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Fujita, Tomoo; Taniguchi, Naoki; Matsui, Hiroya; Tanai, Kenji; Maekawa, Keisuke; Sawada, Atsushi; Makino, Hitoshi; Sasamoto, Hiroshi; Yoshikawa, Hideki; Shibata, Masahiro; et al.
JAEA-Research 2011-001, 193 Pages, 2011/03
This report summarizes the progress of research and development on geological disposal during the surface-based investigation phase (2001-2005) in the Horonobe Underground Research Laboratory project, of which aims are to apply the design methods of geological disposal and mass transport analysis to actual geological conditions obtained from the surface-based investigations in the Horonobe Underground Research Laboratory project as an example of actual geological environment.
Kamei, Gento; Honda, Akira; Mihara, Morihiro; Oda, Chie; Ichige, Satoru; Kurimoto, Yoshitaka; Hoshino, Seiichi; Akagi, Yosuke; Sato, Nobuyuki; Murakami, Hiroshi*; et al.
JAEA-Research 2011-002, 82 Pages, 2011/03
Based on Japanese governmental policy and general scheme, research and development of geological disposal technology for TRU waste has been proceeding to improve reliability of the safety assessment of the co-locational disposal of TRU waste and of HLW, to expand the basement of generic safety assessment, and to develop the alternative technology to cope with the broad geologic environment of Japan. Japan Atomic Energy Agency is dealing with the assignments in the governmental generic scheme. We report here the progress of the studies at the end of H20 (2008) Japanese fiscal year, which are (1) evaluation of long-term mechanical stability in the near-field including development of a creep mode of rock and analyses of mechanical behavior of TRU waste repository, (2) performance assessment of the disposal system including data acquisition and preparation on radionuclides migration, cementitious material alteration, bentonite and hostrock alteration with alkaline solution and nitrate effect, and (3) alternative technology development including decomposition of nitrate.
Hasegawa, Makoto; Kondo, Hitoshi; Kamei, Gento; Hirano, Fumio; Mihara, Morihiro; Takahashi, Kuniaki; Funabashi, Hideyuki; Kawatsuma, Shinji; Ueda, Hiroyoshi*; Oi, Takao*; et al.
JAEA-Research 2011-003, 47 Pages, 2011/02
In 2009, NUMO and JAEA set up a technical commission to investigate the reasonable TRU waste disposal following a cooperation agreement between these two organizations. In this report, the calculation result of radionuclide transport for a TRU waste geological disposal system was described, by using the TIGER code and the GoldSim code at identical terms. Comparing the calculation result, a big difference was not seen. Therefore, the reliability of both codes was able to be confirmed. Moreover, the influence on the disposal site design (Disposal capacity: 19,000 m) was examined when 10% of the amount of TRU waste increased. As a result, it was confirmed that the influence of the site design was very little based on the concept of the Second Progress Report on Research and Development for TRU Waste Disposal in Japan.
Shirai, Nobutoshi; Inano, Masatoshi; Fukuda, Kazuhito; Kosaka, Ichiro; Yamanaka, Atsushi
JAEA-Research 2011-004, 60 Pages, 2011/03
This report describes calculated results of inventory of radioactivity in the Tokai Reprocessing Plant with calculation code, based on initial conditions and nuclear data library. The inventories were compared with three types of spent fuels, High burn up U oxide for light water reactor, U-Pu mixed oxide for advanced thermal reactor and the design based fuel for Tokai Reprocessing Plant.
Shirai, Nobutoshi; Inano, Masatoshi; Fukuda, Kazuhito; Kosaka, Ichiro; Yamanaka, Atsushi
JAEA-Research 2011-005, 95 Pages, 2011/03
This report presents criticality safety evaluation of each equipment in Tokai Reprocessing Plant for two types of spent fuels, High burn up 4.2% enrichment U oxide spent fuel for light water reactor and U-Pu mixed oxide spent fuel for advanced thermal reactor. As a result, it was confirmed that the equipments were safe enough for two types of the spent fuels from view point of criticality safety of single unit and multiple units.
Wakasugi, Keiichiro; Koo, Shigeru*; Shibata, Masahiro
JAEA-Research 2011-006, 31 Pages, 2011/06
Although confirmation of the long-term safety of the constructed geological disposal system has been conducted by using scenario, model and data according to the internationally agreed methodology, there were a few researches that focused on individual safety functions and their relationships. This is because multiple safety functions are a fundamental concept for ensuring the safety of the geological disposal, and the long-term safety is accomplished by the whole system. Therefore, we developed a methodology to identify performance of the individual safety functions and their relationships considering the characteristic of the multiple safety functions, and examined the safety functions in the engineered barrier system based on this methodology. The results from this study are useful for constructing design requirements for the system components of the geological disposal as well as developing repository concept.
Ichikawa, Yasuaki*; Choi, J. H.*; Tanno, Takeo; Hirano, Toru*; Matsui, Hiroya
JAEA-Research 2011-007, 91 Pages, 2011/06
We first surveyed the classical theories of fracture mechanics, and discussed the subcritical crack growth (SCG), which is observed under less load than the fracture toughness Kc. This SCG is a result of coupled mechanical and chemical effect. The SCG for granite was treated on this basis. We performed pressure dissolution experiments using specimens of single crystal quartz, since the dissolution reaction is engaged with a deformation and failure process of polycrystalline rock. The series of experiments were managed by a flow-through type changing temperature, pH and applied stress. Si concentrations we here measured. We first surveyed the theories of pressure solution. Then we proposed a theory of saluting velocity of quart which accounts for the effects of temperature, chemical (pH), solid pressure and pore pressure.
