Core performance requirements and design conditions for next-generation sodium-cooled fast reactor in Japan

Oki, Shigeo; Maruyama, Shuhei; Chikazawa, Yoshitaka; Ohtaki, Akira; Kubo, Shigenobu; Hibi, Koki*; Kan, Taro*

Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 9 Pages, 2017/04

A Forthcoming reprocessing plant for processing fast and thermal reactor fuels

Koma, Yoshikazu; Yano, Kimihiko; Ohtaki, Akira; Sato, Koji

Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10

On the course of changing the fuel cycle of thermal reactors into that based on fast reactors, those reactors share the capacity of electricity generation. The first commercial aqueous reprocessing plant for the fuels from a sodium cooled fast reactor was investigated in having a function of thermal reactor fuel treatment. After summarizing the differences in reprocessing fast and thermal reactor "FATHER" fuels, a process considering the change of head end and addition of secondary crystallization was proposed. Arrangement of the additional equipments was made and the resulted increase of the plant volume seems only a slight difference. For reprocessing the FATHER fuels at a throughput of 200 t/y, a plant for fast reactor fuels is appropriate for the design basis.

Development of hydrogen production technology using FBR (planning report)

Ono, Kiyoshi; Ohtaki, Akira; Chikazawa, Yoshitaka; Nakagiri, Toshio; ; Sekine, Takashi;

JNC TN9410 2004-013, 76 Pages, 2004/06

JNC-TN9410-2004-013.pdf:7.23MB

This report describes the features of technology, the schedule and the organization for the research and development regarding the hydrogen production technology using FBR thermal energy. Now, the hydrogen production system is proposed as one of new business models for FBR deployment. This system is the production of hydrogen either thermal energy at approximately 500deg-C or electricity produced by a sodium cooled FBR. Hydrogen is expected to be one of the future dean secondary energies without carbon-dioxide emission. Meanwhile the global energy demand will increase, especially in Asian countries, and the energy supply by fossil fuels is not the best choice considering the green house effect and the stability of energy supply. The development of the hydrogen technology using FBR that satisfies "sustainable energy development" and "utilization of energies free from environmental pollution" will be one of the promising options. Based on the above mentioned recognition, we propose the direction of the development, the issues to be solved, the time schedule, the budget, and the organization for R&D of three hydrogen production technologies, the thermochemical hybrid process, the low temperature steam reforming process, and the high temperature steam electrolysis process in JNC.

Study on the FBR cycle introduction scenario III; A New harmonized concept of hard energy path and soft energy path in the future hydrogen society

Ohtaki, Akira; ; ;

JNC TN9400 2002-035, 43 Pages, 2002/06

JNC-TN9400-2002-035.pdf:1.79MB

This report provides the results of our investigation about the new harmonized concept of hard energy path and soft energy path in the future hydrogen society, as a part of FBR cycle introduction scenario study in the JNC's "Feasibility Study on Commercialized Fast Reactor Cycle System". First, we considered that an environmental preservation policy and hydrogen utilization might be the current in the 21st century, then, investigated the supply-and-demand status of resources and energy in hydrogen society. Furthermore, the harmonized image of a nuclear fuel cycle and soft energy paths (distributed power supplies, fuel cell vehicle, chemical plant, etc.) was investigated. Nuclear fuel cycle is considered to contribute to the supply of the platinum group metals whose the increase in demand will be expected in hydrogen society in addition to production of the CO free energies (electric power, hydrogen, etc.) by nuclear energy. And the range of the supply-and-demand balance of the platinum group metals recovered from the reprocessed waste was calculated. Fufthermore, its radioactivity characteristics and the problem on the utilization of the recovered elements was evaluated. In order to propose the supply system of the resource and energy preserving the environment. We are going to study the infrastructure for the supply of recovered elements and CO free energy.

Study on the FBR cycle introduction scenario II; An study on the role of nuclear energy under the diversity of energy supply-and-demand

Ohtaki, Akira; ;

JNC TN9400 2002-033, 97 Pages, 2002/03

JNC-TN9400-2002-033.pdf:4.18MB

This report concerns it self with the results of an investigation about the possibility of future nuclear utilization in the part of FBR cycle introduction scenario study in the JNC's "Feasibility Study on Commercialized Fast Reactor Cycle System (theF/S)". We have investigated about the problems that confront energy industries and electric power companies, the capacities of distributed generation, the coexistence method of a distlibuted generation and large-scale power supply generation, and the development status of a small-scale nuclear reactor from a wide viewpoint. Especially the spread of distributed generation causes the decrease of the electlicity demand which the electric power companies supplies. Since introduction scale of a distributed power supply is also expeceted to increase in the future, it will give some influences to a future nuclear plan and a power supply plan. The hydrogen utilization with out greenhouse gas mission is expected to spread with distributed generation, such as a fuel cell and a micro-gas turbine. Therefore,we proposed the new business model that the hydrogen produced by using uclear surplus electricity is consumed distributed generation, such as a fuel cell and a micro-gas turbine. We plan to evaluate quantitatively the best power supply composition based on this load stability business model, FBR introduction capacities, the load factor, and the amount of CO reduction.

