Development of a design optimization framework for sodium-cooled fast reactors; Development of coupled analysis control function

Doda, Norihiro; Nakamine, Yoshiaki*; Igawa, Kenichi*; Iwasaki, Takashi*; Murakami, Satoshi*; Tanaka, Masaaki

Keisan Kogaku Koenkai Rombunshu (CD-ROM), 27, 6 Pages, 2022/06

As a part of the development of the "Advanced Reactor Knowledge- and AI-aided Design Integration Approach through the whole plant lifecycle (ARKADIA)" to automatically optimize the life cycle of innovative nuclear reactors including fast reactors, ARKADIA-design is being developed to support the optimization of fast reactor design in the conceptual stage. ARKADIA-Design consists of three systems (Virtual plant Life System (VLS), Evaluation assistance and Application System (EAS), and Knowledge Management System (KMS)). A design optimization framework controls the cooperation between the three systems through the interfaces in each system. This paper reports on the development status of the "VLS interface," which has a control function of coupling analysis codes in VLS.

Rabi-oscillation spectroscopy of the hyperfine structure of muonium atoms

Nishimura, Shoichiro*; Torii, Hiroyuki*; Fukao, Yoshinori*; Ito, Takashi; Iwasaki, Masahiko*; Kanda, Sotaro*; Kawagoe, Kiyotomo*; Kawall, D.*; Kawamura, Naritoshi*; Kurosawa, Noriyuki*; et al.

Physical Review A, 104(2), p.L020801_1 - L020801_6, 2021/08

https://doi.org/10.1103/PhysRevA.104.L020801

New precise measurements of muonium hyperfine structure at J-PARC MUSE

Strasser, P.*; Abe, Mitsushi*; Aoki, Masaharu*; Choi, S.*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; et al.

EPJ Web of Conferences, 198, p.00003_1 - 00003_8, 2019/01

https://doi.org/10.1051/epjconf/201919800003

Advanced sodium-cooled fast reactor development regarding GIF safety design criteria

Hayafune, Hiroki; Chikazawa, Yoshitaka; Kamide, Hideki; Iwasaki, Mikinori*; Shoji, Takashi*

Proceedings of International Conference on Fast Reactors and Related Fuel Cycles; Next Generation Nuclear Systems for Sustainable Development (FR-17) (USB Flash Drive), 11 Pages, 2017/06

Design studies on a next generation sodium-cooled fast reactor (SFR) considering the safety design criteria (SDC) developed in the generation IV international forum (GIF) was summarized. To meet SDC including the lessons learned from the TEPCO's Fukushima Dai-ichi Nuclear Power Plants accident, the heat removal function was enhanced to avoid loss of the function even if any internal events exceeding design basis or severe external event happen. Several design options have been investigated and auxiliary core cooling system using air as ultimate heat sink has been selected as an additional cooling system regarding system reliability and diversification. Even though the next generation SFR already adopts seismic isolation system, main component designs have been improved considering revised earthquake conditions. For other external events, design measures for various external events are taken into account. Reactor building design has been improved and important safety components are diversified and located separately improving independency. Those design studies and evaluations on the next generation sodium-cooled reactor have contributed to the development of safety design guidelines (SDG) which is under discussion in the GIF framework.

Mizunami Underground Research Laboratory Project, Annual report for fiscal year 2014

Hama, Katsuhiro; Mikake, Shinichiro; Ishibashi, Masayuki; Sasao, Eiji; Kuwabara, Kazumichi; Ueno, Tetsuro; Onuki, Kenji*; Beppu, Shinji; Onoe, Hironori; Takeuchi, Ryuji; et al.

JAEA-Review 2015-024, 122 Pages, 2015/11

JAEA-Review-2015-024.pdf:80.64MB

Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is pursuing a geoscientific research and development project namely the Mizunami Underground Research Laboratory (MIU) Project in crystalline rock environment in order to construct scientific and technical basis for geological disposal of High-level Radioactive Waste (HLW). The MIU Project has three overlapping phases: Surface-based Investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III). The MIU Project has been ongoing the Phase III, as the Phase II was concluded for a moment with the completion of the excavation of horizontal tunnels at GL-500m level in February 2014. This report presents the results of the investigations, construction and collaboration studies in fiscal year 2014.

Influence of boron vapor on transport behavior of deposited CsI during heating test simulating a BWR severe accident condition

Sato, Isamu; Onishi, Takashi; Tanaka, Kosuke; Iwasaki, Maho; Koyama, Shinichi

Journal of Nuclear Materials, 461, p.22 - 28, 2015/06

https://doi.org/10.1016/j.jnucmat.2015.02.032

We observed one of the simplified processes by conducting primitive experiments. CsI was heated at 1323 K to be vaporized and deposited on sampling parts with a temperature range of 1023 - 423 K and then BO was vaporized at 1973 K to be reacted with Cs/I there. After heating tests, each sampling part was soaked into alkali water to dissolve the surface-deposits for ICP-MS analysis. The results showed that CsI deposited at the sampling parts kept above approx. 850 K was striped by BO vapour. This behaviour will be thermodynamically discussed to study the Cs/I/B chemistry in the severe accidents.

