Irradiation test with silicon ingot for NTD-Si irradiation technology

Takemoto, Noriyuki; Romanova, N.*; Kimura, Nobuaki; Gizatulin, S.*; Saito, Takashi; Martyushov, A.*; Nakipov, D.*; Tsuchiya, Kunihiko; Chakrov, P.*

JAEA-Technology 2015-021, 32 Pages, 2015/08

JAEA-Technology-2015-021.pdf:3.15MB

Silicon semiconductor production by neutron transmutation doping (NTD) method using the JMTR has been investigated in Neutron Irradiation and Testing Reactor Center, Japan Atomic Energy Agency in order to expand the industry use. As a part of investigations, irradiation test with a silicon ingot was planned using WWR-K in Institute of Nuclear Physics, Republic of Kazakhstan. A device rotating the ingot made with the silicon was fabricated and was installed in the WWR-K for the irradiation test. And that, a preliminary irradiation test was carried out using neutron fluence monitors to evaluate the neutronic irradiation field. Based on the result, two silicon ingots were irradiated as scheduled, and the resistivity of each irradiated silicon ingot was measured to confirm the applicability of high-quality silicon semiconductor by the NTD method (NTD-Si) to its commercial production.

Research on geosphere stability for long-term isolation of radioactive waste; Scientific programme for fiscal years 2015-2021

Umeda, Koji; Yasue, Kenichi; Kokubu, Yoko; Niwa, Masakazu; Asamori, Koichi; Fujita, Natsuko; Shimizu, Mayuko; Shimada, Akiomi; Matsubara, Akihiro; Tamura, Hajimu; et al.

JAEA-Review 2015-012, 43 Pages, 2015/08

JAEA-Review-2015-012.pdf:1.24MB

The concept of geological disposal of high-level radioactive waste (HLW) in Japan is based on a multibarrier system which combines a stable geological environment with an engineered barrier system. Potential geological host formations and their surroundings are chosen, in particular, for their long-term stability, taking into account the fact that Japan is located in tectonically active zone. This report is to outline 7 years plan (fiscal years 2015-2021) of research and development (R&D) for geosphere stability for long-term isolation of the HLW in JAEA. Background of this research is clarified with the necessity and the significance, and the past progress in this report. The objectives, outline, contents and schedule during the next 7 years are described in detail. In addition, the plan framework is structured into the following categories: (1) Development and Systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques.

Development on nuclear design model for detailed design of clean burn HTGR

Fukaya, Yuji; Goto, Minoru; Nishihara, Tetsuo

JAEA-Technology 2015-017, 61 Pages, 2015/07

JAEA-Technology-2015-017.pdf:1.97MB

A development on nuclear design model for detailed design of Clean Burn HTGR had been performed. In the previous study, the fuel composition assumed in the study of Deep Burn proposed by GA in U.S. was employed. In the present study, that is estimated to reflect the situation of the nuclear fuel cycle in Japan. And, the evaluation method is refined from the viewpoint of traceability and a guarantee of quality. The deployment of control rod columns is investigated. Moreover, the Er loading is also investigated to obtain negative temperature coefficients in all range of operation. This model is developed for MVP code, which solves neutron transportation by Monte Carlo method. Validation of burn-up chain is also performed to adopt very high burn-up calculation. The core design is performed by COREBN code, which solves neutron diffusion equation by deterministic approach. Thus, the convertor which converts the cross section of MVP to COREBN is also developed.

Study on the evaluation method to determine the radioactivity concentration waste generated from post-irradiation examination facilities

Hoshino, Yuzuru; Sakamoto, Yoshiaki; Muroi, Masayuki*; Mukai, Satoru*

JAEA-Technology 2015-015, 96 Pages, 2015/07

JAEA-Technology-2015-015.pdf:20.34MB

In order to dispose of the radioactive waste which generates from post-irradiation examination (PIE) facilities, the common evaluation method of radioactivity in wastes from PIE should be established by the actual data such as radioactivity values and the theoretical calculation. In this study, the radioactivity concentrations of 17 nuclides (H-3, C-14, Co-60, Ni-63, Sr-90, Tc-99, Cs-137, Eu-154, U-234, U-235, U-238, Pu-238, Pu-239, Pu-240, Pu-241, Am-241, Cm-244) in combustible wastes stored in NUCLEAR DEVELOPMENT CORPORATION were measured from 3 samples and the radioactivity was calculated by ORIGEN-2 based on initial contents and operation record of the spent fuel. From the comparison of the obtained data by the radiological measurement with the calculated values, the subject to be solved for establishment of the radioactivity evaluation method for PIE was extracted.

Horonobe Underground Research Laboratory Project; Investigation program for the 2015 fiscal year

Hanamuro, Takahiro

JAEA-Review 2015-010, 22 Pages, 2015/07

JAEA-Review-2015-010.pdf:16.3MB

As part of the research and development program on geological disposal of high-level radioactive waste (HLW), the Horonobe Underground Research Center, a division of the Japan Atomic Energy Agency (JAEA), is implementing the Horonobe Underground Research Laboratory Project (Horonobe URL Project) with the aim at investigating sedimentary rock formations. According to the research plan described in the 3rd Mid- and Long-term Plan of JAEA, according to the Horonobe URL Project, "Near-field performance study", "Demonstration of repository design option", and "Verification of crustal-movement buffering capacity of sedimentary rocks" are the top priority issues, and schedule for finishing the project and backfill plan will be decides by the end of 2019 Fiscal Year. The Horonobe URL Project is planned to extend over a period of about 20 years. This report summarizes the investigation program for the 2015 fiscal year (2015/2016).

Annual report of Nuclear Human Resource Development Center (April 1, 2013 - March 31, 2014)

Nuclear Human Resource Development Center

JAEA-Review 2015-006, 71 Pages, 2015/07

JAEA-Review-2015-006.pdf:10.38MB

This annual report summarizes the activities of Nuclear Human Resource Development Center (NuHRDeC) of Japan Atomic Energy Agency (JAEA) in the FY 2013. In FY2013, we flexibly designed special training courses corresponding with the outside training needs, while organizing the annually scheduled regular training programs. We also actively addressed the challenging issues on human resource development, such as to enhance the collaboration with academia and to organize international training for Asian countries.

Mizunami Underground Research Laboratory Project; Rock mechanical investigations at the -500m stage

Kuwabara, Kazumichi; Sato, Toshinori; Sanada, Hiroyuki; Takayama, Yusuke

JAEA-Research 2015-005, 378 Pages, 2015/07

JAEA-Research-2015-005.pdf:125.5MB
JAEA-Research-2015-005.zip:0.53MB

This report presents the results of following rock mechanical investigations conducted at the -500m Stage. (1) Laboratory tests using cores and block samples obtained at the -500m Stage. (2) In-situ stress measurement using Compact Conical-ended Borehole Overcoring (CCBO) method at the -500m Stage. (3) In-situ stress measurements using Differential Strain Curve Analysis(DSCA) method at the -500m Stage. (4) Development of rock mechanical model.