Takeuchi, Ryuji; Kosaka, Hiroshi; Sato, Atsuya*; Tomiyama, Shingo*; Kageyama, Soichiro*; Ikeda, Makoto*
JAEA-Research 2011-008, 77 Pages, 2011/06
Subsurface water balance observation is a kind of methods in order to estimate a recharge rate. Results of the observation are affected by the various factors such as the scale, the topography, a geological feature, the climate. Therefore, the observation in the regional scale is necessary at many basins. The purpose of this study is to confirm the applicability of the method for the evaluation of runoff volume, which is one of parameters to evaluate the recharge rate by surface water balance observation, by geomorphometry and statistical analyses using digital elevation model (DEM). The runoff index which is the original indicator to evaluate the degree of flow rate on a catchment was calculated by the comparison between the result of geomorphometry and statistics analyses, and the observed data of river flow rate in the monitoring stations. Using this index, the flow rate of the Hiyoshi River was evaluated. The evaluated flow rate was about 60% against the observed flow rate.
Iwatsuki, Teruki; Sato, Haruo; Nohara, Tsuyoshi; Tanai, Kenji; Sugita, Yutaka; Amano, Kenji; Yabuuchi, Satoshi; Oyama, Takuya; Amano, Yuki; Yokota, Hideharu; et al.
JAEA-Research 2011-009, 73 Pages, 2011/06
The research and development plan in Horonobe Underground Research Laboratory are summarized according to the 2nd Midterm Plan till 2014 fiscal year of JAEA. In this midterm, galleries and the infrastructures for the research and development up to the depth of 350 m are constructed by Private Financial Initiative (PFI). Additionally Phase 3: Operation phase at the galleries begins in parallel to Phase 2: Construction phase. In these phases various research and development including collaboration with other institutes are conducted at the galleries. Generallic applicable techniques on the subject of the investigation of geological environment, facility construction in deep underground and the reliability of geological deposal are developed during the phase. The feasibility and reliance of various technologies concerning geological disposal is demonstrated by widely opening the outcome to the public in the society.
Kunimaru, Takanori; Ota, Kunio; Alexander, W. R.*; Yamamoto, Hajime*
JAEA-Research 2011-010, 52 Pages, 2011/06
Work has been currently ongoing to establish an appropriate quality management system (QMS), which is applicable to all aspects of the site characterisation process, in the Horonobe Underground Research Laboratory project. A quality assurance (QA) audit of hydrochemical datasets for JAEA's deep boreholes HDB-1 to HDB-8 was carried out, along similar lines to that of the previous study for boreholes HDB-9 to HDB-11, by applying both the groundwater QA methodology employed in the recent site assessments in Sweden and a porewater QA regime proposed in this study. The results of the QA audit indicated that data were classified into low QA categories because mainly of a lack of relevant information, such as the records of groundwater sampling, which are necessary for more fully assessing the data quality. As such, a formalised field manual for hydrochemical sampling was developed. In addition, work to further improve the site characterisation QMS progressed.
Uchikawa, Sadao
JAEA-Research 2011-011, 50 Pages, 2011/06
An advanced LWR with hard neutron spectrum, named FLWR, aims at efficient and flexible utilization of nuclear resources by evolving its fuel assembly design under the same core configuration, mainly corresponding to available fuel cycle technologies and related infrastructures. The paper summarizes an evolution process of the FLWR fuel assembly design toward a sustainable fuel cycle by dividing the reactor operation into three stages, that is, the one based on the current LWR MOX fuel cycle infrastructure such as reprocessing of UO spent fuel and fabrication of MOX fuel, the one for transitioning from the LWR fuel cycle to the FR fuel cycle, and the one based on the FR fuel cycle infrastructures such as MOX spent fuel reprocessing.
Nakamura, Takahiro; Sanada, Hiroyuki; Sugita, Yutaka; Kato, Harumi*
JAEA-Research 2011-012, 217 Pages, 2011/06
For the purpose of studying the in situ state of stress around Horonobe Underground Research Laboratory, hydraulic fracturing technique was carried out three boreholes drilled from the 250m gallery located near the bottom of the ventilation shaft. The results of the measurements are summarized as follows. Shut-in pressure of inclined transverse cracks and the circumferential position of longitudinal cracks on the wellbore surface were used to determine the magnitude and orientation of principal stress around the 250m gallery on the assumption that all of the target zones of hydraulic fracturing were in a uniform stress state. The determined in situ stress state showed a little difference of magnitude between intermediate stress and minimum stress. The vertical component of the in situ stress was evaluated to be about a half of the overburden at the test site. The maximum principal stress was inclined to about 40 degrees from the level with azimuth of NE orientation.
Tanno, Takeo; Hirano, Toru*; Matsui, Hiroya
JAEA-Research 2011-013, 59 Pages, 2011/06
This report presents the following FY2009 activities undertaken to achieve the above goals. (1) Suitability of Laboratory Tests of Physical and Mechanical Properties on Waste Rock from Excavation of the Shaft, (2) Suitability of the Phase I Rock Mechanical Environment Model, (3) Preliminary Deformation Analysis of Rock Mass around the Underground Facilities, (4) Phenomenological Study on Crystalline Rock for Evaluating Long-term Behavior, (5) Theoretical Study on Crystalline Rock for Evaluating of Long-term Behavior, (6) Fundamental Study on Evaluation Methods of Excavation Distributed Zones. As the result of above 6 activities, suitability of laboratory test and Phase I Rock mechanical Environment Model are confirmed and also methods for EDZ estimation were specified by estimation of in situ stress with core and SWD (Seismic While Drilling).
Matsumoto, Kazuhiro; Fujita, Tomoo
JAEA-Research 2011-014, 26 Pages, 2011/06
The extrusion of bentonite buffer is one of the important issues on the physical stability in the geological disposal of the high level radiation waste. In this report, the long-term extrusion experiment of the bentonite buffer material to an imitation crack was carried out, and the behavior was observed. Moreover, in consideration of the evaluation subject of the closing performance of a disposal site, the extrusion experiment with material with a large sand combination rate was carried out.
Abe, Hitoshi; Kashima, Takao; Uchiyama, Gunzo
JAEA-Research 2011-015, 27 Pages, 2011/06
To contribute on confirmation of safety of fuel cycle facilities, evaluation method for soundness of confinement capability of the facilities under fire has been investigated. Panel materials of glove-box and cable sheath materials were considered to be an examination object as the representative organic materials in the facilities. Combustion property data, such as mass loss rate and soot generation ratio of the materials, and clogging property data of HEPA filter with combustion of the materials were measured as a parameter with radiation heat given to the materials, supply flow rate to the materials and oxygen concentration in the supply flow. Furthermore, progress of rising differential pressure of HEPA filter under hypothetical scenario of fire accident was evaluated quantitatively by applying these data mutually.
