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[en] For the purpose of safety assessments, evaluation of the reactivity effects of inner irradiation sites, being flooded with water in the MNSR reactor was conducted both numerically and experimentally. Measured and calculated effect of different combination of inner irradiation sites being flooded with water was evaluated numerically and experimentally. Good agreement between measurement and calculated results were obtained
[en] An investigation of lowering the fuel enrichment of MNSR was realized. A 3-D neutronic model was developed for the analysis of the reactor. It was found that lower number of fuel elements is needed when UO2 is used with 5.45 g of 235U content in each fuel rod. Sensitivity of the reactor to the purity of the beryllium reflector proved to be an important factor in determining the reactor neutronics as well as the weight of loaded fuel in the core. Inherent safety features of low excess reactivity and shutdown margins are preserved and enhanced. Average thermal fluxes over different zones of the core are kept very much unchanged
[en] Direct photo-neutron source strength was dynamically evaluated for the miniature neutron source reactor (MNSR) in subcritical condition. Two different static methods were applied for comparison. In addition, measurement of the photo-neutron source was made using neutron flux monitors and neutron activation analysis technique. Results for both methods were in good agreement. Dynamics effect of the photo-neutron source on reactor response to reactivity insertions was demonstrated. Photo-neutron source existence due to beryllium reflector was realized
[en] The reliable supply of water and energy is an important prerequisite for sustainable development. Desalination is a feasible option that can solve the problem of water scarcity in some areas, but it is a very energy intensive technology. Moreover, the rising cost of fossil fuel, its uncertain availability and associated environmental concerns have led to a need for future desalination plants to use other energy sources, such as renewables and nuclear. Nuclear desalination has thus the potential to be an important option for safe, economic and reliable supply of large amounts of fresh water to meet the ever-increasing worldwide water demand. Different approaches to use nuclear power for seawater desalination have been considered including utilisation of the waste heat from nuclear reactors to further reduce the cost of nuclear desalination. Various options to implement nuclear desalination relay mainly on policy making based on socio-economic and environmental impacts of available technologies. This paper examines nuclear desalination costs and proposes a methodology for exploring interactions between critical parameters. - Highlights: • The paper demonstrated desalination costs under uncertainty conditions. • Uncertainty for nuclear power prevails only during the construction period. • Nuclear desalination proved to be cheaper and with less uncertainty
[en] The DEEP benchmark is now well on the way. It is to be shortly proposed to a large number of interested Member States. First results from reference calculations have confirmed the following observations: Nuclear systems have much lower water and electricity costs as compared to fossil fuelled systems; Escalation in fuel cycle costs do not significantly affect the water costs for nuclear systems. On the contrary fuel cost escalation very significantly increase the water costs for fossil energy based systems. Results from hybrid system calculations also show the same tendencies
[en] The closed-loop transfer function of Syrian miniature neutron source reactor (MNSR) has been measured experimentally using the prompt jump approximation technique. Analysing the reactor stability behaviour, a physical model has been formulated based on the open-loop (neutronics) transfer function employing the lumped parameter concept to describe the reactor thermohydraulic characteristics. The reactor kinetics is described by the point kinetic model for one-group of delayed neutrons. Inherent internal feedback effect is considered as a single reactivity feedback that represents the coolant temperature effect. Comparison of the analytically derived transfer-function with the experimental one shows good agreement. Stability analysis of the closed-loop transfer function has been made using the Nyquist criterion and Bode diagram. Routh-Hurwitz criterion has been applied to estimate the stability limit of the MNSR closed-loop. The Nyquist and Bode criteria have shown that the MNSR closed-loop transfer function is indeed stable. The Routh-Hurwitz criterion enabled the estimation of the upper limit of temperature feedback coefficient of reactivity. Results indicate that MNSR has high inherently safety features. Various relationships that govern relation amongst reactor variables such as the isothermal reactivity coefficient of moderator temperature, temperature difference across the core and coolant flow rate of the natural circulation and mean time for heat transfer to the coolant have been concluded
[en] Delayed neutron fraction β and prompt neutron generation time Λ were determined for the Miniature Neutron Source Reactor of Syria using noise analysis technique. Small reactivity perturbations, step-wise and impulse in time, were introduced into the reactor at low power level i.e. zero-power. Power and reactivity versus time were obtained. Using the generalized least square algorithm and transfer function analysis, measurement of both the delayed neutron fraction and the neutron generation time were made. The MNSR values obtained for the prompt neutron generation time and delayed neutron fraction are 78.3±1.3 μs and 7.94±0.11x10-3 respectively. Both measured values of β and Λ were found to be very consistent with previously measured and calculated ones reported in the Safety Analysis Report
[en] This chapter consists of some points including atomic structure, nuclear reactions, radiative decay including α decay and β decay, radiation sources including neutrons, charged bodies and gamma rays, the principle of neutron activation analysis including its advantages and disadvantages, methods of radiation measurement and the devices of measurement, methods of calculation, statistic analysis and the quality control of results, absolute activation analysis, single comparator method, proportional method, special methods of neutron activation analysis including fast neutron activation, high energy charged bodies activation, high energy gamma ray activation, applications of neutron activation analysis in biology, environment, crime investigation, archaeology, geology and industry.
[en] Measurement of the thermal self shielding coefficient ( Gth ) in the Syrian Miniature Neutron Source Reactor (MNSR) inner irradiation site using Dy foils is presented in this paper. The thermal self shielding coefficient is measured as a function of the foil thickness or numbers. The mathematical equation which calculates the average relative radioactivity (Bq/g) versus the foil number is found as well.
[en] For the purpose of training operators and other educational aspects, a mathematical model capable of assessing potential accidents and safety implications of the research Miniature Neutron Source Reactor (MNSR) has been developed. The model considers relevant physical phenomena that govern the core such as reactor kinetics, reactivity feed-backs due to coolant temperature and xenon, and thermal hydraulics. Natural convection and point kinetics including the prompt jump and complete mixing approximations were employed. Peak power, reactivity core load, core outlet temperature, and other variables are predicted during self-limiting power excursions. Compared to related references, close results have been obtained. The simulating model proves to be a useful tool to train operators and students to assess qualitatively the transient behaviour of the MNSR as a result of sudden reactivity insertion in the core. In addition, the model was utilized to verify some of the design basis accidents already presented in both the Safety Analysis Report (SAR) and the Commissioning Report (CR) of the reactor, as can be seen in Table 1. Furthermore, the dynamic model generates other core variables that are of interest to update the SAR on one side, and confirms others measured and reported in the CR. (author)