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JAEA Reports

Final report on feasibility study of Pu monitoring and solution measurement of high active liquid waste containing fission product at Reprocessing Facility

Sekine, Megumi; Matsuki, Takuya; Suzuki, Satoshi*; Tsutagi, Koichi; Nishida, Naoki; Kitao, Takahiko; Tomikawa, Hirofumi; Nakamura, Hironobu; LaFleur, A.*; Browne, M.*

JAEA-Technology 2019-023, 160 Pages, 2020/03

JAEA-Technology-2019-023.pdf:9.43MB

The International Atomic Energy Agency (IAEA) has proposed in its Research and Development plan (STR-385), the development of technology to enable real-time flow measurement of nuclear material as a part of an advanced approach to effective and efficient safeguards for reprocessing facilities. To address this, Japan Atomic Energy Agency (JAEA) has been tackling development of a new detector to enable monitoring of Pu in solutions with numerous FPs as a joint research program with U.S. DOE to cover whole reprocessing process. In this study, High Active Liquid Waste (HALW) Storage Facility in Tokai Reprocessing Plant was used as the test field. At first, the design information of HALW storage tank and radiation (type and intensity) were investigated to develop a Monte Carlo N-Particle Transport Code (MCNP) model. And then, dose rate distribution outside/ inside of the concrete cell where the HALW tank is located was measured to design new detectors and check MCNP model applicability. Using the newly designed detectors, gamma rays and neutron were continuously measured at the outside/ inside of the concrete cell to assess the radiation characteristics and to optimize detector position. Finally, the applicability for Pu monitoring technology was evaluated based on the simulation results and gamma-ray/neutron measurement results. We have found that there is possibility to monitor the change of Pu amount in solution by combination both of gamma-ray and neutron measurement. The results of this study suggested the applicability and capability of the Pu motoring to enhance safeguards for entire reprocessing facility which handles Pu with FP as a feasibility study. This is final report of this project.

Journal Articles

New precise measurements of muonium hyperfine structure at J-PARC MUSE

Strasser, P.*; Abe, Mitsushi*; Aoki, Masaharu*; Choi, S.*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; et al.

EPJ Web of Conferences, 198, p.00003_1 - 00003_8, 2019/01

 Times Cited Count:13 Percentile:99.28

JAEA Reports

Preliminary tests on adsorption / desorption of alumina adsorbents

Suzuki, Yoshitaka; Ishida, Takuya*; Suzuki, Yumi*; Matsukura, Minoru*; Kurosaki, Fumio*; Nishikata, Kaori; Mimura, Hitoshi*; Tsuchiya, Kunihiko

JAEA-Technology 2016-027, 24 Pages, 2016/12

JAEA-Technology-2016-027.pdf:4.15MB

The research and development (R&D) on the production of $$^{99}$$Mo/$$^{99m}$$Tc by (n,$$gamma$$) method has been carried out in the Neutron Irradiation and Testing Reactor Center. The $$^{99}$$Mo production by (n,$$gamma$$) reaction is a simple and easy method, and it also is advantageous from viewpoints of nuclear proliferation resistance and waste management. However, it is difficult to produce the $$^{99m}$$Tc solution with high radioactive concentration because the specific radioactivity of $$^{99}$$Mo by this method is extremely low. Up to now, various Mo absorbents such as Polyzirconium Compound (PZC) and Polytitanium Compound (PTC) have been developed with high Mo adsorption efficiency. It is necessary for utilization to the generator of these absorbents to evaluate the effect of elements containing these absorbents and to assure the quality of $$^{99m}$$Tc solution. In this report, the status of R&D of the Mo adsorbents was investigated. The alumina as Mo adsorbent, which uses in medical $$^{99}$$Mo/$$^{99m}$$Tc generator, was focused and Mo adsorption/desorption properties of three kinds of alumina was evaluated by different properties such as crystal structure and specific surface.

Journal Articles

New muonium HFS measurements at J-PARC/MUSE

Strasser, P.*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; Ito, Takashi; Iwasaki, Masahiko*; et al.