Moriyama, Kiyofumi; Tashiro, Shinsuke; Chiba, Noriaki; Maruyama, Yu; Nakamura, Hideo; Watanabe, Atsushi*
JAEA-Research 2011-016, 125 Pages, 2011/06
The volatile iodine production due to radiation chemical effects in the containment vessel of light water reactors (LWRs) during severe accidents was investigated by experiments in small scale and with well controlled conditions. Cesium iodide solutions, 10M, labeled with I, at controlled pH by boric acid-sodium hydroxide buffer, were -irradiated and swept with a constant gas flow rate. The gaseous iodine released from the solution was collected by species selective filters and quantified separately for I and organic iodines. The influences of pH, temperature, inorganic and organic impurities, oxygen and hydrogen concentrations in the cover gas on the iodine release behavior were examined. Data including time dependent gaseous iodine release fractions, comparison of the final iodine release fractions in terms of the parameter effects, as well as the initial, boundary and interface conditions necessary for simulating the experiments by computer codes are provided.
Shimo, Michito*; Kumamoto, So*; Onoe, Hironori; Saegusa, Hiromitsu
JAEA-Research 2011-017, 132 Pages, 2011/09
In this study, hydrogeological modeling and groundwater flow simulations on the Local scale area have been carried out in order to predict hydraulic impacts around the MIU Construction Site and inflow rate into the MIU facilities using the result of Surface-based Investigation phase (Phase 1), the data of hydraulic responses in monitoring boreholes, inflow rate into the MIU facilities and the result of pilot borehole investigation in Construction phase (Phase 2). As a result of this study, the significant hydrogeological structures around the MIU Construction Site could be estimated. The inflow rate into the MIU facilities and hydraulic impacts around the MIU Construction Site with the MIU facilities construction could be predicted. The effect of pre-grouting to the MIU facilities could be also confirmed.
Morihira, Masayuki
JAEA-Research 2011-018, 32 Pages, 2011/07
In the FaCT project, high bundle peak burn-up to 250 GWd/t is targeted. Cladding inner corrosion is one of the life control factors of FBR MOX fuels. Because it increases with extension of burn-up, significant corrosion is expected in the high burn-up. Considering the excess oxygen during fission is the cause of corrosion, reduction of initial O/M ratio of MOX fuel pellets is one of the solutions. But it is not always easy to obtain low O/M ratio pellets especially in mass production. Oxygen getter option is an idea to coexistence of oxidizable metal fragments in a fuel element as an excess oxygen absorber. A feasibility study for oxygen getter options which was focused on pellet type MOX fuel was conducted. This report describes latest evaluation result for the loading options of oxygen getter materials and the oxidation behavior of the candidates such as Ti and Zr as well as their compatibilities with FMS cladding material and UO.
Hirano, Toru*; Seno, Yasuhiro*; Hikima, Ryoichi; Matsui, Hiroya
JAEA-Research 2011-019, 51 Pages, 2011/09
In order to establish the scientific and technical basis for geological disposal of high-level radioactive waste, Japan Atomic Energy Agency (JAEA) is proceeding with the geoscientific research in the research galleries excavated at the Mizunami Underground Research Laboratory (MIU). One of the scientific and technical objective of this project is to understand the change of geological environment due to excavation of research galleries. The investigation described herein is the measurement of the rock strain / displacement while pre-excavation grouting or excavating of the shaft around the GL.-200m level research gallery.
Yoshida, Kazuo
JAEA-Research 2011-020, 16 Pages, 2011/08
An experimental study of boiling event using actual radioactive liquid waste has been conducted and reported by CEA for safety analysis of radioactive release accident of reprocessing plant. These experimental results obtained from open document have been analyzed to clarify the transfer mechanisms of radioactive material for applying these results to safety analysis of an actual plant. From analysis of these data, information have been obtained about concentration and activity of nitric acid of radioactive liquid waste in boiling condition on which ruthenium (Ru) transfer into gas phase depends. Transfer rate into gas phase of Ru has been estimated using these data. The result is over estimated by 200 times compared with experiment. It could be explained that NO coexisting with nitrous acid generated radio-chemically suppress the Ru(VIII) formation in the liquid waste.
FBR Safety Unit
JAEA-Research 2011-021, 35 Pages, 2011/09
JAEA has been developing a flow-induced vibration methodology applied to the JSFR piping under the FaCT project. As part of this development, flow pattern in the single-elbow pipe has been investigated with the measurement of fluid force induced by turbulence flow and of the flow-induced vibration response. The experimental results have served to the development and vibration of the flow-induced vibration evaluation methodology. Based on these outcomes, JAEA has established a working group on a guideline of large-diameter piping flow-induced vibration evaluation under the JAEA's Thermal-Hydraulic Research Committee for creating the guideline. This report is a first proposal of the guideline from the achievements of the working group activity.
Hata, Haruhi; Yokoyama, Kaoru; Tsunashima, Yasumichi; Ohashi, Yusuke; Koga, Osamu; Sugitsue, Noritake
JAEA-Research 2011-022, 35 Pages, 2011/09
For disposal of Very low-level radioactive Waste (VLLW) from nuclear related facilities, one of important factors for safety assessment is the characteristics of elution. As for VLLW from the nuclear power plant, concrete pit and trench disposals have been performed and the evaluation methods for the characteristics have been established. On the other hand, as for the uranium waste, the concept on how to test the elution characteristics is not shown yet. Based on these circumstances, preliminary tests have been conducted to study elution characteristics of uranium waste. The results show that the important factors for the uranium elution are how uranium exists in waste. In addition, the elution characteristics also depend on the precipitation amount on the disposal site. Therefore, to assess the elution rate from uranium waste, these factors must be considered.