Assessment report of research and development activities in FY2014; Activity "Nuclear Science and Engineering Research" (Result and in-advance evaluation)

Nuclear Science and Engineering Center; Center for Computational Science & e-Systems

JAEA-Evaluation 2015-003, 58 Pages, 2015/07

JAEA-Evaluation-2015-003.pdf:1.39MB
JAEA-Evaluation-2015-003-appendix(CD-ROM)..zip:9.94MB

Japan Atomic Energy Agency (hereinafter referred to as "JAEA") consults an assessment committee, "Evaluation Committee of Research Activities for Nuclear Science and Engineering" (hereinafter referred to as "Committee") for result and in-advance evaluation of "Nuclear Science and Engineering", in accordance with "General Guideline for the Evaluation of Government Research and Development (R&D) Activities" by Cabinet Office, Government of Japan, "Guideline for Evaluation of R&D in Ministry of Education, Culture, Sports, Science and Technology" and "Regulation on Conduct for Evaluation of R&D Activities" by the JAEA. In response to the JAEA's request, the Committee assessed the research program of the Nuclear Science and Engineering Center (hereinafter referred to as "NSEC") and Center for Computational Science and e-Systems (hereinafter referred to as "CCSE"). The Committee evaluated the management and research activities of the NSEC and the CCSE based on explanatory documents prepared by the NSEC and the CCSE, and oral presentations with questions-and-answers.

Development of the versatile reactor analysis code system, MARBLE2

Yokoyama, Kenji; Jin, Tomoyuki; Hirai, Yasushi*; Hazama, Taira

JAEA-Data/Code 2015-009, 120 Pages, 2015/07

JAEA-Data-Code-2015-009.pdf:1.93MB

The second version of the versatile reactor analysis code system, MARBLE2, has been developed. A lot of new functions have been added inMARBLE2 by using the base technology developed in the first version (MARBLE1). Introducing the remaining functions of the conventional code system (JOINT-FR and SAGEP-FR), MARBLE2 enables one to execute almost all analysis functions of the conventional code system with the unified user interfaces of its subsystem, SCHEME. In particular, the sensitivity analysis functionality is available in MARBLE2. On the other hand, new built-in solvers have been developed, and existing ones have been upgraded. Furthermore, some other analysis codes and libraries developed in JAEA have been consolidated and prepared in SCHEME. In addition, several analysis codes developed in the other institutes have been additionally introduced as plug-in solvers. Consequently, -ray transport calculation and heating evaluation become available. As for another subsystem, ORPHEUS, various functionality updates and speed-up techniques have been applied based on user experience of MARBLE1 to enhance its usability.

Sensitivity of radioactive nuclide leaching rate under the sub-surface disposal

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.

Validation of system analysis code with HTTR thermal load fluctuation test data (non-nuclear heating) and evaluation of reactor temperature behavior during upsets in hydrogen production plant

Honda, Yuki; Sato, Hiroyuki; Nakagawa, Shigeaki; Takada, Shoji; Tochio, Daisuke; Sakaba, Nariaki; Sawa, Kazuhiro

JAEA-Technology 2015-012, 17 Pages, 2015/06

JAEA-Technology-2015-012.pdf:11.38MB

Japan Atomic Energy Agency (JAEA) proposed a draft safety requirement, which consists of the requirements for constructing a H plant under conventional chemical plant regulations as well as the requirements for collocation of a nuclear facility and a H plant. One of the key requirements is to maintain reactor normal operation condition during every possible condition in the H plant. In order to show that the requirement can be reasonably achieved, a system analysis code is validated with the HTTR experimental data obtained in January 2015. The validated code is applied for the evaluation of a postulated abnormal event in H plant to be connected to the HTTR. The results showed that the evaluation items such as reactor power and reactor outlet coolant temperature do not exceed evaluation criteria. As a conclusion, a feasibility of H plant construction under non-nuclear regulations is validated by showing that the stable reactor operation can be achieved against temperature transients induced by abnormal conditions in the H plant.

Document collection of the 31st Technical Special Committee on Fugen Decommissioning

Kutsuna, Hideki; Yamazaki, Koichi; Kadowaki, Haruhiko; Iguchi, Yukihiro

JAEA-Review 2015-008, 39 Pages, 2015/06

JAEA-Review-2015-008.pdf:8.77MB

Fugen Decommissioning Engineering Center has been establishing "Technical special committee on Fugen decommissioning" which consists of the members well-informed, aiming to make good use of Fugen as a place for technological development which is opened inside and outside the country, as the central point in the energy research and development base making project of Fukui prefecture, and to utilize the outcome in our decommissioning to the technical development effectively. This report compiles presentation materials "The Current Situation of Fugen Decommissioning", "Applicability Test for Dismantling with the Diamond Wire Saw using equipments used in Fugen", "Status of the Tritium Removal and Evaluation of the Efficiency of the Room-Temperature Vacuum drying" and "Integration Policy of Knowledge Management System for Fugen", presented in the 31st Technical special committee on Fugen decommissioning which was held on March 13, 2015.

Annual report on the activities in Safety Administration Department; Report of the fiscal year 2011

Aoki, Yoshikazu

JAEA-Review 2014-053, 371 Pages, 2015/06

JAEA-Review-2014-053.pdf:85.29MB

The activities of Safety Administration Department covers many fields in Nuclear Fuel Cycle Engineering Laboratories such as the management of the occupational safety and health, the crisis management, the security, and the management of a quality assurance. This report is the summary of the activities of Safety Administration Department since April, 2011 until March, 2012.

Analysis of FCA VIII-2 fuel slumping experiments by SIMMER-III and SIMMER-IV

Ishida, Shinya; Mizuno, Masahiro*

JAEA-Research 2015-002, 47 Pages, 2015/06

JAEA-Research-2015-002.pdf:7.22MB

An advanced safety analysis computer code, SIMMER-III and SIMMER-IV, has been developed to investigate the complex phenomena under the core disruptive accidents in LMFRs. Fuel slumping experiments performed in the Fast Critical Assembly (FCA) VIII-2 facility were analyzed by SIMMER-III (two dimensions) and SIMMER-IV (three dimensions) in order to validate the neutronics model of the code for the disrupted core analysis. The results of the SIMMER-III and SIMMER-IV analysis (70-group constants from the unified cross-section set ADJ2000R, multi-group transport approximation for the anisotropic scattering, S8 approximation for the discrete-ordinate order) indicated that the SIMMER-III and SIMMER-IV simulated the FCA VIII-2 experiments with sufficient precision. In addition, the parameter surveys showed that the simulation of the FCA VIII-2 experiments with sufficient precision can be performed with the 18-group constants and S4 approximation for the discrete-ordinate order.

HTFP for calculation of amount of additionally released fission products from fuel rods of pin-in-block-type high temperature gas-cooled reactors during accident

Nomoto, Yasunobu; Aihara, Jun; Nakagawa, Shigeaki; Isaka, Kazuyoshi; Ohashi, Hirofumi

JAEA-Data/Code 2015-008, 39 Pages, 2015/06

JAEA-Data-Code-2015-008.pdf:10.32MB

HTFP is a calculation code for amount of additionally released fission product (FP) from fuel rods of pin-in-type according to transient of core temperature at the accident of high temperature gas-cooled reactors (HTGRs). This code analyzes FP release inventory from core according to the transient of core temperature at the accident as an input data and considering FP release rate from a fuel compact and a graphite sleeve and radioactive decay of FP. This report describes the outline of HTFP code and its input data. The computed solutions using the HTFP code were compared to those of HTCORE code, which was used for the design of the High Temperature Engineering Test Reactor (HTTR) to validate the analysis models of the HTFP code. The comparison of HTFP code results with HTCORE code results showed the good agreement.

