JOPSS - Search Results

Journal Articles

Development of fabrication technology for oxidation-resistant fuel elements for high-temperature gas-cooled reactors

Aihara, Jun; Honda, Masaki*; Ueta, Shohei; Ogawa, Hiroaki; Ohira, Koichi*; Tachibana, Yukio

Nihon Genshiryoku Gakkai Wabun Rombunshi, 18(1), p.29 - 36, 2019/03

https://doi.org/10.3327/taesj.J17.027

Japan Atomic Energy Agency carried out development of fabrication technology of oxidation resistant fuel element for improvement of safety of high temperature gas-cooled reactors in serious oxidation accident, based on precursor research in former JAEA. Dummy coated fuel particles (alumina particles) were over-coated with mixed powder of Si, C and small amount of resin to form over-coated particles, and over-coated particles were molded and hot-pressed to sinter dummy oxidation resistant fuel elements with SiC/C mixed matrix. We fabricated dummy oxidation resistant fuel elements with matrix whose Si/C mole ratio (about 0.551) is three times as large as that in precursor research. Si peak was not detected by X-ray diffraction of matrix. Better oxidation resistant was confirmed with oxidation test in 20% O $_{2}$ at 1673 K than that of ordinal fuel compact with ordinal graphite/carbon matrix. All dummy coated fuel particles were held in specimen after 10 h oxidation.

Journal Articles

Nuclear thermal design of high temperature gas-cooled reactor with SiC/C mixed matrix fuel compacts

Aihara, Jun; Goto, Minoru; Inaba, Yoshitomo; Ueta, Shohei; Sumita, Junya; Tachibana, Yukio

Proceedings of 8th International Topical Meeting on High Temperature Reactor Technology (HTR 2016) (CD-ROM), p.814 - 822, 2016/11

Japan Atomic Energy Agency (JAEA) has started R&D for apply SiC/C mixed matrix to fuel element of high temperature gas-cooled reactors (HTGRs) to improve oxidation resistance of fuel. Nuclear thermal design of HTGR with SiC/C mixed matrix fuel compacts was carried out as a part of above R&Ds. Nuclear thermal design was carried out based on a small sized HTGR for developing countries, HTR50S. Maximum enrichment of uranium is set to be 10 wt%, because coated fuel particles with 10 wt% uranium have been fabricated in Japan. Numbers of kinds of enrichment and burnable poisons (BPs) were set to be same as those of original HTR50S (3 and 2, respectively). We succeeded in nuclear thermal design of a small sized HTGR which performance was equivalent to original HTR50S, with SiC/C mixed matrix fuel compacts. Based on nuclear thermal design, intactness of coated fuel particles was evaluated to be kept on internal pressure during normal operation.

JAEA Reports

Mechanical strength evaluation of the glass base material in the JRR-3 neutron guide tube

Kobayashi, Tetsuya

JAERI-Tech 2003-001, 21 Pages, 2003/02

JAERI-Tech-2003-001.pdf:1.12MB

no abstracts in English

Journal Articles

Preparation and characterization of PuN pellets containing ZrN and TiN

Arai, Yasuo; Nakajima, Kunihisa

Journal of Nuclear Materials, 281(2-3), p.244 - 247, 2000/10

https://doi.org/10.1016/S0022-3115(00)00393-7

Times Cited Count：40 Percentile：92.08(Materials Science, Multidisciplinary)

no abstracts in English

JAEA Reports

Analysis of weld residual stresses by FINAS (1)

JNC TN9400 2000-047, 114 Pages, 2000/03

JNC-TN9400-2000-047.pdf:8.25MB

Prediction of weld residual stresses by a general finite element code is beneficial to the improvement of the accuracy of integrity assessment and residual life assessment of FBR plants. This reports develops an evaluation method of weld residual stresses using FINAS. Firstly, we suggested a basic procedure derived from parametric analyses with a simple weld joint model. The procedure can be summarized as follows: (1)For heat conduction analysis, prepare different models corresponding to the number of layers to be modeled. Hand over the analytical results to the following model. (2)Use multi-linear stress-strain curves for modeling the stress-strain response of base metal and weld metal. Use the isotropic hardening rule. (3)When metals are melt, use a user-subroutine to keep stresses from arising. (4)Put the thermal expansion coefficient as zero when heat is being input. Then, using the above procedure and TIG welding, we predicted the weld residual stresses of plate and tube. The results agreed well with the other reports, showing the suggested procedure was reasonable.

JAEA Reports

Development of bonding techniques between tungsten and copper alloy for plasma facing components by HIP method, 1; Bonding between tungsten and Oxygen Free Copper

Saito, Shigeru; Fukaya, Kiyoshi; Ishiyama, Shintaro; Eto, Motokuni; Akiba, Masato

JAERI-Research 99-049, 36 Pages, 1999/08

JAERI-Research-99-049.pdf:3.81MB

no abstracts in English

Journal Articles

Koi, Mamoru

PNC TN9410 90-105, 163 Pages, 1990/07

PNC-TN9410-90-105.pdf:2.32MB

Fatigue and creep crack growth data of SUS304 stainless steel, 2.25Cr-1Mo steel and Mod.9Cr-1Mo steel, which were accumulated in PNC in last several years, were treated as a data base. Average trend equations of crack growth rate were proposed and also statistical analysis was carried out. Finite Elements analysis of center cracked tensioned plate was performed and simplified prediction method of modified J-integral J'(C $^{*}$ ) was developed. 0btained results are summerized as follows: (1)In all tested materials, fatigue crack growth rate and creep crack growth rate were successfully represented using cyclic J-integral range J and modified J-integral J', respectivery. (2)In all tested materials, meaningful difference of crack growth rate could not be detected between hot rolled plate and forged material, and also between base metal and welded material. (3)Averaged trend equations of fatigue crack growth rate and creep crack growth rate of all tested materials were proposed on the basis of power low with cyclic J-integral range and modified J-integral, respectively. (4)Assuming that the coefficient and exponent of the above power low obey joint normal distribution, statistical analysis of crack growth rate was carried out and relationship between variance and J, J' were obtained. (5)Simplified method was developed to predict modified J-integral of center cracked tensioned plate. Prediction results show good agreement with experimental results, and this fact suggests that J-integral evaluation method of 3-dimensional surface crack, which has been developed in PNC, has good prediction accuracy.