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Sugawara, Takanori; Kashima, Takao; Gabrielli, F.*; Rineiski, A.*; Yamanaka, Masao*
no journal, ,
The benchmark problem for JAEA-ADS was proposed in IAEA CRP (Coordinated Research Program) on ADS (Accelerator-Driven System). The purpose of this benchmark problem is to obtain fundamental knowledge of calculation accuracy for the neutronics design of a commercial grade ADS at the present time. In this benchmark problem, the calculations of a criticality and a burnup behaviour for JAEA-ADS were proposed and three institutes aimed the problem. The sensitivity and uncertainty analyses were also performed to know the current situation of covariance data prepared in nuclear data libraries. Through the benchmark calculations, it was confirmed that the prediction accuracy of the criticality and the transmutation amount for the ADS had the problem.
Katano, Ryota
no journal, ,
We have proposed the linear combination method for accurate prompt neutron decay constant measurement, which improves accuracy of the 
fitting method using pulsed neutron source (PNS). In this study, we perform PNS simulation with a continuous energy Monte Carlo code to confirm applicability of the proposed method to ADS core. The results indicate that thermal neutrons, which have less contribution to fissions, have long lifetime due to small absorption cross sections of LBE nuclides and could degrade accuracy of .
Watanabe, Nao; Obayashi, Hironari; Nishihara, Kenji
no journal, ,
JAEA investigates lead-bismuth eutectic alloy (LBE) as a candidate of coolant and spallation target of Accelerator Driven System (ADS). Construction of an experimental facility for LBE spallation target is planned within the J-PARC project for feasibility study of ADS's beam window, which is exposed to high temperature LBE flow and strong proton and neutron irradiation environment. As a demonstration, an LBE target mock-up loop "IMMORTAL" was constructed to confirm the operation of a primary cooling system and to implement integration tests of developing components of LBE technologies. The thermal-hydraulic characteristic of LBE is very important, however, studies about it are still limited compared with that of light water. Therefore, in this research, a calculation model of IMMORTAL's primary loop was made and the thermal-hydraulic behavior was numerically simulated by using the RELAP5-3D code. Then, simulation results and experimental data are compared to validate heat transfer coefficient correlations and properties of LBE.
Morishita, Takatoshi
no journal, ,
Accelerators for Accelerator Driven Systems (ADS) are required to have extremely high operational stability to reduce the fluctuations in the thermal load for the subcritical reactor by beam trips. The J-PARC linac, which is also a high-intensity proton accelerator, has been focused on improving the operational stability of the accelerator to achieve both stable beam quality and high availability. Accelerator cavities in the J-PARC linac contain an RFQ, DTLs, SDTLs, and ACS. Beam commissioning started in November 2006 and beam delivery to users started in 2008. To contribute to the development of ADS accelerators, the operating status of RF accelerator cavities in recent years, especially the RF trips that causes a beam stop, and future improvement plans are presented in this workshop. Additionally, the beam stop event such as equipment failure and the details of preventive maintenance will be reported.
Sasa, Toshinobu; Saito, Shigeru; Obayashi, Hironari; Ariyoshi, Gen; Wan, T.*; Okubo, Nariaki; Ohdaira, Naoya*; Yamaki, Kenichi*; Kita, Satoshi*; Yoshimoto, Hidemitsu*
no journal, ,
Japan Atomic Energy Agency (JAEA) proposes to reduce the minor actinides by Partitioning and Transmutation Technology using Accelerator-driven system (ADS). To realize ADS, JAEA plans to locate Lead-Bismuth Eutectic alloy (LBE) spallation target in J-PARC. LBE spallation target will be used to solve technical issues for ADS design by preparing irradiation database. The 400 MeV - 250 kW proton beam can be used for ADS studies. The spallation target is optimized by thermal-hydraulic analysis and structural analysis to increase proton/neutron irradiation of ADS materials by sharply focused proton beam injection. The studies for elemental technologies such as a fully-remote target exchange procedure and freeze-sealed drain valve system are also performed and integrated into the design of LBE target. The latest design of the J-PARC LBE spallation target system will be presented.
Nishihara, Kenji; Sugawara, Takanori; Tsujimoto, Kazufumi
no journal, ,
Japan Atomic Energy Agency has reorganized past R&Ds and launched PSi project (PSi: Proton accelerator-driven Subcritical virtual system) for R&D on ADS (Accelerator-Driven System). The PSi project aims efficient R&D toward industrialization of partitioning and transmutation by Accelerator-Driven System (ADS) by constructing "virtual" ADS on computer. The project is planed for around 10 years and final goal is to be ready for final design and approval application of demo-scale ADS. The project consists of four R&D fields: reactor physics and nuclear data, ADS plant and safety, lead-bismuth eutectic (LBE) and material, and, accelerator. Each field includes computation code for efficient engineering design, construction of model assembled in the code, and experiments to verify and validate the model. The experiment is not large-scale mock-up but small one using existing facility in Japan and the world.