Annual data compilation of water balance observation in the Regional Hydrogeological Study Project (RHS Project); For the fiscal year 2013

Ueno, Tetsuro; Takeuchi, Ryuji

JAEA-Data/Code 2015-006, 22 Pages, 2015/06

JAEA-Data-Code-2015-006.pdf:5.05MB
JAEA-Data-Code-2015-006-appendix(CD-ROM).zip:14.52MB

Tono Geoscience Center of Japan Atomic Energy Agency (JAEA) has carried out the subsurface water balance observation in order to estimate groundwater recharge rate for setting the upper boundary conditions on groundwater flow simulation and to obtain data for calibration of hydrogeological model. In the subsurface water balance observations, precipitation data and river flow rate have been observed in the Garaishi River and the Hiyoshi River watersheds. The missing or abnormal data in the monitoring data during the fiscal year 2013 were complemented or corrected, and these data were compiled in data set.

Data on fractures in the Toki Granite based on the deep borehole investigations

Ishibashi, Masayuki; Sasao, Eiji

JAEA-Data/Code 2015-004, 8 Pages, 2015/06

JAEA-Data-Code-2015-004.pdf:2.0MB
JAEA-Data-Code-2015-004-appendix(CD-ROM).zip:3.61MB

Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is pursuing a geoscientific research in crystalline rock environment in order to construct scientific and technological basis for the geological disposal of High-level Radioactive Waste. This report compiles the information of the fracture in the Toki Granite, central Japan, obtained by deep borehole investigation, drilled from the ground surface.

Developments of high-performance moderator vessel for JRR-3 cold neutron source

Arai, Masaji; Tamura, Itaru; Hazawa, Tomoya

JAEA-Technology 2015-010, 52 Pages, 2015/05

JAEA-Technology-2015-010.pdf:7.11MB

In the Department of Research Reactor and Tandem Accelerator, developments of high-performance CNS moderator vessel that can produce cold neutron intensity about two times higher compared to the existing vessel have been performed in the second medium term plans. We compiled this report about the technological development to solve several problems with the design and manufacture of new vessel. In the present study, design strength evaluation, mockup test, simulation for thermo-fluid dynamics of the liquid hydrogen and strength evaluation of the different-material-bonding were studied. By these evaluation results, we verified that the developed new vessel can be applied to CNS moderator vessel of JRR-3.

Maintenance of helium refrigerator/liquefier system in ITER CS Model Coil Test Facility

Ebisawa, Noboru; Kiuchi, Shigeki*; Kikuchi, Katsumi*; Kawano, Katsumi; Isono, Takaaki

JAEA-Testing 2014-003, 37 Pages, 2015/03

JAEA-Testing-2014-003.pdf:11.7MB

Objective of the ITER CS Model Coil Test Facility is to evaluate a large scale superconducting conductor for fusion using the Central Solenoid (CS) Model Coil, which can generate a 13-T magnetic field in the inner bore with a 1.5m diameter. The facility is composed of a helium refrigerator / liquefier system, a DC power supply system, a vacuum system and a data acquisition system. This report describes that maintenance of the helium refrigerator / liquefier system since the Great East Japan Earthquake in March 2011 until the first operation after the earthquake in December 2012.

The Uranium waste fluid processing examination by liquid and liquid extraction method using the emulsion flow method

Kanda, Nobuhiro; Daiten, Masaki; Endo, Yuji; Yoshida, Hideaki; Mita, Yutaka; Naganawa, Hirochika; Nagano, Tetsushi; Yanase, Nobuyuki

JAEA-Technology 2015-007, 43 Pages, 2015/03

JAEA-Technology-2015-007.pdf:5.33MB

The centrifuge which has the subtlety information concerning the nuclear nonproliferation used for uranium enrichment technical development exists in the uranium enrichment facilities of Ningyo-toge Environmental Engineering Center, Japan Atomic Energy Agency. This centrifugal is performing separation processing of the radioactive material adhering to the surface of parts by wet decontamination of ultrasonic cleaning by dilute sulfuric acid and water, etc. By removing the uranium contained in waste fluid, generated sludge reduces activity concentration. And the possibility of reduction of sludge processing is examined. For this reason, from the 2007 fiscal year, Nuclear Science and Engineering Directorate and cooperation are aimed at, and development of the extraction separation technology of the "uranium" by the emulsion flow method is furthered. The test equipment using the developed emulsion flow method was tested. And dilute sulfuric acid and water were used for the examination as actual waste fluid. The result checked whether the various performances in Basic test carried out in Nuclear Science and Engineering Directorate would be obtained.

Inspection and repair techniques in the reactor vessel of the experimental fast reactor Joyo; Observation techniques development in a reactor vessel of the fast reactor, 2

Okuda, Eiji; Sasaki, Jun; Suzuki, Nobuhiro; Takamatsu, Misao; Nagai, Akinori

JAEA-Technology 2015-005, 36 Pages, 2015/03

JAEA-Technology-2015-005.pdf:44.42MB

In-Vessel Observations (IVO) techniques for Sodium cooled Fast Reactors (SFRs) are important in confirming its safety and integrity. In order to secure the reliability of IVO techniques, it was necessary to demonstrate the performance under the actual reactor environment with high temperature, high radiation dose and remained sodium. The IVO equipment for the Upper Core Structure (UCS) fitting area was specifically developed in the experimental fast reactor "Joyo". And the IVO was successfully completed as shown below. (1) Improvement of picture quality and resolution. The IVO of UCS fitting area with the gap of 5mm in minimum was achieved using the IVO equipment with video-scope under the actual reactor environment. The picture quality and resolution could be improved comparing with the radiation resistant fiberscope which was used in past IVO. (2) Prevention of video-scope hypofunction by high temperature / radiation dose. Since video-scope is inferior in thermal and radiation resistance, the IVO equipment was designed to be able to withdraw and insert video-scopes with cooling gas. This measure could achieve the observation in short radiation time with available temperature under the actual reactor environment. The IVO equipment for UCS fitting area provided useful information on UCS replacement. In addition, the experience provided valuable insights into further improvements for IVO techniques in SFRs.

Preliminary examination about the seal leak using the photocoagulation resin (Joint research)

Ooka, Makoto; Maekawa, Yasunari; Tomizuka, Chiaki; Murakami, Tomoyuki*; Katagiri, Genichi*; Ozaki, Hiroshi*; Kawamura, Hiroshi

JAEA-Technology 2015-003, 31 Pages, 2015/03

JAEA-Technology-2015-003.pdf:3.95MB

An action for the decommissioning of the Fukushima Daiichi Nuclear Power Station (Tokyo Electric Power Company) is pushed forward now. For fuel debris Remove, it is necessary to fill the Primary Containment Vessel (PCV) with water. Because a coolant leaks out from the PCV, it becomes the most important problem to seal leak the coolant. Nuclear Plant Decommissioning Safety Research Establishment has examined the method of seal leak using the photocoagulation resin. However, originally the photocoagulation resin is used as coating or the painting, and the applicability to seal leak water is unknown. This report describes the result that examined the applicability to seal leak using photocoagulation resin.

