Riyana, E. S.*; Suda, Shoya*; Ishibashi, Kenji*; Matsuura, Hideaki*; Katakura, Junichi*; Sun, G. M.*; Katano, Yoshiaki
Journal of Nuclear Science and Technology, 56(5), p.369 - 375, 2019/05
Nuclear reactors produce a great number of electron antineutrinos mainly from beta-decay chains of fission products. Such neutrinos have energies mostly in MeV range. We are interested in neutrinos in a region of keV, since they may have information on fuel burn-up and may be detected in future with advanced measurement technology. We calculate reactor antineutrino spectra especially in the low energy region. In this work we present neutrino spectra from various reactors such as typical PWR reactor and others types of reactors for comparison. Our result shows the electron antineutrino flux in the low energy region increases with burn-up of nuclear fuel by accumulated nuclides with low Q values in beta decay.
Kadowaki, Haruhiko; Matsushima, Akira; Nakajima, Yoshiaki
Proceedings of 24th International Conference on Nuclear Engineering (ICONE-24) (DVD-ROM), 6 Pages, 2016/06
Advanced thermal reactor "FUGEN" is a heavy water-moderated boiling light water-cooled pressure tube-type reactor. Because tritium had been generated in the heavy water during the reactor operation, the heavy water system and helium system were contaminated by tritium. The chemical form of the tritium was water molecule in FUGEN. Air-through drying and vacuum drying were applied to the system drying, and it was demonstrated that both methods were effective for drying treatment of heavy water in system. Helium system, low-contamination and non inclusion, could finish the vacuum drying rapidly. However, Heavy water purification system needed long period for drying treatment. The result showed that it needed long period to dry up if the objects include the adsorbent of water such as alumina pellet, resin and silica gel. But it can be accelerated by replacement absorbed heavy water to light water from the result of drying treatment of the rotary type dehumidifier.
Koda, Yuya; Tezuka, Masashi; Yanagihara, Satoshi*
JAEA-Technology 2015-050, 74 Pages, 2016/03
The implementation of the decommissioning work is accompanied by long-term period and considerable expense, so it is important that we make the most optimized work scenario in consideration of safety or the work and effectiveness. For this reason, we are studying selection method of the optimal work scenarios as a management index of the manpower and dose etc., in dismantling work for Fugen. In this report, results of a study shows the method of selecting the best scenarios for the heat exchangers of the reactor coolant purification system by evaluating execution multiple work scenarios, as well as evaluating the manpower and dose, etc., moreover by setting the importance of each evaluation item.
Iwai, Hiroki; Nakamura, Yasuyuki; Mizui, Hiroyuki; Sano, Kazuya
JAEA-Technology 2015-046, 110 Pages, 2016/03
Advanced Thermal Reactor (ATR) FUGEN is a proto-type heavy water moderated, boiling light water cooled, pressure tube-type reactor with the thermal power of 557 MW and the electrical power of 165 MW. The reactor of FUGEN is classified into the core region and the shielding region. The core region is highly activated owing to the long term operation, and characterized by its tube-cluster construction that contains 224 fuel channels arranging both the pressure and the calandria tubes coaxially in each channel closely. And the shielding region surrounding the core region has the laminated structure composed of up to 150 mm thickness of carbon steel. The reactor is planning to be dismantled under water remotely in order to shield the radiation around the core and prevent airborne dust generated by the cutting, and firing of zirconium material. This paper reports on the result of development of the basic dismantling procedure of the reactor of FUGEN.
Nakamura, Yasuyuki; Iwai, Hiroki; Mizui, Hiroyuki; Sano, Kazuya
JAEA-Technology 2015-045, 137 Pages, 2016/03
FUGEN is 9 m outer-diameter and 7m height, and characterized by its tube-cluster construction that contains 224 fuel channels arranging both the pressure and the calandria tubes coaxially in each channel. And the periphery part of the core has the laminated structure composed of up to 150 mm thickness of carbon steel for radiation shielding. The structure of the reactor, which is made of various materials such as stainless steel, carbon steel, zirconium alloy and aluminum. The reactor is planning to be dismantled under water in order to shield the radiation ray around the core and prevent airborne dust generated by the cutting, the temporary pool structure and the remote-operated dismantling machines needs to be installed on the top of reactor. In consideration of above the structure of Fugen reactor, the cutting method was selected for dismantling the reactor core in order to shorten the dismantling term and reduce the secondary waste.