Yasue, Kenichi; Asamori, Koichi; Tanikawa, Shinichi; Yamada, Kunimi; Yamasaki, Seiko; Kokubu, Yoko; Niwa, Masakazu; Doke, Ryosuke; Kusano, Tomohiro; Hanamuro, Takahiro; et al.
JAEA-Research 2011-023, 113 Pages, 2011/10
This annual report documents the progress of R&D in the first fiscal year during the JAEA 2nd Midterm Plan (FY 2010 - 2014) to provide the scientific base for assessing geosphere stability for long-term isolation of the high-level radioactive waste. The planed framework is structured into the following categories: (1) development and systematization of investigation techniques for selecting suitable sites in geosphere stability, (2) development, application and verification of prediction models for evaluating the changes of geological environment in thermal, hydraulic, mechanical and geochemical conditions for a long period of time, and (3) development of new dating techniques for providing information about geologic history and the timing of geologic events. In this paper, the current status of R&D activities with previous scientific and technological progress is summarized.
Shimizu, Hiroyuki*; Kikuchi, Hirohito; Tanai, Kenji; Fujita, Tomoo
JAEA-Research 2011-024, 74 Pages, 2011/10
For geological isolation systems for HLW, due to the lack of standardization of swelling test method for bentonite as a buffer material, the accuracy and reproducibility of the results are not sufficiently proved. In this study, bentonite swelling pressure test were simulated by newly developed distinct element method, and the effects of wall friction force and aspect ratio of bentonite specimen were discussed.
Serizawa, Hiroyuki; Matsunaga, Junji*; Haga, Yoshinori; Nakajima, Kunihisa; Kashibe, Shinji*; Iwai, Takashi
JAEA-Research 2011-025, 32 Pages, 2011/11
This report deals with the precipitation of helium in UO matrix to deform the microstructure. The examination was performed using single and polycrystalline UO sample. The helium-treated samples under 900 atm at 1473 K were reheat-treated at much more high temperature, 1573 K or 1973 K to release the infused helium. The microstructure of the sample was examined by FIB, FE-STEM and FE-TEM. It was confirmed that precipitated helium atoms form a negative crystal in the grain or the matrix of the single crystal. At 1573 K, helium can be released without formation of intergranular tunnel since the surface diffusion coefficient of helium is large. However, some open grain boundaries were observed in the sample heat-treated at 1973 K. This might be related to the activity of helium in the grain boundary region. The structure of the negative crystal was analyzed from the view point of the thermodynamics of the surface growth.
Department of Partnership Operations for Environmental Remediation, Headquarters of Fukushima Partne; Ningyo-toge Environmental Engineering Center; Vitrification Technology Development Department, Tokai Reprocessing Technology Development Center; Environmental Protection Section, Radiation Protection Department
JAEA-Research 2011-026, 74 Pages, 2011/11
After the Fukushima nuclear accident, extensive area was contaminated with radionuclides from the Fukushima Daiichi Nuclear Power Plant and various methods have been investigated to remedy such contamination. To understand potential of in-situ ground heating and radionuclide desorption, behaviors of ground temperature and of radiocesium volatility by in-situ heating was investigated. More than 15 minutes was necessary to accomplish melting temperature of several cesium compounds by heating using portable burner and maximum temperature was about 700 degree in Celsius. At the time ground surface temperature was about 600 degree, the temperature at 1cm depth was about 300 degree, whereas the temperature at 5cm depth was 50-60 degree. Under the condition of heating temperature of 600-1,300 degree and heating period of 5-60 minutes, activity of Cs-134 and Cs-137 varied in the range of -9.8 to +14.0% after heating using electric furnace and any volatility of radiocesium was not recognized. TG/DTA analysis for soil and zeolite (mordenite) which mixed with nonradioactive Cs compound each were also carried out to understand chemical form and volatility behavior of radiocesium. It is suggested that chemical compound e.g., CsAlSiO would be formed when SiO and AlO3 were composed in the system and radiocesium would remain in soil under the high temperature condition, whereas Cs in CsCO would be volatized in the SiO and/or AlO free system.
Yamada, Satoshi*; Kita, Makoto*; Goto, Yukari*; Ishimori, Yuu
JAEA-Research 2011-027, 38 Pages, 2011/11
Tottori University and Japan Atomic Energy Agency started a joint study to investigate the effect of hot spring water on the growth of vegetable plants in 2009. The aim of the study is to examine a feasibility of producing a regionally special vegetable with considering the characteristics of the Misasa district, where radon hot springs are historically famous. This report illustrates the intermediate results obtained from the study carried out from 2009 to 2010. (1) Screening test: Eighteen plants were examined for screening. As the results, Misasa hot spring water used in the water culture enlarged the growths of 14 plants. Lastly, 9 plants were selected as candidate plants for further examinations. (2) Sample preparation: Plants sampled in the water culture were lyophilized and stored in a freezer for nutrio-physiological analyses to select the suitable plant from the 9 plants. (3) Examination in labor-saving cultivation: Preliminary examinations were performed with a large-scale system to establish a practical labor-saving water culture system.
Sanada, Masanori; Hayashi, Katsuhiko*; Kishi, Hirokazu; Takebe, Atsuji*; Okubo, Seisuke*
JAEA-Research 2011-028, 102 Pages, 2011/11
In this study, strength recovery, generalized stress relaxation and two tensile strength tests were carried out using shale sampled in the Wakkanai-formation. As the results, recovery of failed rocks in strength and hydraulic conductivity were observed under a certain condition. We believe this result is very important for the stability evaluation of underground space in the bedrock that needs good sealing up characteristic, isolation characteristic, safety and high reliability for long term. Generalized stress relaxation test was conducted submerging samples in water. Experimental results showed comparatively smaller scatter than those in air-dried condition. It was also found that testing results were affected by strain rate up to the starting point of generalized relaxation test. Indirect and uniaxial tensile strength tests were also conducted submerging samples in water and smaller tensile strength with smaller scatter were obtained than those in air-dried condition.
