Mimura, Ryuji; Muraguchi, Yoshinori; Nakashio, Nobuyuki; Nemoto, Koichi; Shiraishi, Kunio
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 5 Pages, 2015/05
The JAERI's Reprocessing Test Facility (JRTF) was the first engineering-scale reprocessing facility constructed in Japan. The JRTF was operated from 1968 to 1969 to reprocess spent fuels from the Japan Research Reactor No.3 (JRR-3). As a result of the operation (total 3 runs) by PUREX process, 200 g of highly purified plutonium (Pu) were extracted. In this operation, about 70 m of liquid waste was generated and part of this waste, which including Pu, with relatively high radioactivity, was stored in six large tanks. After shutdown of the facility, the JRTF decommissioning program was started in 1990 to develop decommissioning technologies and to obtain experiences and data on dismantling of fuel cycle facilities. Liquid waste in the tanks was treated from 1982 to 1998. Dismantling of tanks started in 2002. The tanks were installed in narrow concrete cells and inside of the cell was high dose area. Dismantling method for the tank is important factor to decide manpower and time for dismantlement. In this paper, in-situ dismantling of the liquid waste storage tank and its preparation work are discussed.
Tachibana, Mitsuo; Kishimoto, Katsumi; Shiraishi, Kunio
International Nuclear Safety Journal (Internet), 3(4), p.16 - 24, 2014/11
Three research reactors were permanently shut down in the Nuclear Science Research Institute (NSRI) of the Japan Atomic Energy Agency (JAEA) as of October 2014. Safe storage or one-piece removal method was applied to decommissioning of these research reactors depending on decommissioning cost and utilization of facilities and so on. Various kinds of data and experiences were obtained through decommissioning of these research reactors. This report shows data and experiences on the research reactors decommissioning in the NSRI of the JAEA.
Kanayama, Fumihiko; Hagiya, Kazuaki; Sunaoshi, Mizuho; Muraguchi, Yoshinori; Satomi, Shinichi; Nemoto, Koichi; Terunuma, Akihiro; Shiraishi, Kunio; Ito, Shinichi
JAEA-Technology 2011-011, 36 Pages, 2011/06
Dismantling activities of equipments in JAERI's Reprocessing Test Facility (JRTF) started from 1996 as a part of decommissioning of this facility. Removing out of the large liquid waste storage tank LV-2 as a whole tank without cutting in pieces from the annex building B to confirm safety and efficiency of this method started from 2006. After preparatory works, ceiling of LV-2 room was opened, and LV-2 was transferred. Useful data were collected on manpower, radiation control and waste amount through the preparatory works, and work efficiency was analyzed by use of these data.
Terunuma, Akihiro; Naito, Akira; Nemoto, Koichi; Usami, Jun; Tomii, Hiroyuki; Shiraishi, Kunio; Ito, Shinichi
JAEA-Review 2010-038, 96 Pages, 2010/09
Japan Atomic Energy Agency (JAEA) has midterm plan for decommissioning the facilities being finished their role and the facilities that became unnecessary by shifting their functions to other facilities. In the first midterm plan (from the latter half of fiscal year 2005 to fiscal year 2009), decommissioning of five facilities (Ceramic Research Facility, Plutonium Research Facility No.2, Metallurgy Research Facility, Isotope Separation Research Facility and Reprocessing Test Facility) had been carried out in order to release controlled area and dismantle the facilities in Nuclear Science Research Institute (NSRI), JAEA. The decommissioning activity for each facility had been reported to the regulatory body and municipalities. On this report, we summarize the each activity for five facilities by reviewing the reports to the regulatory body and municipalities. We also added the knowledge obtained through the activity.