Hyperfine Interactions, 237(1), p.124_1 - 124_9, 2016/12

 Times Cited Count:7 Percentile:91.29

Journal Articles

Neutron irradiation effect of high-density MoO$$_{3}$$ pellets for Mo-99 production, 3

Ishida, Takuya; Suzuki, Yoshitaka; Nishikata, Kaori; Yonekawa, Minoru; Kato, Yoshiaki; Shibata, Akira; Kimura, Akihiro; Matsui, Yoshinori; Tsuchiya, Kunihiko; Sano, Tadafumi*; et al.

KURRI Progress Report 2015, P. 64, 2016/08

no abstracts in English

Journal Articles

Feasibility study of technology for Pu solution monitoring including FP; Composition research of high active liquid waste and radiation measurement results on the surface of cell

Matsuki, Takuya; Masui, Kenji; Sekine, Megumi; Tanigawa, Masafumi; Yasuda, Takeshi; Tsutagi, Koichi; Ishiyama, Koichi; Nishida, Naoki; Horigome, Kazushi; Mukai, Yasunobu; et al.

Proceedings of INMM 57th Annual Meeting (Internet), 9 Pages, 2016/07

The International Atomic Energy Agency (IAEA) has proposed in its long-term research and development (R&D) plan, development of a real-time measurement technology to monitor and verify nuclear material movement continuously as part of an advanced approach to effectively and efficiently conduct safeguards for reprocessing facilities. Since the Tokai Reprocessing Plant (TRP) has solutions containing both Pu and fission products (FP), a new detector development project to monitor Pu with FP is being carried out from 2015 to 2017. This project is mainly conducted in the High Active Liquid Waste Storage (HALWS) in the TRP. For the first step of this project, as the confirmation of composition of high active liquid waste (HALW) to evaluate neutron/$$gamma$$-ray emitted from solution in the selected HALW tank which has the most amount of Pu in HALW tanks at the TRP, we took HALW sample and conducted $$gamma$$-ray spectrum measurement for HALW. As a study of detector setting location, to survey the available neutron/$$gamma$$-ray (i.e. intensity) at the outside surface of the cell where HALW tank is located, we implemented continuous measurement by neutron/$$gamma$$-ray detector. In this paper, we report three $$gamma$$-ray peaks related with $$^{238}$$Pu and $$^{239}$$Pu measured in the composition research of HALW, which is needed to identify Pu amount by the new detector that we are developing and the result of radiation measurement on the surface of the cell.

Journal Articles

Technical estimation for mass production of highly-concentrated $$^{rm 99m}$$Tc solution from $$^{99}$$Mo to be obtained by ($$n,gamma$$) reaction; A Preliminary study using inactive Re instead of $$^{rm 99m}$$Tc

Tanase, Masakazu*; Fujisaki, Saburo*; Ota, Akio*; Shiina, Takayuki*; Yamabayashi, Hisamichi*; Takeuchi, Nobuhiro*; Tsuchiya, Kunihiko; Kimura, Akihiro; Suzuki, Yoshitaka; Ishida, Takuya; et al.

Radioisotopes, 65(5), p.237 - 245, 2016/05

no abstracts in English

JAEA Reports

Performance tests of radiation detectors for inspection of $$^{99}$$Mo/$$^{99m}$$Tc solution, 1

Suzuki, Yumi*; Nakano, Hiroko; Suzuki, Yoshitaka; Ishida, Takuya; Shibata, Akira; Kato, Yoshiaki; Kawamata, Kazuo; Tsuchiya, Kunihiko

