Honda, Yuki; Inaba, Yoshitomo; Nakagawa, Shigeaki; Yamazaki, Kazunori; Kobayashi, Shoichi; Aono, Tetsuya; Shibata, Taiju; Ishitsuka, Etsuo
JAEA-Technology 2017-013, 20 Pages, 2017/06
Decay heat is one of an important factor for a safety evaluation of depressurized loss-of-forced cooling accident, a representative high consequence accident, in high temperature gas-cooled reactor (HTGR). Traditionally, a conservative decay heat curve is used for safety analysis according to the regulatory standards. On the other hand, there is growing interest in obtaining test data related to decay heat for the use of uncertainty analysis. However, such data has not been obtained for prismatic-type HTGR. Therefore, we have launched a test program to obtain the decay heat data from the HTTR. As an initial step, an applicability confirmation test of decay heat evaluation method for HTGR was conducted in February 2017 without non-nuclear heating condition. This report introduces an estimation method for the decay heat based on test data using HTTR and shows the results of validation of the reactor residual heat evaluation method which will be used to obtain the decay heat data based on test data.
Seto, Hideki; Ito, Shinichi; Yokoo, Tetsuya*; Endo, Hitoshi*; Nakajima, Kenji; Shibata, Kaoru; Kajimoto, Ryoichi; Kawamura, Seiko; Nakamura, Mitsutaka; Kawakita, Yukinobu; et al.
Biochimica et Biophysica Acta; General Subjects, 1861(1), p.3651 - 3660, 2017/01
J-PARC, Japan Proton Accelerator Research Complex provides short pulse proton beam at a repetition rate 25 Hz and the maximum power is expected to be 1 MW. Materials and Life Science Experimental Facility (MLF) has 23 neutron beam ports and 21 instruments have already been operated or under construction / commissioning. There are 6 inelastic / quasi-elastic neutron scattering spectrometers and the complementary use of these spectrometers will open new insight for life science.
Honda, Yuki; Saito, Kenji; Tochio, Daisuke; Aono, Tetsuya; Hirato, Yoji; Kozawa, Takayuki; Nakagawa, Shigeaki
Journal of Nuclear Science and Technology, 51(11-12), p.1387 - 1397, 2014/11
The operational experiments of the HTTR would be useful for future high-temperature gas-cooled reactors (HTGRs). Main PID control constants of the HTTR are selected with reasonably damped characteristics and without undershoot or overshoot. For utilization the HTGR as a commercial reactor, it should be demonstrated that the HTGR system can supply stable heat to a heat utilization system for the long-term operation. The control characteristics in the long-term high-temperature operation are evaluated by the result of operation performed in 2010. In addition, from a viewpoint of HTGRs with heat utilization system, a future possibility of the experiments for heat utilization design is examined.
Shibata, Akira; Nakano, Junichi; Omi, Masao; Kawamata, Kazuo; Nakagawa, Tetsuya; Tsukada, Takashi
Journal of Nuclear Materials, 422(1-3), p.14 - 19, 2012/03
To simulate Irradiation assisted stress corrosion cracking (IASCC) behavior by in-pile experiments, it is necessary to irradiate specimens up to a neutron fluence that is higher than the IASCC threshold fluence. Pre-irradiated specimens must be relocated from pre-irradiation capsules to in-pile capsules. Hence, a remote welding machine has been developed. And the integrity of capsule housing for a long term irradiation was evaluated by tensile tests in air and slow strain rate tests in water. Two type specimens were prepared. Specimens were obtained from the outer tubes of capsule irradiated to 1.0-3.9 10 n/m (E 1 MeV). And specimens were irradiated in a leaky capsule to 0.03-1.0 10 n/m. Elongation more than 15% in tensile test at 423 K was confirmed and no IGSCC fraction was shown in SSRT at 423 K which was estimated as temperature at the outer tubes of the capsule under irradiation.
Ito, Masayasu; Kawamata, Kazuo; Tayama, Yoshinobu; Kanazawa, Yoshiharu; Yonekawa, Minoru; Nakagawa, Tetsuya; Omi, Masao; Iwamatsu, Shigemi
JAEA-Technology 2011-022, 44 Pages, 2011/07
Hot laboratory are facilities that execute the post irradiation examination of sample irradiated in material testing reactors etc. The handling of high burn-up fuel is scheduled in the JMTR (Japan Materials Testing Reactor) hot laboratory with JMTR re-operate in FY 2011. This report describes evaluation, production and installation of shielding of the hot cells in the JMTR hot laboratory.
