Development Of Accelerator Driven Systems Research Articles

Neutron-production double-differential cross sections of natPb and 209Bi in proton-induced reactions near 100 MeV

The lack of double-differential cross-section (DDX) data for neutron production below the incident proton energy of 200 MeV hinders the validation of spallation models in technical applications, such as research and development of accelerator-driven systems (ADSs). The present study aims to obtain experimental DDX data for ADS spallation target materials in this energy region and identify issues related to the spallation models by comparing them with the analytical predictions. The DDXs for the (p,xn) reactions of natPb and 209Bi in the 100-MeV region were measured over an angular range of 30° to 150° using the time-of-flight method. The measurements were conducted at Kyoto University utilizing the FFAG accelerator. The DDXs obtained were compared with calculation results from Monte Carlo-based spallation models (INCL4.6/GEM, Bertini/GEM, JQMD/GEM, ISOBAR/GEM, CEM03.03, INCL4/ABLA, Bertini/ABLA, ISABEL/ABLA, INCL++/ABLA07, INCL++/GEMINI++, and INCL++/SMM) and the evaluated nuclear data library, JENDL-5. Comparison between the measured DDX and analytical values based on the spallation models and evaluated nuclear data library indicated that, in general, the CEM03.03 model demonstrated the closest match to the experimental values. Additionally, the comparison highlighted several issues that need to be addressed in order to improve the reproducibility of the proton-induced neutron-production DDX in the 100 MeV region by these spallation models and evaluated nuclear data library. To enhance the reproducibility of underperforming spallation models and evaluated nuclear data library, it is recommended to address each of the issues identified in this study.

Measurement of double-differential neutron yields for iron, lead, and bismuth induced by 107-MeV protons for research and development of accelerator-driven systems

For the research and development of accelerator-driven systems (ADSs) and fundamental ADS reactor physics research using the Kyoto University Critical Assembly combined with the fixed-field alternating gradient (FFAG) accelerator, we are conducting a series of experiments on double-differential neutron yields using the FFAG accelerator at Kyoto University. This paper presents an overview of the experiments together with preliminary results.

Measurement of 107-MeV proton-induced double-differential thick target neutron yields for Fe, Pb, and Bi using a fixed-field alternating gradient accelerator at Kyoto University

ABSTRACT Double-differential thick target neutron yields (TTNYs) for Fe, Pb, and Bi targets induced by 107-MeV protons were measured using the fixed-field alternating gradient accelerator at Kyoto University for the research and development of accelerator-driven systems (ADSs) and fundamental ADS reactor physics research at the Kyoto University Critical Assembly (KUCA). Note that TTNYs were obtained with the time-of-flight method using a neutron detector system comprising eight neutron detectors; each detector has a small EJ-301 liquid organic scintillator and photomultiplier tube. The TTNYs obtained were compared with calculation results using Monte Carlo-based spallation models (i.e. INCL4.6/GEM, Bertini/GEM, JQMD/GEM, and JQMD/SMM/GEM) and the evaluated high-energy nuclear data library, i.e. JENDL-4.0/HE, implemented in the particle and heavy ion transport code system (PHITS). All models, including JENDL-4.0/HE, failed to predict high-energy peaks at a detector angle of . Comparing the energy- and angle-integrated spallation neutron yields at energies of ≤20 MeV estimated using the measured TTNYs and the PHITS indicated that INCL4.6/GEM would be suitable for the Monte Carlo transport simulation of ADS reactor physics experiments at the KUCA.

Physics and technology for development of accelerator driven systems in India

A number of countries around the world have set up research programs for development of Accelerator Driven Systems (ADS) aimed towards Thorium Utilisation or Nuclear Waste Transmutation. Towards the beginning of this century, a Road Map for development of ADS was drawn up in India. The article gives a glimpse of the research being carried out around the world in this direction. The article begins with a brief historical introduction giving a description of various ADS concepts proposed and studied in the past. The Physics of ADS and how it is different from that of critical reactors is discussed. This is followed by a review of the work in the three areas of accelerator, target and sub critical reactor development, with particular emphasis on the activities in India.The accelerator program in India is oriented towards development of a high current high energy proton accelerator. The targeted energy and current are 1 GeV and 30 mA respectively. The first stage, presently under development, is a 30 mA 20 MeV Linac injector, the Low Energy High Intensity Proton Accelerator (LEHIPA). The article gives the present status of this program.The target development research includes studies related to heat removal and window damage such as irradiation creep, and void induced swelling due to hydrogen and helium generation and transmutation. Experimental facilities such as lead bismuth eutectic (LBE) loops for studying thermal hydraulics, and irradiation facilities for testing of targets have been set up. The reactor physics program includes basic theoretical studies on the Physics of ADS, development of advanced computer codes, compilation of nuclear data, an experimental program for studying the physics of sub critical ADS, and conceptual design studies of ADS systems for thorium utilisation.