Tachibana, Mitsuo; Shiraishi, Kunio; Ishigami, Tsutomu
Nihon Genshiryoku Gakkai Wabun Rombunshi, 9(3), p.271 - 278, 2010/09
DECOST code was developed in consideration of the features and structures of nuclear facilities and the similarity of dismantling methods. DECOST code could calculate 8 items of decommissioning cost. Actual data of dismantling activities was evaluated. Unit conversion factors of general components could be classified into three kinds. The weights of components in the facility and of structures of the facility were necessary for the calculation of the manpower. Methods for evaluating weight of components and structures of the facility were studied. The weight of components in the facility was proportional to weight of structures of the facility. The weight of structures of the facility was proportional to total area of floors in the facility. Decommissioning costs of 7 nuclear facilities are calculated. Outline of DECOST code, evaluation results of unit conversion factors, evaluation method of weight of components and structures were described.
Shimada, Taro; Shiraishi, Kunio; Tachibana, Mitsuo; Ishigami, Tsutomu
JAEA-Review 2009-009, 42 Pages, 2009/07
The Japan Atomic Energy Agency (JAEA: the former Japan Atomic Energy Research Institute) has been collecting wide variety of information on decommissioning nuclear facilities by the cooperative program with US Department of Energy (DOE) since 1988. In the course of the cooperation, the cooperative program has continued under the newly established specific memorandum in the field of decontamination and decommissioning nuclear facilities since 2001 on the framework agreement of USDOE and JAERI. On the other hand, the US DOE environmental management program, which was initiated in 1989, has developed resulting in achievement of dismantlement, decontamination and cleanup of nuclear facilities mainly used for Manhattan project and demonstration of various technologies developed for this program. In the cooperative activities, information on decommissioning activities including innovated technology developments has been exchanged with CP-5 and Mound plant as designated main facilities of DOE, and with JRR-2 and the reprocessing test facility of JAERI. The experiences and technologies applied in the environmental management program are expected to contribute to planning and implementing decommissioning nuclear facilities in JAEA. This report describes the summary of the information on decommissioning activities and technology development and deployment of the environmental management program in DOE obtained through the cooperation under the specific memorandum agreement.
Tachibana, Mitsuo; Shiraishi, Kunio; Ishigami, Tsutomu; Tomii, Hiroyuki
JAEA-Technology 2008-005, 33 Pages, 2008/03
The PL measuring device was produced to apply to the clearance verification measurement and the radiation measurement for releasing controlled areas. The basic characteristic test and the actual test were confirmed using the PL measuring device. As a result of these tests, it was found that the evaluation value of radioactivity with the PL measuring device was accuracy equal with the existing measuring device. The PL measuring device has feature of the existing measuring device with a light weight and easy operability. The PL measuring device can correct the ray too. The PL measuring device is effective to the clearance verification measurement of concrete on buildings and the radiation measurement for releasing controlled areas.
Sukegawa, Takenori; Shimada, Taro; Shiraishi, Kunio; Tachibana, Mitsuo; Ishigami, Tsutomu
JAEA-Data/Code 2008-009, 57 Pages, 2008/03
We developed the RADO code system for evaluating residual radioactive inventory in decommissioning of nuclear reactor. The code system consists of computer programs which calculate macroscopic effective cross section, neutron flux, and radioactive inventory. This report describes an evaluation method of radioactive inventory, structure and functions of RADO, input and output of RADO, and sample run with RADO.
Shiraishi, Kunio; Tachibana, Mitsuo; Ishigami, Tsutomu; Tomii, Hiroyuki
JAEA-Technology 2007-057, 46 Pages, 2007/09
The method for evaluating efficiently decommissioning cost in a short time was made based on the features of various types of nuclear facilities where the feature of nuclear facilities was arranged. The evaluation method can calculate decommissioning cost using conversion factors corresponding to weight of components and structures of nuclear facilities, etc. The conversion factors were made based on the experience of the JPDR decommissioning projects in the Japan Atomic Energy Research Institute (JAERI) and of improvements of the reprocessing plant of the Japan Nuclear Cycle Development Institute (JNC). In this report, the decommissioning cost evaluation method of nuclear facilities that had been made before unification of JAERI and JNC was revaluated as a new decommissioning cost evaluation method to reasonably advance decommissioning plans of various nuclear facilities.