JAEA-Technology 2015-031, 58 Pages, 2015/11

JAEA-Technology-2015-031.pdf:14.57MB

Technetium-99m ($$^{99m}$$Tc) is one of the most commonly used radioisotopes in the field of nuclear medicine. In the Japan Atomic Energy Agency (JAEA), the research and development (R&D) have been carried out for production of molybdenum-99 ($$^{99}$$Mo) by (n, $$gamma$$) method, a parent nuclide of $$^{99m}$$Tc, with the Japan Material Testing Reactor (JMTR). On the other hand, the new project as "Domestic Production of Medical Radioisotope (Technetium preparation) in Japan" was adopted in the Tsukuba International Strategic Zone on October, 2013 and the demonstration tests will be planned for the domestic production of $$^{99}$$Mo/$$^{99m}$$Tc with the JMTR. Thus, new facilities and analysis devices were equipped in the JMTR Hot Laboratory in 2014 as the part of this project. As the part of the analytical device equipment, the $$gamma$$-TLC analyzer and the radiation detector connected with the High Performance Liquid Chromatography (HPLC) were installed for quality inspection of the $$^{99}$$Mo/$$^{99m}$$Tc solution and the extracted $$^{99m}$$Tc solution in the JMTR Hot Laboratory. The performance tests of these devices such as detection sensitivity, resolution, linearity and selectivity of energy range were carried out with $$^{137}$$Cs and $$^{152}$$Eu as alternative radionuclides of $$^{99}$$Mo and $$^{99m}$$Tc, respectively. In the results, bright prospects were obtained concerning the quality inspection of the $$^{99}$$Mo/$$^{99m}$$Tc and $$^{99m}$$Tc solutions using these devices. This report describes the results of those performance tests.

JAEA Reports

Establishment of experimental system for $$^{99}$$Mo/$$^{99m}$$Tc production by neutron activation method

Ishida, Takuya; Shiina, Takayuki*; Ota, Akio*; Kimura, Akihiro; Nishikata, Kaori; Shibata, Akira; Tanase, Masakazu*; Kobayashi, Masaaki*; Sano, Tadafumi*; Fujihara, Yasuyuki*; et al.

JAEA-Technology 2015-030, 42 Pages, 2015/11

JAEA-Technology-2015-030.pdf:4.82MB

The research and development (R&D) on the production of $$^{99}$$Mo/$$^{99m}$$Tc by neutron activation method ((n, $$gamma$$) method) using JMTR has been carried out in the Neutron Irradiation and Testing Reactor Center. The specific radioactivity of $$^{99}$$Mo by (n, $$gamma$$) method is extremely low compared with that by fission method ((n,f) method), and as a result, the radioactive concentration of the obtained $$^{99m}$$Tc solution is also lowered. To solve the problem, we propose the solvent extraction with methyl ethyl ketone (MEK) for recovery of $$^{99m}$$Tc from $$^{99}$$Mo produced by (n, $$gamma$$) method. We have developed the $$^{99}$$Mo/$$^{99m}$$Tc separation/extraction/concentration devices and have carried out the performance tests for recovery of $$^{99m}$$Tc from $$^{99}$$Mo produced by (n, $$gamma$$) method. In this paper, in order to establish an experimental system for $$^{99}$$Mo/$$^{99m}$$Tc production, the R&D results of the system are summarized on the improvement of the devices for high-recovery rate of $$^{99m}$$Tc, on the dissolution of the pellets, which is the high-density molybdenum trioxide (MoO$$_{3}$$) pellets irradiated in Kyoto University Research Reactor (KUR), on the production of $$^{99m}$$Tc, and on the inspection of the recovered $$^{99m}$$Tc solutions.

Journal Articles

Neutron irradiation effect of high-density MoO$$_{3}$$ pellets for Mo-99 production, 2

Nishikata, Kaori; Ishida, Takuya; Yonekawa, Minoru; Kato, Yoshiaki; Kurosawa, Makoto; Kimura, Akihiro; Matsui, Yoshinori; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; et al.

KURRI Progress Report 2014, P. 109, 2015/07

As one of effective applications of the Japan Materials Testing Reactor (JMTR), JAEA has a plan to produce $$^{99}$$Mo by (n,$$gamma$$) method ((n,$$gamma$$)$$^{99}$$Mo production), a parent nuclide of $$^{99m}$$Tc. In this study, preliminary irradiation test was carried out with the high-density molybdenum trioxide (MoO$$_{3}$$) pellets in the hydraulic conveyer (HYD) of the Kyoto University Research Reactor (KUR) and the $$^{99m}$$Tc solution extracted from $$^{99}$$Mo was evaluated. After the irradiation test of the high-density MoO$$_{3}$$ pellets in the KUR, $$^{99m}$$Tc was extracted from the Mo solution and the recovery rate of $$^{99m}$$Tc achieved the target values. The $$^{99m}$$Tc solution also got the value that satisfied the standard value for $$^{99m}$$Tc radiopharmaceutical products by the solvent extraction method.

