Ladislav Vesely

Design of Experimental Loop With Supercritical Carbon Dioxide

Supercritical carbon dioxide (S-CO2) cycles are recently very perspective and are researched all around the world. For successful deployment of these cycles experimental research is necessary. This paper describes the design and research program of S-CO2 experimental loop that was performed in collaboration of the Czech Technical University in Prague (CTU) and the Research Centre Rez i.n.c.. The loop will be constructed at the premises of the Research Centre Rez i.n.c a part of the project SUSEN. This paper particularly focuses on the design of components, their thermotechnical calculations, construction and arrangement of the experimental loop. It also deals with the preparation of experimental measurements to be implemented. The loop is envisioned for the research of the heat transfer for various operating conditions, testing of the material in the environment of S-CO2 and sampling of gas from the loop.Copyright

STUDY OF IDENTIFICATION OF TWO-PHASE FLOW PARAMETERS BY PRESSURE FLUCTUATION ANALYSIS

This paper deals with identification of parameters of simple pool boiling in a vertical rectangular channel by analysis of pressure fluctuation. In this work is introduced a small experimental facility about 9 kW power, which was used for simulation of pool boiling phenomena and creation of steam-water volume. Several pressure fluctuations measurements and differential pressure fluctuations measurements at warious were carried out. Main changed parameters were power of heaters and hydraulics resistance of channel internals. Measured pressure data was statistically analysed and compared with goal to find dependencies between parameters of two-phase flow and statistical properties of pressure fluctuation. At the end of this paper are summarized final results and applicability of this method for parameters determination of two phase flow for pool boiling conditions at ambient pressure.

Accident at Fukushima Dai-Ichi Nuclear Power Plant: Lessons Learned for the Czech Republic

Accident at Fukushima Dai-Ichi nuclear power plant significantly affected the nuclear industry at time when everybody was expecting the so called nuclear renaissance. There is no question that the accident has at least slowed it down. Research into this accident is taking place all over the world. In this paper we present the findings of research on Fukushima nuclear power plant accident in relation to the Czech Republic. The paper focuses on the analysis of human performance during the accident. Lessons learned from the accident and main human errors are presented. First the brief factors affecting the human performance are discussed. They are followed by the short description of activities on units 1–3. The key human errors in the accident mitigation are then identified. On unit 1 the main error is wrong understanding and operation of isolation condenser. On unit 2 the main errors were unsuccessful depressurization with subsequent delay of coolant injection. On unit 3 the main error is the shutdown of high pressure cooling injection system without first confirming that different means of cooling are available. These errors lead to fuel damage. On unit 1 the fuel damage was probably impossible to prevent, however on unit 2 and 3 it could be probably prevented. The lessons learned for the Czech Republic were presented. They can be summarizes as follows: be sure that plant personnel can and knows how to monitor and operate the crucial plant components, be sure that the procedures on how to fulfill the critical safety functions are available in the symptomatic manner for situations when there is no power available at the plant, train personnel for these situations and have sufficient human resource available for these situations.Copyright