Report on research and development of nuclear forensics technologies

Okubo, Ayako; Kimura, Yoshiki; Shinohara, Nobuo; Toda, Nobufumi; Funatake, Yoshio; Watahiki, Masaru; Sakurai, Satoshi; Kuno, Yusuke

JAEA-Technology 2015-001, 185 Pages, 2015/03

JAEA-Technology-2015-001.pdf:56.65MB

Nuclear forensics is the analysis of intercepted illicit nuclear or radioactive material and any associated material to provide evidence for nuclear attribution by determining origin, history, transit routes and purpose involving such material. Nuclear forensics activity includes sampling of the illicit material, analysis of the samples and evaluation of the attribution by comparing the analyzed data with database or numerical simulation. Because the nuclear forensics technologies specify the origin of the nuclear materials used illegal dealings or nuclear terrorism, it becomes possible to identify and indict offenders, hence to enhance deterrent effect against such terrorism. Worldwide network on nuclear forensics can contribute to strengthen global nuclear security regime. In this paper, the results of research and development of fundamental nuclear forensics technologies performed in Japan Atomic Energy Agency during the fiscal term of 2011-2013 were reported.

Environmental impact of nitrate nitrogen in sub-surface disposal system on surface water and sensitivity analysis of distribution coefficient of nitrate ion and porosity of waste layer on the environmental safety assessments

Nakamura, Yasuo; Nakatani, Takayoshi

JAEA-Technology 2014-048, 18 Pages, 2015/03

JAEA-Technology-2014-048.pdf:7.75MB

Sodium nitrate is included bituminized waste generating from the reprocessing plant of spent fuel which is disposed of in sub-surface disposal facility. Because the sodium nitrate is soluble material in surface water, it is a concern impact on surface water. Such as non-radioactive materials are not strictly regulated by "the Law for the Regulations of Nuclear Source Material, Nuclear Fuel Material and Reactors", but should be considered by related laws and regulations according to former basic policy. Because it is regulated as nitrate nitrogen by "The Basic Environment Law", the valuation of the environmental impact on general sub-surface disposal system was carried out. As the results, the concentration of nitrate nitrogen in river water whose annual quantity of water is rather than 110m/y is below the regulated value at the small scale surface waters as evaluation point.

User's guide of cement solidification test for incinerated ash

Nakayama, Takuya; Kawato, Yoshimi; Osugi, Takeshi; Shimazaki, Takejiro; Hanada, Keiji; Suzuki, Shinji; Sakakibara, Tetsuro; Nakazawa, Osamu; Meguro, Yoshihiro

JAEA-Technology 2014-046, 56 Pages, 2015/03

JAEA-Technology-2014-046.pdf:7.61MB

The combustible and flame-retardant radioactive wastes generated as a result of the research activities in Japan Atomic Energy Agency (JAEA) are incinerating to reduce their volume. The incinerated ash is planned to be solidified using cement for disposal. Since the properties of ashes generated in each institute of JAEA are varied with the type of incinerator and the wastes to be incinerated, it is necessary to do fundamental solidification tests in each institute to decide operating conditions of the planning cement solidification facility. It is important to standardize evaluating methods of cement and solidified waste because some characters depend on measuring method. This user's guide have been prepared how to decide the cement solidifying conditions of ash to design the cement solidification facility in JAEA. Requirements on the regulations of solidified radioactive waste have been examined and seven technical criteria, e.g. compressive strength, fluidity, have been selected as characters to be evaluated. Some empirical notes about selection of cement, admixtures, procedure on making a test piece, evaluation of expanding, compressive strength, solubility have been described. The strategy of tests and tips for finding optimized solidification condition has been summarized. Finally the example of optimized conditions satisfied the requirements and some problems to be solved have been described.

Conceptual study of transmutation experimental facility, 5; Investigation of MA fuel handling

Sugawara, Takanori; Nishihara, Kenji; Sasa, Toshinobu; Tsujimoto, Kazufumi; Tazawa, Yujiro; Oigawa, Hiroyuki

JAEA-Technology 2014-044, 59 Pages, 2015/03

JAEA-Technology-2014-044.pdf:14.46MB

Transmutation Physics Experimental Facility (TEF-P) planned in the J-PARC is a critical assembly with low thermal output and it will treat large amount of highly-radioactive minor actinide (MA) fuels in the experiments. Handling of the MA fuels in each stage of storage, transport and loading/unloading to the core was conceptually investigated, then, criticality, dose and cooling performance were assessed. For the criticality, it was shown that the effective multiplication factors in each step, storage, transport and loading, were sufficiently lower than 1.0. For the dose, the dose for workers will be reduced by installing remote handling devices to treat the MA fuels. For the cooling performance, it was found that the temperature of the core would be kept low in the normal operation. On the other hand, in the case which the air conditioning or the blower for the core stopped for long period, it was shown that there would be a possibility of the MA fuel failure.

Annual report for FY2013 on the activities of Department of Decommissioning and Waste Management (April 1, 2013 - March 31, 2014)

Department of Decommissioning and Waste Management

JAEA-Review 2015-004, 90 Pages, 2015/03

JAEA-Review-2015-004.pdf:17.29MB

This report describes the activities of Department of Decommissioning and Waste Management (DDWM) in Nuclear Science Research Institute (NSRI) in the period from April 1, 2013 to March 31, 2014. The report covers organization and missions of DDWM, outline and operation/maintenance of facilities which belong to DDWM, treatment and management of radioactive wastes, decommissioning activities, and related research and development activities which were conducted in DDWM.

Handbook on Process and Chemistry of Nuclear Fuel Reprocessing, 3rd Edition

Committee of Handbook on Process and Chemistry of Nuclear Fuel Reprocessing

JAEA-Review 2015-002, 726 Pages, 2015/03

JAEA-Review-2015-002.pdf:43.63MB
JAEA-Review-2015-002(errata).pdf:0.21MB

The fundamental data on spent nuclear fuel reprocessing and related chemistry was collected and summarized as a new edition of "Handbook on Process and Chemistry of Nuclear Fuel Reprocessing". The purpose of this handbook is contribution to development of the fuel reprocessing and fuel cycle technology for uranium fuel and mixed oxide fuel utilization. Contents in this book was discussed and reviewed by specialists of science and technology on fuel reprocessing in Japan.

Environmental performance data in Environmental Report 2014

Safety and Environmental Management Section, Safety and Nuclear Security Administration Department

JAEA-Review 2014-060, 220 Pages, 2015/03

JAEA-Review-2014-060.pdf:15.28MB
JAEA-Review-2014-060(errata).pdf:0.2MB

In September, 2014 Japan Atomic Energy Agency published the Environmental Report 2014 concerning the activities of FY 2013 under "Law Concerning the Promotion of Business Activities with Environmental Consideration by Specified Corporations, etc, by Facilitating Access to Environmental Information, and Other Measures". This report has been edited to show detailed environmental performance data in FY 2013 as the base of the Environmental Report 2014. This report would not only ensure traceability of the data in order to enhance the reliability of the environmental report, but also make useful measures for promoting activities of environmental considerations in JAEA.

