Decommissioning of Pre-dismantling Temporary Waste Storage Facility 3 (FPG-03a,b,c) in Plutonium Fuel Production Facility

Shinozaki, Masaru; Aita, Takahiro; Iso, Takahito*; Odakura, Manabu*; Haginoya, Masahiro*; Kadowaki, Hiroyuki*; Kobayashi, Shingo*; Inagawa, Takumu*; Morimoto, Taisei*; Iso, Hidetoshi; et al.

JAEA-Technology 2021-043, 100 Pages, 2022/03

JAEA-Technology-2021-043.pdf:7.49MB

It is planned that the MOX (Mixed Oxide) from the decommissioned facilities in Nuclear Fuel Cycle Engineering Laboratories is going to be consolidated and stored stably and safely for a long term in Plutonium Fuel Production Facility of the Plutonium Fuel Development Center of Nuclear Fuel Cycle Engineering Laboratories. For this purpose, it is necessary to pelletize nuclear fuel materials in the facility and store them in the assembly storage (hereinafter referred to as "waste packaging work") to secure storage space in the plutonium material storage. As a countermeasure to reduce the facility risk in this waste packing work, it was decided to construct a new powder weighing and homogenization mixing facility to physically limit the amount (batch size) of nuclear fuel materials handled at the entrance of the process. In order to secure the installation space for the new facility in the powder preparation room (1) (FP-101), the pre-dismantling temporary waste storage facility 3 (FPG-03a, b, c) was dismantled and removed. This facility consists of a granulating and sizing facility, an additive mixing facility, and a receiving and delivering guided facility, which started to be used from January 1993, and was discontinued on February 3, 2012 and became a waste facility. Subsequently, the dismantling and removal of the interior equipment was carried out by pellet fabrication section for glove operation to reduce the amount of hold-up, and before the main dismantling and removal, there was almost no interior equipment except for large machinery. This report describes the dismantling and removal of the glove box and some interior equipment and peripherals of the facility, as well as the Green House setup method, dismantling and removal procedures, and issues specific to powder process equipment (dust, etc.).

Occupation sites and valence states of Co dopants in (La, Co)-codoped M-type Sr ferrite; Fe and Co nuclear magnetic resonance studies

Sakai, Hironori; Hattori, Taisuke; Tokunaga, Yo; Kambe, Shinsaku; Ueda, Hiroaki*; Tanioku, Yasuaki*; Michioka, Chishiro*; Yoshimura, Kazuyoshi*; Takao, Kenta*; Shimoda, Aiko*; et al.

Physical Review B, 98(6), p.064403_1 - 064403_10, 2018/08

https://doi.org/10.1103/PhysRevB.98.064403

To specify preferential occupation sites of Co substituents and to clarify charge and spin states of Co ions in (La, Co)-cosubstituted hexagonal magnetoplumbite-type (M-type) Sr ferrite, Fe and Co nuclear magnetic resonance (NMR) spectra are measured under zero and external magnetic fields using powdered and single crystalline specimens. To a considerable degree, the charge compensation between La and Co works in the equal (La, Co)-codoped case, where more than half of the Co ions are considered to be present in the minority spin sites at the center of the oxygen tetrahedra, with the = 3/2 state carrying a small orbital moment owing to spin-orbit interaction. The remaining small number of high-spin Co ( = 3/2, = 1) ions with unquenched orbital moments would be distributed to the other octahedral , , and sites.

SAS4A analysis study on the initiating phase of ATWS events for generation-IV loop-type SFR

Kubota, Ryuzaburo; Koyama, Kazuya*; Moriwaki, Hiroyuki*; Yamada, Yumi*; Shimakawa, Yoshio*; Suzuki, Toru; Kawada, Kenichi; Kubo, Shigenobu; Yamano, Hidemasa

Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 10 Pages, 2017/04

This paper describes an analysis study on the initiating phase of the ATWS events with SAS4A in order to confirm the appropriateness of the core design for the medium-scale SFR (750MWe-1765MWt). Not using a conventional lumping method that multiple fuel sub-assemblies having a similar characteristic were assigned to one channel (representing fuel assembly in SAS4A), each channel represents only the sub-assemblies of identical operating condition. In addition, the detailed power and reactivity distribution were set reflecting the change of insertion position of control rods. Applying these detailed analysis conditions, the SAS4A analyses were performed for unprotected loss-of-flow (ULOF) and unprotected transient overpower (UTOP) during both of the nominal power and the partial power operation. As a result, more proper event progression including incoherency of events especially fuel dispersion after fuel failure was successfully evaluated and then this analysis study suggested that the power excursion with prompt criticality leading to large mechanical energy release can be prevented in the initiating phase of the current design.