Jo, Takahisa; Goto, Takehiro; Yabuki, Kentaro; Ikegami, Kazunori; Miyagawa, Takayuki; Mori, Tetsuya; Kubo, Atsuhiko; Kitano, Akihiro; Nakagawa, Hiroki; Kawamura, Yoshiaki; et al.
JAEA-Technology 2010-052, 84 Pages, 2011/03
The prototype fast breeder reactor MONJU resumed the System Startup Test (SST) on May 6th 2010 after five months and fourteen years shutdown since the sodium leakage of the secondary heat transport system on December 1995. Core Confirmation Test (CCT) is the first step of SST, which consists of three steps. CCT was finished on July 22nd after 78 days tests. CCT is composed 20 test items including control rods' worth evaluation, radiation dose measurement etc..
Yonekawa, Minoru; Sozawa, Shizuo; Kato, Yoshiaki; Shibata, Akira; Nakagawa, Tetsuya; Kusunoki, Tsuyoshi
JAEA-Review 2010-049, 18 Pages, 2010/11
The hot laboratory (JMTR-HL) was founded to examine the objects mainly irradiated in the JMTR (Japan Materials Testing Reactor), and has been operated since 1971. The JMTR has been stopped from FY2006 for the refurbishment and will be re-started from FY2011. The post irradiation examination for high burn up fuels and large specimen will be carried out in the restarted JMTR. The JMTR-HL plans to put a three dimensional X-ray Computerized Tomography (CT) inspection system in place until the restart of JMTR in order to satisfy the requirement of valuable irradiation data for safety and plant life time management of nuclear power plants in the future. The three dimensional X-ray CT inspection system is able to observe a defect geometry closely and visually compared with a two dimensional system. In this paper, system design, production, installation and performance tests of an X-ray CT inspection system in a hot cell are reported. The X-ray CT inspection system consists of a computed tomography scanner, an X-ray source, a movable sample positioned, an X-ray detector, a collimator, and so on. After installation of apparatus, performance tests using irradiated fuel rods and radioisotopes were carried out to confirm the influence of rays and transmission X-ray property. By this development of the X-ray CT inspection system, it became possible to provide data with high technical value for post irradiation examination of high burn-up fuels and large type specimens.
Kato, Yoshiaki; Takada, Fumiki; Sozawa, Shizuo; Nakagawa, Tetsuya
JAEA-Testing 2009-008, 29 Pages, 2010/03
This report summarizes about the new equipment for the microstructural observation on the nuclear materials such as the structural material of light water reactor, which was installed in the JMTR hot laboratory. This experimental device, one of the PIE apparatuses, is useful to obtain the technical knowledge on the material degradation behavior by neutron irradiation damage and accumulate the data base for the integrity evaluation of nuclear power plant.
Iwamatsu, Shigemi; Kanazawa, Yoshiharu; Hayashi, Koji; Sozawa, Shizuo; Nakagawa, Tetsuya
JAEA-Testing 2009-006, 17 Pages, 2010/03
This report is concerned with replacement of the power manipulator in the No.2 concrete cell of JMTR hot laboratory in the 2008 fiscal year. It was carried out the replacement of power manipulator mainly on a chassis part including the remarkably aged wrist, shoulder and controller. The specifications of the machinery to be replaced, the installation and the acceptance inspection were described.
Sozawa, Shizuo; Nakagawa, Tetsuya; Iwamatsu, Shigemi; Hayashi, Koji; Tayama, Yoshinobu; Kawamata, Kazuo; Yonekawa, Minoru; Taguchi, Taketoshi; Kanazawa, Yoshiharu; Omi, Masao
JAEA-Technology 2009-070, 27 Pages, 2010/03
Refurbishment of the Japan Materials Testing Reactor (JMTR), which is recognized as one of important facilities in Japan for safety research, is in progress by the JAEA. In Extensive safety research of light-water reactor (LWR) fuels and materials under a contract with the Nuclear and Industrial Safety Agency of Ministry of Economy, Trade and Industry of Japan, the irradiation tests are planned in order to examine integrity of the LWR fuels and structure materials. For the irradiation tests of high burnup fuels and irradiated materials in the JMTR, modification of the hot laboratory facilities are needed, which are (1) making of application books for strengthening JMTR hot-lab. cell-shielding, (2) the capsule assembling device of detailed design, (3) safety analysis for domestic transportation cask and (4) confirmatory testing of diamond drill of fuel-rod center-hole processing device.