Study on nuclear analysis method for high temperature gas-cooled reactor and its nuclear design (Thesis)

Goto, Minoru

JAEA-Review 2014-058, 103 Pages, 2015/03

JAEA-Review-2014-058.pdf:22.36MB

The following issues were investigated using experimental data of HTTR, which is a Japan's HTGR with 30 MW thermal power. (1)Applicability of nuclear data libraries to nuclear analysis for HTGR, (2) Applicability of the improved nuclear analysis method for HTGR, (3) Effectiveness of a rod-type burnable poison on HTGR reactivity control. Using these investigation results, a nuclear design of a small-sized HTGR with 50 MW thermal power (HTR50S) was performed. In the nuclear design of HTR50S, we challenged to decrease the number of the fuel enrichments and to increase the power density compared with HTTR. As a result, the nuclear design was completed successfully by reducing the number of the fuel enrichment to only three from twelve of HTTR and increasing the power density by 1.4 times of HTTR.

Proceedings of Information and Opinion Exchange Conference on Geoscientific Study, 2014

Nishio, Kazuhisa; Iyatomi, Yosuke

JAEA-Review 2014-056, 79 Pages, 2015/03

JAEA-Review-2014-056.pdf:79.01MB

Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) has been conducting a geoscientific studies in order to establish a scientific and technological basis for the geological disposal of HLW. Information and Opinion Exchange Conference on Geoscientific Study has been held by TGC annually. Technical information of the result on the geoscientific studies conducted at TGC will be provided at the conference for exchanging opinions with researchers and engineers from Japanese universities, research organizations and private companies. This document compiles research presentations, posters of the conference in Mizunami on November 11, 2014.

Research report on the users' needs for next research reactor

Needs Research Task Force for Next Research Reactor

JAEA-Review 2014-054, 43 Pages, 2015/03

JAEA-Review-2014-054.pdf:6.57MB

JRR-3 has been operated for more than 25 years for that it is time to investigate the role of a next research reactor. A task force under the Committee for Promotion of JRR-3 Neutron Beam Application has been organized by Department of Research Reactor and Tandem Accelerator to survey neutron beam application trends in the future. This is a report on the survey results and users' requirements for the next research reactor have been summarized in this report carried by the task force.

Remediation of contaminated areas in the aftermath of the accident at the Fukushima Daiichi Nuclear Power Station: Overview, analysis and lessons learned, 1; A report on the "decontamination pilot project"

Fukushima Environmental Safety Center, Sector of Fukushima Research and Development

JAEA-Review 2014-051, 121 Pages, 2015/03

JAEA-Review-2014-051.pdf:64.45MB

The Japan Atomic Energy Agency (JAEA) was charged with conducting a range of "Decontamination Pilot Project" to examine the applicability of decontamination technologies. The project was implemented at 16 sites in 11 municipalities within the evacuated zone. Despite tight boundary conditions in terms of timescale and resources, the project provides a good basis for developing recommendations on how to assure decontamination efficiency and worker safety whilst additionally constraining costs, subsequent waste management and environmental impacts. This report, based on the Japanese detailed reports that have been published elsewhere, consists of two volumes. This volume 1 summarises the Decontamination Pilot Project, providing the background required to put this work in context for an international audience. In volume 2, the subsequent application of output from these projects to regional remediation now being conducted by the Japanese government and municipalities, is discussed, along with a status update on such work, an overview of associated JAEA's R&D and international input to/review of regional environmental decontamination in Fukushima.

A Study on the strength properties of the rock mass based on triaxial tests conducted at the Horonobe Underground Research Laboratory

Aoyagi, Kazuhei; Ishii, Eiichi; Kondo, Keiji*; Tsusaka, Kimikazu*; Fujita, Tomoo

JAEA-Research 2015-001, 46 Pages, 2015/03

JAEA-Research-2015-001.pdf:4.92MB
JAEA-Research-2015-001-appendix(CD-ROM).zip:67.95MB

Japan Atomic Energy Agency (JAEA) has been conducting R&D activities at the off-site URL at Horonobe, Hokkaido, Japan in order to enhance reliability of technology related to deep geological disposal of HLW in sedimentary rocks. In this report, strength properties (cohesion and frictional angle) of rock masses in the Koetoi and Wakkanai formations are investigated on the basis of triaxial tests conducted in the Horonobe URL considering the relative depths to the formation. Strength properties investigated in this report are compared with the properties obtained in the designing phase. The cohesion in the Koetoi Formation increased with increasing depth. On the other hand, in the transition zone of the Wakkanai Formation, the cohesion increased significantly in the shallow Wakkanai formation (transition zone). Below the transition zone, the cohesion does not significantly depend on the depth. Thus the strength properties between two formations were found to be different. Comparing the cohesions and frictional angles determined from triaxial tests with the values determined in the designing phase, there was no agreement between these values in almost all the depth. Thus it is essential to determine cohesion and frictional angle considering the relative depths to the formation for detailed understanding of strength properties of rock mass.

Multi-faceted evaluation for nuclear fuel cycles with transmutation

Nishihara, Kenji

JAEA-Research 2014-032, 29 Pages, 2015/03

JAEA-Research-2014-032.pdf:5.0MB

Environment impact, economy and proliferation resistance were estimated for nuclear fuel cycles involving transmutation by fast reactor and accelerator-driven system in equilibrium state. As the result, the transmutation scenario using only fast reactor was superior to the scenarios combined with accelerator-driven system in all estimation, but the differences were insignificant.

Enhancement of the methodology of repository design and post-closure performance assessment for preliminary investigation stage, 3; Progress report on NUMO-JAEA collaborative research in FY2013 (Joint research)

Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Makino, Hitoshi; Wakasugi, Keiichiro; Mitsui, Seiichiro; Kitamura, Akira; Yoshikawa, Hideki; Oda, Chie; Ishidera, Takamitsu; et al.

JAEA-Research 2014-030, 457 Pages, 2015/03

JAEA-Research-2014-030.pdf:199.23MB

JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and post-closure performance assessment in preliminary investigation stage. With regard to (1) study on rock suitability in terms of hydrology, based on some examples of developing method of hydro-geological structure model, acquired knowledge are arranged using the tree diagram, and model uncertainty and its influence on the evaluation items were discussed. With regard to (2) study on scenario development, the developed approach for "defining conditions" has been reevaluated and improved from practical viewpoints. In addition, the uncertainty evaluation for the effect of use of cementitious material, as well as glass dissolution model, was conducted with analytical evaluation. With regard to (3) study on setting radionuclide migration parameters, based on survey of precedent procedures, multiple-approach for distribution coefficient of rocks was established, and the adequacy of the approach was confirmed though its application to sedimentary rock and granitic rock. Besides, an approach for solubility setting was developed including the procedure of selection of solubility limiting solid phase. The adequacy of the approach was confirmed though its application to key radionuclides.

Statistical properties of material strength for reliability evaluation of components of fast reactors; Austenitic stainless steels

Takaya, Shigeru; Sasaki, Naoto*; Tomobe, Masato*

JAEA-Data/Code 2015-002, 54 Pages, 2015/03

JAEA-Data-Code-2015-002.pdf:25.53MB

Many efforts have been made to implement the System Based Code concept of which objective is to optimize margins dispersed in several codes and standards. Failure probability is expected to be a promising quantitative index for optimization of margins, and statistical information for random variables is needed to evaluate failure probability. Statistical information of material strength has not been provided enough yet. In this report, the statistical properties of material strength was estimated for SUS304, 316FR steel and some other austenitic stainless steels. These materials are registered in the JSME code of design and construction of fast reactors, so test data used for developing the code were used as much as possible in this report.

