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Journal Articles

Impact of using JENDL-5 on neutronics analysis of transmutation systems

Sugawara, Takanori; Kunieda, Satoshi

Proceedings of International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2023) (Internet), 7 Pages, 2023/08

This study investigates the impact of the change from JENDL-4 to JENDL-5 on neutronics analysis of transmutation systems. As the transmutation systems, the following two systems are targeted: JAEA-ADS, a lead-bismuth cooled accelerator-driven system, and MARDS, a molten salt chloride accelerator-driven system. For the JAEA-ADS, the k-eff value increased 189 pcm from JENDL-4 to JENDL-5. It was found that the revisions of various nuclides affected to this difference. For example, the revision of $$^{15}$$N indicated an increase of 200 pcm from the JENDL-4 result. For the MARDS, it was found that the major revision of $$^{37}$$Cl and $$^{35}$$Cl cross sections was the main cause of the k-eff differences. This study confirmed that the difference in the nuclear data libraries still indicated differences in calculation results for the transmutation systems.

Journal Articles

Benchmark simulation code for the thermal-hydraulics design tool of the accelerator-driven system; Validation and benchmark simulation of flow behavior around the beam window

Yamashita, Susumu; Kondo, Nao; Sugawara, Takanori; Monji, Hideaki*; Yoshida, Hiroyuki

Journal of Nuclear Science and Technology, 22 Pages, 2023/00

To confirm the validity of the thermal-hydraulics design tool based on the Ansys Fluent, we used a detailed computational fluid dynamics code named JAEA Utility Program for Interdisciplinary Thermal-hydraulics Engineering and Research (JUPITER) for the thermal-hydraulics around the beam window (BW) of the Accelerator-Driven System (ADS). The Fluent uses the Reynolds-Averaged Navier-Stokes (RANS) model and can quickly calculate the turbulent flow around the BW as a BW design tool. At first, we compared the results of JUPITER with the experimental results using a mock-up BW system in water to confirm the validity of JUPITER. As a result, we confirmed that numerical results are in good agreement with the experimental results. Thus, we showed that JUPITER could be used as a benchmark code. We also performed a benchmark simulation for the Fluent calculation using validated JUPITER to show the applicability of JUPITER as an alternative of experiments. As a result, the mean values around the BW agreed with each other, e.g., the mean velocity profile for stream and horizontal directions. Therefore, we confirmed that JUPITER showed a good performance in validating the thermal-hydraulics design tool as a fluid dynamics solver. Moreover, Fluent has enough accuracy as a thermal-hydraulics design tool for the ADS.

Journal Articles

Measurement of density and viscosity for molten salts

Sato, Rika*; Nishi, Tsuyoshi*; Ota, Hiromichi*; Hayashi, Hirokazu; Sugawara, Takanori; Nishihara, Kenji

Dai-43-Kai Nihon Netsu Bussei Shimpojiumu Koen Rombunshu (CD-ROM), 3 Pages, 2022/10

no abstracts in English

Journal Articles

Beam physics design of a 30-MW beam transport to the target for an accelerator-driven subcritical system

Yee-Rendon, B.; Meigo, Shinichiro; Kondo, Yasuhiro; Tamura, Jun; Nakano, Keita; Maekawa, Fujio; Iwamoto, Hiroki; Sugawara, Takanori; Nishihara, Kenji

Journal of Instrumentation (Internet), 17(10), p.P10005_1 - P10005_21, 2022/10

 Times Cited Count:0 Percentile:0(Instruments & Instrumentation)

To reduce the hazard of minor actinides in nuclear waste, JAEA proposed an accelerator-driven subcritical system (JAEA-ADS). The JAEA-ADS drives a subcritical reactor 800-MWth by 30-MW proton linac delivering the beam to the spallation neutron target inside the reactor. The beam transport to the target (BTT) is required for high-beam power stability and low peak density to ensure the integrity of the beam window. Additionally, the design should have compatible with the reactor design for the maintenance and replacement of the fuel and the beam window. A robust-compact BTT design was developed through massive multiparticle simulations. The beam optics was optimized to guarantee beam window feasibility requirements by providing a low peak density of less than 0.3 $$mu$$A/mm$$^2$$. Beam stability was evaluated and improved by simultaneously applying the linac's input beam and element errors. The input beam errors to the reactor were based on the beam degradation obtained by implementing fast fault compensation in the linac. Those results show that the BTT fulfills the requirements for JAEA-ADS.

