 

Bibliographical reference

Aksenova А.Е., Vasilev A.D., Varenkov V.V., Volchek A.M., Krylov S.F., Pakhomov E.P., Pervichko V.A., Popkov A.G., Strizhov V.F., Chudanov V.V. A COMPUTER CODE FOR NUMERICAL MODELING THE EXPERIMENTS ON INTERACTION OF A HIGH-TEMPERATURE MOLTEN METALS WITH ZIRCONIUM DIOXIDE CONCRETE (in Russian). Preprint IBRAE-97-19. Moscow: Nuclear Safety Institute. November 1997. 42 p. – Refs.: 35 items.

Preprint IBRAE-97-18

Vasilev A.D., Krylov S.F., Pakhomov Е.Р., Popkov A.G., Strizhov V.F., Filippov A.S., Chudanov V.V. 

A brief description of ex- vessel core retention devices (core catchers) concepts is presented. Main requirements for core catchers designs are considered. The results of numerical estimates and brief description of experiments with corium simulants and prototypes are given. The results of preliminary numerical modeling of thermal behavior of core catcher with zirconium dioxide concrete as protective material are presented. 

Bibliographical reference

Vasilev A.D., Krylov S.F., Pakhomov Е.Р., Popkov A.G., Strizhov V.F., Filippov A.S., Chudanov V.V.  AN ANALYSIS OF CORE-CATCHERS CONCEPTS AND NUMERICAL ESTIMATES OF A THERMAL BEHAVIOR OF A FLAT CORE-CATCHER WITH THE PROTECTIVE MATERIALS OF ZIRCONIUM DIOXIDE CONCRETE (in Russian). Preprint IBRAE-97-18. Moscow. Nuclear Safety Institute. November 1997. 47 p. – Refs.: 51 items.

Preprint IBRAE-97-17

Aksenova А.Е., Pervichko V.A., Semenov V.N., Chudanov V.V. 

The some approaches for the numerical simulation of multicomponent molten corium behavior under severe accident in reactor are discussed. Thermal-concentration convection model taking account of phase changes in thermodynamic equilibrium approximation is considered. Results for the simplified setting are reported. Classification of approaches for the modelling of the multiphase flows is given and the some possible multifluid models are considered. 

Bibliographical reference

Aksenova А.Е., Pervichko V.A., Semenov V.N., Chudanov V.V. SOME MODELS FOR THE NUMERICAL SOLVING OF DIFFUSION/CONVECTION PROBLEMS TAKING ACCOUNT OF MACROSEGREGATION AND STRATIFICATION (in Russian). Preprint IBRAE-97-17. Moscow. Nuclear Safety Institute. November 1997. 19 p. – Refs.: 9 items.

Preprint IBRAE-97-16

Glushko V.A., Kiselyov V.P., Kudeshov E.V., Ogar V.P., Semin N.N. 

The article deals with the database of  nuclear power plants parameters of the russian NPPs, researched under contract 312571—A–RO with Pacific NorthEast National Laboratory (U.S.A.). The database structure and interface programs are described. 

Bibliographical reference

Glushko V.A., Kiselyov V.P., Kudeshov E.V., Ogar V.P., Semin N.N. Database of  nuclear power plants parameters. Preprint IBRAE-97-16. Moscow. Nuclear Safety Institute. October 1997. 25 p. — Refs.: 1 items.

Preprint IBRAE-97-15

Karabasov S.A. 

An application of the new direct three–layers “Cabaret” scheme with a space splited time–derivative to two non-linear problems of two–phase filtration was considered. Based upon the problems solved there was shown that the superb transport characteristics of “Cabaret” pattern, superior to classic linear schemes, have a special application to the non–linear problems when a high accuracy is required. 

Bibliographical reference

Karabasov S.A.THE APPLICATION OF “CABARET” FINITE DIFFERENCE SCHEME TO TWO-PHASE FILTRATION PROBLEMS OF NOT-MINGLED FLUIDS. Preprint IBRAE-97-15. Moscow. Nuclear Safety Institute. August 1997. 11 p. — Refs.: 5 items.

Preprint IBRAE-97-14

Vorobiev V.A, Kiselev V.P,, Korgov M.Yu., Krylov A.L. 

Surface water radionuclides behavior prediction system of models is presented. All coefficients, parameters and results are presented as databases. There also presented models and databases description, verification, user manual, screen samples. 

Bibliographical reference

Vorobiev V.A, Kiselev V.P,, Korgov M.Yu., Krylov A.L.  COMPUTER SYSTEM OF MODELS FOR PREDICTION RADIONUCLIDES BEHAVIOR IN SURFACE WATER. Preprint IBRAE-97-14. Moscow. Nuclear Safety Institute. August 1997. 60 p. — Refs.: 16 items.

Preprint IBRAE-97-13

Kanevski M., Koptelova N., Demyanov V. 

The work includes description and a User’s Guide for RamisW software for Windows for modelling radionuclide migration in soil. RamisW is a computer realization of advection–diffusion model of vertical migration of radionuclides in soil. User’s guide is accompanied by a detailed case study based on data from the Chernobyl fallout. 

Bibliographical reference

Kanevski M., Koptelova N., Demyanov V. RamisW — SOFTWARE FOR MODELLING MIGRATION OF RADIONUCLIDES IN SOIL. Preprint IBRAE-97-13. Moscow. Nuclear Safety Institute. July 1997. 21 p. — Refs.: 6 items.