Straight tube steam generator three-dimensional thermal-hydraulic code TSG; User's manual of water side simulation

Yoshikawa, Ryuji; Ohshima, Hiroyuki; Tanaka, Masaaki; Imai, Yasutomo*

JAEA-Data/Code 2014-034, 84 Pages, 2015/03

JAEA-Data-Code-2014-034.pdf:2.35MB

TSG (Three-dimensional Thermal-hydraulics Analysis Code for Steam Generators) is being developed for analyses of thermal hydraulics in double wall straight tube steam generator of Fast Breeder Reactor. TSG code is a thermal hydraulics simulation system which couples sodium side three dimensional simulation with water side multi-channel simulation. The three dimensional flow field in the sodium side is simulated by a commercial code FLUENT with porous media model. The multi-channel two-phase flow is simulated by an in-house module with drift-flux model. The sodium side simulation is coupled with the water side simulation by the transmission of heat transfer rate through the heat transfer tube. This report presents a description of the computational models, input and output as the user's manual of TSG water side module.

Statistical compilation on meteorological observation in Hokushin from 2003 to 2014

Yamamoto, Nobuyuki; Matsuoka, Toshiyuki

JAEA-Data/Code 2014-032, 33 Pages, 2015/03

JAEA-Data-Code-2014-032.pdf:6.38MB
JAEA-Data-Code-2014-032-appendix(CD-ROM).zip:5.94MB

Horonobe Underground Research Center has carried out meteorological observation at Horonobe-cho in northern Hokkaido as a part of the Horonobe Underground Research Laboratory project. The meteorological observation data in Hokushin meteorological station from 2003 to 2014 is compiled in this report. Hourly data, daily data and monthly data are included in the data set, and the data set is recorded on CD-ROM.

Establishment of benchmark problems for TRU fission rate ratios of FCA-IX assemblies

Fukushima, Masahiro; Oizumi, Akito; Iwamoto, Hiroki; Kitamura, Yasunori

JAEA-Data/Code 2014-030, 50 Pages, 2015/03

JAEA-Data-Code-2014-030.pdf:10.34MB

In the IX-th experimental series in 1980's at the fast critical assembly (FCA) facility, central fission rate ratios for TRU such as Np, Pu, Pu, Am, Am and Cm to Pu were measured in the seven uranium-fueled assemblies with systematically changed neutron spectra. In the present report, benchmark problems with respect to central fission rate ratios were established for the assessment of the TRU's fission cross sections. We reported the sample calculation results on the benchmark problems by using JENDL-4.0.

SWAT4.0; The Integrated burnup code system driving continuous energy Monte Carlo codes MVP, MCNP and deterministic calculation code SRAC

Kashima, Takao; Suyama, Kenya; Takada, Tomoyuki*

JAEA-Data/Code 2014-028, 152 Pages, 2015/03

JAEA-Data-Code-2014-028.pdf:13.39MB

There have been two versions of SWAT depending on details of its development history: the revised SWAT that uses the deterministic calculation code SRAC as a neutron transportation solver, and the SWAT3.1 that uses the continuous energy Monte Carlo code MVP or MCNP5 for the same purpose. It takes several hours, however, to execute one calculation by the continuous energy Monte Carlo code even on the super computer of the Japan Atomic Energy Agency. Moreover, two-dimensional burnup calculation is not practical using the revised SWAT because it has problems on production of effective cross section data and applying them to arbitrary fuel geometry when a calculation model has multiple burnup zones. Therefore, SWAT4.0 has been developed by adding, to SWAT3.1, a function to utilize the deterministic code SARC2006, which has shorter calculation time, as an outer module of neutron transportation solver for burnup calculation. SWAT4.0 has been enabled to execute two-dimensional burnup calculation by providing an input data template of SRAC2006 to SWAT4.0 input data, and updating atomic number densities of burnup zones in each burnup step. This report describes outline, input data instruction, and examples of calculations of SWAT4.0.

Development of three-dimensional diffusion and burn-up code HIZER for Monju core management

Kato, Shinya; Shimomoto, Yoshihiko; Kato, Yuko; Kitano, Akihiro

JAEA-Technology 2014-043, 36 Pages, 2015/02

JAEA-Technology-2014-043.pdf:8.94MB

The core management and operation code system aims to perform core management task efficiently by systematic management of data, analyses and edits, which are needed in the reactor core management and operation. The system consists of the five calculation modules: the reactor constant generation module, the neutronic-thermal calculation module, the radiation analysis module, the core structural integrity estimation module, and the core operation analysis module. In these modules, the neutronic-thermal calculation module is based on the dedicated three-dimensional diffusion and burn-up code HIZER. HIZER can execute core calculations easily for specific design specification and operation patterns of Monju, enabling efficient and accurate evaluation of the Monju core characteristics. This report describes its calculation method and validation results.

Mizunami Underground Research Laboratory Project; Rock mechanical investigations annual report for fiscal year 2013

Sato, Toshinori; Sanada, Hiroyuki; Tanno, Takeo*

JAEA-Review 2014-049, 34 Pages, 2015/02

JAEA-Review-2014-049.pdf:26.38MB

This report presents the results of following rock mechanical investigations conducted in FY 2013. In-situ stress measurements using Compact Conical-ended Borehole Overcoring Technique were performed at the - 500m stage. Measurement system for rock mass displacement using optical fiber was installed at the - 500m stage as one of the reflooding test. Study on the modeling based on equivalent continuum model was continued. Phenomenological study and theoretical study on long-term behavior of crystalline rock were continued. Additionally, joint research, "Study on estimation of in-situ rock stress based on the results of various measurements" with Tokai University was also performed.

Annual report of Department of Research Reactor and Tandem Accelerator, JFY2013; Operation, utilization and technical development of JRR-3, JRR-4, NSRR, Tandem Accelerator and RI Production Facility

Department of Research Reactor and Tandem Accelerator

JAEA-Review 2014-047, 153 Pages, 2015/02

JAEA-Review-2014-047.pdf:23.43MB

The Department of Research Reactor and Tandem Accelerator is in charge of the operation, utilization and technical development of JRR-3, JRR-4, NSRR, Tandem Accelerator and RI Production Facility. This annual report describes a summary of activities of services and technical developments carried out in the period between April 1, 2013 and March 31, 2014.

Dose estimation for the use of recycled products from waste affected by radioactive cesium

Takai, Shizuka; Takeda, Seiji; Kimura, Hideo

JAEA-Research 2014-028, 13 Pages, 2015/02

JAEA-Research-2014-028.pdf:1.92MB

A large amount of waste contaminated by radioactive cesium released by Fukushima Daiichi Nuclear Power Plant has been recycled as much as possible in order to reduce the quantity to be disposed of and to use resources effectively. At present, a standard concentration of radioactive cesium for recycled products from disaster waste is defined as 100 Bq/kg. In order to understand the actual situation of radioactivity concentration of recycled products, Ministry of the Environment conducted a survey on recycled products. The survey found that several recycled products had relatively high radioactive cesium concentration. In this study, we specified exposure pathways to calculate doses for using the recycled products detected high cesium concentration in the survey. We calculate the doses based on the survey of concentration of the recycled products and compare them with a dose criterion of 10Sv/y for the use of recycled products. It was shown that the calculated doses were less than 10Sv/y for all recycled products but one sample of recycled asphalt with 26Sv/y. However, 26Sv/y is within the range of trivial dose indicated in ICRP Pub.104 and safety for reuse of the recycled asphalt is ensured.

