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

Iwamoto, Hiroki; Nakano, Keita; Meigo, Shinichiro; Satoh, Daiki; Iwamoto, Yosuke; Sugihara, Kenta; Nishio, Katsuhisa; Ishi, Yoshihiro*; Uesugi, Tomonori*; Kuriyama, Yasutoshi*; et al.

Journal of Nuclear Science and Technology, 60(4), p.435 - 449, 2023/04

https://doi.org/10.1080/00223131.2022.2115423

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 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 NE213 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 iontransport code system (PHITS). All models, including JENDL-4.0/HE, failed to predict high-energy peaks at a detector angle of 5. 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.

Corrosion behavior of iron-chrome alloys in liquid bismuth

Takai, Toshihide; Furukawa, Tomohiro; Watanabe, Shigeki*; Ishioka, Noriko*

Mechanical Engineering Journal (Internet), 9(4), p.21-00397_1 - 21-00397_11, 2022/08

https://doi.org/10.1299/mej.21-00397

For the mass production of astatine-211, a promising radiopharmaceutical for cancer treatment, the National Institute for Quantum and Radiological Science and Technology has proposed the innovative "Liquid Bismuth Target System." The target window in this system must be made from a material that resists the highly corrosive liquid bismuth environment. To meet this requirement, a promising target window material was selected in corrosion experiments performed in stagnant liquid bismuth. Based on knowledge of corrosion in liquid lead-bismuth eutectic gained during the development of fast reactors and accelerator-driven subcritical systems, experiments were carried out under saturated dissolved oxygen and low oxygen conditions, and the corrosion behaviors of the specimens were evaluated. The FeCrAl-alloy exhibited the most excellent corrosion resistance, followed by FeCrMo-alloy. Both materials are suitable candidates for the target window.

Flow measurement in high temperature liquid metal by using electro-magnet probe

Ariyoshi, Gen; Obayashi, Hironari; Saito, Shigeru; Sasa, Toshinobu

Proceedings of 19th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-19) (Internet), 10 Pages, 2022/03

To clarify the flow characteristics of heavy liquid-metal (HLM) is important to achieve the construction of nuclear transmutation facility that utilizes HLM as a spallation target and coolant. At present, lead-bismuth eutectic (LBE) spallation target plans to be installed in Japan proton accelerator research complex (J-PARC). LBE is also selected as one of the candidate media of a spallation target and a coolant for innovative nuclear systems such as accelerator-driven system (ADS) and LBE-cooled fast reactor, due to its adequate physical/chemical properties. The characteristics of LBE flowing inside the target are usually clarified with computational fluid dynamics analysis since the measurement techniques for the HLM flow are not well established, especially for high temperature region over 450C that is delivered from ADS's criteria. Therefore, the objective of this study is to develop measurement method for flow characteristics in the high temperature LBE. A miniature electro-magnet is introduced to electro-magnetic probe to overcome the limitation caused by a curie temperature of permanent magnet. To evaluate performance of the new probe, experimental apparatus equipping annular rotating vessel were also manufactured. The new probe was applied to high temperature LBE up to 480C. As a result, proportional induced voltage to the rotation speed of LBE were clearly observed, where excitation currents of the miniature electro-magnet were 0.2 A or 1 A. In this paper, configuration and performance of the newly developed electro-magnet probe to the high temperature LBE will be presented.

Status of LBE study and experimental plan at JAEA

Saito, Shigeru; Wan, T.*; Okubo, Nariaki; Obayashi, Hironari; Watanabe, Nao; Ohdaira, Naoya*; Kinoshita, Hidetaka; Yamaki, Kenichi*; Kita, Satoshi*; Yoshimoto, Hidemitsu*; et al.

JPS Conference Proceedings (Internet), 33, p.011041_1 - 011041_6, 2021/03

https://doi.org/10.7566/JPSCP.33.011041

An Accelerator Driven System (ADS) for waste transmutation investigated in JAEA employs lead-bismuth eutectic (LBE) as a neutron production target material and coolant. The neutrons are to be produced via the spallation with 1.5 GeV proton beam injection. As materials irradiation data are important for ADS development, JAEA plans to construct an irradiation facility with LBE neutron production target in J-PARC. There are many technical issues on LBE for practical use. In JAEA, various R&Ds are being carried out. Concerning corrosion study, conditioning operation and functional tests of OLLOCHI started. Oxygen concentration control technology has also developing. In the large scale LBE loop experiment, the operation for steady state and transient experiments was performed by using IMMORTAL. In the area of instrument, development of ultrasonic flow meter and freeze seal valve are progressing as a key technology for the LBE loop system. Investigation of behavior of impurities in LBE, which is important for design of the irradiation facility, started. In this paper, the status of the LBE studies and experimental plan will be presented.

Corrosion behaviour of Al-added high Mn austenitic steels in molten lead bismuth eutectic with saturated and low oxygen concentrations at 450C

Wang, H.*; Yu, H.*; Kondo, Sosuke*; Okubo, Nariaki; Kasada, Ryuta*

Corrosion Science, 175, p.108864_1 - 108864_12, 2020/10

https://doi.org/10.1016/j.corsci.2020.108864

Corrosion tests were performed on newly developed alumina-forming austenitic (AFA) steels in stagnant lead bismuth eutectic (LBE) with saturated and low oxygen concentrations at 450C for 430 h. The steels exhibited enhanced corrosion resistance to the LBE environments with the increasing of Al content. A continuous and protective Al-rich oxide scale formed on the steel specimens that were exposed to LBE with a low oxygen concentration, whereas a non-protective and stratified oxide scale formed in the oxygen saturated LBE.