Sakai, Ryutaro; Munakata, Masahiro; Kimura, Hideo; Ooka, Masao*; Seguchi, Mariko*
JAEA-Research 2011-029, 24 Pages, 2011/11
In the safety assessment for a geological disposal of radioactive waste, it is important to establish validation methods for regional groundwater flow system to estimate radionuclide migration to human environment through groundwater flow. It is necessary to validate the groundwater flow property and flow boundary, as multi-groundwater systems including the different groundwater origins are possible to exist at deep underground. This results show that mixing analysis based on hydrochemical data and spatial plotting with hydrochemical data and thermal data are applicable to validate groundwater flow pattern and groundwater flow boundary in case of Horonobe area. It also demonstrates that mixing analysis based on hydrochemical data and spatial plotting with hydrological and hydrochemical data are applicable to validate the groundwater flow property and groundwater flow boundary in case of Nagaoka area.
Ishikawa, Jun; Yoshida, Kazuo
JAEA-Research 2011-030, 24 Pages, 2011/11
Development of accident consequence analysis method bas been under carried out at Japan Atomic Energy Agency as a part of research activities for development of probabilistic safety assessment method of nuclear fuel facilities. A computer tool has been developed to simulate boiling event of reprocessed liquid waste which is postulated to be occurred caused by the loss of cooling function at a fuel reprocessing plant. Thermodynamic properties of boiling and condensed nitric acid aqueous solution containing radioactive waste are necessary to assess quantitatively the amount of radioactive materials transferring to gas phase. The developed tool simulates boiling and condensation process of liquid waste based on the ebullioscopy. A simulation study of experimental result has been carried out and it was demonstrated that behavior of temperature and concentration of nitric acid of liquid waste are simulated well.
Doke, Ryosuke; Yasue, Kenichi; Nakayasu, Akio; Niizato, Tadafumi; Tanikawa, Shinichi; Tanaka, Takenobu*; Aoki, Michinori*; Sekiya, Ayako*
JAEA-Research 2011-031, 109 Pages, 2011/12
In this study, existing information related to methods for the estimation of the beginning age of the faulting in the present faulting pattern on the active fault were collected and reviewed. A principle of method, noticing points and technical know-hows in the application of the methods, data uncertainty, and so on were extracted from the existing information. Based on these extracted information, task-flows indicating working process on the estimation of the beginning age for the faulting of the active fault were illustrated on each method. Additionally, the distribution map of the beginning age with accuracy of faulting in the present faulting pattern on the active fault was illustrated.
Saito, Hironori*; Takeda, Seiji; Kimura, Hideo
JAEA-Research 2011-032, 92 Pages, 2011/11
The objective of this study is to estimate the parameter uncertainty of soil-to-plant transfer factor used in the safety assessment. The database on the soil-to-plant factors was improved to clarify the factors associated with the uncertainty of soil-to-plant transfer factor. The factors were specified based on investigating the relation between published data of soil-to-plant transfer factor and some kinds of experimental conditions. Under the assumption of stylization by both general habits of ingestion of farm products and soil conditions in Japan, we proposed the procedure to estimate the parameter uncertainty of soil-to-plant transfer factor according to the investigation results of the factors. Based on the procedure, the variation of soil-to-plant transfer factors for main radionuclides of high level radioactive waste and TRU waste were estimated in this report.
Kojima, Keiji*; Onishi, Yuzo*; Watanabe, Kunio*; Nishigaki, Makoto*; Tosaka, Hiroyuki*; Shimada, Jun*; Aoki, Kenji*; Tochiyama, Osamu*; Yoshida, Hidekazu*; Ogata, Nobuhisa; et al.
JAEA-Research 2011-033, 126 Pages, 2012/02
The next advancements for the research of radioactive waste repository was started to improve and systematize the investigation and evaluation techniques on geological environment in consideration of intra-field of science and technology. Intra-field means the various fields among each study area of (a) geological environment, (b) design and engineering, (c) safety evaluation for radioactive waste repository, here. The following items were studied and discussed this year. (1) To Reconstruct Near Field (NF) Concept in consideration of coupled phenomena on geological environment. (2) To develop systematic investigation techniques on the geological environment in consideration of intra-field among each study area above mentioned (a), (b) and (c). Regarding (1), examination of NF concept focused on the realistic crystalline rock was carried out. Also through the overall discussion in the committee, comments from the all commissioners in relation to the intra-field of their study area were made to reflect on reconstruction of NF concept. Regarding (2), the research and development in consideration of NF and intra-field among each study area were conducted.
Chiba, Go*; Hazama, Taira; Kinjo, Hidehito*; Nishi, Hiroshi; Suzuki, Takayuki
JAEA-Research 2011-034, 42 Pages, 2011/12
Uncertainty of Doppler coefficient is quantified for a Monju core, reflecting present knowledge. Various uncertainty sources are evaluated: (1) Nuclear data and numerical method, (2) Fission product nuclear data, (3) Control rod position, (4) Approximated treatment of temperature dependence, (5) Averaged fuel temperature, (6) Approximated treatment of temperature spatial distribution, etc. Resulting uncertainty for Doppler coefficient is estimated at 11.7% for the 2 reliability.
Hyakutake, Toru*; Muto, Akinori*; Sasakura, Mariko*; Minowa, Hirotsugu*; Suzuki, Kazuhiko*; Yokoyama, Kaoru; Takahashi, Nobuo; Hata, Haruhi; Sugitsue, Noritake
JAEA-Research 2011-035, 53 Pages, 2012/01
System decontamination has been generally carried out with the aim of reducing the amount of radioactive waste generated and minimizing exposure to radiation released from nuclear fuel facilities. At the Ningyo-Toge Environmental Engineering Center, metal surfaces that are contaminated by uranium are dry decontaminated by using iodine heptafluoride (IF) as a system decontaminator. Only a few studies have been carried out on the decontamination efficiency, mechanism, level, etc. of dry decontamination techniques that use a decontamination gas. Therefore, the generalization of dry decontamination techniques is required. In the present study, the efficiency of a dry decontamination technique was assessed by a numerical method using decontamination data obtained at the Ningyo-Toge Environmental Engineering Center. A concrete analytical content is a depositing of uranium hexafluoride.