JAEA Reports

Fabrication technology development and characterization of irradiation targets for $$^{99}$$Mo/$$^{rm 99m}$$Tc production by (n,$$gamma$$) method

Nishikata, Kaori; Kimura, Akihiro; Ishida, Takuya; Shiina, Takayuki*; Ota, Akio*; Tanase, Masakazu*; Tsuchiya, Kunihiko

JAEA-Technology 2014-034, 34 Pages, 2014/10

JAEA-Technology-2014-034.pdf:3.26MB

As a part of utilization expansion after the Japan Material Testing Reactor (JMTR) re-start, research and development (R&D) on the production of medical radioisotope $$^{99}$$Mo/$$^{99m}$$Tc by (n, $$gamma$$) method using JMTR has been carried out in the Neutron Irradiation and Testing Reactor Center of the Japan Atomic Energy Agency. $$^{99}$$Mo is usually produced by fission method. On the other hand, $$^{99}$$Mo/$$^{99m}$$Tc production by the (n, $$gamma$$) method has advantages for radioactive waste, cost reduction and non-proliferation. However, the specific radioactivity per unit volume by the (n, $$gamma$$) method is low compared with the fission method, and that is the weak point of the (n, $$gamma$$) method. This report summarizes the investigation of raw materials, the fabrication tests of high-density MoO$$_{3}$$ pellets by the plasma sintering method for increasing of $$^{98}$$Mo contents and the characterization of sintered high-density MoO$$_{3}$$ pellets.

Journal Articles

Neutron irradiation effect of high-density MoO$$_{3}$$ pellets for Mo-99 production

Nishikata, Kaori; Ishida, Takuya; Yonekawa, Minoru; Kato, Yoshiaki; Kurosawa, Makoto; Kimura, Akihiro; Matsui, Yoshinori; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; et al.

KURRI Progress Report 2013, P. 242, 2014/10

As one of effective applications of the Japan Materials Testing Reactor (JMTR), JAEA has a plan to produce Mo-99 ($$^{99}$$Mo) by (n,$$gamma$$) method ((n,$$gamma$$)$$^{99}$$Mo production), a parent nuclide of $$^{99m}$$Tc. In this study, preliminary irradiation tests were carried out with the high-density MoO$$_{3}$$ pellets in the KUR and the $$^{99}$$Mo production amount was evaluated between the calculation results and measurement results.

Journal Articles

Mo recycling property from generator materials with irradiated molybdenum

Kakei, Sadanori*; Kimura, Akihiro; Niizeki, Tomotake*; Ishida, Takuya; Nishikata, Kaori; Kurosawa, Makoto; Yoshinaga, Hideo*; Hasegawa, Yoshio*; Tsuchiya, Kunihiko

Proceedings of 6th International Symposium on Material Testing Reactors (ISMTR-6) (Internet), 7 Pages, 2013/10

The Japan Materials Testing Reactor (JMTR) is expected to contribute to the expansion of industrial utilization, such as the domestic production of $$^{99}$$Mo for the medical diagnosis medicine $$^{rm 99m}$$Tc. Production by the (n, $$gamma$$) method is proposed as domestic $$^{99}$$Mo production in JMTR because of the low amount of radioactive wastes and the easy $$^{99}$$Mo/$$^{rm 99m}$$Tc production process. Molybdenum oxide (MoO$$_{3}$$) pellets, poly zirconium compounds (PZC) and poly titanium compounds (PTC) are used as the irradiation target and generator for the production of $$^{99}$$Mo/$$^{rm 99m}$$Tc by the (n, $$gamma$$) method. However, it is necessary to use the enriched $$^{98}$$MoO$$_{3}$$, which is very expensive, to increase the specific activity of $$^{99}$$Mo. Additionally, a large amount of used PZC and PTC is generated after the decay of $$^{99}$$Mo. Therefore, this recycling technology of used PZC/PTC has been developed to recover molybdenum (Mo) as an effective use of resources and a reduction of radioactive wastes. The total Mo recovery rate of this process was 95.8%. From the results of the hot experiments, we could demonstrate that the recovery of MoO$$_{3}$$ and the recycling of PZC are possible. In the future, the equipment of recovering Mo will be installed in JMTR-Hot Cell, and this recycling process will be able to contribute to the reduction of production costs of $$^{rm 99m}$$Tc and the reduction of radioactive wastes.

