Neutronic Performance of the VVER-1000 Reactor Using Thorium Fuel with ENDF Library

In this paper, neutronic calculations and the core analysis of the VVER-1000 reactor were performed using MCNP6 code together with both ENDF/B-VII.1 and ENDF/B-VIII libraries. The effect of thorium introduction on the neutronic parameters of the VVER-1000 reactor was discussed. The reference core was initially filled with enriched uranium oxide fuel and then fueled with uranium-thorium fuel. The calculations determine the delayed neutron fraction βeff, the temperature reactivity coefficients, the fuel consumption, and the production of the transuranic elements during reactor operation. βeff and the Doppler coefficient (DC) are found to be in agreement with the design values. It is found that the core loaded with uranium and thorium has lower delayed neutron fraction than the uranium oxide core. The moderator temperature coefficients of the uranium-thorium core are found to be higher than those of the uranium core. Results indicated that thorium has lower production of minor actinides (MAs) and transuranic elements (mainly plutonium isotopes) compared with the relatively large amounts produced from the uranium-based fuel UO2.

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Estimation of Fuel Burnup Rate for Core Conversion for the Nigeria Research Reactor-1 (NIRR-1) Fueled With 19.75% Enriched UO2 USING VENTURE PC Code

Physical Science International Journal ◽

10.9734/psij/2020/v24i230177 ◽

2020 ◽

pp. 42-49

Author(s):

J. A. Rabba ◽

M. Y. Onimisi ◽

D. O. Samson

Keyword(s):

Uranium Dioxide ◽

Research Reactor ◽

Fuel Burnup ◽

Reactor Operation ◽

The Core ◽

Computer Codes ◽

Enriched Uranium ◽

Conversion Study ◽

Good Agreement

A standardized burnup analysis using VENTURE-PC computer codes system has been performed for the core conversion study of Nigeria Research Reactor-1. The result obtained from this analysis showed that the mass of Uranium decreases with increase in the number of days of reactor operation while the quantity of Plutonium continues to build up linearly. The buildup of the fissile isotope in the Low Enriched Uranium (LEU) core is very much greater than in the Highly Enriched Uranium (HEU) core. The quantity of Uranium-235 consumed and the amount of Plutonium-239 produce in the core of the reactor were 13.95 g and 0.766745 g respectively for the period of 11 years of reactor operation which is in good agreement with other literatures. This results obtained showed that uranium dioxide (UO2) fuel is a potential material for future Low Enriched Uranium (LEU) core conversion of Nigeria Research Reactor.

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Nuclear Analysis During Modification of NPP Core

18th International Conference on Nuclear Engineering: Volume 2 ◽

10.1115/icone18-30177 ◽

2010 ◽

Author(s):

Andrius Slavickas

Keyword(s):

Reactor Core ◽

Reactor Power ◽

Physical Parameters ◽

Reactor Operation ◽

Reactor Control ◽

The Core ◽

Burnable Absorber ◽

Reactivity Coefficients ◽

Control Rods ◽

Neutron Activity

Reactor power and neutron activity control is the main key for safe reactor operation. Reactivity coefficients and effects are main measures to estimate reactor control and safety. These characteristics outline reactors behavior during usually exploitation and accident events. Reactivity coefficients and effects quantify the effect, which various parameters (e.g. fuel and graphite temperatures, amount of steam) have for the core neutron activity. Many modifications of RBMK-1500 reactor cores in Ignalina NPP were made during their lifetime. Reactor core modifications like load of higher enriched fuel with burnable absorber and new design control rods affected reactivity coefficients and effects. Neutron-physical parameters calculations of reactor core states with variant fuel loads and new design control rods were performed using QUABOC/CUBBOC-HYCA software. The changes of reactivity coefficients and effects were quantified in this paper.

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Monte Carlo analysis of nondestructive assay techniques for highly enriched uranium oxide

2011 IEEE Nuclear Science Symposium Conference Record ◽

10.1109/nssmic.2011.6154511 ◽

2011 ◽

Cited By ~ 1

Author(s):

S. D. Clarke ◽

M. Flaska ◽

S. A. Pozzi

Keyword(s):

Monte Carlo ◽

Uranium Oxide ◽

Monte Carlo Analysis ◽

Nondestructive Assay ◽

Enriched Uranium

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Measurements of Thermal Utilization, Resonance Escape Probability, and Fast Effect in Water-Moderated, Slightly Enriched Uranium and Uranium Oxide Lattices

Nuclear Science and Engineering ◽

10.13182/nse58-a25478 ◽

1958 ◽

Vol 3 (4) ◽

pp. 403-427 ◽

Cited By ~ 30

Author(s):

D. Klein ◽

A. Z. Kranz ◽

G. G. Smith ◽

W. Baer ◽

J. DeJuren

Keyword(s):

Uranium Oxide ◽

Escape Probability ◽

Enriched Uranium

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Neutronic Analysis of LEU-started Molten Chloride Fast Reactor without Fuel Reprocessing

Computational And Experimental Research In Materials And Renewable Energy ◽

10.19184/cerimre.v4i1.24962 ◽

2021 ◽

Vol 4 (1) ◽

pp. 8

Author(s):

R. Andika Putra Dwijayanto ◽

Andang Widi Harto

Keyword(s):