Research on interaction of laser light and non-metals; Evaluation of laser irradiation behavior to concrete

Yamada, Tomonori; Muramatsu, Toshiharu

JAEA-Research 2014-026, 28 Pages, 2015/02

JAEA-Research-2014-026.pdf:18.03MB

In this study the response of hardened cement pastes, which is a major component of concrete, to laser irradiation was investigated under various experimental conditions aiming at the future application to "laser-processing" of concrete. (1) Evaluation of water-cement ratio for laser irradiation. It was found that hardened cement paste subjected to laser irradiation explodes very easily to be hollowed in all the experimental conditions; this response is applicable to "laser-drilling" of a hardened cement paste. (2) Evaluation of the kind of mortar for laser irradiation. Totally 75 laser irradiation tests for fixed mortar blocks were performed with combinations of following experimental conditions: fine aggregate in the mortar blocks was either of quartz, limestone, or Nachiguro-ishi. Although it was found that all kinds of the mortar fuse under laser irradiation after all, difference in the response to laser irradiation among the mortars was also found.

Scenario development on application of engineering technology for geological disposal; Study on accidents and human factors caused at site characterization, construction, operation and closure stages and that impact on safety functions after closure of disposal facility (Contract research)

Takayama, Hideki*; Takai, Shizuka; Takeda, Seiji

JAEA-Data/Code 2014-026, 189 Pages, 2015/02

JAEA-Data-Code-2014-026.pdf:8.03MB

In the safety assessment for the high-level radioactive waste geological disposal, scenarios need to be developed in consideration of influence on barrier features by applying engineering technologies at each stage of site selection, construction, operation and closure of disposal facility. To develop scenarios on application of engineering technologies from the point of view of safety regulation, it is important to grasp information of the engineering technologies which are possibly applied to geological disposal and to organize relationships between accidents and human factors caused by application of engineering technologies and influence by the factors on safety functions of engineered and natural barriers after closure stage. In this study, the engineering technologies are listed for site selection, construction, operation and closure activities at disposal site. From this information, "deviation events" which are deviated states of engineered and natural barriers from intended design were identified. We assumed influence on geological disposal facility due to the occurrence of the deviation events and identified the accidents and human factors which can progress the deviation events. Finally, we showed the sequence of influence by the accidents and human factors on long-term safety after closure of the disposal facility as scenarios. We provided a database with these results for development of scenario on engineering technology of geological disposal.

Development of three-dimensional reactor analysis code system for accelerator-driven system, ADS3D

Sugawara, Takanori; Hirai, Yasushi*; Nishihara, Kenji; Iwamoto, Hiroki; Sambuu, O.*; Ushio, Tadashi*

JAEA-Data/Code 2014-024, 86 Pages, 2015/02

JAEA-Data-Code-2014-024.pdf:6.04MB

To investigate an Accelerator-Driven System (ADS) with sub-criticality control mechanism such as control rods or burnable poison, the ADS3D code has been developed on MARBLE which is a next generation reactor analysis code system developed by JAEA. In the past neutronics calculation for the ADS, JAEA employed RZ calculation models to realize efficient investigations. However, it was very difficult to model sub-criticality control mechanisms in RZ calculation models. The ADS3D code system is available to calculate the transportation of protons and neutrons, the burn-up calculation and the fuel exchange in three-dimensional calculation models. It means this code system can treat ADS concepts with sub-criticality control mechanism and makes it possible to investigate a new concept of ADS.

Development of the control system with versatile PLCs for the long-pulse negative ion source

Komata, Masao; Shimizu, Tatsuo; Ozeki, Masahiro; Kojima, Atsushi; Hanada, Masaya

JAEA-Technology 2014-041, 50 Pages, 2015/01

JAEA-Technology-2014-041.pdf:22.68MB

In JT-60 Super Advanced, the machine for nuclear fusion research with superconducting magnets for long pulse operation, the negative-ion-base neutral beam injector is required to extend the pulse duration time 10 s to 100 s. In order to realize the long-pulse N-NB injector, the control system of the power supplies for the negative ion source has been newly developed. The control system with use of the versatile devices such as PLC was designed for an ease extension of the functions. Since the control system should have the many different functions which require the wide range of the sampling time of 1 milli-second to 10, all of the functions are performed by distributing PLCs for each of the function. The developed control system has been applied in the tests of the JT-60 negative ion source, where a 100 s negative ion beam has been successfully produced. Through this test, the controllability of this system has been confirmed to be feasible for JT-60SA operation.

Application of Cherenkov light observation to reactor measurements, 1; Estimation of reactor power from Cherenkov light intensity

Yamamoto, Keiichi; Takeuchi, Tomoaki; Sano, Tadafumi*; Homma, Ryohei*; Kimura, Nobuaki; Otsuka, Noriaki; Kosuge, Fumiaki*; Nakajima, Ken*; Tsuchiya, Kunihiko

JAEA-Technology 2014-028, 56 Pages, 2015/01

JAEA-Technology-2014-028.pdf:9.23MB

Development of the reactor measurement system was started to obtain real-time in-core nuclear and thermal information, where the quantity measurement of brightness of Cherenkov light was applied. The system would be applied as monitoring system in severe accidents and for advanced operation management technology in existing LWRs. In this report, the calculation and the observation results were summarized about the quantity of the Cherenkov light caused by the and ray emitted from the fuels in the core of Kyoto University Research Reactor.

Document collection of the 30th Technical Special Committee on Fugen Decommissioning

Kutsuna, Hideki; Koda, Yuya; Imagawa, Yasuhiro

JAEA-Review 2014-045, 38 Pages, 2015/01

JAEA-Review-2014-045.pdf:67.33MB

Fugen Decommissioning Engineering Center, in planning and carrying out our decommissioning technical development, has been establishing "Technical special committee on Fugen decommissioning" which consists of the members well-informed, aiming to make good use of Fugen as a place for technological development which is opened inside and outside the country, as the central point in the energy research and development base making project of Fukui prefecture, and to utilize the outcome in our decommissioning to the technical development effectively. This report compiles presentation materials "The Current Situation of Fugen Decommissioning", "Evaluation for Dismantlement Work Experience on Turbine System and its Future Plan" and "Completion of Taking-Out Heavy Water from Fugen", presented in the 30th Technical special committee on Fugen decommissioning which was held on September 19, 2014.

Annual report on the environmental radiation monitoring around the Tokai Reprocessing Plant FY2013

Watanabe, Hitoshi; Nakano, Masanao; Fujita, Hiroki; Takeyasu, Masanori; Mizutani, Tomoko; Isozaki, Tokuju; Morisawa, Masato; Nagaoka, Mika; Hokama, Tomonori; Yokoyama, Hiroya; et al.

JAEA-Review 2014-042, 175 Pages, 2015/01

JAEA-Review-2014-042.pdf:10.89MB

Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2013 to March 2014. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Co. in March 2011.