Characterization of mechanical strain induced by lead-bismuth eutectic (LBE) freezing in stainless steel cup

Ohdaira, Naoya*; Saito, Shigeru

Heliyon (Internet), 6(2), p.e03429_1 - e03429_8, 2020/02

https://doi.org/10.1016/j.heliyon.2020.e03429

Lead-bismuth eutectic (LBE) is a candidate liquid metal coolant for a fast reactor, especially accelerator driven system (ADS). Freeze sealed valve is a candidate design to be possible to add passive safety to the reactor. On the other hand, since LBE is known that it causes expansion after its solidification, quantitative evaluation of the stress to the pipe produced by the LBE expansion should be considered. Many researchers produced related data for the expansion, however, evaluations of the strain by LBE expansion was barely reported. Therefore, the strain measurement using a stainless steel cup and the stress evaluation was performed together with visual observation using an optical microscopy. The results indicated keeping above room temperature (RT) was a significantly effective way to reduce the strain to the pipe.

Anomaly of structural relaxation in complex liquid metal of bismuth; Dynamic correlation function of coherent quasi-elastic neutron scattering

Kawakita, Yukinobu; Kikuchi, Tatsuya*; Inamura, Yasuhiro; Tahara, Shuta*; Maruyama, Kenji*; Hanashima, Takayasu*; Nakamura, Mitsutaka; Kiyanagi, Ryoji; Yamauchi, Yasuhiro*; Chiba, Kaori*; et al.

Physica B; Condensed Matter, 551, p.291 - 296, 2018/12

https://doi.org/10.1016/j.physb.2017.12.037

There are elemental liquid metals with complex structures far from the hard sphere (HS) packing model. Liquid Bi has an asymmetric first peak in the structure factors S(Q). The pair distribution function g(r) exhibits strange distance ratio of 1:2 between the first and the second peaks. Since a HS model with two kinds of radius produces asymmetry of the main peak in S(Q), existence of short-lived covalent bonds was discussed. Contrarily, modulation of the atomic distribution by the Friedel oscillations of shielding electrons around metallic ions was discussed. To examine its bonding nature from viewpoints of dynamic correlation functions, we have measured neutron quasielastic scattering of liquid Bi by using cold disk chopper spectrometer installed at MLF of J-PARC. The van Hove function revealed that the shoulder structure located at a longer side of the first peak in g(r) exhibits a longer relaxation time than the main structures such as the first and second peaks.

Present state of partitioning and transmutation of long-lived nuclides, 4; Transmutation system using accelerator driven system and technology maturity of partitioning and transmutation

Tsujimoto, Kazufumi; Arai, Yasuo; Minato, Kazuo

Nihon Genshiryoku Gakkai-Shi ATOMO, 59(11), p.644 - 648, 2017/11

no abstracts in English

Design optimization of ADS plant proposed by JAERI

Saito, Shigeru; Tsujimoto, Kazufumi; Kikuchi, Kenji; Kurata, Yuji; Sasa, Toshinobu; Umeno, Makoto*; Nishihara, Kenji; Mizumoto, Motoharu; Ouchi, Nobuo; Takei, Hayanori; et al.

Nuclear Instruments and Methods in Physics Research A, 562(2), p.646 - 649, 2006/06

https://doi.org/10.1016/j.nima.2006.02.078

JAERI is conducting R&D on the Accelerator Driven System (ADS) to transmute minor actinides (MAs) contained in the high-level radioactive waste under the OMEGA (Options Making Extra Gains from Actinides and fission products) program. The present study discusses the design of the ADS plant and various R&D on the ADS. The reference design of ADS plant in JAERI is the 800 MWth, Pb-Bi eutectic (LBE) cooled, tank-type subcritical reactor loaded with (MA+Pu) nitride fuel. LBE is selected as a spallation target material. In our results of the optimization study on the neutronics of the ADS, we have adopted the maximum multiplication factor (k) of 0.97. From the results of the thermal-hydraulic analysis around the LBE spallation target, partition wall and flow control nozzle are required to keep the structural integrity around the core and the beam window. Feasibility of beam window was also discussed for transient conditions of proton beam.

Technology for cleaning of Pb-Bi adhering to steel, 1; Basic tests

Saito, Shigeru; Sasa, Toshinobu; Umeno, Makoto*; Kurata, Yuji; Kikuchi, Kenji; Futakawa, Masatoshi

JAERI-Tech 2004-074, 41 Pages, 2004/12

JAERI-Tech-2004-074.pdf:24.5MB

The accelerator driven system (ADS) is proposed to transmute minor actinides (MA) in high-level waste from spent fuels of nuclear power reactors. Liquid Pb-Bi alloy is a candidate material for spallation target and coolant of ADS. Pb-Bi cleaning technology is required to reduce radiation exposure during maintenance service and to decontaminate replaced components. In this study, three cleaning methods were tested; silicon oil cleaning at 170C, mixture of acetic acid and nitric acid cleaning. Specimens were prepared by immersion in melted Pb-Bi. After silicon oil tests, most of Pb-Bi remained on the surface of the specimens. It was found that blushing was needed to remove Pb-Bi effectively. On the other hands, Pb-Bi was easily dissolved and almost removed in the mixed acid and nitric acid. Silicon oil cleaning did not affect on base metals. The surface of base metals was slightly blacked after mixed acid cleaning. F82H base metals were corroded by nitric acid.