Journal Articles

Report on the 34th Meeting of Working Party on International Nuclear Data Evaluation Co-operation (WPEC)

Iwamoto, Osamu; Iwamoto, Nobuyuki; Kimura, Atsushi; Tada, Kenichi; Sugawara, Takanori; Yokoyama, Kenji

Kaku Deta Nyusu (Internet), (133), p.1 - 6, 2022/10

no abstracts in English

Journal Articles

Vibration of cantilever by jet impinging in axial direction

Tobita, Daiki*; Monji, Hideaki*; Yamashita, Susumu; Horiguchi, Naoki; Yoshida, Hiroyuki; Sugawara, Takanori

Proceedings of 12th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS12) (Internet), 5 Pages, 2022/10

Journal Articles

Material attractiveness evaluation of fuel assembly of accelerator-driven system for nuclear security and non-proliferation

Oizumi, Akito; Sugawara, Takanori; Sagara, Hiroshi*

Annals of Nuclear Energy, 169, p.108951_1 - 108951_9, 2022/05

 Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)

Research and development of the partitioning and transmutation (P&T) cycle with accelerator-drive systems (ADSs) transmuting minor actinides separated from the commercial cycles have been continuously conducted to reduce the amount of high-level radioactive waste contained in spent fuel discharged from nuclear power plants. Because the chemical form and composition of the fuels are different from those of the current commercial cycles, it is necessary to examine the inspection goal of the safeguards (SGs) and the design level of physical protections (PPs) that are required for the P&T cycle. In this study, the material attractiveness was evaluated assuming the theft or diversion of fuel assemblies from the fuel storage pool of the ADS facility in terms of nuclear security and non-proliferation. According to the results, quantitative components based on the fundamental fuel property were created as an important factor to decide the inspection goal for SGs and the design level for PPs required for the ADS facility. Additionally, the attractiveness of mixed oxide (MOX) fuel assemblies stored in the commercial boiling water reactor (BWR) facility was compared with that of the ADS. With regard to nuclear security, the ADS fuel was less attractive than the BWR MOX in every cycle. Regarding nuclear non-proliferation, the ADS fuel assembly had less attractive plutonium (Pu) than the BWR MOX, and the uranium (U) in the ADS fuel assembly was as attractive as (or slightly more attractive than) that of the BWR MOX owing to low spontaneous fission neutron. Furthermore, new issues were identified through this evaluation. With the current regulations, it was difficult to decide whether the ADS fuel before irradiation should be treated as fresh or spent, because the ADS fresh fuel contained more transuranium and rare earth than U and contained U whose main component was U-234 instead of U-238.

JAEA Reports

Neutronic analysis of beam window and LBE of an Accelerator-Driven System

Nakano, Keita; Iwamoto, Hiroki; Nishihara, Kenji; Meigo, Shinichiro; Sugawara, Takanori; Iwamoto, Yosuke; Takeshita, Hayato*; Maekawa, Fujio