Study of steady-state heat transfer with various large beam intensities in ADS windowless spallation target

Thermal hydraulics of spallation target, which is regarded as the ‘heart’ of the accelerator driven system (ADS), is very complicated due to the flow of the heavy liquid metal, spallation reaction and the coupling. In this paper, the steady-state temperature distribution, based on the flow pattern and the heat deposition, in the windowless spallation target with various large beam intensities from 10 mA to 40 mA is obtained to be in line with the development of ADS in China. The results show that the shape of temperature distribution is the same as broken wing of the butterfly but the temperature gradient and the maximum temperature vary in proportion with beam intensity. The variation of temperature gradient in different zones is also used to figure out the effect of large beam intensity. It has been found that large radial and axial temperature gradient leads to large temperature gradient on the wall. This may cause extremely large thermal stresses which leads to structural material damage. The results may be applied to the future design and optimization of ADS in China.

Perspectives of research and development of accelerator-driven system in Kyoto University Research Reactor Institute

The experimental studies on the accelerator-driven system (ADS) are being conducted for the basic research of nuclear transmutation analyses with the combined use of the core at the Kyoto University Critical Assembly (KUCA) and the fixed-field alternating gradient (FFAG; 100 MeV protons) accelerator, in the Kyoto University Research Reactor Institute. The ADS experiments with 100 MeV protons were carried out to investigate the neutronic characteristics of ADS, and the static and kinetic parameters were accurately analyzed through both the measurements and the Monte Carlo simulations of reactor physics parameters. An upcoming ADS at KUCA could be composed of highly-enriched uranium fueled and Pb–Bi zoned core, and the conversion analyses (237Np and 241Am) of nuclear transmutation could be conducted in ADS (hard spectrum core) at KUCA. Also, thermal hydraulics of liquid Pb–Bi are expected to be examined with the use of Pb–Bi test loop and test facilities for the investigation of Pb–Bi liquid characteristics from the viewpoints of single-phase heat transfer and two-phase flow.

The Issue of Accelerator Beam Trips for Efficient ADS Operation

The development of accelerator-driven systems (ADSs) is motivated by the potential of these machines to reduce the volume and the radiotoxicity of accumulated nuclear waste, more particularly that of minor actinides currently generated by the operation of existing pressurized water reactors. The reduction of both volume and radiotoxicity of nuclear waste is achieved by transmutation and fission of minor actinides into less-active isotopes or shorter-lived by-products.Various technical challenges exist regarding designing reliable and efficient ADSs. The key points are very much linked to the design of the spallation module, the assurance that reactivity remains below criticality under any circumstances, and the accelerator reliability.This paper addresses the latter two challenges imposed on the accelerator in order to assure safe and reliable ADS operation. It discusses the possibility of performing online absolute reactivity measurements and the limits in the number of allowable accelerator beam trips, which might impede plant integrity and/or plant efficiency.

Experience from the post-test analysis of MEGAPIE

The (MEGAWatt Pilot Experiment) MEGAPIE target was successfully irradiated in 2006 at the SINQ facility of the Paul Scherrer Institut. During the irradiation a series of measurements to monitor the operation of the target, the thermal hydraulics behavior and the neutronic and nuclear aspects, has been performed. In the post-test analysis phase of the project, the data were analyzed and important information relevant to accelerator-driven systems (ADS) was gained, in particular: (i) from the operation of the target several recommendations concern the simplification of the system and the improved reliability; (ii) data from the thermal hydraulic measurements have offered the opportunity to validate the codes used in the design phase; (iii) the neutronic analysis confirm the high performance of a liquid metal target and the importance of the delayed neutron measurements in an ADS target; (iv) the nuclear measurements of the gas released gave the opportunity to validate the codes used during the design phase and provided indications for the operation. From the results in these different domains recommendations to further development of ADS and heavy liquid metal targets are discussed.

Review of research and development of accelerator-driven system in Japan for transmutation of long-lived nuclides

Review of research and development of accelerator-driven system in Japan for transmutation of long-lived nuclides

Review of research and development of accelerator-driven system in Japan for transmutation of long-lived nuclides

Active and comprehensive studies on an accelerator-driven subcritical system (ADS) for transmutation of long-lived nuclides have been carried out at the Japan Atomic Energy Research Institute (JAERI). In the late 1970's, JAERI started the basic study of this subject and later, comprehensive studies have been performed under the “OMEGA” program of Japan: the long-term program for research and development on partitioning and transmutation (P&T) technology. Based on a design study of a dedicated transmutation system, JAERI decided to concentrate its efforts for transmutation study on the development of ADS. The construction of an experimental facility for the ADS development was proposed as a part of the Neutron Science Project of JAERI, which aimed at the construction of the world most powerful spallation neutron source. Since 1998, JAERI and the High Energy Accelerator Research Organization (KEK) are jointly proposing a High-Intensity Proton Accelerator Project. An ADS experimental facility composed of a subcritical assembly and a liquid lead-bismuth target/coolant engineering facility will be constructed under this project. In this paper, the development of ADS at JAERI, together with related technologies of P&T, both under the OMEGA program and the joint proposal, is reviewed. Other activities on ADS study in Japan are also reviewed.