Validation of plant dynamics analysis code using shutdown heat removal test-17 performed at the EBR-II

Ohira, Hiroaki; Doda, Norihiro; Kamide, Hideki; Iwasaki, Takashi*; Minami, Masaki*

Proceedings of 2015 International Congress on Advances in Nuclear Power Plants (ICAPP 2015) (CD-ROM), p.2585 - 2592, 2015/05

IAEA's Coordinated Research Project on Benchmark Analyses of Shutdown Heat Removal Test (SHRT) performed at the Experimental Breeder Reactor-II (EBR-II) has been carried out since 2012. The benchmark specifications were provided by the Argonne National Laboratory (ANL) and the model development for thermal-hydraulics codes and/or plant dynamics codes has been conducted by participating organizations. The experimental data were also provided by the ANL after the calculations have been performed as the blind simulation. JAEA participated in this benchmark analyses, and the plant dynamics analysis code; Super-COPD was applied to the SHRT-17 simulation. The calculated inlet temperature of the high pressure plenum agreed well with the test data in all simulation time. Although the Z-pipe inlet temperature and the IHX intermediate outlet temperature had some discrepancy in the first 400 sec. caused by larger mass flow rate of the primary pump and the perfect mixing model of upper plenum, these temperatures and the flow rate agreed well with the measured data after 400 sec. Hence it was concluded the present analytical model could predict the natural circulation in good accuracy.

Research program for the evaluation of fission product release and transport behavior focusing on FP chemistry

Sato, Isamu; Miwa, Shuhei; Tanaka, Kosuke; Nakajima, Kunihisa; Hirosawa, Takashi; Iwasaki, Maho; Onishi, Takashi; Osaka, Masahiko; Takai, Toshihide; Amaya, Masaki; et al.

Proceedings of 2014 Water Reactor Fuel Performance Meeting/ Top Fuel / LWR Fuel Performance Meeting (WRFPM 2014) (USB Flash Drive), 6 Pages, 2014/09

A new research program on severe accidents is lunched for the evaluation of FP release and transport behavior in BWR system. The purpose of the program is to improve the FP release and transport model using experimental database about FP chemistry focusing on Cs and I chemistry. In this program, effects of B including in control rod materials, BC for the Cs and I chemistry are paid attention. The experimental database used for the improvement will consist of results to obtain with newly-prepared test device under atmosphere with broad-ranging oxygen and/or steam partial pressure simulated those in BWR. The state of preparation for these experimental studies and analyses is introduced. In addition, the preliminary test was moved into action to show B chemical effect on Cs and I transport under one of the processes, which is deposited Cs compounds and B vapor and aerosol interaction. In this experiment, a "B stripping effect" to deposited CsI was observed.

Full-coherent free electron laser seeded by 13th- and 15th-order harmonics of near-infrared femtosecond laser pulses

Sato, Takahiro*; Iwasaki, Atsushi*; Owada, Shigeki*; Yamanouchi, Kaoru*; Takahashi, Eiji*; Midorikawa, Katsumi*; Aoyama, Makoto; Yamakawa, Koichi; Togashi, Tadashi*; Fukami, Kenji*; et al.

Journal of Physics B; Atomic, Molecular and Optical Physics, 46(16), p.164006_1 - 164006_6, 2013/08

https://doi.org/10.1088/0953-4075/46/16/164006

By introducing 13th- (61.7 nm) and 15th-order harmonics (53.4 nm) of femtosecond laser pulses at 800 nm into an undulator of SCSS (SPring-8 Compact SASE Source) test accelerator at RIKEN, these harmonic pulses were amplified by a factor of more than 10 with a high contrast ratio through the interaction between accelerated electron bunches and the harmonic pulses. From numerical simulations of the amplification processes of high-order harmonic pulses in the undulator, optimum conditions of the electron bunch duration interacting with the high-order harmonic pulses were investigated for generating full-coherent and intense pulses in the extreme ultraviolet wavelength region.

High intense full-coherent radiation of free electron laser seeded by high-order harmonics in extreme-ultraviolet region

Togashi, Tadashi*; Takahashi, Eiji*; Midorikawa, Katsumi*; Aoyama, Makoto; Yamakawa, Koichi; Sato, Takahiro*; Iwasaki, Atsushi*; Owada, Shigeki*; Yamanouchi, Kaoru*; Hara, Toru*; et al.

Proceedings of Ultrafast Optics IX (CD-ROM), 2 Pages, 2013/03

We have demonstrated free-electron laser radiation seeded by high-order harmonics in the extreme-ultraviolet region. Strong enhancement of the radiation intensity by a factor of 104 was observed with timing control of an electro-optical sampling technique.