Technological study report on synthetic evaluation for FBR cycle; The report of the feasibility studyies on commercialized FBR cycle system (Phase I)

; Ohtaki, Akira; Kofuji, Hirohide; ;

JNC TN9400 2001-061, 335 Pages, 2001/03

JNC-TN9400-2001-061.pdf:17.62MB

This report is intended to explain the outline of the characteristic evaluation work on various FR cycle system concepts, following the design work, in the 1st phase of the JNC's "Feasibility Study on Commercialized Fast Reactor Cycle System (the F/S)" (from 1999 to March 2001). The purpose of this characteristic evaluation is to reveal the performance of candidate FR cycle systems. For this synthetic estimation, six viewpoints, such as Economics, Effective utilization of uranium resource, Reduction of environmental impact, Safety, Proliferation resistance, and Technological feasibility, are selected. In addition, aiming at the practical use in phase 2, we examined an application to FBR research and development of cost benefit analysis method used for the policy evaluation. Furthermore, long-term nuclear material mass flow was analyzed and the scenario of "FBR application for the hydrogen production" is proposed, considering how FBR would be utilized for the 21st century. And, a database including the various documents & data used for evaluation was constructed.

Scenario study on the global nuclear energy

; Ohtaki, Akira; ; *; *

JNC TN9400 2001-028, 51 Pages, 2000/12

JNC-TN9400-2001-028.pdf:1.96MB

This scenario study on the global nuclear energy was performed from the viewpoints of the maximum utilization of natural uranium resources, in order to clarify the role of nuclear energy in the future global primary energy supply. Social conditions, such as site issue and financial issue, aren't taken into consideration. Main three scenarios set up in this study are as follows, (1)LWR once-through (2)LWR with plutonium recycling (3)LWR+FBR From preliminary estimation, the following results were obtained. In the LWR once-through scenario and the LWR with plutonium recycling scenario, the nuclear energy can't support energy supply in the reference case B estimated by IIASA/WEC in the Global Energy Perspectives 1998. The nuclear energy decreases gradually after the middle of 21 century and exhausts uranium resource to phase out till the beginning of 22 century. On the other hand, if the FBR cycle is introduced in the future for Plutonium utilization, the nuclear energy is expected to be one of the most important sustainable energy options beyond the next century.

Development of plant dynamics analysis code : Super-COPD(III); Input and output interface program manual

*; Ohtaki, Akira

PNC TN9460 96-005, 66 Pages, 1996/05

PNC-TN9460-96-005.pdf:1.21MB

In order to facilitate plant dynamic analysis by Super-COPD, the pre- and post-processor programs of the code were developed. The pre-processor program converts the measured data into the input data as boundary conditions of Super-COPD. The post-processor program converts the measured data into the output format of Super-COPD. This data conversion enables direct comparisons between measured and calculated data through the plotting utility programs. The pre- and post-processor programs developed in this report are very useful to set the input data and the post process data in short time.

Development of plant dynamics analysis code Super-COPD, 2; Validation of natural circulation analysis function by MONJU experimental data

Ohtaki, Akira

PNC TN9410 96-054, 170 Pages, 1995/12

PNC-TN9410-96-054.pdf:5.89MB

In this paper analyses of natural circulation simulation tests in Monju were conducted to study the applicability of a plant dynamics analysis code (Super-COPD) to the evaluation of decay heat removal by natural circulation. At first basic characteristics of both primary and secondary heat transport systems were examined by separate analyses and then integral system analyses with primary and secondary systems were conducted to confirm the whole system behavior. A modeling of the reactor core and pressure loss characteristics were selected as analysis parameters in the primary system analyses. The effect of the overflow line on natural circulation characteristics were examined in the secondary system analyses. By the separate analyses it was indicated that a precise modeling of core flow channels and input data of axial height for calculating natural circulation head were important for the evaluation of natural circulation characteristics. In addition in the case of low flow condition (about 1-2% of rated flow), the effect of thermal stratification in the horizontal pipe on natural circulation head was observed during the transition to natural circulation condition. Therefore, the need of modeling for thermal stratification in the piping system was pointed out. The switching of flow direction from forward flow to back flow observed at the evaporator side in the secondary system was successfully simulated by the consideration of the overflow line. The results of synthesis analyses with primary and secondary systems were agreed with the measured data in Monju within the accuracy of 10%. Thus it was confirmed that Super-COPD is applicable to the evaluation of decay heat removal by natural circulation.

Development of plant dynamics analysis code Super-COPD; Validation by MONJU function test

Ohtaki, Akira; Miyakawa, Akira; Nakai, Satoru

PNC TN9410 95-060, 204 Pages, 1995/02

PNC-TN9410-95-060.pdf:7.96MB

The modular integrated plant dynamics analysis code "Super-COPD" is being developed. The validation of the code by using the MONJU functional test data was carried out to evaluate the accuracy of the calculation models and the validation results that had been carried out by using scale model test data. The procedure of the validation was as follows: (1)Setting up of the MONJU system data. The plant system data were set up by the tests data. (2)Refinement of the I/O. An input/output program for the MONJU test data was added to the code. (3)Evaluation of the test data. The test data to be used for the validation and program module to be validated were identified. The intermediate heat exchanger (IHX), steam generator (SG) and auxiliary cooling system (ACS) were selected as validation components. (4)Validation. The performance of some components was evaluated. The calculation and modification of the code were carried out. The following results were obtained. (1)IHX. The recommended calculation mesh number and plenum heat capacity and the items to be validated by the start up test were obtained. (2)SG. The recommended heat loss, validity of plenum model and the effectiveness of the flow rate to the thermal calculation were confirmed. A new model for the change of effective flow area in the SG may be needed at very low flow rate. (3)ACS. The ACS thermal/hydraulics were evaluated. The accuracy of air cooler thermal/hydraulics models, interlock/control system models, vane/blower models were validated. The accuracy of the calculation models and the validation results by using scale models was confirmed. Validation of the code using the start up test results under power operation is scheduled.