Parametric Lattice Study of a Graphite-Moderated Molten Salt Reactor

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Boris A. Hombourger ◽  
Jiří Křepel ◽  
Konstantin Mikityuk ◽  
Andreas Pautz
Keyword(s):  
Molten Salt ◽  
Fuel Cycle ◽  
Block Size ◽  
Equilibrium Composition ◽  
Reaction Rates ◽  
Point Of View ◽  
Fission Rate ◽  
Slowing Down ◽  
Channel Radius ◽  
Uranium Fuel

Molten salt reactors (MSRs) are promising advanced nuclear reactors for closure of the fuel cycle. This paper discusses the core design of graphite-moderated MSRs, thanks to a parametric study of the fuel and moderator lattice. The study is conducted at equilibrium of the thorium-uranium fuel cycle for several fuel channel radius and moderator block size combinations. The equilibrium composition for each studied configuration is derived with the help of an in-house MATLAB code, EQL0D, which uses the Serpent 2 Monte Carlo neutronics code for the calculation of reaction rates. The results include excess reactivity at equilibrium, mirroring the breeding gain, and the actinide vector composition for each configuration. Moreover, the occurence of an optimum of the excess reactivity per percent uranium-233 was observed. The investigations showed that it is systematically seen at an interchannel distance equal to the neutron slowing-down length in graphite for each configuration and does not depend on the salt channel radius beyond a certain size, which is given by the thermal fission rate reaching the levels of the fast fission rate. In this way, an exotic energy and spatial distribution of the neutrons are attained. The investigations highlight the potential attractiveness, from a neutronics/fuel cycle point of view, of both large fuel channels and moderators with a shorter neutron slowing-down length.

scholarly journals Breed-and-burn fuel cycle in molten salt reactors

2019 ◽  
Vol 5 ◽  
pp. 15 ◽  
Author(s):  
Boris Hombourger ◽  
Jiři Křepel ◽  
Andreas Pautz
Keyword(s):  
Molten Salt ◽  
Fuel Cycle ◽  
Three Dimensional ◽  
Point Of View ◽  
Cell Level ◽  
Neutron Excess ◽  
Breed And Burn ◽  
A Cell ◽  
The Cost ◽  
Fast Spectrum Reactors

The operation of a reactor on an open but self-sustainable cycle without actinide separation is known as breed-and-burn. It has mostly been envisioned for use in solid-fueled fast-spectrum reactors such as sodium-cooled fast reactors. In this paper the applicability of breed-and-burn to molten salt reactors is investigated first on a cell level using a modified neutron excess method. Several candidate fuel salts are selected and their performance in a conceptual three-dimensional reactor is investigated. Chloride-fueled single-fluid breed-and-burn molten salt reactors using enriched chlorine are shown to be feasible from a neutronics and fuel cycle point of view at the cost of large fuel inventories.

scholarly journals Numerical design of thorium and uranium fuel samples irradiation in lead environment

2020 ◽  
Vol 6 ◽  
pp. 51
Author(s):  
Mikolaj Oettingen
Keyword(s):  
Monte Carlo ◽  
Numerical Model ◽  
Fuel Cycle ◽  
Radiation Transport ◽  
Three Dimensional ◽  
Reaction Rates ◽  
Current Analysis ◽  
Continuous Energy ◽  
Uranium Fuel ◽  
Numerical Design

The paper shows capabilities of thorium-lead fuel assembly for design of irradiation experiments on ThO2 and natural UO2 fuel samples using radioisotope neutron source. The main purpose of the current analysis was to determine the irradiation environment in the samples, especially: neutron spectrum, power, activity, reaction rates, production of 233Pa and 239Np as well as breeding of 233U and 239Pu. An advanced three-dimensional numerical model for Monte Carlo radiation transport and burnup simulations was developed using the Monte Carlo Continuous Energy Burnup Code (MCB). The versatility of the assembly gives a perfect opportunity to perform many irradiation experiments for R&D on the thorium and uranium fuel cycle in a different material and geometrical environments.

scholarly journals On the Dimensions Required for a Molten Salt Zero Power Reactor Operating on Chloride Salts

2021 ◽  
Vol 11 (15) ◽  
pp. 6673
Author(s):  
Bruno Merk ◽  
Anna Detkina ◽  
Seddon Atkinson ◽  
Dzianis Litskevich ◽  
Gregory Cartland-Glover
Keyword(s):  
Heavy Metal ◽  
Molten Salt ◽  
Spent Nuclear Fuel ◽  
Fuel Cycle ◽  
Power Reactor ◽  
Modelling And Simulation ◽  
Advanced Technology ◽  
Electricity Production ◽  
Eutectic System ◽  
Low Carbon

Molten salt reactors have gained substantial interest in the last years due to their flexibility and their potential for simplified closed fuel cycle operation for massive expansion in low-carbon electricity production, which will be required for a future net-zero society. The importance of a zero-power reactor for the process of developing a new, innovative rector concept, such as that required for the molten salt fast reactor based on iMAGINE technology, which operates directly on spent nuclear fuel, is described here. It is based on historical developments as well as the current demand for experimental results and key factors that are relevant to the success of the next step in the development process of all innovative reactor types. In the systematic modelling and simulation of a zero-power molten salt reactor, the radius and the feedback effects are studied for a eutectic based system, while a heavy metal rich chloride-based system are studied depending on the uranium enrichment accompanied with the effects on neutron flux spectrum and spatial distribution. These results are used to support the relevant decision for the narrowing down of the configurations supported by considerations on cost and proliferation for the follow up 3-D analysis. The results provide for the first time a systematic modelling and simulation approach for a new reactor physics experiment for an advanced technology. The expected core volumes for these configurations have been studied using multi-group and continuous energy Monte-Carlo simulations identifying the 35% enriched systems as the most attractive. This finally leads to the choice of heavy metal rich compositions with 35% enrichment as the reference system for future studies of the next steps in the zero power reactor investigation. An alternative could be the eutectic system in the case the increased core diameter is manageable. The inter-comparison of the different applied codes and approaches available in the SCALE package has delivered a very good agreement between the results, creating trust into the developed and used models and methods.