Kudo, Kenji; Kawatsuma, Shinji; Rindo, Hiroshi; Watabe, Kozo; Tomii, Hiroyuki; Shiraishi, Kunio; Yagi, Naoto; Fukushima, Tadashi; Zaitsu, Tomohisa
Proceedings of 14th International Conference on Nuclear Engineering (ICONE-14) (CD-ROM), 8 Pages, 2006/07
Japan Atomic Energy Research Institute (JAERI) played a leading role in basic research in the field of atomic energy research and development, while Japan Nuclear Cycle Development Institute (JNC) did a major role in FBR cycle development and high level waste disposal. Following the Government's decision in December 2001, JAERI and JNC was merged as of October 1st, 2005. The new organization, Japan Atomic Energy Agency (JAEA), is an institute for comprehensive R&D for atomic energy, and is the largest research and development institute among Governmental R&D organizations. Its missions are basic research on atomic energy, R&D for nuclear fuel cycle, decommissioning of own facilities and disposal of waste, contribution to safety and non-proliferation, etc. The JAEA owns a number of nuclear facilities: research reactors such as JRR-2 and Joyo, prototype reactors such as ATR "Fugen" and FBR "Monju", fuel cycle plants such as Uranium Enrichment Demonstration Plant at Ningyo-Toge, MOX fuel plants at Tokai, Reprocessing Plant at Tokai, and Hot Laboratories such as JRTF and FMF. As a part of preparation of the mergence, JNC and JAERI have jointly developed a comprehensive cost estimation method for decommissioning, based on decommissioning and refurbishing experiences of JAERI and JNC. This method involves more estimation parameters from typical decommissioning activities than before, so as to make it more reliable. JAERI and JNC have estimated the total cost for decommissioning by using this method, and concluded that the cost would be 600 billion yen (approx. 5 billion USD).
Shiraishi, Kunio; Sukegawa, Takenori; Ishigami, Tsutomu
JAEA-Data/Code 2005-002, 162 Pages, 2006/01
In order to efficiently develop a decommissioning plan of a nuclear facility, it is useful to develop a database containing information on decommissioning technology, cost and risk analysis results, and decommissioning projects such as the JPDR decommissioning project by collecting the information systematically. A decommissioning database has been developed by collecting decommissioning related information and analyzing it. The database provides information on not only data of decommissioning technology and decommissioning projects but also laws and safety standards for decommissioning in each country and international organizations. The database is released in a Homepage on Web and is available for use via intranet with functions of retrieval, display and printing.
Oshima, Soichiro; Shiraishi, Kunio; Shimada, Taro; Sukegawa, Takenori; Yanagihara, Satoshi
JAERI-Tech 2005-046, 46 Pages, 2005/09
A model for estimating decommissioning costs consisting of labor cost, device cost and expense, was developed for items which OECD/NEA had standardized, and was installed into the computer system for planning and management of reactor decommissioning (COSMARD). Input data files and databases for the decommissioning of JPDR were prepared, and the decommissioning cost was calculated with COSMARD. In addition, the decommissioning cost for a large scale BWR power plant was also calculated on the assumption of the advantage of scale. The calculations have shown that it is useful and efficient for studying the decommissioning costs for nuclear reactors to apply the COSMARD with database for cost estimation to the decommissioning cost calculation.