Journal Articles

Development of post-irradiation test facility for domestic production of $$^{99}$$Mo

Taguchi, Taketoshi; Yonekawa, Minoru; Kato, Yoshiaki; Kurosawa, Makoto; Nishikata, Kaori; Ishida, Takuya; Kawamata, Kazuo

UTNL-R-0483, p.10_5_1 - 10_5_13, 2013/03

JMTR focus on the activation method. By carrying out the preliminary tests using irradiation facilities existing, and verification tests using the irradiation facility that has developed in the cutting-edge research and development strategic strengthening business, as irradiation tests towards the production of $$^{99}$$Mo, we have been conducting research and development that can contribute to supply about 25% for $$^{99}$$Mo demand in Japan and the stable supply of radiopharmaceutical. This report describes a summary of the status of the preliminary tests for the production of $$^{99}$$Mo: Maintenance of test equipment in the facility in JMTR Hot Laboratory in preparation for research and development for the production of $$^{99}$$Mo in JMTR and using MoO$$_{3}$$ pellet irradiated at Kyoto University Research Reactor Institute (KUR).

JAEA Reports

Establishment of experimental equipments in irradiation technology development building

Ishida, Takuya; Tanimoto, Masataka; Shibata, Akira; Kitagishi, Shigeru; Saito, Takashi; Omi, Masao; Nakamura, Jinichi; Tsuchiya, Kunihiko

JAEA-Testing 2011-001, 44 Pages, 2011/06

JAEA-Testing-2011-001.pdf:4.52MB

The Neutron Irradiation and Testing Reactor Center has developed new irradiation technologies to provide irradiation data with high technical value for the refurbishment and resume of the Japan Materials Testing Reactor (JMTR). For the purpose to perform assembling of capsules, materials tests, materials inspection and analysis of irradiation specimens for the development of irradiation capsules, improvement and maintenance of facilities were performed. The RI application development building was refurbished and maintained for above-mentioned purpose. After refurbishment, the building was named Irradiation Technology Development Building. It contains eight laboratories based on the purpose of use, and experimental apparatuses were installed. This report describes the refurbishment work of the RI application development building, the installation work and operation method of the experimental apparatuses and the basic management procedure of the Irradiation Technology Development Building.

JAEA Reports

Development of new molybdenum adsorbent

Kimura, Akihiro; Tanimoto, Masataka; Ishida, Takuya; Tsuchiya, Kunihiko; Hasegawa, Yoshio*; Hishinuma, Yukio*; Suzuki, Masashi*

JAEA-Technology 2011-012, 17 Pages, 2011/06

JAEA-Technology-2011-012.pdf:1.72MBJP, 2010-263801   Patent publication (In Japanese)

PZC (Poly-Zirconium Compound) was developed as adsorbent of molybdenum for $$^{99}$$Mo-$$^{rm 99m}$$Tc generator. However, PZC has some faults. So, new adsorbent based on titanium (PTC), was developed for getting rid of faults. This time, $$^{99}$$Mo adsorption and $$^{rm 99m}$$Tc elution tests with PZC and PTC were carried out. As a result, the $$^{99}$$Mo adsorption performance of the PTC was lower than PZC, on the other hand, $$^{rm 99m}$$Tc elution performance of the PTC was higher than PZC.

JAEA Reports

Studies on planning and conducting for reducing water inflow due to underground construction in crystalline rock

Mikake, Shinichiro; Yamamoto, Masaru; Ikeda, Koki; Sugihara, Kozo; Takeuchi, Shinji; Hayano, Akira; Sato, Toshinori; Takeda, Shinichi; Ishii, Yoji; Ishida, Hideaki; et al.

JAEA-Technology 2010-026, 146 Pages, 2010/08

JAEA-Technology-2010-026.pdf:41.08MB
JAEA-Technology-2010-026-appendix(CD-ROM).zip:83.37MB

The Mizunami Underground Research Laboratory (MIU), one of the main facilities in Japan for research and development of the technology for high-level radioactive waste disposal, is under construction in Mizunami City. In planning the construction, it was necessary to get reliable information on the bedrock conditions, specifically the rock mass stability and hydrogeology. Therefore, borehole investigations were conducted before excavations started. The results indicated that large water inflow could be expected during the excavation around the Ventilation Shaft at GL-200m and GL-300m Access/Research Gallery. In order to reduce water inflow, pre-excavation grouting was conducted before excavation of shafts and research tunnels. Grouting is the injection of material such as cement into a rock mass to stabilize and seal the rock. This report describes the knowledge and lessons learned during the planning and conducting of pre-excavation grouting.