Sozawa, Shizuo; Nakagawa, Tetsuya; Omi, Masao; Hayashi, Koji; Iwamatsu, Shigemi; Kawamata, Kazuo; Kato, Yoshiaki; Kanazawa, Yoshiharu
JAEA-Technology 2009-069, 32 Pages, 2010/03
Refurbishment of the Japan Materials Testing Reactor (JMTR), which is recognized as one of important facilities in Japan for safety research, is in progress by the JAEA. In Extensive safety research of light-water reactor (LWR) fuels and materials under a contract with the Nuclear and Industrial Safety Agency of Ministry of Economy, Trade and Industry of Japan, the irradiation tests are planned in order to examine integrity of the LWR fuels and structure materials. For the irradiation tests of high burnup fuels and irradiated materials in the JMTR, modification of the hot laboratory facilities are needed, which are (1) strengthening JMTR hot-lab. cell-shielding, (2) the capsule assembling device, (3) domestic transportation cask, (4) fuel-rod center-hole processing device, (5) master-slave manipulators, (6) power manipulator, and (7) scanning electron microscope.
Kimura, Akihiro; Iimura, Koichi; Hosokawa, Jinsaku; Izumo, Hironobu; Hori, Naohiko; Nakagawa, Tetsuya; Kanno, Masaru; Ishihara, Masahiro; Kawamura, Hiroshi
JAEA-Review 2009-072, 18 Pages, 2010/03
JAEA has a plan to produce Mo, a parent nuclide of Tc. At present, radioisotopes are indispensable for a diagnosis and treatment in the medical field. Demand of Tc (half life 6h) used as a radiopharmaceutical increases up year by year. Moreover, the expansion of demand will be expected in future. However, the supply of Mo in Japan depends fully on the import from foreign countries. Therefore, it is necessary to supply Mo stably by the domestic production. There are two methods of Mo (half life 65.9h) production; the one is the nuclear fission (n,fiss) method, and the other is the (n,) method using the Mo target. Mo production in the JMTR with the (n,) method was studied and evaluated. As a result, it was found that the partial amount of Mo demand is possible to supply stably if a new hydraulic-rabbit-irradiation-facility (HR) is used.
Kaminaga, Masanori; Niimi, Motoji; Hori, Naohiko; Takahashi, Kunihiro; Kanno, Masaru; Nakagawa, Tetsuya; Nagao, Yoshiharu; Ishihara, Masahiro; Kawamura, Hiroshi
JAEA-Review 2009-056, 20 Pages, 2010/02
The JMTR is a light water moderated and cooled, beryllium reflected tank- type reactor using LUE silicide plate-type fuels. Its thermal power is 50 MW, maximum thermal and fast neutron flux is 4 10 ms. First criticality was achieved in March 1968, and its operation was stopped from August, 2006 for the refurbishment. The refurbishment is scheduled from the beginning of FY2007 to the end of FY2010. The renewed and upgraded JMTR will be re-started from FY2011. An investigation on aged components (aged-investigation) was carried out for concrete structures of the JMTR reactor building, exhaust stack, etc., and for tanks in the primary cooling system, heat exchangers, pipes in the secondary cooling system, cooling tower, emergency generators and so on, in order to identify their integrity. The aged-investigation was carried out at the beginning of FY2007. As a result, some components were decided to replace from viewpoints of future maintenance and improvement of reliability, and some components or structures were decided to repair. A visual inspection of inner side of the pressure vessel was carried out using an underwater camera in FY2008, and no serious damage was observed. Up to now, refurbishment works are in progress according to the planned schedule. In this paper, current status of JMTR refurbishment project is presented.
Hayashi, Kimio; Nakagawa, Tetsuya; Onose, Shoji; Ishida, Takuya; Nakamichi, Masaru; Takatsu, Hideyuki; Nakamura, Mutsumi*; Noguchi, Tsuneyuki*
Journal of Nuclear Materials, 386-388, p.1083 - 1086, 2009/04
no abstracts in English
Hayashi, Kimio; Nakagawa, Tetsuya; Onose, Shoji; Ishida, Takuya; Nakamichi, Masaru; Katsuyama, Kozo; Iwamatsu, Shigemi; Hasegawa, Teiji; Kodaka, Hideo; Takatsu, Hideyuki; et al.