Transition to thorium fuel cycle on a heavy water moderated molten salt reactor by using low enrichment uranium

2022 ◽  
Vol 165 ◽  
pp. 108638
Author(s):  
Jianhui Wu ◽  
Jingen Chen ◽  
Chunyan Zou ◽  
Chenggang Yu ◽  
Xiangzhou Cai ◽  
...  
Keyword(s):  
Molten Salt ◽  
Heavy Water ◽  
Fuel Cycle ◽  
Molten Salt Reactor

Molten Salt Reactor With Simplified Fuel Recycling and Delayed Carrier Salt Cleaning

2014 ◽  
Author(s):  
Jiři Křepel ◽  
Valentyn Bykov ◽  
Konstantin Mikityuk ◽  
Boris Hombourger ◽  
Carlo Fiorina ◽  
...  
Keyword(s):  
Molten Salt ◽  
Fuel Cycle ◽  
Ex Situ ◽  
Molten Salt Reactor ◽  
Inherent Safety ◽  
Neutron Spectra ◽  
Fuel Fabrication

The Molten Salt Reactor (MSR) represents an old concept, but its properties are qualifying it for the advanced utilization: inherent safety, excellent neutron economy, possibility of continuous or batch reprocessing without fuel fabrication. The aim of this paper is to characterize the MSR unique fuel cycle advantages in different neutron spectra using the results of ERANOS-based EQL3D and ECCO-MATLAB based EQL0D procedures. It also focuses on the low production of higher actinides in the Th-U cycle and based on the results, it proposes a simplified in situ recycling of the fuel and the delayed ex situ carrier salt cleaning or direct disposal by vitrification.

scholarly journals Ecstasy from a physiological point of view

1982 ◽  
Vol 11 ◽  
pp. 74-86 ◽  
Author(s):  
Kaj Björkqvist
Keyword(s):  
Religious Tradition ◽  
Mental States ◽  
Human Mind ◽  
Point Of View ◽  
The Body ◽  
Biological Study ◽  
Physiological Basis ◽  
Slowing Down ◽  
Psychosomatic Diseases ◽  
The Brain

The biological study of man is one of today's most rapidly advancing sciences. There is no reason for not utilizing these methodologies of research and the knowledge already gained when studying ecstasy and other similar religious phenomena. Drugs have been used in all parts of the world as an ecstasy technique. Since mental states and physiological correlates always accompany each other, it is obvious that the human mind can be affected by external means, for instance by drugs. But the opposite is also true; mental changes affect the body, as they do in the case of psychosomatic diseases. Ecstasy is often described as an extremely joyful experience; this pleasure must necessarily also have a physiological basis. It is of course too early to say anything for certain, but the discovery of pleasure centres in the brain might offer an explanation. It is not far-fetched to suggest that when a person experiences euphoric ecstasy, it might, in some way or other, be connected with a cerebral pleasure center. Can it be, for example, that religious ecstasy is attained only by some mechanism triggering off changes in the balance of the transmitter substances? Or is it reached only via a change in the hormonal balance, or only by a slowing down of the brain waves, or is a pleasure centre activated? When a person is using an ecstasy technique, he usually does so within a religious tradition. When he reaches an experience, a traditional interpretation of it already exists.

scholarly journals Thermodynamic properties of fission products in liquid bismuth

2021 ◽  
Vol 2125 (1) ◽  
pp. 012048
Author(s):  
Guohua Ding ◽  
Limeng Liang
Keyword(s):  
Thermodynamic Properties ◽  
Activity Coefficient ◽  
Molten Salt ◽  
Fuel Cycle ◽  
Great Influence ◽  
Fission Products ◽  
Interaction Coefficients ◽  
Natural Logarithm ◽  
Molecular Interaction Volume Model ◽  
Infinite Dilute Activity Coefficient

Abstract The thermodynamic properties of fission products in molten salt and liquid metal have a great influence on the disposal of nuclear waste in the nuclear fuel cycle industrial system. This paper attempts to extract useful thermodynamic information from the only few experimental activities of lanthanides (Ce, Pr, La) in liquid Bi at different temperatures. The molecular interaction volume model (MIVM) was adopted to model and predict some temperature-dependent thermodynamic functions, including activity, infinite dilute activity coefficient, and molar excess Gibbs energy. The minor average of Δ G ¯ error indicated that assuming εji − εii is a constant is reasonable. On this basis, the natural logarithm of the interaction coefficients and the natural logarithm of the infinite dilute activity coefficient of lanthanides (Ce, Pr, La) in the Bi-based metal melt, these two parameters, show the linear relationship with the reciprocal of temperature. The reasonable agreement of the modeled thermodynamic parameters with the existing experimental data verified that the MIVM is quite convenient and reliable, which can provide guidance for separating fission products from molten salt reactors.

Accelerator-driven subcritical fission in molten salt core: Closing the nuclear fuel cycle for green nuclear energy

2013 ◽  
Author(s):  
Peter McIntyre ◽  
Saeed Assadi ◽  
Karie Badgley ◽  
William Baker ◽  
Justin Comeaux ◽  
...  
Keyword(s):  
Molten Salt ◽  
Nuclear Fuel ◽  
Nuclear Energy ◽  
Fuel Cycle ◽  
Nuclear Fuel Cycle
Sign in / Sign up

Export Citation Format

Share Document