Iwamoto, Hiroki; Nishihara, Kenji; Tsujimoto, Kazufumi; Sugino, Kazuteru; Numata, Kazuyuki*
JAEA-Research 2011-036, 64 Pages, 2012/01
An analytical study of minor actinide (MA) transmutation systems was conducted using JENDL-4.0, with a comparison to JENDL-3.3 in terms of reactor physics parameters (criticality, void reactivity and the Doppler reactivity) and those uncertainties. As objects of the analyses, Accelerator driven system (ADS) and MA loaded fast reactor (FR) were assumed. It was found that there were considerable changes for both systems. As the results of the sensitivity and uncertainty analysis, we found that the difference of the parameters of ADS is due mainly to the inelastic scattering cross sections of lead isotopes and several reactions of Am. For FR, a large difference of the void reactivity uncertainty results primarily from the covariance data of the inelastic cross section of Na.
Ban, Yasutoshi; Yamagishi, Isao; Morita, Yasuji
JAEA-Research 2011-037, 11 Pages, 2012/01
Adsorption of Cs with five types of inorganic adsorbents (CST: Crystalline SilicoTitanate) powder, CST grain, synthetic mordenite powder, synthetic mordenite grain, and natural mordenite) was carried out by batch methods in the aqueous solution of NaCl at room temperature, respectively. The concentration of Cs after the batch experiments decreased compared with the initial concentration of Cs when the ratio of the solution volume (ml) to the amount of the adsorbent (g) was 100 ml/g, and it was confirmed that the adsorbents used in the present study adsorbed Cs ion in the presence of Na and Cl ions.
Sanada, Hiroyuki; Hikima, Ryoichi; Tanno, Takeo; Matsui, Hiroya; Sato, Toshinori; Kato, Harumi*
JAEA-Research 2011-038, 26 Pages, 2012/01
The Mizunami Underground Research Laboratory Project has been implemented to establish the techniques for investigation, analysis and assessment of the deep geological environment and to develop a range of engineering techniques for application deep underground. In this paper, results of differential strain curve analysis (DSCA) and elastic wave measurements using polyhedral specimens at the 08MI13 and 09MI20 boreholes in -300 m stage are described. The objectives of this work are to evaluate in situ stress condition on the -300 m stage.
Furukawa, Tomohiro; Kato, Shoichi; Maeda, Shigetaka; Yamamoto, Masaya; Sekine, Takashi; Ito, Chikara
JAEA-Research 2011-039, 20 Pages, 2012/02
Application of zirconium alloy as a neutron reflector around the driver fuel region of the Japanese experimental fast reactor JOYO has been planned for a further increase of core average burn-up. In order to investigate the compatibility of the zirconium alloys with high-temperature sodium which is coolant of the JOYO, corrosion test in sodium and tensile test of the exposed alloys were performed. The corrosion test was done at 500C and 650C in stagnant/flowing sodium for two kinds of zirconium alloys, and then weight change measurement and metallurgical observation were carried out. The tensile test was performed in air at the same temperature with the sodium exposure.
Okubo, Seisuke*; Fukui, Katsunori*; Hashiba, Kimihiro*; Hikima, Ryoichi; Tanno, Takeo; Sanada, Hiroyuki; Matsui, Hiroya; Sato, Toshinori
JAEA-Research 2011-040, 54 Pages, 2012/02
With respect to high-level radioactive waste disposal, knowledge of the long-term mechanical stability of shafts and galleries excavated in rock are required, not only during construction and operation but also over a period of thousands of years after closure. Therefore, it is very important to understand the time-dependent behavior of rock for evaluating long-term mechanical stability. This report describes the results of the activities in FY2010. In Chapter 1, we provide an overview and the background to this study. In Chapter 2, the results of a long-term creep test on Tage tuff, started in FY1997 are described. In Chapter 3, the relation of loading-rate dependency of strength and stress dependency of creep life, the relationship of time dependency and probability distribution of strength or creep life and size effects are discussed to indicate more clearly the meaning of the value of "n" to express the degree of time dependency of the rock. In Chapter 4, failure criterions of a rock mass considering time dependency are discussed. In Chapter 5, the FEM analysis implemented with a generalized variable-compliance-type constitutive equation considering the change of "n" in confining pressure and strength distribution of rock mass carried out to clarify the long-term behavior of Toki granite is described. Finally, based on the numerical analysis, an in situ testing method is proposed.
Terada, Atsuhiko; Noguchi, Hiroki; Takegami, Hiroaki; Kamiji, Yu; Inagaki, Yoshiyuki
JAEA-Research 2011-041, 62 Pages, 2012/02
We have proposed a hydrogen supply-chain system, which is a storage/supply system of large amount of hydrogen produced by HTGR-IS hydrogen production system. The organic chemical hydride method is one of the candidate techniques in the system for hydrogen storage and transportation. In this study, properties of organic hydrides and conventional hydrogen storage/supply system were examined to help the conceptual design of the hydrogen supply system using an organic hydrides method with VHTR-IS hydrogen production process (hydrogen production: 85,400 Nm/h). Conceptual specifications of the main apparatus were designed for the hydrogen supply system with hydrogenation and dehydrogenation process. It was also clarified the problems of hydrogen supply system, such as efficiency of energy and system optimization.
Yamamoto, Yoichi; Maekawa, Keisuke; Yokota, Hideharu; Yamazaki, Masanori
JAEA-Research 2011-042, 97 Pages, 2012/02
The surface hydrogeological investigation has been carried out in and around the Horonobe Underground Research Laboratory area as a part of Horonobe URL project. Observations of meteorological, river flux, water quality, soil moisture and groundwater level have been continued in order to understand the groundwater recharge rate and groundwater flow in the shallow part, which are required for the setting of boundary and initial condition of the groundwater flow analysis. This report shows the summary of the surface hydrogeological investigation and results of recharge rates of investigation basins from December 2004 to November 2009 are calculated by using the water budget method. Spatial estimation of hydrological quantities for the groundwater recharge rate is demonstrated by the runoff analysis. As a result, average of the groundwater recharge rate of whole basins is estimated to 131mm/yr. Suggestive observations related to hydraulic properties of the geology and faults are obtained from consideration to the groundwater recharge rate for each basin.