Tomii, Hiroyuki; Matsuo, Kiyoshi*; Shiraishi, Kunio; Kato, Rokuro; Watabe, Kozo; Higashiyama, Yutaka; Nagane, Satoru*; Hanawa, Yukimitsu*
JAERI-Tech 2005-017, 65 Pages, 2005/03
no abstracts in English
Tomii, Hiroyuki; Matsuo, Kiyoshi*; Shiraishi, Kunio; Watabe, Kozo; Saiki, Hideo*; Kawatsuma, Shinji*; Rindo, Hiroshi*; Zaitsu, Tomohisa*
Dekomisshoningu Giho, (31), p.11 - 20, 2005/03
no abstracts in English
Tomii, Hiroyuki*; Matsuo, Kiyoshi*; Shiraishi, Kunio*; Watabe, Kozo*; Saiki, Hideo; Kawatsuma, Shinji; Rindo, Hiroshi; Zaitsu, Tomohisa
Dekomisshoningu Giho, (31), p.11 - 20, 2005/03
Japanese Government decided that Japan Atomic Energy Research Institute ( JAERI ) and Japan Nuclear Cycle Development Institute ( JNC ) shall be consolidated to a New rganization as of October 2005, which organization would be an Institute for comprehensive research and development for atomic.Through the preparation for unification, JAERI and JNC have been developing the Decommissioning program for own facilities, estimating decommissioning cost and the amount of waste from the decommissioning, and developing Management Program. Planning the Decommissioning program, it is important to estimate decommissioning cost effectively, because JAERI and JNC retain about 230 nuclear facilities which are reactors, fuel cycle facilities and research facilities. Then the decommissioning cost estimation method has developed based on several dismantling and replacement experiences. This method has adopted more estimation fomulae for decommissioning various works than ever, so as to be more reliable. And decommissioning cost for the facilities has estimated under the common condition. This method would be improved, reflecting future nuclear facilities dismantling and replacement events.This paper shows the cost estimation method for nuclear facilities and cost evaluation result for about 230 facilities of both JAERI and JNC.
Oshima, Soichiro; Sukegawa, Takenori; Shiraishi, Kunio; Yanagihara, Satoshi
JAERI-Tech 2001-086, 83 Pages, 2001/12
Project management data on dismantling the Japan Power Demonstration Reactor (JPDR) was calculated using the Code System for Planning and Management of Reactor Decommissioning (COSMARD), and then its validity was studied by comparing the calculation results with actual data. In addition, work breakdown structure models and database were modified to meet an evaluation with changing work difficulty of preparation and cleanup activities, and calculations were further conducted to analyze feasibility by changing various conditions on cutting and conditioning activities. As the results, COSMARD was verified to be useful by confirming calculation capability on reflection of actual work conditions and relatively good agreement between actual data and calculations. Moreover, it was cleared that main parameters such as work difficulty of preparation and cleanup activities and the cutting speed in demolition work could affect to manpower within 30% in each calculations.
Shiraishi, Kunio; Sukegawa, Takenori; Yanagihara, Satoshi
JAERI-Data/Code 2001-028, 86 Pages, 2001/11
The data on worker dose in dismantling of the Japan Power Demonstration Reactor (JPDR) was analyzed to characterize its features. It was appeared from the study that the collective dose to the workers was 306 man-mSv, in which maximum individual dose was 8.5 mSv, almost all doses were received in the activities for dismantling of reactor internals, the reactor pressure vessel and the biological shield, and that the worker dose distribution was similar to that in the maintenanee of the facilities which was characterized by the hybrid log normal distribution model. Farthermore, it was found that the dismantling activities were categorized into three groups depending on dose rates in workplaces, then contribution factors for radiation exposure in terms of dose rates in different groups were derived based on the analysis. The study would be useful for estimation of worker dose in future decommissioning of commercial nuclear power plants in Japan.
Tachibana, Mitsuo; Shiraishi, Kunio; Yanagihara, Satoshi
JAERI-Tech 2001-014, 42 Pages, 2001/03
In the JPDR dismantling demonstration project, the dismantling activities were conducted for the purpose of verification of remote dismantling machines and collection of various kinds of data on work activities. These lessons were categorized into safety consideration, waste treatment and work efficiency by analyzing the data on work activities. Exemplified are necessities of facility information, efficiency of mock-up tests for evaluation of remote dismantling procedures. There will be useful for implementing other decommissioning projects in safe and efficiency. This report describes the measure taken for remote dismantling activities and the lessons learned from the dismantling activities.
Yanagihara, Satoshi; Sukegawa, Takenori; Shiraishi, Kunio
Journal of Nuclear Science and Technology, 38(3), p.193 - 202, 2001/03
no abstracts in English
Shiraishi, Kunio; Sukegawa, Takenori; Yanagihara, Satoshi
JAERI-Data/Code 99-050, p.113 - 0, 2000/01
no abstracts in English