Fast Reactor ◽

Molar Fraction ◽

Chloride Salt ◽

Inherent Safety ◽

Delayed Neutron ◽

Core Zone ◽

Molten Chloride ◽

Enriched Uranium ◽

Fuel Reprocessing ◽

Coefficient Of Reactivity

One of the rarely explored molten salt reactor (MSR) designs is the molten chloride fast reactor (MCFR). This MSR design employs chloride salt instead of fluoride and operated in a fast spectrum. MCFR brings all the advantages of an MSR including breeding whilst being able to burn plutonium and minor actinides efficiently. Since not many countries have access to civilian plutonium, MCFR can also be started using low-enriched uranium (LEU). This study is an initial neutronic analysis of an MCFR using LEU as its startup fuel. Parameters analyzed are conversion ratio (CR) and its neutronic safety, namely effective delayed neutron fraction (βeff), temperature coefficient of reactivity (TCR), and void coefficient of reactivity (VCR). The core is divided into Core Zone and Blanket Zone. The fuel composition of NaCl-UCl3 with a molar fraction ratio of 60:40 and 50:50 is used in Core Zone and Blanket Zone, respectively. The neutronic calculation is performed using MCNP6 code with ENDF/B-VII library. For reference geometry, CR is valued at 0.9298, βeff at 0.00731, TCR at -19.8 pcm/°C, and average VCR at -154.31 pcm/void%. Thereby, the MCFR fulfills inherent safety criteria. Although its value is remarkably high, CR can be further optimized by modifying the separator and reflector material.

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The Heron Fan: Concept Description and Preliminary Aerothermodynamic Analysis

Volume 3: Coal, Biomass, and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration; Organic Rankine Cycle Power Systems ◽

10.1115/gt2018-76529 ◽

2018 ◽

Author(s):

Finn Schöning ◽

Dragan Kozulovic

Keyword(s):

Axial Compressor ◽

Internal Flow ◽

Operating Costs ◽

Radial Compression ◽

The Core ◽

Blade Tip ◽

Fan Blade ◽

Influential Parameters ◽

Lower Production ◽

Critical Aspects

The Heron Fan is a new concept of a fuel powered jet engine that does not utilize a conventional core engine. The fan, a single axial compressor of high diameter, creates thrust, similar to a turbofan. Its blades are hollow with inner channels to transport the core air from the hub to the tip, inducing radial compression. The combustion chamber is located in the casing region, either integrated in the blades or in an external ring. After burning, the core air is returned to the blades and is blown out through an expansion device with a large component in circumferential direction. This propels the fan in the opposite direction. The expansion device may be realized by nozzles integrated in the blade trailing edge or by turbine stages integrated in the blade tip region. Subsequently, the core air mixes with the bypass air, which passes the fan axially, and ejects through the main nozzle, producing thrust. To achieve higher compression ratios, it is possible to install core air compressor stages ahead of the fan. The main purpose of this concept is to reduce weight and complexity of the engine, leading to lower production and operating costs. This is achieved by simplifying the engine architecture, integrating the functions and shortening some of the components. In particular, the core engine has been rearranged, thus eliminating the second and in some cases the third shaft. Further, the complete expansion and parts of the compression have been integrated in the fan blade. To assess the aero-thermodynamic parameters, a preliminary cycle analysis has been done, where the most influential parameters were varied. The results show, that the above listed benefits can be achieved while maintaining an efficiency comparable to conventional turbofans. Further, a feasibility study in terms of geometry, internal flow, component implementation and installation has been done, in order to qualify the concept and to identify the most critical aspects. To incorporate the corresponding thoughts and results, as well as to find and eliminate conceptual conflicts and opposing trends, a CAD model has been generated. Overall, the results are sound and encouraging, hence justifying future investigations. However, the Heron Fan concept also brings structural, thermal and aerodynamic challenges which are illustrated and briefly discussed, but still need detailed investigation.

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New Human-Machine Interface at VR-1 Training Reactor

18th International Conference on Nuclear Engineering: Volume 1 ◽

10.1115/icone18-29799 ◽

2010 ◽

Author(s):

Martin Kropi´k ◽

Jan Rataj ◽

Monika Jurˇicˇkova´

Keyword(s):

User Interface ◽

Foreign Students ◽

Nuclear Power ◽

English Language ◽

Reactor Power ◽

Text Messages ◽

Reactor Operation ◽

The Core ◽

Machine Interface ◽

And Training

The paper describes a new human-machine (HMI) interface of the VR-1 nuclear training reactor at the Czech Technical University in Prague. The VR-1 reactor is primarily used for training of university students and future nuclear power plant staff. The new HMI was designed to meet functional, ergonomic and aesthetic requirements. It contains a PC with two monitors. The first alphanumerical monitor presents text messages about the reactor operation and status; next, the operator can enter commands to control the reactor operation. The second graphical monitor provides parameters of reactor operation and shows the course of the reactor power and other parameters. Furthermore, it is able to display the core configuration, perform reactivity calculations, etc. The HMI is also equipped with an alarm annunciator. Due to a high number of foreign students and visitors at the reactor, the Czech and English language versions of the user interface are available. The HMI contains also a History server which provides a very detailed storage and future presentation of the reactor operation. The new HMI improves safety and comfort of the reactor utilization, facilitates experiments and training, and provides better support for foreign visitors.

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