Article is dedicated to the analysis of some terms and definitions of the normative document "General safety provisions for subcritical nuclear installation". The main attention is given to the ...discussion of such terms as effective multiplication factor, self-sustaining fission chain reaction, subcritical nuclear installation. For correct definition of these terms there should be considered the reactor kinetics equations, from which it follows that the stationary neutron flux can be realized both in the critical and subcritical reactor. Meanwhile, definitions in the corresponding normative document take into account only the critical state of the reactor, whereas other stationary states in "subcritical state" were not properly considered. It is offered "to clarify" corresponding definitions of these terms based on the analysis of nuclear reactor kinetics equations.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Results of simulation and measurements on the LEETECH facility with quartz Cherenkov detector prototype which is one of the candidates for the time-of-flight technique implementation at the upgraded ...BES-III and HIEPA (China) experiments are presented. The dependence of the electrons time variation from opening of the collimators is determined. The results of the dependence of time registration of Cherenkov exposure from spatial displacement of the quartz bar with the size 20 ⨯ 40 ⨯ 200 mm are presented. Time resolution of 50 ps was measured during the experiment. The obtained results are in agreement with the expected and demonstrate the possibility of the application of quartz detectors of this type for determining the kinds of the particles.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The atomic mass distribution of nuclides in an ultramagnetized astrophysical plasma is considered by employing a model of nuclear statistical equilibrium. The magnetization of atomic nuclei is shown ...to enhance the portion of light nuclear species in the iron region.
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BFBNIB, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
The results of an investigation of the operating regime of a nuclear power plant with VVER-1000 with actuation of accelerated preventative protection at power 100%
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with one of two turbo pumps ...switched off are presented. The modeling was performed using the improved accuracy RELAPSCDAPSIM/Mod3.4 code and a corresponding model for the No. 2 unit of the Khmelnitsky NPP. It is shown that the actuation of emergency protection based on the fact that the three main circulation pumps are switched off because of a drop in the feed water in the steam generators cannot be avoided. On the basis of the results obtained, it is proposed that for the second half of the fuel run an emergency protection signal instead of an accelerated preventative protection be immediate generated when one of the turbo pumps is switched off at power level >95%
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; this will make it possible to secure more forgiving temperature regimes for fuel and equipment, avoid additional thermal cycling loads, and prevent violation of the safe operating limits on the basis of the feed water level in the steam generators.
The LEETECH (Low Energy Electron TECHnique) electron test beam facility has been designed and manufactured at Laboratoire de l’Accelerateur Lineaire (Orsay, France). Energy of electron beam can vary ...from 100 keV to 5 MeV. Two measurement sessions with application of the diamond sensor and the Micromegas/InGrid tracking module characterization were performed. Complete facility design with the Geant4 simulation, mechanical design, implementation of remote control and readout system is presented. An option to generate the electron bunches including a few particles only is confirmed, the obtained results are in rather good agreement with the corresponding simulation within uncertainty. Main results with the preliminary analysis from the Micromegas/InGrid measurement session are also presented.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A new versatile facility LEETECH for detector R&D, tests and calibration is designed and constructed. It uses electrons produced by the photoinjector PHIL at LAL, Orsay and provides a powerful tool ...for wide range R&D studies of different detector concepts delivering “mono-chromatic” samples of low energy electrons with adjustable energy and intensity. Among other innovative instrumentation techniques, LEETECH will be used for testing various gaseous tracking detectors and studying new Micromegas/InGrid concept which has very promising characteristics of spatial resolution and can be a good candidate for particle tracking and identification. In this paper the importance and expected characteristics of such facility based on detailed simulation studies are addressed.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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