Conceptual design of engineering-scale plant applied the simplified MA-bearing fuel fabrication process

Yamada, Yoshikazu; Segawa, Tomoomi; Kato, Masato

Proceedings of International Conference on Fast Reactors and Related Fuel Cycles; Next Generation Nuclear Systems for Sustainable Development (FR-17) (USB Flash Drive), 8 Pages, 2017/06

Japan Atomic Energy Agency (JAEA) have proposed the transmutation of minor actinides by fast reactors as a way to contribute significantly to the reduction of the volume and the potential radiotoxicity of radioactive wastes. In order to achieve this goal, it is important to introduce a fully automated and remote operation fuel fabrication plant with shielded hot cells and manipulators. JAEA's facilities including Plutonium Fuel Production Facility (PFPF) have fabricated MOX fuel. On the basis of the operational and technical experience obtained in above facilities, the conceptual design of engineering-scale plant applied the simplified MA-bearing fuel fabrication process with shielded hot cells and manipulator was done. It will be able to fabricate high MA-bearing fuel and to perform the maintenance and repairing of each equipment with manipulators. This plant will be constructed based on this concept and development plan.

Dynamic analysis of ITER tokamak based on results of vibration test using scaled model

Takeda, Nobukazu; Kakudate, Satoshi; Nakahira, Masataka

JAERI-Tech 2004-072, 43 Pages, 2005/01

JAERI-Tech-2004-072.pdf:6.06MB

The vibration experiments of the support structures with flexible plates for the ITER major components such as the vacuum vessel (VV) and the toroidal field (TF) coil were performed aiming to obtain its basic mechanical characteristics. Based on the experimental results, numerical analysis regarding the actual support structure was performed and a simplified model of the support structure was proposed. A support structure was modeled by only two spring elements. The stiffness calculated by the spring model agrees well with that of shell model, simulating actual structures based on the experimental results. It is therefore found that the spring model with the only two values of stiffness enables to simplify the complicated support structure with flexible plates. Using the spring model, the dynamic analysis of the VV and TF coil were performed to estimate the integrity under the design earthquake. As a result, the maximum relative displacement of 8.6 mm between VV and TF coil is much less than designed clearance, 100 mm, so that the integrity of the components is ensured.

System pressure effect on density-wave instability; Simplified model analysis and experiments

Shibamoto, Yasuteru; Iguchi, Tadashi; Nakamura, Hideo; Kukita, Yutaka*

Proceedings of 11th International Conference on Nuclear Engineering (ICONE-11) (CD-ROM), 11 Pages, 2003/04

The pressure effect on the onset of flow instability in a vertical upflow through a boiling channel is studied both analytically and experimentally. The analytical model is based on the Wallis-Heasley model for linear analysis of one-dimensional homogeneous two-phase flow in thermal equilibrium. The dead-time elements commonly used to represent the time lag in the responses of variables to the inlet velocity perturbation is replaced by first-order lag elements to allow the system characteristic equation to be solved analytically. This approach, although approximate, makes it much easier to identify the main contributor to the instability because the individual components are represented by separate terms in the characteristic equation. The predictions are in reasonable agreement with the data when the system pressure effect on the irreversible pressure loss in the two-phase region is appropriately considered based on calibration experiments.

Development of simplified computer codes for impact analysis of radioactive materials transport casks, 1st report; Computer code CRUSH for impact analysis of casks with shock absorbers

; *

Nihon Genshiryoku Gakkai-Shi, 33(4), p.381 - 390, 1991/04

https://doi.org/10.3327/jaesj.33.381

no abstracts in English

Research on pipe whip and jet under LOCA conitions, Part 1; Pipe whip under BWR-LOCA conditions

Ueda, Shuzo; ; *;

Atsuryoku Gijutsu, 22(6), p.281 - 290, 1984/00

http://joi.jlc.jst.go.jp/JST.Journalarchive/hpi1972/12.281

no abstracts in English

Aseismic Analysis of Vertical Two-Dimensonal VHTR Core with Simpliefied Model

;

JAERI-M 9075, 32 Pages, 1980/09

JAERI-M-9075.pdf:0.88MB

no abstracts in English

Technological investigation of the simplified MA-bearing fuel fabrication process for fast reactors and accelerator driven systems

Yamada, Yoshikazu; Kawaguchi, Koichi; Segawa, Tomoomi; Matsumura, Tatsuro; Kato, Masato

no journal, , 

Researchers at Japan Atomic Energy Agency (JAEA) have proposed the transmutation of minor actinides (MAs) by both fast reactors (FRs) and accelerator driven systems (ADSs) as a way to contribute significantly to the reduction of the volume and the potential radiotoxicity of radioactive wastes. Pu-U mixed oxide with small amount of MA is adopted as fuel of FRs, while U-free nitride and mixed oxide of MA, Pu and inert element are candidates for fuel of ADSs. JAEA researchers have also studied the simplified MOX fuel fabrication process to decrease the fabrication cost. This report describes a technological investigation of the simplified MA-bearing fuel fabrication process that prepares fuel suitable for both FRs and ADSs. Furthermore, this report includes an analysis of the feasibility of fabricating MA macro-dispersion pellets and MA micro-dispersion pellets for ADSs by using the simplified MOX fabrication process. The flowabilities of both de-nitrated raw powders were improved with the tumbling granulator, and the Carr flowability index was more than 70 for both. The green pellets had no defects in their appearance such as cracks. The CeO particles were dispersed homogeneously in both macro-dispersion and micro-dispersion pellets. As a result, it was judged that the simplified MOX fuel fabrication process is applicable to fabrication of MOX pellets for ADSs as well as FRs.