Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Dwijayanto, A. P.*; Nishihara, Kenji; Okamura, Tomohiro*; Nakase, Masahiko*
no journal, ,
NMB4 is a nuclear fuel cycle simulator capable of modelling various nuclear fuel cycle scenarios from front-end to back-end. However, its capability to simulate a Molten Chloride Fast Reactor (MCFR), a subset of Molten Salt Reactor (MSR), had yet to be tested. Verifying NMB4 capability to model MCFR fuel cycle in a nuclear energy system is crucial for determining the limit of applicability and future development of the NMB4 simulator. A mass balance comparison between the NMB4 nuclear fuel cycle simulator and the Monte Carlo code Serpent-2 was then performed. A long-lived marine-based MCFR core with minimal reprocessing was modeled in a Monte-Carlo code as the closest scheme with the depletion capability supported by NMB4. From the results, NMB4 was found to generate an acceptable mass balance compared to Serpent-2, and a simple case study using a marine-based MCFR was subsequently simulated to analyse the mass balance and the disposal area required in a once-through cycle. Several discrepancies in code verification have been discussed, and future developments are suggested.
Nishihara, Kenji; Takeshita, Kenji*; Shimada, Takashi*; Aizawa, Naoto*; Nakase, Masahiko*; Wada, Satoshi*; Wakasaki, Shingo*; Matsui, Minefumi*; Yasunaga, Yoshiaki*; Okamura, Tomohiro*; et al.
no journal, ,
This study presents benchmark activities conducted by a research committee of the Atomic Energy Society of Japan to enhance the reliability of nuclear fuel cycle simulators. Standard reactor libraries and phased benchmark scenarios were developed and applied to stepwise validation exercises. The results clarify consistency of simulators on burnup calculation and impact of human error. The results for 11 large-scale scenarios are also provided for future activity.
Tsujimoto, Kazufumi
no journal, ,
no abstracts in English
Takino, Kazuo; Yasumatsu, Naoto*; Kato, Atsushi
no journal, ,
Oizumi, Akito; Luzieux, C.*; Abe, Takumi; Nishihara, Kenji
no journal, ,
The Japan Atomic Energy Agency has developed a Nuclear Material Balance code, NMB, that can evaluate nuclear material quantities throughout the nuclear fuel cycle, accounting for various advanced reactor systems and fuel types. Recently, concepts of security by design and safeguards by design, which consider nuclear security and safeguards from the early stages of conceptual design, have been introduced in the design of advanced nuclear systems. Considering this trend, the NMB has a plan to implement calculation functions regarding the 
evaluation, which is an effective method for estimating nuclear non-proliferation features. In this study, we discuss the implementation of bare critical mass (BCM) and heat content (HC) calculation functions, which are important indices for the utilization phase of the 
evaluation, into the NMB using a neural network model, Multi-Layer Perceptron (MLP). For BCM, the comparison with the Monte Carlo calculation (MCNP) values is further proof of the MLP model's accuracy, as the maximum relative error for the tested values was 0.38%. For HC, the ranges were similar to the existing paper's results as well. To release the NMB code capable of scenario analysis considering nuclear non-proliferation features, it is necessary to implement functions that can estimate indicators for the acquisition phase (e.g. net weight, acquisition time, and dose rate) and the processing phase (e.g. processing complexity and conversion time) in addition to the utilization phase (BCM and HC), which are necessary for the evaluation in future work.
Abe, Takumi; Shishido, Hiroki*; Ito, Satoshi*
no journal, ,
Fukaya, Yuji; Yan, X.; Matsumura, Tatsuro; Nishihara, Kenji*; Hayashi, Reona*
no journal, ,
In the present study, legal suitability on no HLW emission nuclear fuel cycle option had been investigated. As a part of a public acceptance study, we had to show no HLW emission nuclear fuel cycle option, as an extreme option to reflect the public will. For the option, the Sr-90, Cs-137 transmutation, which was already proposed for total waste volume control, were employed. But, the legal suitability is not confirmed. Then, the waste from the proposed fuel cycle is categorized to IAEA's classification and the characteristics are evaluated. As a result, the waste removed Sr-90, and Cs-137 is categorized to intermediate level waste (ILW) which is LLW in Japanese category. In addition, revision of final disposal law was investigated. Finally, we could provide the legal suitable no HLW emission nuclear fuel cycle option to the public acceptance study.
Ogata, Takanari*; Washiya, Tadahiro; Sugihara, Hideyuki; Ambai, Hiromu; Yoshida, Sachimasa; Yamada, Yoshikazu; Sakamura, Yoshiharu*; Murakami, Tsuyoshi*
no journal, ,
Conceptual design study is in progress for metal fuel cycle facilities which consist of metal fuel fabrication facilities and pyroprocessing facilities for the demonstration fast reactor and commercial fast reactors in order to evaluate fast reactor fuels from the standpoints of technical practicability and economic effectiveness for the determination of a fuel form for the demonstration fast reactor. The methods of remote operation, maintenance and repair in the hot cells, and the performance and number of main process equipment can be determined based on relevant domestic research and development experiences, and reported experiences in the Fuel Cycle Facility operated in 1960's and the Fuel Conditioning Facility recently operated in US. Technical practicability and economic effectiveness including the facility construction cost and operation cost estimations will be evaluated as a result of the conceptual design study.