JAEA-Research 2021-018, 41 Pages, 2022/03

JAEA-Research-2021-018.pdf:2.93MB

Neutronic analysis of beam window of the Accelerator-Driven System (ADS) proposed by Japan Atomic Energy Agency (JAEA) has been conducted using PHITS and DCHAIN-PHITS codes. We investigate gas production of hydrogen and helium isotopes in the beam window, displacement per atom of beam window material, and heat generation in the beam window. In addition, distributions of produced nuclides, heat density, and activity are derived. It was found that at the maximum 12500 appm H production, 1800 appm He production, and damage of 62.1 DPA occurred in the beam window by the ADS operation. On the other hand, the maximum heat generation in the beam window was 374 W/cm$$^3$$. In the analysis of LBE, $$^{206}$$Bi and $$^{210}$$Po were found to be the dominant nuclides in decay heat and radioactivity. Furthermore, the heat generation in the LBE by the proton beam was maximum around 5 cm downstream of the beam window, which was 945 W/cm$$^3$$.

Journal Articles

CFD analysis of natural circulation in LBE-cooled accelerator-driven system

Sugawara, Takanori; Watanabe, Nao; Ono, Ayako; Nishihara, Kenji; Ichihara, Kyoko*; Hanzawa, Kohei*

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

Japan Atomic Energy Agency (JAEA) has investigated an accelerator-driven system (ADS) to transmute minor actinides (MAs) included in high level wastes discharged from nuclear power plants. The ADS is a lead-bismuth cooled tank-type reactor with 800 MW thermal power. It is supposed that the ADS is safer than conventional critical reactors because it is operated in a subcritical state. The previous study performed the transient analyses for the typical ADS accidents such as unprotected loss of flow or beam overpower. It was shown that all calculation cases except loss of heat sink (LOHS) satisfied the no-damage criteria. To avoid the damage by LOHS, the ADS equips Direct Reactor Auxiliary Cooling System (DRACS) to remove the decay heat. The most important points of a DRACS operation are its reliability and to ensure the flowrate in a natural circulation state. This study aims to perform the CFD analysis of the natural circulation to clarify the flowrate in the ADS reactor vessel.

JAEA Reports

Radiation shielding analysis of the upper structure of an accelerator-driven system

Iwamoto, Hiroki; Meigo, Shinichiro; Nakano, Keita; Yee-Rendon, B.; Katano, Ryota; Sugawara, Takanori; Nishihara, Kenji; Sasa, Toshinobu; Maekawa, Fujio

JAEA-Research 2021-012, 58 Pages, 2022/01

JAEA-Research-2021-012.pdf:7.23MB

A radiation shielding analysis was performed for the structure located above the spallation target of an accelerator-driven system (ADS), assuming one cycle of an 800 MW thermal and 30 MW beam power operation. In this analysis, the Monte Carlo particle transport code PHITS and the activation analysis code DCHAIN-PHITS were used. The structures to be analyzed are a beam duct above the target, a beam transport room located above the ADS reactor vessel, beam transport equipment, and the room ceiling. For each structure, the radiation doses and radioactivities during and after the operation were estimated. Furthermore, the shielding structure of the ceiling was determined. As a result, it was found that the radiation dose at the site boundary would be sufficiently lower than the legal limit by applying the determined shielding structure. Moreover, under the condition of this study, it was shown that the effective dose rate around the beam transport equipment positioned above the target after the operation exceeded 10 mSv/h, and that the maintenance and replacement of the equipment in the room would require remote handling.

Journal Articles

Non-proliferation features in partitioning and transmutation cycle using accelerator-driven system, 2; Evaluation of ${it Material Attractiveness}$ of uranium in ADS fuel assembly

