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Izawa, Kazuhiko; Aoyama, Yasuo; Sono, Hiroki; Ogawa, Kazuhiko; Yanagisawa, Hiroshi; Miyoshi, Yoshinori
Proceedings of 9th International Conference on Nuclear Criticality (ICNC 2011) (CD-ROM), 11 Pages, 2012/02
For reactor physics and criticality safety researches, the Static Experiment Critical Facility (STACY) will be modified. In the modification, the present STACY, solution-fuel-type homogeneous cores, will be converted to fuel-pin-type heterogeneous cores moderated by light water. For nuclear safety design of the modified STACY, computational analyses have been carried out by using a Monte Carlo code MVP and a transport code system DANTSYS with cross-section data based on the JENDL-3.3. In the analyses, basic nuclear characteristics have been evaluated, such as criticality, water-level worth and reactor shutdown margin. By the results of these analyses, the feasibility of reactivity control mechanism and the sufficiency of reactor shutdown margin of the modified STACY were confirmed. In addition, temperature and void coefficients of reactivity and kinetic parameters were obtained to comprehend nuclear characteristics of the modified STACY.
Nakamura, Kinya*; Ogata, Takanari*; Kikuchi, Hironobu; Iwai, Takashi; Nakajima, Kunihisa; Kato, Tetsuya*; Arai, Yasuo; Uozumi, Koichi*; Hijikata, Takatoshi*; Koyama, Tadafumi*; et al.
Nihon Genshiryoku Gakkai Wabun Rombunshi, 10(4), p.245 - 256, 2011/12
Sodium-bonded metallic fuel elements were fabricated for the first time in Japan for the irradiation test in the experimental fast test reactor JOYO. U-20Pu-10Zr fuel slugs of 200 mm in length and approximately 5 mm in diameter were fabricated in a small-scale injection casting furnace. Each fuel slug was loaded into the ferritic martenstic stainless steel (PNC-FMS) cladding tube with the sodium thermal bond, thermal insulator and reflector in a helium gas atmosphere glove box. After top-end plug welding to the cladding tube and heat treatment of the welding area, each fuel element was subjected to the sodium bonding process. After the inspection such as element length, gas plenum length and helium-leak tightness, six metallic fuel elements are transported to the JOYO site for the coming irradiation test.
Nakamura, Kinya*; Ogata, Takanari*; Kikuchi, Hironobu; Iwai, Takashi; Nakajima, Kunihisa; Kato, Tetsuya*; Arai, Yasuo; Koyama, Tadafumi*; Itagaki, Wataru; Soga, Tomonori; et al.
Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 8 Pages, 2011/12
CRIEPI and JAEA have fabricated sodium-bonded metallic fuel elements for the first time in Japan as a collaborative research, for use in the irradiation test at the experimental fast test reactor Joyo. The irradiation test aims to assess the irradiation behavior of the fuel and the internal wastage of the stainless-steel cladding by rare-earth fission products at a maximum cladding temperature above 873 K. U-20 wt% Pu-10 wt% Zr alloy fuel slugs of 200 mm length were fabricated in an injection-casting furnace using U metal, U-Pu alloy and Zr metal. Two types of fuel slug were fabricated, i.e., 5.05 mm and 4.95 mm in diameter, and loaded into a ferritic-martensitic stainless-steel cladding tubes, respectively. After top-end-plug welding to the cladding tube, each fuel element was subjected to sodium bonding to fill the annular gap between the fuel slug and the cladding with melted sodium. The fabrication results indicated that the characteristics of the fuel elements were within the required specifications.
Izawa, Kazuhiko; Aoyama, Yasuo; Sono, Hiroki; Ogawa, Kazuhiko; Yanagisawa, Hiroshi
JAEA-Technology 2007-001, 40 Pages, 2007/02
A series of critical experiments is conducted in FY 2006 using a heterogeneous core of the Static Experiment Critical Facility (STACY) in the Japan Atomic Energy Agency (JAEA). In the experiment, the core is composed of uranyl nitrate solution (U enrichment 6wt%) containing soluble poison (gadolinium) and 333 pins of uranium dioxide (U enrichment 5wt%) loaded at a latticepitch of 1.5cm. Prior to the experiment, the following neutronic characteristics were analyzed to assess safety of the core and operation parametor limits: criticality, reactivity and reactor shutdown margins. In the analyses, a Monte Carlo code, MVP, and a neutronics code system, SRAC, were used with an evaluated nuclear data library, JENDL-3.3. From these analyses, it was confirmed that the reactor shutdown margins would comply with the safety criteria under all conditions of the fuel used in the experiments. Simplified formulas for criticality and reactivity were also evaluated based on the analyzed values which are utilized to confirm the operation parameter limits during operations of the core.
Izawa, Kazuhiko; Seki, Masakazu; Hirose, Hideyuki; Kaminaga, Jota; Aoyama, Yasuo; Yoshida, Hiroshi; Sono, Hiroki; Ogawa, Kazuhiko; Sakuraba, Koichi
UTNL-R-0453, p.9_1 - 9_10, 2006/03
no abstracts in English
Izawa, Kazuhiko; Miyoshi, Yoshinori; Aoyama, Yasuo; Sono, Hiroki; Ogawa, Kazuhiko; Yanagisawa, Hiroshi
no journal, ,
Prior to modification of STACY, neutronic characteristics are analyzed to contribute the safety design and regulation. The analyzed items are reactivity coefficients (temperature and void ratio), kinetic parameter (prompt neutron lifetime and effective delayed neutron fraction), and reactor shutdown margin. In the analyses, a Monte Carlo code, MVP, and a neutron transport code system, DANTSYS, have been used with an evaluated nuclear data library, JENDL-3.3.
Izawa, Kazuhiko; Aoyama, Yasuo; Sono, Hiroki; Ogawa, Kazuhiko; Yanagisawa, Hiroshi; Miyoshi, Yoshinori
no journal, ,
no abstracts in English
Aoyama, Yasuo; Komuro, Michiyasu; Seki, Masakazu; Izawa, Kazuhiko; Sono, Hiroki; Ogawa, Kazuhiko; Yanagisawa, Hiroshi; Miyoshi, Yoshinori
no journal, ,
no abstracts in English
Izawa, Kazuhiko; Maekawa, Tomoyuki; Aoyama, Yasuo; Sono, Hiroki; Ogawa, Kazuhiko; Yanagisawa, Hiroshi; Miyoshi, Yoshinori
no journal, ,
no abstracts in English