Sugita, Yutaka; Sanada, Hiroyuki; Aizawa, Takao*; Ito, Shunichiro*
JAEA-Research 2011-043, 25 Pages, 2012/02
A simplified seismic velocity survey system was developed for the repeat performance of surveys in conjunction with tunnel excavation, to monitor the various changes that occur in a rock mass around tunnels or galleries as they are excavated in the deep underground. The simplified seismic velocity survey system developed consists of a hammer to transfer seismic energy to the borehole wall and receivers installed and anchored in the borehole, and then backfilled. The hammer is operated with compressed air, necessitated by the potential presence of flammable gas such as methane. The system developed was used in the EDZ Experiment in a horizontal tunnel in the Horonobe URL. Changes in seismic velocity were monitored during and after excavation of the tunnel and the tomograms obtained are high quality. These results show that the system developed can provide the information needed to monitor the development and the variations in an EDZ.
FBR Safety Unit
JAEA-Research 2011-044, 185 Pages, 2012/02
JAEA has been developing a flow-induced vibration methodology applied to the JSFR piping under the FaCT project. As part of this development, flow pattern in the single-elbow pipe has been investigated with the measurement of fluid force induced by turbulence flow and of the flow-induced vibration response. The experimental results have served to the development and vibration of the flow-induced vibration evaluation methodology. Based on these outcomes, JAEA has established a working group on a guideline of large-diameter piping flow-induced vibration evaluation under the JAEA's Thermal-Hydraulic Research Committee for creating the JAEA internal guideline. The first proposal of the guideline was summarized from the achievements of the working group activity. Since technical discussion has been made deeply in developing the guideline, this report summarizes technical background and understanding for the guideline.
Iwamae, Atsushi*; Ogawa, Hiroaki; Sugie, Tatsuo; Kusama, Yoshinori
JAEA-Research 2011-045, 11 Pages, 2012/02
In order to investigate reflection properties on plasma-facing material in ITER, the bi-directional reflectance distribution function (BRDF) of a tungsten block sample has been measured. On the machining surface of the block, one-directional machining lines are engraved. Two laser diodes 652 nm and 473 nm were used to simulate H and H emissions, respectively. The reflected light is affected by the machining surface. The reflected light traces a line when the incident light is injected in the perpendicular direction to the engraved line. On the other hand the reflected light traces an arc shape when the incident light is injected in the parallel direction to the engraved lines. Ray tracing simulation qualitatively explains the experimental results.
Ishitoya, Kimihide; Sugaya, Toshikatsu; Funabashi, Hideyuki
JAEA-Research 2011-046, 32 Pages, 2012/02
Nuclear Safety Commission of Japan (NSC) issued "Policy of the Safety Assessment of Sub-surface Disposal after the Period for Active Control" (April 1, 2010). Then, we investigated the parameters for dose assessment in tunnel excavation scenario and large-scale land use scenario which were described in the "Policy of the Safety Assessment", in order to perform the assessment based on actual conditions. To be concrete, we investigated the tunnel excavating speeds in Japan for the former scenario, and investigated technical standards of the filling for the latter scenario. We studied the realistic parameters for the dose assessment with the results of those investigations.
Yotsuji, Kenji; Tachi, Yukio; Nishimaki, Yuichiro*
JAEA-Research 2011-047, 105 Pages, 2012/02
We have developed integrated sorption and diffusion model (ISD model) for assessment of diffusion parameters consistent with sorption processes in compacted bentonite. Conventional ISD model is unsatisfactory because for multivalent cation/anion and complex ion model predictions disagree with experimental data, and because the model contains additional non-physical fitting parameter. Accordingly we extract the factors influencing the assessment from fundamental assumptions of the conventional ISD model. In this report we incorporated the excluded volume effect, the dielectric saturation effect and the fluctuation potential effect caused by ion-ion electrostatic interaction into ISD model. As results of numerical analysis of these models the considering factors influence hardly the effective diffusivity. Therefore it does not mean that the disagreement with experimental data are caused by considering factors in this report.
Nanjo, Isao; Amano, Yuki; Iwatsuki, Teruki; Kunimaru, Takanori; Murakami, Hiroaki; Hosoya, Shinichi*; Morikawa, Keita
JAEA-Research 2011-048, 162 Pages, 2012/03
The observation technique of hydrochemical condition in low permeable sedimentary rock around the facility is one of R&D subjects. We report, (1) development of hydrochemical monitoring system to observe water pressure, pH, electric conductivity, dissolved oxygen, redox potential and temperature, (2) hydrochemical observation results around URL under construction. The applicability of the hydrochemical monitoring system is evaluated for low permeable sedimentary rock bearing abundant dissolved gases. The hydrochemical observation during facility construction demonstrates that pH and redox potential of groundwater almost did not changed even at hydraulic disturbed zone (water pressure decreased zone).
Iwatsuki, Teruki; Mizuno, Takashi; Amano, Yuki; Kunimaru, Takanori; Semba, Takeshi
JAEA-Research 2011-049, 68 Pages, 2012/03
This report summarizes technical basis and the Know-how on hydrochemical investigations for deep underground as a part of METI project "Development of Information Synthesis and Interpretation System (ISIS)". We describe the procedures and methods of hydrochemical investigation in following stages; (1) initial analysis of previous information, (2) planning of borehole investigation, (3) borehole investigation at field, and (4) construct the "hydrochemical model" representing hydrochemical condition and the evolution process. The contents of this report are inputted to "Expert system" developed by METI project and are available via WEB system (internet).
Yamagishi, Hideshi*; To, Kentaro
JAEA-Research 2011-050, 16 Pages, 2012/10
For development of two-dimensional position sensitive (2-D) neutron detectors with fast response and high spatial resolution, an ASIC with fast response and low noise performances is required. The MP8 and MP16, consisting of p-MOSFETs, with high g and low noise have been proposed (1) to develop the ASIC. In this paper a simple low noise amplifier (LNA) was designed and the noise power and the noise figure were analytically calculated. The results were also applied to LNAs using MP8 or MP16 configuration. The results showed that the MP8 and MP16 had enough performances for the ASIC.