Oizumi, Akito; Sugawara, Takanori; Sagara, Hiroshi*

Dai-42-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2021/11

Research and development of partitioning and transmutation cycle with accelerator drive systems (ADSs) transmuting minor actinides (MAs) separated from the commercial cycles has been continuously conducted to reduce the high-level radioactive waste (HLW) contained in spent fuel discharged from nuclear power plants. Since the chemical form and composition of the fuels are different from those of the current commercial cycles, it is necessary to examine the inspection goal of the safeguards (SGs) and the design level of physical protections (PPs) which are required for the partitioning and transmutation cycle. In this study, ${it Material Attractiveness (Attractiveness)}$ of the uranium (U) in the fuel assembly in the fuel storage pool in the ADS facility was evaluated and it was compared with the plutonium (Pu) in the MOX fuel assembly for a general boiling water reactor (BWR). As a result, it made clear that the U in the ADS fuel assembly had equal to or less attractive than the Pu in the BWR MOX fuel assembly. Moreover, a new issue has been extracted. It is difficult to determine whether the ADS fresh fuel should be considered as non-irradiated or irradiated fuel under the current regulatory standards because the ADS fresh fuel contains many MAs, rare-earths, and $$^{234}$$U rich U.

JAEA Reports

Re-examinations of MA fuel composition for accelerator-driven system and its heat removal

Sugawara, Takanori; Moriguchi, Daisuke*; Ban, Yasutoshi; Tsubata, Yasuhiro; Takano, Masahide; Nishihara, Kenji

JAEA-Research 2021-008, 63 Pages, 2021/10

JAEA-Research-2021-008.pdf:4.43MB

This study aims to perform the neutronics calculations for accelerator-driven system (ADS) with a new fuel composition based on the SELECT process developed by Japan Atomic Energy Agency because the previous studies had used the ideal MA (minor actinide) fuel composition without uranium and rare earth elements. Through the neutronics calculations, it is shown that two calculation cases, with/without neptunium, satisfy the design criteria. Although the new fuel composition includes uranium and rare earth elements, the ADS core with the new fuel composition is feasible and consistent with the partitioning and transmutation (P&T) cycle. Based on the new fuel composition, the heat removal during fuel powder storage and fuel assembly assembling is evaluated. For the fuel powder storage, it is found that a cylindrical tube container with a length of 500 [mm] and a diameter of 11 - 21 [mm] should be stored under water. For the fuel assembly assembling, CFD analysis indicates that the cladding tube temperature would satisfy the criterion if the inlet velocity of air is larger than 0.5 [m/s]. Through these studies, the new fuel composition which is consistent with the P&T cycle is obtained and the heat removal with the latest conditions is investigated. It is also shown that the new fuel composition can be practically handled with respect to heat generation, which is one of the most difficult points in handling MA fuel.

JAEA Reports

Manufacturing miniature beam window for accelerator-driven system by cutting T91 steel

Watanabe, Nao; Sugawara, Takanori; Okubo, Nariaki; Nishihara, Kenji

JAEA-Technology 2020-026, 59 Pages, 2021/03

JAEA-Technology-2020-026.pdf:3.95MB

As a part of partitioning and transmutation technology development to reduce the burden of radioactive disposal, an investigation of Accelerator-Driven System (ADS) has been performed by Japan Atomic Energy Agency. A beam window, which is an inherent structure of the ADS, is planned to be made from T91 steel and its shape is a thin hemisphere shell. However, it had never been tried to manufacture it out of T91 steel. In this investigation, we tried to manufacture miniature beam windows by cutting T91 steel, and to discuss the process, manufacturing accuracy and geometry measurement methods. As a result, considering a real scale ADS beam window, a figure error between designing and machining ones is estimated to be about 5%. Its effect would be very small to the structural strength.

JAEA Reports

Estimation of oxygen consumption amount in LBE-cooled accelerator-driven system

Sugawara, Takanori; Komatsu, Atsushi

JAEA-Research 2020-016, 44 Pages, 2021/01

JAEA-Research-2020-016.pdf:2.94MB

It is required to control the oxygen concentration in lead-bismuth eutectic (LBE) to prevent the corrosion of structures in LBE-cooled nuclear system. This study estimated the oxygen consumption amount in the LBE-cooled accelerator-driven system (ADS). We used the evaluation formula for the oxide layer thickness, which were derived by various experiments, to estimate the oxygen consumption amount. It was found that the maximum oxide layer thicknesses for the fuel assembly and the beam window were about 35 [$$mu$$m] and 20 [$$mu$$m], respectively. Based on these results, the oxygen consumption amount for the ADS plant was estimated as 30 [kg] during one cycle (one year). Through this study, it was indicated that an oxygen supply device which could supply 3-4 [g/h] oxygen in the normal operation, 150 [g/h] in the peak and about 30 [kg] during one cycle was necessary.

