INIS - INTERNATIONAL NUCLEAR INFORMATION SYSTEM
by Nada MARINKOVIĆ

Abstract: INIS is the world's leading decentralized information system on the peaceful uses of nuclear energy. It is operated by the International Atomic Energy Agency in co-operation with the member states and international organizations. Being one of the INIS member states, our country has begun co-operation with INIS in 1975. INIS National Centre is acting within the Institute of Nuclear Sciences and according to the strictly defined organization of the information system supplies the users with the available INIS products, meaning bibliographic data from the INIS data base. At the same time it is responsible for submitting information concerning domestic publications to the INIS Secretariat, including supplying foreign users with non-conventional literature if demanded. During the period 1990 - 1996 co-operation with INIS Secretariat was interrupted due to reasons which are not subject of this paper. Since then collaboration is established again, and updated INIS data base on CD-ROM is available at the National Centre. INIS on-line retrieval is not yet available.

Key words: INIS, MAAE, nuclear energy, data base management, data acquisition, data processing, international co-operation

Note: Full text published in Serbian

APPLICATION OF REACTOR NOISE METHODS IN SAFETY AND RELIABILITY OF NUCLEAR POWER PLANTS OPERATION
by Ljiljana KOSTIĆ

Abstract: Continuously working measuring chains of the standard reactor instrumentation produce a more or less stationary mean value of a signal (DC component) which is overlaid by a noise or AC component. The essential part of the noise is caused by fluctuations of the measured quantity. Using the noise or correlation analysis technique additional information about the process itself and its circumstances can be obtained from the fluctuating signal component. This additional information regarding the integrity of the complete signal transmission line, vibrations of nearly all components of the primary loop and several thermo hydraulic and nuclear conditions would not be available by processing only the DC values of the signals. Noise analysis is a cost saving and reliable technique, not only for vibration surveillance in nuclear power plants.
It is shown that, without any impairing of the normal reactor operation and without the need of any additional instrumentation, information about the core behaviour and the operating conditions of the primary loop of nuclear power plants can be obtained by noise analysis of the standard reactor instrumentation signals. The purpose is to detect possible changes of mechanical and operating conditions at the very beginning to contribute not only to more safety, but also to higher availability of the nuclear power plant.

Key words: reactor noise, safety, reliability, vibrations, thermo hydraulic parameters, primary loop, nuclear power plant

PRODUCTION OF RADIONUCLIDES AND RADIOPHARMACEUTICALS IN THE VINČA INSTITUTE
PART II. BASIC RESEARCH IN PHYSICAL CHEMISTRY AND BIOCHEMISTRY
by Nadežda VANLIĆ-RAZUMENIĆ

Abstract: Research activities in radiochemistry, physical chemistry, and biochemistry performed in Radioisotope laboratory as a basis for production of radionuclides and radiopharmaceuticals are described. A time span from the foundation of the Institute in 1948 up to date is reviewed. A series of radioelements was investigated from the beginning until early seventies, then technetium and its complex compounds, applied widely as radiopharmaceuticals, prevailed. So emphasis was put to development of technetium kits and technetium complexes. Research in physical, analytical, and coordination chemistry, as well as in bio chemistry of Tc compounds is described, including works over a period of more than two last decades. Also research in tin complexes is included, because this topic always accompany technetium complexes (with the same ligands) in radiopharmaceutical solution, where stannous tin is used as a reductant.

Key words: radionuclides, radiopharmaceuticals, technetium-99m and -99, complexes, bivalent tin, stability constants, protein binding, subcellular localization

CORROSION OF ALUMINUM, URANIUM AND PLUTONIUM IN THE PRESENCE OF WATER IN SPENT FUEL STORAGE TANKS
PART I: CHEMICAL CORROSION
by Ivan GRŽETIĆ

Abstract: General problem associated with research reactor exploitation is safe storage of spent nuclear fuel. One of the possible solutions is its storage in aluminum containers filled and cooled with water. With time aluminum starts to corrode. The chemical corrosion of aluminum, as a heterogeneous process, could be investigated in two ways. First, is direct investigation of Al corrosion per se, following Eh and pH conditions of the corrosion environment. Second is indirect investigation of Al corrosion, following hydrogen generation during the corrosion of Al in the presence of water. Both ways are based on available physico-chemical and thermo dynamical data. Recent measurements of water quality in the VINČA Institute spent fuel pool clearly indicate that the aluminum corrosion is likely to be present. For the particular case, corrosion process could be considered in two directions. The first one discusses the corrosion process of reactor fuel aluminum cladding in general. The second consideration is related with theoretically and empirically based calculations of hydrogen pressure in the closed aluminum containers in order to predict their resistance to the increased pressure. Finally, the corrosion of U, Pu and Cd is discussed with respect to solubility and influence of hydrogen on U and UO ₂ under wet conditions.

Key words: heterogeneous systems, corrosion of Al, U, Pu and Cd, Eh-pH diagrams, hydrogen    

BORON NEUTRON CAPTURE THERAPY
by Marina ŠOKČIĆ-KOSTIĆ

Abstract: The Boron Neutron Capture Therapy (BNCT) will provide powerful treatment of surface and deeper seated tumors. The basic principle is relatively straight forward. The stabile nuclide boron-10, with a large cross section for absorption of thermal neutrons, is concentrated in a tumor by means of a transfer substance like p-boron phenylalanine. The tumor is exposed to neutrons and the radiation emitted after neutron capture, 10B(n, a)7Li, has a short range in the tissue, in such a way that only tumor cells are destroyed. Thermal neutron beams can be applied for near surface tumors, while the epithermal neutron beams have their application in treatment of deeper-seated tumors. The epithermal neutron beams can be produced by reactors and accelerators. Different targets and reactions are used at accelerators to obtain an appropriate neutron beam.

Key words: boron neutron capture therapy, reactors, accelerators

EXPERIMENTAL STUDY OF THE ONSET OF SUBCOOLED NUCLEATE BOILING DOWN-FLOW
by Larisa JOVlĆ, Dušan SPASOJEVlĆ, Valerije JOVIĆ

Abstract: An experimental program was performed in order to investigate flow boiling in the vertical down-flow. Hydraulic characterization of the experimental loop and the test section was done. For a ratio L/D =125 the hydrodynamic and thermal characteristics of the down-flow under uniformly heated subcooled boiling conditions were obtained for a wide range of operating parameters.
A mathematical model for predicting thermal hydraulic parameters in one and two phase flow in the down-flow of subcooled liquid was developed. Based on the Bowring formulation stating the onset of subcooled boiling was determined by using Thom's correlation. The axial temperature distribution of the heated wall in the subcooled and saturated regions was calculated by applying Chen correlation, for the heat transfer coefficients of subcooled and saturated boiling. The hydrodynamic properties of the main loop as well as axial and total hydrodynamic characteristics of the experimental channel were determined for the turbulent-convective regions. The experimental and analytical results of the axial wall and the fluid distribution clearly indicate the onset of subcooled and/or saturated boiling.

Key words: subcooled boiling, down-flow, onset of subcooled boiling