No abstract available

No abstract available

[en] Short communication

[en] A method is presented of forming the membership functions to the terms of fuzzy management of energy objects presented as linguistic variables using the estimates of a group of experts

[en] Expert system has been for diagnosis of turbine K-210-130 with the aim to evaluate the need for repairs, the expected volume of repair work, and the effect of the repair. It uses the results of pre-repair and / or post-repair fast-testing. The Expert system processes the ^tree of criteria ^containing a main criterion, seven criteria and thirty-two input parameters and indicators. The processing criteria structure performed using three different processes: direct processing in one-dimensional fuzzy standards; additional calculations reflecting the implicit links between quantitative and qualitative evaluations, and post-processing using one-dimensional standards; treatment by linguistic rules (mega implications) for input for the one-dimensional standards and forming conclusions about the state of subsystems and turbine in general, and to generate advice to the person working with the Expert system about the most probable failures in the individual turbine subsystems

[en] In the paper is presented comparative analysis of different models for assessment of energy potential of renewable energy sources (wind, solar, hydro, geothermal, biomass, biogas). The analysis is based on preliminary selected/identified criterions for assessment of the models as: scope of the model, structure of the model, sensitive of the model, functionality of the model, sphere of implementation of the model. In the paper is presented 8 models, implemented in the practice in Bulgaria and other European countries, including 2 models developed in Bulgaria

[en] In order to reduce the residual risk associated with hypothetical severe nuclear accidents, systems and components for filtered containment venting and H2 reduction were implemented in the Kozloduy NPP units 3 and 4. The system technologies developed have to fulfill the following main tasks: 1) Creating a new pressure barrier system to confine the activity inventory by maintaining a slight containment sub-atmospheric pressure thereby preventing any relevant unfiltered activity releases. 2) Retaining a great extend of the airborne activity in the liquid phase of the venturi scrubber unit and return these activity back into the containment. 3) Controlling the containment atmosphere H2 gas mixture to prevent fast deflagration that may jeopardize the containment integrity. To meet above mentioned requirement a system was developed, consisting of a venturi scrubber unit which comprises a high speed long venturi section, a metal fibre filter section and molecular sieve. The system is operated by a turbo blower unit supplied with electrical power from the unaffected unit. The system keeps a slight sub-atmospheric pressure (approx. 5 - 10 mbar) in the containment with the purpose to minimize the uncontrolled radioactive release from the containment to the environment. The final analysis showed that the containment performance in combination with above mentioned countermeasures could be increased significantly and the impact to the environment is minimized

[en] In the paper is presented a model of the water level in steam generator PGV-4EM, obtained by active identification of the investigated plant properties. It is carried out a series of experiments with the steam generators of unit 3 at the 'Kozloduy' NPP. The experimental information (records) is processed to obtaining of continued transfer functions, with using of the MATLAB resources. (authors)

[en] A fuzzy nonlinear simulation method for neutron flux allocation at the elevation of the nuclear reactor core is considered. This method is based on linguistic rule system and strategies for obtaining of the fuzzy conclusion by using of Mamdani's minimization rule or Larsen's operation rule. A demonstration example is also given

[en] In the paper is presented a mathematical model of the dynamics of pressure and level in the pressurizer for nuclear reactor VVER-1000. The model is developed by using of the analytic approach - application of the laws of energy and the mass preservation in the pressurizer. The solving of the equations system, describing the dynamics of pressure and level, is done numerically. As a result it is obtained the step responses of the main dynamic channels. The created model will be used to study the behavior of the control algorithms for control of the pressure and level in the pressurizer of the reactor VVER-1000. (authors)