Development of deterministic approach to assess doses to the public from external exposures in the areas contaminated by the Fukushima Daiichi Nuclear Power Station Accident

Takahara, Shogo; Iijima, Masashi; Shimada, Kazumasa; Kushida, Teruo; Shiratori, Yoshitake

JAEA-Research 2014-024, 57 Pages, 2015/01

JAEA-Research-2014-024.pdf:5.49MB

In order to assess the doses to representative person using deterministic approach, we measured radiation dose rates and surveyed on behavioral patterns in the areas contaminated by the Fukushima Daiichi Nuclear Power Station Accident. Statistical analyzes were also performed to identify the characteristics of individual doses from external exposures, as well as radiation dose rates and behavioral patterns. Radiation dose rates measured in living areas distribute with lognormal form. Behavioral patterns of the populations were different corresponding to their occupation. Time spent outdoors of indoor workers were distributed in lognormal form and those of outdoor workers had the normal distribution. Multi-regression analyses were made to explore a significant relationship between individual doses and relevant contributors. These results indicated that the significant differences were given in individual doses due to the spatial differences of radiation dose rates as well as the interindividual differences of behavioral patterns. Based on the results of analyses of relevant contributors to the external exposures, deterministic dose assessment model was developed. The validity of this model was confirmed because the assessed values were higher than those measured.

Development of refilling techniques of LA-type bituminized waste products

Irisawa, Keita; Komatsuzaki, Toshio; Kawato, Yoshimi; Sakakibara, Tetsuro; Nakazawa, Osamu; Meguro, Yoshihiro

JAEA-Technology 2014-039, 28 Pages, 2014/12

JAEA-Technology-2014-039.pdf:6.13MB

In JAEA, 13,296 drums of low-radioactivity bituminized waste products (BWPs) have been stored in asphalt solidification storages. In order to effectively utilize the space of the BWP in a repository site, we studied refilling techniques of the BWP from the drum to a box-shaped container. Tentative processes, which we devised, consisted of (1) take-off of BWP from the drum, (2) separation of a post filling part from BWP and (3) filling of BWP to a box-shaped container. Two methods for each process were selected, and work efficiencies of the methods were investigated by using a synthetic BWP.

Measurement of pure water resistivity in a high temperature region

Yamanaka, Haruhiko; Maejima, Tetsuya; Terunuma, Yuto; Watanabe, Kazuhiro; Kashiwagi, Mieko; Hanada, Masaya

JAEA-Technology 2014-037, 12 Pages, 2014/12

JAEA-Technology-2014-037.pdf:4.27MB

Resistivity of a high temperature pure water has been measured up to 180C which is the maximum water temperature in the ITER Neutral Beam Injector. The resistivity of the pure water is decreased by increasing the water temperature. It was found that even different resistivity water of 9 Mcm and 5 Mcm showed almost the same resistivity at the higher temperature region of 100C. The resistivity of 0.36 Mcm was measured at the temperature of 180C. This resistivity agreed well to the calculated value for the theoretical pure water.

Mizunami Underground Research Laboratory Project, Annual report for fiscal year 2013

Hama, Katsuhiro; Mikake, Shinichiro; Nishio, Kazuhisa; Kawamoto, Koji; Yamada, Nobuto; Ishibashi, Masayuki; Murakami, Hiroaki; Matsuoka, Toshiyuki; Sasao, Eiji; Sanada, Hiroyuki; et al.

JAEA-Review 2014-038, 137 Pages, 2014/12

JAEA-Review-2014-038.pdf:162.61MB

Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is pursuing a geoscientific research and development project namely the Mizunami Underground Research Laboratory (MIU) Project in crystalline rock environment in order to construct scientific and technological basis for geological disposal of High-level Radioactive Waste (HLW). The MIU Project has three overlapping phases: Surface-based Investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III). The MIU Project has been ongoing the Phase II and the Phase III in fiscal year 2013. This report presents the results of the investigations, construction and collaboration studies in fiscal year 2013, as a part of the Phase II and Phase III based on the MIU Master Plan updated in 2010.

Study of receptivity of wastes in natural environment (Joint research)

Tanaka, Masaru*; Gofuku, Akio*; Ishizaka, Kaoru*; Sato, Kazuhiko; Nagahama, Yoji

JAEA-Research 2014-019, 103 Pages, 2014/12

JAEA-Research-2014-019.pdf:12.1MB

We had been conducting a research on risk perception and confidence-building among stakeholders regarding environmental remediation of Uranium mine site and disposal of industrial waste from FY 2007. FY 2011, we study how the Great East Japan Earthquake and Fukushima nuclear accident affects public risk perception. Therefore, a questionnaire survey on public risk perception of environmental remediation of Uranium mine site and disposal of the industrial waste in Okayama prefecture had been carried out. Another questionnaire survey on public risk perception of the disposal of disaster waste for residents in Okayama prefecture has been carried out. Following are some of the results: (1) For risk perception regarding environmental remediation of Uranium mine site, "knowledge of radiation" and "Concern about radioactive material" and "Information literacy" did not change significantly. Conversely trust in "Public administration" and "facility owner" and "Science and technology" was decreased significantly. (2) For risk perception regarding disaster waste, many people recognize the need for wide area disposal of disaster waste. Conversely, many residents are concerned about radioactive materials.

Hydrochemical investigation at the Mizunami Underground Research Laboratory; Compilation of groundwater chemistry data in the Mizunami group and the Toki granite (fiscal year 2013)

Omori, Kazuaki; Hasegawa, Takashi; Munemoto, Takashi; Masuda, Kaoru*; Aosai, Daisuke*; Inui, Michiharu*; Iwatsuki, Teruki

JAEA-Data/Code 2014-019, 121 Pages, 2014/12

JAEA-Data-Code-2014-019.pdf:56.12MB

Japan Atomic Energy Agency has been investigating the groundwater chemistry on excavating the underground facilities as part of the Mizunami Underground research Laboratory (MIU) Project at Mizunami City, Gifu Prefecture, Japan. In this report, we compiled data obtained by geochemical research for groundwater at the MIU in the fiscal year 2013.

Data report of ROSA/LSTF experiment SB-CL-32; 1% cold leg break LOCA with SG depressurization and no gas inflow

Takeda, Takeshi

JAEA-Data/Code 2014-021, 59 Pages, 2014/11

JAEA-Data-Code-2014-021.pdf:5.16MB

Experiment SB-CL-32 was conducted on May 28, 1996 using the LSTF. The experiment SB-CL-32 simulated 1% cold leg small-break LOCA in PWR under assumptions of total failure of HPI system and no inflow of non-condensable gas from ACC tanks. Secondary-side depressurization of both SGs as AM action to achieve the depressurization rate of 200 K/h in the primary system was initiated 10 min after break. Core uncovery started with liquid level drop in crossover leg downflow-side. The core liquid level recovered rapidly after first LSC. The surface temperature of simulated fuel rod then increased up to 669 K. Core uncovery took place before second LSC induced by steam condensation on ACC coolant. The core liquid level recovered rapidly after second LSC. The maximum fuel rod surface temperature was 772 K. The continuous core cooling was confirmed because of coolant injection by LPI system. This report summarizes the test procedures, conditions and major observation.