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Journal Articles

JENDL-5 benchmarking for fission reactor applications

Tada, Kenichi; Nagaya, Yasunobu; Taninaka, Hiroshi; Yokoyama, Kenji; Okita, Shoichiro; Oizumi, Akito; Fukushima, Masahiro; Nakayama, Shinsuke

Journal of Nuclear Science and Technology, 21 Pages, 2023/04

 Times Cited Count:6 Percentile:98.92(Nuclear Science & Technology)

The new version of the Japanese evaluated nuclear data library, JENDL-5, was released in December 2021. This paper demonstrates the validation of JENDL-5 for fission reactor applications. Benchmark calculations are performed with the continuous-energy Monte Carlo codes MVP and MCNP and the deterministic code system MARBLE. The benchmark calculation results indicate that the performance of JENDL-5 for fission reactor applications is better than that of the former library JENDL-4.0.

JAEA Reports

In-vessel source term analysis code TRACER Version 2.4.1 (User's manual)

Ono, Masahiro*; Uchibori, Akihiro; Okano, Yasushi; Takata, Takashi*

JAEA-Testing 2022-004, 193 Pages, 2023/03

JAEA-Testing-2022-004.pdf:3.31MB

A computer code TRACER (Transport phenomena of Radionuclides for Accident Consequence Evaluation of Reactor) version 2.4.1 has been developed to evaluate species and quantities of fission products (FPs) released into cover gas due to a fuel pin failure in an LMFBR. The TRACER version 2.4.1 includes the models related to NUREG-0772 and also new or modified computational program codes in order to possess a new function shown below, and partial modify of coefficient of FP transition model between coolant and cover gas. This manual includes manual conventions for TRACER Version 2.3, addition of reference such as formula, improvement of explanation of input file creation method, addition of improvement of NUREG-0772 model added to TRACER code, modification of figure of sample analysis performed in appendix. It includes modifications and additions of sample analysis.

Journal Articles

Calculation of deuteron-induced reaction cross-sections for nuclear transmutation of long-lived fission products

Nakayama, Shinsuke; Furutachi, Naoya; Iwamoto, Osamu; Watanabe, Yukinobu*

NEA/NSC/R(2020)4 (Internet), p.345 - 349, 2022/10

Long-lived fission products (LLFPs) generated in nuclear reactors are strongly desired to be converted to stable or short-lived nuclides. Recently, it has been considered to transmute LLFPs by spallation reactions with high energy particles, and some experimental studies revealed that spallation reaction cross-sections induced by deuteron are larger than proton-induced ones. These results suggest the possibility that nuclear transmutation of LLFPs using deuteron beams is more efficient than one using proton beams. On the other hand, we have been developing a code system dedicated for deuteron-induced reactions, called DEURACS. DEURACS has been originally developed to contribute to the design of deuteron accelerator neutron sources. In the present study, we apply DEURACS to calculation of deuteron-induced spallation reactions on LLFPs. Through comparison with measured data, the applicability of DEURACS will be discussed.

Journal Articles

Unified description of the fission probability for highly excited nuclei

Iwamoto, Hiroki

JAEA-Conf 2021-001, p.24 - 29, 2022/03

Various spallation reaction models have been developed for the use of neutronic and shielding design of high-energy accelerator facilities such as J-PARC and ADS. However, their complicated theory for the de-excitation process has made improving their prediction accuracy difficult. In particular, it has been pointed out that the conventional models underestimate the yield of the spallation products produced from the fission reaction. This work has thus aimed to model the probability was described using a simpler, systematic expression, and then confirmed to predict fission cross sections for various incident energies and target nuclei with improved accuracy [1]. In this presentation, we will present the description of our model and research results. [1] H. Iwamoto and S. Meigo, "Unified description of the fission probability for highly excited nuclei", Journal of Nuclear Science and Technology, 56:2, 160-171 (2019).