JAEA Reports

Study on $$^{99}$$Mo production by Mo-solution irradiation method, 3; Activation analysis of irradiation target

Huynh, T. P.*; Inaba, Yoshitomo; Ishida, Takuya; Ishikawa, Koji*; Tatenuma, Katsuyoshi*; Ishitsuka, Etsuo

JAEA-Technology 2009-039, 21 Pages, 2009/07

JAEA-Technology-2009-039.pdf:2.53MB

The impurity concentration in both (NH$$_{4}$$)$$_{6}$$Mo$$_{7}$$O$$_{24}$$ and K$$_{2}$$MoO$$_{4}$$ solutions, which are selected as advanced targets of Mo-solution irradiation method for $$^{99}$$Mo production, was determined by the Instrumental Neutron Activation Analysis (NAA) using k$$_{0}$$-standardization method. As a result, Na, Mn and W were identified as impurities in the as received molybdate. After the compatibility test with structural material (SUS304) under $$gamma$$-ray irradiation, activation analysis of molybdate solutions was also carried out. It was found that the identified impurity concentration was stably staying in solutions and no element comes from the structural material by the NAA method. However, small corrosion of structural material was observed from the ICP measurement.

JAEA Reports

Preliminary investigation on capsule for low-temperature irradiation tests

Inaba, Yoshitomo; Ishida, Takuya; Onuma, Yuichi; Saito, Takashi

JAEA-Technology 2009-014, 42 Pages, 2009/05

JAEA-Technology-2009-014.pdf:6.09MB

In order to carry out low-temperature irradiation tests under the high neutron flux in the JMTR core, desirable capsules were investigated from a survey and evaluation of current heat removal techniques. As a result, it was found that the low-temperature irradiation tests can be realized by the development of the capsule with cooling fins or the capsule using a boiling medium. In the case of the irradiation tests at about 100$$^{circ}$$C, the capsule with the fins can be used, and the reactor cooling water cools the capsule including specimens. This technique has few subjects to realize. In the case of the irradiation tests at below 0$$^{circ}$$C, the capsule using the boiling medium can be used, and the cooling of specimens in the capsule by liquid nitrogen is needed. In the present status, it is difficult that the liquid nitrogen is supplied to the capsule, and this technique has to overcome various subjects to realize. The investigation to solve these subjects will be carried out in the near future.

JAEA Reports

Development on crack growth and crack initiation test units for stress corrosion cracking examinations in high-temperature water environments under neutron irradiation, 1 (Contract research)

Izumo, Hironobu; Chimi, Yasuhiro; Ishida, Takuya; Kawamata, Kazuo; Inoue, Shuichi; Ide, Hiroshi; Saito, Takashi; Ise, Hideo; Miwa, Yukio; Ugachi, Hirokazu; et al.

JAEA-Technology 2009-011, 31 Pages, 2009/04

JAEA-Technology-2009-011.pdf:4.38MB

Regarding Irradiation Assisted Stress Corrosion Cracking (IASCC) for austenitic stainless steel of the light water reactor (LWR), a lot of data that concerns the post irradiation evaluation (PIE) is acquired. However, IASCC occurs in LWR condition. Therefore, it is necessary to confirm adequacy of the PIE data comparing the experiment data under the simulated LWR condition. Bigger specimen is needed to acquire the effective data for the destruction dynamics in the study of stress corrosion cracking under neutron irradiation condition. Therefore, development of a new crack growth unit which can load to bigger is necessary to the neutron irradiation test. As a result, a prospect was provided in the unit that could load to specimen by changing load mechanism to the lever type from the linear type. And also, in the development of crack propagation unit, some technical issues were extracted from the discussion of the unit structure adopting the LVDT (Linear Variable Differential Transformer).

63 (Records 1-20 displayed on this page)