Journal Articles

Neutronics design for molten salt accelerator-driven system as TRU burner

Sugawara, Takanori

Annals of Nuclear Energy, 149, p.107818_1 - 107818_7, 2020/12

 Times Cited Count:2 Percentile:24.76(Nuclear Science & Technology)

Treatment of surplus plutonium has been one of the most important issues in the utilization of nuclear power in Japan. This study investigates a molten salt accelerator-driven system (ADS) to transmute transuranic (TRU) nuclides to address the issue. MARDS (Molten salt Accelerator Driven System) concept employs lead chloride (PbCl$$_2$$) as a fuel salt to achieve a hard spectrum. Since the fuel salt is used as a spallation target, a dedicated spallation target is not required in this concept. Furthermore, a beam window which is a boundary between an accelerator and subcritical core is designed to avoid touching the fuel salt. It mitigates the difficulties of the beam design for ADS. Neutronics calculation for the MARDS concept was performed for a condition of 400 MW thermal power with 800 MeV proton beam. The calculation results showed that the proton beam current was about 7 mA and about 4400 kg plutonium could be transmuted during 40-year operation.

Journal Articles

Non-proliferation features in partitioning and transmutation cycle using accelerator-driven system; Evaluation of ${it Material Attractiveness}$ of fuel assembly in early period of burnup cycle

Oizumi, Akito; Sugawara, Takanori; Sagara, Hiroshi*

Dai-41-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2020/11

Research and development of partitioning and transmutation cycle with accelerator drive systems (ADSs) transmuting minor actinides (MAs) separated from the commercial cycles has been continuously conducted to reduce the high-level radioactive waste (HLW) contained in spent fuel discharged from nuclear power plants. Since the chemical form and composition of the fuels are different from those of the current commercial cycles, it is necessary to examine the accuracy of the safeguards (SGs) and the level of physical protections (PPs) which are required for the partitioning and transmutation cycle. In this study, ${it Material Attractiveness}$ of the first cycle fuel assemblies (fresh and spent fuels) in the fuel storage pool in the ADS facility was evaluated and it was compared with that of the MOX fuel assemblies (fresh and spent fuels) for a general boiling water reactor (BWR). As a result, it made clear that the fuel storage pool in the ADS facility storing the first cycle fuel assemblies were required the SG detection accuracy and PP level equal to or lower than the MOX fuel assembly of the BWR since the ADS fuel assembly in the first cycle was less attractive than the MOX fuel assembly for the BWR.

Journal Articles

Current Status of R&D and PIE Program for ADS Material Development in JAEA

Saito, Shigeru; Okubo, Nariaki; Obayashi, Hironari; Wan, T.; Sugawara, Takanori; Sasa, Toshinobu; Maekawa, Fujio

JPS Conference Proceedings (Internet), 28, p.071003_1 - 071003_6, 2020/02

Japan Atomic Energy Agency (JAEA) proposes transmutation of minor actinides (MA) by accelerator-driven systems (ADS). The ADS designed by JAEA is a system composed by LBE (Lead-Bismuth Eutectic) spallation target and a subcritical core. In the ADS, a beam window (BW) is exposed in complex field of heavy irradiation by proton/neutron and corrosion by flowing LBE. To develop ADS structural materials, it is of critical importance to investigate materials used in such environment. Thus, JAEA plans to construct a proton irradiation facility at the J-PARC to prepare an irradiation database for candidate ADS structural materials and to investigate irradiation effects in flowing LBE environment. In this paper, giving a whole scope of the JAEA ADS development, some results of experimental measurements and the specific program for planed R&D will be presented.