Journal Articles

Fission mechanism inferred from nuclear shape fluctuation by the Langevin equation

Aritomo, Yoshihiro*; Iwamoto, Akira*; Nishio, Katsuhisa; Ota, Masahisa*

Physical Review C, 105(3), p.034604_1 - 034604_8, 2022/03

 Times Cited Count:2 Percentile:52.69(Physics, Nuclear)

Journal Articles

Angular momentum transfer in multinucleon transfer channels of $$^{18}$$O + $$^{237}$$Np

Tanaka, Shoya*; Hirose, Kentaro; Nishio, Katsuhisa; Kean, K. R.*; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Aritomo, Yoshihiro*

Physical Review C, 105(2), p.L021602_1 - L021602_5, 2022/02

 Times Cited Count:2 Percentile:33.4(Physics, Nuclear)

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

Journal Articles

Experimental evidence for common driving effects in low-energy fission from sublead to actinides

Schmitt, C.*; Lemasson, A.*; Schmidt, K.-H.*; Jhingan, A.*; Biswas, S.*; Kim, Y. H.*; Ramos, D.*; Andreyev, A. N.; Curien, D.*; Ciemala, M.*; et al.

Physical Review Letters, 126(13), p.132502_1 - 132502_6, 2021/04

 Times Cited Count:16 Percentile:84.11(Physics, Multidisciplinary)

JAEA Reports

Selection of nuclides for mass-balance analysis of fission products

Okamura, Tomohiro*; Oizumi, Akito; Nishihara, Kenji; Nakase, Masahiko*; Takeshita, Kenji*

JAEA-Data/Code 2020-023, 32 Pages, 2021/03

JAEA-Data-Code-2020-023.pdf:1.67MB

Nuclear Material Balance code (NMB code) have been developed in Japan Atomic Energy Agency. The NMB code will be updated with the function of mass balance analysis at the backend process such as reprocessing, vitrification and geological disposal. In order to perform its analysis with high accuracy, it is necessary to expand the number of FP nuclides calculated in the NMB code. In this study, depletion calculation by ORIGEN code was performed under 3 different burn-up conditions such as spent uranium fuel from light water reactor, and nuclides were selected from 5 evaluation indexes such as mass and heat generation. In addition, the FP nuclides required to configure a simple burnup chain with the same calculation accuracy as ORIGEN in the NMB code was selected. As the result, two lists with different number of nuclides, such as "Detailed list" and a "Simplified list", were created.

Journal Articles

Journal Articles

Measurement of fission-fragment mass distributions in the multinucleon transfer channels of the $$^{18}$$O+$$^{237}$$Np reaction

Vermeulen, M. J.; Nishio, Katsuhisa; Hirose, Kentaro; Kean, K. R.; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Tsekhanovich, I.*; Andreyev, A. N.; Ishizaki, Shoma*; et al.

Physical Review C, 102(5), p.054610_1 - 054610_11, 2020/11

 Times Cited Count:5 Percentile:52.72(Physics, Nuclear)

Journal Articles

Origin of the dramatic change of fission mode in fermium isotope investigated using Langevin equations

Aritomo, Yoshihiro*; Miyamoto, Yuya*; Nishio, Katsuhisa

Nihon Butsuri Gakkai-Shi, 75(10), p.631 - 636, 2020/10

no abstracts in English

Journal Articles

Separation and recovery of long-lived fission products from high level radioactive waste using electrochemical technique

Kanamura, Shohei*; Takahashi, Yuya*; Omori, Takashi*; Nohira, Toshiyuki*; Sakamura, Yoshiharu*; Matsumura, Tatsuro

Denki Kagaku, 88(3), p.289 - 290, 2020/09

no abstracts in English

Journal Articles

Research development of separation for nuclear fuel reprocessing and reduction of hazardous substance in high level radioactive waste

Sasaki, Yuji

Kagaku Kogaku, 84(9), p.425 - 427, 2020/09

The reduction of waste volume and hazardous substance though separation methods concerning atomic energy must be requested. As disposal methods or temporary measures, geological disposal, transmutation and interim storage are proposed. In order to perform effectively the disposal methods, the development of separation method of aimed elements is indispensable. Here, the new separation method of U and Pu from spent nuclear fuel and minor actinide separation and fission products from high level radioactive waste are explained.

Journal Articles

Simultaneous determination of neutron-induced fission and radiative capture cross sections from decay probabilities obtained with a surrogate reaction

P$'e$rez S$'a$nchez, R.*; Jurado, B.*; M$'e$ot, V.*; Roig, O.*; Dupuis, M.*; Bouland, O.*; Denis-Petit, D.*; Marini, P.*; Mathieu, L.*; Tsekhanovich, I.*; et al.