Yamagishi, Hideshi*; To, Kentaro; Nakamura, Tatsuya; Sakasai, Kaoru; Soyama, Kazuhiko
JAEA-Research 2011-051, 19 Pages, 2012/02
An ASD-ASIC (Amplifier-Shaper-Discriminator ASIC) with fast response and low noise performances has been designed for two-dimensional position sensitive neutron gas detectors (InSPaD). The InSPaD is a 2D neutron detector system with He gas and provides a high spatial resolution by making distinction between proton and triton particles generated in the gas chamber. The new ASD-ASIC is required to have very low noise, a wide dynamic range, good output linearity and high counting rate. The new ASD-ASIC has been designed by using CMOS and consisted of 64-channel ASDs, a 16-channel multiplexer with LVTTL drivers and sum amplifier system for summing all analog signals. The performances were evaluated by the Spice simulation. It was confirmed that the new ASD-ASIC had very low noise performance, wide dynamic range and fast signal processing functions.
Sato, Hisashi; Sawada, Atsushi
JAEA-Research 2011-052, 55 Pages, 2012/02
In order to obtain the hydraulic property, mass transport property and three-dimensional fracture void geometry which need for elucidate the permeability and mass transport phenomena in a single fracture, we conducted a flow test, measurement of fracture shape, aperture measurement by optical method, tracer test by optical method for three transparent replica specimens. As a result, the flow rate of two-dimensional seepage flow analysis based on LCL became about 1.5 to 2 times of the flow test results, which results was consistent with previously reported results. To investigate the influence of fracture shape for the flow analysis results, corrected the transmissivity using the acquired data of aperture distribution and fracture shape data. As a results, the fracture permeability by applying the corrected transmissivity considering local slope of the fracture was decreased which is closer to the flow test results.
Tanaka, Tadao; Mukai, Masayuki
JAEA-Research 2011-053, 41 Pages, 2012/08
To understand the migration phenomenon of radionuclide, actual migration data are experimentally acquired by a batch test, a column test and field trial. In the present study, experimental models about the interactions of radionuclide between the solid phase and the liquid phase were discussed systematically to interpret the migration data acquired by the various techniques and conditions. Equilibrium, reversibility, linearity, mechanism and chemistry in the interactions were considered in discussion of the experimental models. A calculation program, which can analyze migration data obtained under various conditions by applying the selected 9 types of experimental models, was maintained. The calculation program makes it be able to predict the migration behavior of radionuclide under various conditions and to decide the important parameter by a fitting analysis of the migration data.
Sakai, Ryutaro; Munakata, Masahiro; Kimura, Hideo
JAEA-Research 2011-054, 19 Pages, 2012/03
In the safety assessment for a geological disposal of radioactive waste, it is important to establish validation methods for deep groundwater flow system to estimate radionuclide migration to human environment through groundwater flow. This study discussed the method which estimates groundwater mixing condition and groundwater flow process using principal component analysis (PCA) to groundwater chemistry and isotopic compositions, together with data of groundwater age and trace element in case of Horonobe area. The results show that hydrochemical system can be divided into two systems: (1) three deep groundwater mixing system at depths greater than 200 to 400 m, (2) mixing area of deep groundwater and surface water at depths less than 200 to 400 m. Groundwater in the deep aquifer is suggested to be discharged at surface through Omagari Fault.
Sanada, Masanori; Kishi, Hirokazu; Hayashi, Katsuhiko*; Takebe, Atsuji*
JAEA-Research 2011-055, 79 Pages, 2012/03
In order to refine and rationalize a design method of multi tunnels in the deep geological repository, various study have been conducted. In this study, an effect of procedure for excavating multi-tunnels on extent of EDZ was examined by 3D FEM analysis. In modeling the multi tunnels and setting cases of analysis, workability, cost and safeness under construction were considered. Results of 3D FEM analysis showed that 3D effect of procedure for excavating such as a gap of progress with tunnel faces can be considered by 3D FEM and extent of EDZ is demonstrated more practically compared with 2D FEM. Another 2D FEM analysis modeling for crystalline rock (granite) was executed and the results showed that plastic zone did not appear in all cases.
Inagaki, Manabu*; Tanaka, Tatsuya*; Hashimoto, Shuji*; Maekawa, Keisuke; Shibata, Masahiro
JAEA-Research 2011-056, 37 Pages, 2012/03
In Japan, a step-wise approach is applied in the site selection process for the geologic disposal site. Preliminary surface-based investigations will be followed by detailed investigations. The basic repository concept, including underground design and layout, will be discussed at the end of surface-based investigations. The repository concept will depend on the spatial extent of the candidate rock formation(s) and their barrier performance. However, information obtained from the surface is limited and includes uncertainties. It is thus important to assess host rock performance considering uncertainties. In this study, methodology for evaluation of geological conditions has been developed that focuses on determining the usable volume of host rock with specific performance characteristics. Initially, multiple performance indices have been discussed and defined from the viewpoint of barrier performance. Then the evaluation procedure is illustrated by using the dataset obtained from the Horonobe Underground Research Laboratory Project. Finally the proposed procedure is reviewed and future challenges are extracted.
Inoue, Masaki; Ikeuchi, Hirotomo; Takeuchi, Masayuki; Koyama, Shinichi; Suto, Mitsuo
JAEA-Research 2011-057, 100 Pages, 2012/03
Corrosion resistance of fuel pin cladding tube materials is one of the most important properties to design aqueous reprocessing process. The martensitic oxide dispersion strengthened ferritic steel, names as "9Cr-ODS" steel, is the primary candidate of high burnup fuel pin cladding tube for fast reactor cycle. Because 9Cr-ODS steel contains lower chromium than stainless steels, oxidizing species in nitric acid medium needs to reduce its corrosion rate. In spent fuel dissolvers, although both nitric acid and metallic ions concentrations change, corrosion potential of 9Cr-ODS steel tends to increase gradually and stabilize protective passive layer effectively.