Tokai Reprocessing Technology Development Center
JAEA-Evaluation 2015-012, 83 Pages, 2015/12
Japan Atomic Energy Agency (hereafter referred as "JAEA") consulted the "Evaluation Committee of Research and Development Activities for Fast Reactor Cycle" to assess the issue on "Research and Development on Reprocessing of Nuclear Fuel Materials" conducted by JAEA during the period from FY2010 to FY2014. In response to the JAEA's request, the committee assessed the R&D programs and the activities of JAEA related to the issue and concluded the mission was accomplished. This evaluation was performed based on the "General guideline for the evaluation of government R&D activities", the "Guideline for evaluation of R&D in Ministry of Education, Culture, Sports, Science and Technology (MEXT)" and the "Operational rule for evaluation of R&D activities" by JAEA.
Tsuji, Tomoyuki; Nakamura, Yasuo; Nakatani, Takayoshi
JAEA-Technology 2015-014, 34 Pages, 2015/06
[The article has been found to have a problem about reliability of the corrosion data acquisition, and thus it is unavailable to download the full text in accordance with authors' intentions to retract the report.] In order to dispose of radioactive wastes for sub-surface disposal, JAEA has studied the safety assessment for likely scenario and less-likely scenario. Radioactive nuclide leaching rate under the sub-surface disposal is important parameter in the safety assessment because radioactive nuclides in activated metal wastes are released with its corrosion. In this report, sensitivity of radioactive nuclide leaching rate is studied for the safety assessment. As the result, it is confirmed that Cl-36 which is dominant for the safety assessment in groundwater scenario is sensitive to radioactive nuclide leaching rate, but Nb-94 which is dominant in tunnel excavation scenario is not sensitive to radioactive nuclide leaching rate but to distribution coefficients in engineered barrier.
Hayashi, Hirokazu; Soejima, Goro; Mizui, Hiroyuki; Sano, Kazuya
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 7 Pages, 2015/05
In the Fugen Nuclear Power Plant, we are going to conduct appropriate classification of the waste according to the contamination level of the material of the plant, to reduce the amount of radioactive waste and to promote dismantling work rationally and efficiently. For this reason, we are going to apply the clearance system to the dismantled material generated from dismantling work of the turbine system, and to reduce the radioactive waste amount as much as possible. In order to operate the clearance system properly, the target nuclides need to be selected accurately, and the evaluation method of them should be established. The assessment was conducted as follows.
Kitamura, Koichi; Kutsuna, Hideki; Matsushima, Akira; Koda, Yuya; Iwai, Hiroki
Dekomisshoningu Giho, (51), p.2 - 10, 2015/04
Fugen Decommissioning Engineering Center (herein after called as "FUGEN") obtained the approval of the decommissioning program on February 2008. FUGEN has been carrying out decommissioning works based on its decommissioning program since then. Now is in initial stage, the dismantling works was launched in turbine system whose contamination was relatively low level and their various data have been accumulating. And the draining heavy water, tritium decontamination and transferring of heavy water were carried out safely and reasonably. The preparation for the clearance system and the research and development works for the reactor core dismantling have been progressed steadily as well. Meanwhile, FUGEN has affiliation with local industries and universities for collaboration research, and has exchanged the decommissioning information with domestic and overseas organizations continuously.
JNC-TN1400 2001-002, 172 Pages, 2001/01
no abstracts in English
JNC-TN1400 2000-012, 250 Pages, 2000/11
no abstracts in English
JNC-TN1400 2000-010, 70 Pages, 2000/10
no abstracts in English
; ; ; Iguchi, Yukihiro; ;
JNC-TN3410 2000-014, 43 Pages, 2000/09
*; *; *; *
JNC-TJ3410 2000-021, 73 Pages, 2000/03
no abstracts in English
*; *; *; *
JNC-TJ3410 2000-020, 80 Pages, 2000/03
no abstracts in English
JNC-TN9200 2000-001, 133 Pages, 2000/02
The 11th Meeting for Reporting Safety Research on FBR and ATR was held at the exhibition hall (TECHNO O-ARAI) in OEC on the 15th of December in 1999. The reports of each subject in FY1996-1998 were presented before discussion at this meeting. The 11 subjects had been selected from the subjects (34 in total) on power reactor in fast breeder reactor, earthquake-proof and probabilistic safety assessment according to the decisions of sub-meetings in Sectional Meeting of Safety Research. This meeting was open to the public, and large attendance outside of JNC was invited for the purpose of getting some advice from related specialists. This report contains presentation papers, questions and answers, list of attendance, etc. Refer to the JNC open report for detailed results of safety research in FY1996-1998.