JAEA-Technology 2009-007, 168 Pages, 2009/03
In-pile functional tests of breeding blankets have been planned by Japan Atomic Energy Agency (JAEA), using a test blanket module (TBM) which will be loaded in the International Thermonuclear Experimental Reactor (ITER). In preparation for the in-pile functional tests, JAEA has been being performed irradiation experiments of lithium titanate (LiTiO), which is the first candidate of solid breeder materials for the blanket of the demonstration reactor (DEMO) under designing in Japan. The present report describes (1) results of a detailed design and trial fabrication tests of a dismantling apparatus for irradiation capsules which were used in irradiation experiments by the Japan Materials Testing Reactor (JMTR) of JAEA, and (2) results of a preliminary investigation of a glove box facility for post-irradiation examinations (PIEs). In the detailed design of the dismantling apparatus, datailed specifications and the installation methods were examined, based on results of a conceptual design and basic design. In the trial fabrication, cutting tests were curried out by making a mockup of a cutting component. Furthermore, a preliminary investigation of a glove box facility was carried out in order to secure a facility for PIE work after the capsule dismantling, which revealed a technical feasibility.
Yonekawa, Minoru; Sozawa, Shizuo; Omi, Masao; Nakagawa, Tetsuya
UTNL-R-0471, p.5_6_1 - 5_6_7, 2009/03
no abstracts in English
Taguchi, Taketoshi; Kato, Yoshiaki; Takada, Fumiki; Omi, Masao; Nakagawa, Tetsuya
UTNL-R-0471, p.5_7_1 - 5_7_8, 2009/03
no abstracts in English
Kawamata, Kazuo; Nakagawa, Tetsuya; Omi, Masao; Hayashi, Koji; Shibata, Akira; Saito, Junichi; Niimi, Motoji
JAEA-Conf 2008-011, p.78 - 86, 2009/01
The JMTR-HL was founded to examine the objects mainly irradiated in the JMTR in 1971. The JMTR-HL has an advantage that the hot cell is connected with the reactor vessel of the JMTR by a canal. Hence it is easy to transport irradiated radioactive capsules and specimens through the canal. Since 1971, about 2,400 irradiated capsules have been treated in the JMTR-HL and various PIEs have been widely performed there. In recent years, several new techniques, e.g., an in-cell IASCC test, a scanning-electron microscope (SEM) / electron-back scattering-diffraction pattern (EBSD) observation, were added to the conventional PIEs. In addition, the JMTR-HL had contributed to realize an in-pile IASCC test program at the JMTR through the development of a TIG welding technique by remote-handling with manipulators in the hot cell for re-assembling of capsules. A modification of the facility to treat high burn-up fuels, up to about 100 GWD/t, is planned at the JMTR-HL now.
Shibata, Akira; Omi, Masao; Nakagawa, Tetsuya
JAEA-Conf 2008-010, p.54 - 66, 2008/12
The hot laboratory accompanied with the Japan Materials Testing Reactor (JMTR-HL) was founded in 1971 to examine objects irradiated mainly at the JMTR. The JMTR-HL has three kinds of beta- hot-cell lines for research and development of nuclear fuels and materials. The JMTR-HL has the advantage of being connected by a canal between the hot cell and the JMTR. Hence it is easy to transport irradiated capsules and specimens through the canal. Since 1971, about 2,400 irradiated capsules have been treated in the JMTR-HL. Many various post irradiation examinations (PIEs) have been widely performed here. Mentioned in this report are overview of the hot laboratory, the present organization, the current status of the PIEs, and the modification plan of the facility to treat high burn-up fuels up to about 100 GWD/t in this presentation.
Taguchi, Taketoshi; Inaba, Yoshitomo; Kawamata, Kazuo; Nakagawa, Tetsuya; Tsuchiya, Kunihiko
JAEA-Conf 2008-010, p.193 - 202, 2008/12
The JMTR-HL is directly connected with reactor core by a water canal. Hence irradiated radioactive capsules are efficiently transported under water through the canal in a short time. As the part of PIE technology development, several kinds of welding techniques have been systematically developed. These techniques are as follows; (1) re-instrumentation of FP gas pressure gauge and thermocouple to an irradiated fuel rod, (2) welding procedure development for re-capsuling of irradiated materials, (3) joining technique and PIEs development of different materials with friction welding for new typed irradiation capsules and (4) rewelding with irradiated and un-irradiated materials and fabrication of test specimen with the rewelding for fusion reactor development. These welding techniques have been very indispensable for supporting the irradiation tests and post-irradiation examinations and were introduced in this seminar.