Journal Articles

Immortal experimental loop at JAEA; Post-process and validation

Watanabe, Nao; Obayashi, Hironari; Sugawara, Takanori; Sasa, Toshinobu; Nishihara, Kenji; Castelliti, D.*

Proceedings of 18th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-18) (USB Flash Drive), p.248 - 261, 2019/08

For the R&D for lead-bismuth eutectic alloy (LBE) cooled Accelerator Driven System (ADS), installation of experimental facility using LBE spallation target dedicated for ADS materials irradiation under flowing high temperature LBE environment is planned within the J-PARC project. JAEA has recently finalized the construction of "IMMORTAL", a demonstrative test loop representing a 1:1 model of the above LBE spallation target system. Such facility pursues several different objectives such as studies on the thermal-hydraulic behavior of the target, and validation of the LBE physical properties, the pressure drops and the heat transfer correlations. These results will be useful for design of the facility and LBE target/cooled ADS. In the frame of a bi-lateral collaboration between JAEA and SCK-CEN, a benchmark exercise on the experimental results from IMMORTAL has been carried out. The calculations have been performed with RELAP5-3D System Thermal-Hydraulic code. To assess and predict the thermal-hydraulic behavior of its primary loop, RELAP5-3D calculation models have been configured. The calculated results from these models represented that a valid contribution towards the validation of the LBE properties and empirical correlations present in RELAP5-3D code.

JAEA Reports

Development of prototype for TEF-T integral control system of J-PARC

Sakai, Kenji; Obayashi, Hironari; Saito, Shigeru; Sasa, Toshinobu; Sugawara, Takanori; Watanabe, Akihiko*

JAEA-Technology 2019-009, 18 Pages, 2019/07

JAEA-Technology-2019-009.pdf:2.34MB

Construction of Transmutation Experimental Facility (TEF) is under planning in the Japan Proton Accelerator Research Complex (J-PARC) program to promote R&D on the transmutation technology with using accelerator driven systems (ADS). ADS Target Test Facility (TEF-T) in TEF will develop spallation target technology and study on target materials with irradiating high intensity proton beams on a lead-bismuth eutectic (LBE) target. For safe and efficient beam operation, a general control system (GCS) will be constructed in TEF-T. GCS comprises several subsystems, such as a network system (LAN), an integral control system (ICS), an interlock system (ILS), and a timing distribution system (TDS) according to their roles. Especially, the ICS plays the important role that executes integral operations in the entire facility, acquires, stores and distributes operation data. We planned to develop a prototype of the ICS, to evaluate its concrete performances such as data transmission speeds, data storage capability, control functions, long-term stability of the system, and to utilize them for design of the actual ICS. This report mentions to product the prototype of ICS and to apply it to remote operations of instruments for developing LBE target technology.

Journal Articles

Design of accelerator-driven system consistent to partitioning technology

Sugawara, Takanori; Ban, Yasutoshi; Katano, Ryota; Tateno, Haruka; Nishihara, Kenji

Proceedings of International Conference on the Management of Spent Fuel from Nuclear Power Reactors 2019 (Internet), 9 Pages, 2019/06

The JAEA has proposed the double-strata strategy which will introduce a dedicated minor actinide (MA) transmutation cycle using an accelerator-driven system (ADS). In the previous study, the ideal fuel condition was supposed in the neutronics design of the ADS. For example, impurities such as rare earth (RE) nuclides which would accompany with MA, were not assumed. However, these nuclides would accompany with the ADS fuel and the capture reaction of these nuclides deteriorates the neutron economy of the ADS core. This study investigates a new fuel composition based on the SELECT (Solvent Extraction from Liquid-waste using Extractants of CHON-type for Transmutation) process proposed by JAEA. By performing the neutronics calculation of the ADS with the new fuel composition, a feasibility of the new fuel composition will be investigated.

161 (Records 1-20 displayed on this page)