Document collection of the 28th Technical Special Committee on Fugen Decommissioning

Kutsuna, Hideki; Iwai, Hiroki; Mizui, Hiroyuki; Kadowaki, Haruhiko; Nakamura, Yasuyuki

JAEA-Review 2013-049, 49 Pages, 2014/02

JAEA-Review-2013-049.pdf:5.59MB

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. This report compiles presentation materials "The Current Situation of Fugen Decommissioning", "The Current Status of the Cutting Test toward the Practical Use of Laser Cutting Technology and the Future Plan", "Study on Radioactive Substance Osmosis for Basis Concrete of Equipment", "Verification Tests of the Room-Temperature Vacuum Drying and the Evaluation Method of Residual Amount of Heavy Water in the Tritium Removal" and "Applicability Test of Thermal and Mechanical Cutting Technology for the Dismantlement of the Internal Core of Fukushima Daiichi NPS", presented in the 28th Technical special committee on Fugen decommissioning which was held on September 24, 2013.

Operation report Ningyo-toge brick manufacturing plant

Yamawaki, Hiroyuki; Torikai, Kazuyoshi; Arimoto, Yosuke*

JAEA-Technology 2012-049, 64 Pages, 2013/03

JAEA-Technology-2012-049.pdf:8.28MB

An agreement was concluded among MEXT (Ministry of Education, Culture, Sports, Science and Technology), Tottori Prefecture, Misasa Town and JAEA (Japan Atomic Energy Agency) on May 31st, 2006, aiming at resolving the problem due to the waste soil deposited at JAEA's Katamo Waste Soil Yards. Based on the agreement, a plant was constructed in the land JAEA rented form the Misasa Town to manufacture bricks from the micture of the waste soil and additives such as cement. The plant manufactured about 1.45 million bricks during the period of operation between April 28th, 2008, and December 13th, 2010. This report summarizes the outline of the brick manufacturing plant, the results of trial and pilot operations and the performance of full-scale operation.

Observation of the partial Fermi surface quenching in the noncentrosymmetric superconductor MoAlC

Koyama, Takehide*; Ozaki, Yuzuru*; Ueda, Koichi*; Mito, Takeshi*; Kohara, Takao*; Waki, Takeshi*; Tabata, Yoshikazu*; Michioka, Chishiro*; Yoshimura, Kazuyoshi*; Suzuki, Michito; et al.

Journal of the Physical Society of Japan, 81(Suppl.B), p.SB008_1 - SB008_5, 2012/12

https://doi.org/10.1143/JPSJS.81SB.SB008

The normal state properties of a noncentrosymmetric superconductor MoAlC are studied by means of the nuclear magnetic resonance (NMR) experiment. The change of NMR line shape and the peak of the nuclear spin-echo decay rate at 130 K indicate that the MoAlC exhibits the phase transition prior to the emergence of superconductivity. The reduction in the conduction electron density is inferred from the decrease in the nuclear spin-lattice relaxation rate. The nature of the newly found phase transition is discussed by considering the result of the first principle calculations, indicating a good nesting property of the Fermi surfaces.

Partial gap opening on the Fermi surface of the noncentrosymmetric superconductor MoAlC

Koyama, Takehide*; Ozaki, Yuzuru*; Ueda, Koichi*; Mito, Takeshi*; Kohara, Takao*; Waki, Tsuyoshi*; Tabata, Yoshikazu*; Michioka, Chishiro*; Yoshimura, Kazuyoshi*; Suzuki, Michito; et al.

Physical Review B, 84(21), p.212501_1 - 212501_4, 2011/12

https://doi.org/10.1103/PhysRevB.84.212501

The results of Al nuclear magnetic resonance and specific-heat measurements of the noncentrosymmetric superconductor MoAlC are reported. The phase transition around 130 K is inferred from a distinct change in the NMR spectrum, a clear peak in the spin-echo decay rate, and an anomaly in the specific heat. Possibility of charge-density wave ordering around 130 K is discussed by calculating the Fermi surfaces in the normal states and considering the partial quenching of the Fermi surfaces with the decrease in 1/ below the superconducting transition temperature.

Operation of the AVF cyclotron

Nara, Takayuki; Ishibori, Ikuo; Kurashima, Satoshi; Yoshida, Kenichi; Yuyama, Takahiro; Ishizaka, Tomohisa; Okumura, Susumu; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Yuri, Yosuke; et al.

JAEA-Review 2010-065, JAEA Takasaki Annual Report 2009, P. 180, 2011/01

https://jopss.jaea.go.jp/pdfdata/JAEA-Review-2010-065.pdf

no abstracts in English

Polarization-dependent dissociation selectively induced by core-electron excitation in methyl ester terminated self-assembled monolayer

Kizaki, Hiroyuki*; Wada, Shinichi*; Sako, Erika*; Sumii, Ryohei*; Waki, Satoshi*; Isari, Koji*; Sekitani, Tetsuji*; Sekiguchi, Tetsuhiro; Tanaka, Kenichiro*

Journal of Electron Spectroscopy and Related Phenomena, 144-147, p.447 - 451, 2005/06

https://doi.org/10.1016/j.elspec.2005.01.183

no abstracts in English

High-precision carbon-ion microsurgery system for the least invasive treatments of various tumors

Arakawa, Kazuo; Fukuda, Mitsuhiro*; Shimada, Hirofumi*; Sakai, Takuro; Sato, Takahiro; Oikawa, Masakazu*; Agematsu, Takashi; Kashiwagi, Hirotsugu; Okumura, Susumu; Kurashima, Satoshi; et al.

no journal, , 

no abstracts in English