Physical Review Letters, 125(12), p.122502_1 - 122502_5, 2020/09

 Times Cited Count:14 Percentile:70.32(Physics, Multidisciplinary)

JAEA Reports

Production of the minor actinide sources using the electrodeposition method

Nakamura, Satoshi; Kimura, Takahiro; Ban, Yasutoshi; Tsubata, Yasuhiro; Matsumura, Tatsuro

JAEA-Technology 2020-009, 22 Pages, 2020/08

JAEA-Technology-2020-009.pdf:2.92MB

Partitioning and transmutation technology division is planning to measure fission rate ratios that contribute to validate nuclear data of minor actinides (MA). For this purpose, MA sources for fission chambers were prepared using electrodeposition method. The radioactivity of each MA source was quantified, and its uncertainty was evaluated. Seven types of MA sources with different radioactivity were prepared using four nuclides of $$^{237}$$Np, $$^{241}$$Am, $$^{243}$$Am, and $$^{244}$$Cm. A $$^{244}$$Cm source solution of which radioactivity was quantified by isotope dilution method was used to prepare working standard sources of $$^{244}$$Cm. The radioactivities were quantified as 1461 Bq, 2179 Bq, and 2938 Bq for $$^{237}$$Np sources, 1.428 MBq for $$^{241}$$Am source, 370.5 kBq and 89.57 kBq for $$^{243}$$Am sources, and 2.327 MBq for $$^{244}$$Cm source with, the uncertainty of 0.35% (1$$sigma$$). This report summarizes the method for preparation and quantification of MA sources, and uncertainty evaluation.

Journal Articles

First online operation of TRIGA-TRAP

Grund, J.*; Asai, Masato; Blaum, K.*; Block, M.*; Chenmarev, S.*; D$"u$llmann, Ch. E.*; Eberhardt, K.*; Lohse, S.*; Nagame, Yuichiro*; Nagy, Sz.*; et al.

Nuclear Instruments and Methods in Physics Research A, 972, p.164013_1 - 164013_8, 2020/08

 Times Cited Count:6 Percentile:60.71(Instruments & Instrumentation)

We report on the successful coupling of the Penning-trap mass spectrometry setup TRIGA-TRAP to the research reactor TRIGA Mainz. This offers the possibility to perform direct high-precision mass measurements of short-lived nuclei produced in neutron-induced fission of a $$^{235}$$U target located near the reactor core. An aerosol-based gas-jet system is used for efficient transport of short-lived neutron-rich nuclei from the target chamber to a surface ion source. In conjunction with new ion optics and extended beam monitoring capabilities, the experimental setup has been fully commissioned. The design of the surface ion source, efficiency studies and first results are presented.

Journal Articles

$$beta$$-delayed fission of isomers in $$^{188}$$Bi

Andel, B.*; Andreyev, A. N.; Antalic, S.*; Al Monthery, M.*; Barzakh, A.*; Bissell, M. L.*; Chrysalidis, K.*; 29 of others*

Physical Review C, 102(1), p.014319_1 - 014319_12, 2020/07

 Times Cited Count:6 Percentile:59.56(Physics, Nuclear)

Journal Articles

Effects of multichance fission on isotope dependence of fission fragment mass distributions at high energies

Tanaka, Shoya; Aritomo, Yoshihiro*; Miyamoto, Yuya*; Hirose, Kentaro; Nishio, Katsuhisa

Physical Review C, 100(6), p.064605_1 - 064605_6, 2019/12

 Times Cited Count:13 Percentile:79.29(Physics, Nuclear)

Fission fragment mass distributions of $$^{234-240}$$U, $$^{236-242}$$Np, and $$^{238-244}$$Pu are studied using the Langevin approach in the widely excitation energy range as $$E^{*}$$ = 15-55 MeV. In the present calculation, neutron emission before fission, so called multichance fission, was introduced. The calculated results well demonstrated the experimental data, which shows the double-peak structure up to the highest excitation energies and the clear dependence on the initial fissioning nuclides. The trend is nicely correlated with the neutron binding energy of the compound nucleus that dominates the neutron emission probability before fission.

519 (Records 1-20 displayed on this page)