Ijima, Takashi; ; Matsumoto, Mitsuo; *
JNC-TN3410 2000-002, 93 Pages, 2000/01
Fugen Nuclear Power Station ("Fugen") is a prototype Advanced Thermal Reactor (ATR), it has been demonstrated the plutonium utilization by loading many Mixed Oxide Fuels (MOX) since the reactor start up March 1979, and no fuel defect had been occurred, The MOX fuel assemblies has the high reliability and has been loaded more than 700 fuel assemblies. This is the largest in the world as a thermal neutron reactor. However, "Fugen" is planning to stop its operation in the year 2003, because the role of the Fugen almost finished. Therefore, we are going to summarize the ATR project including the Plutonium utilization experience. This paper is summarized as part of the experience.
Matsumoto, Mitsuo; ;
PNC-TN1410 98-005, 96 Pages, 1998/03
no abstracts in English
PNC-TN3410 98-002, 34 Pages, 1998/01
A new and improved Graphical User Interface (GUI) to the Modular Accident Analysis Program for FUGEN (MAAP/FUGEN) has been developed and implemented at Fugen. The new user interface is a superset of the existing GUI to MAAP - the MAAP/FUGEN/GRAAPH - in the meaning that it contains all the features of the GRAAPH, but in addition offers a number of new features. The new interface, named MAAP-PICASSO is based on the Picasso-3 technology developed by Institutt for Energiteknikk/OECD Halden Reactor Project. The main difference between the MAAP-PICASSO and MAAP-FUGEN-GRAAPH GUIs is that the MAAP-PICASSO GUI is completely decoupled from the numerical simulator. This gives a far higher flexibility regarding enhancement of the GUI, connection to other, external software and user friendliness. It also includes techniques for presenting 2 byte character set - i.e. displaying text in Japanese characters. A special software has been developed for automatic extraction and reuse of the graphical plant information provided in MAAP/GRAPH into Picasso language. This software-has been demonstrated not only on the Fugen plant data, but also other Nuclear Power Plant picture definitions provided by Fauske Inc. The new GUI requires a minimal modification of the MAAP code itself However, these modification is only for parameter communication and is not intrusive to the numerical computations of MAAP itself. The GUI has been developed using modular and object-oriented programming techniques, which makes it relatively easy to extend and modify to fulfill present and future requirements from the users at Fugen, and makes it compatible with future versions of the MAAP code. MAAP-PICASSO is developed on and currently running only on HP UNIX workstations. However, a new NT-based version of Picasso-3 will be released from the Halden Project in February 1998. This will further enhance the applicability and usability of the MAAP-PICASSO GUI.
PNC-TN3410 98-001, 14 Pages, 1998/01
At the FUGEN Power Station a system for online monitoring of selected process component behavior, CONFU (CONdition monitoring at FUgen) has been implemented. This system is based on MOCOM (Model Based Condition Monitoring System), developed at IFE/OECD Halden Reactor Project. The system is currently monitoring the heat exchangers for the Reactor Auxiliary Cooling Water System. These heat exchangers has shown a slowly degrading performance over time due to fouling, i.e. accumulation of a heat resisting layer of organic material on the sea water side. This slow degradation, which is not detected by the conventional control and alarm systems, is not an operational, but rather a maintenance problem. CONFU is using dynamically updated mathematical models to compute the performance degradation of the heat exchangers, expressed in overall heat transfer, heat transfer coefficients or heat exchanger efficiency. The results of testing CONFU on real plant data identify the expected degradation trends. The data from CONFU can, in addition to give the plant operator a good impression of the component's operational state, be utilized by the maintenance planning personnel for determination of the most optimal maintenance schedule. Furthermore, the process models in CONFU have been used for simulation purposes.